Add Authority Advisory AI and API Lifecycle Configuration

- Introduced AuthorityAdvisoryAiOptions and related classes for managing advisory AI configurations, including remote inference options and tenant-specific settings.
- Added AuthorityApiLifecycleOptions to control API lifecycle settings, including legacy OAuth endpoint configurations.
- Implemented validation and normalization methods for both advisory AI and API lifecycle options to ensure proper configuration.
- Created AuthorityNotificationsOptions and its related classes for managing notification settings, including ack tokens, webhooks, and escalation options.
- Developed IssuerDirectoryClient and related models for interacting with the issuer directory service, including caching mechanisms and HTTP client configurations.
- Added support for dependency injection through ServiceCollectionExtensions for the Issuer Directory Client.
- Updated project file to include necessary package references for the new Issuer Directory Client library.

src/Api/StellaOps.Api.OpenApi/authority/openapi.yaml

@@ -29,15 +29,32 @@ components:
         password:
           tokenUrl: /token
           refreshUrl: /token
-          scopes:
-            advisory:ingest: Submit advisory ingestion payloads.
-            advisory:read: Read advisory ingestion data.
-            aoc:verify: Execute Aggregation-Only Contract verification workflows.
-            authority.audit.read: Read Authority audit logs.
-            authority.clients.manage: Manage Authority client registrations.
-            authority.users.manage: Manage Authority users.
-            authority:tenants.read: Read the Authority tenant catalog.
-            concelier.jobs.trigger: Trigger Concelier aggregation jobs.
+          scopes:
+            attestor.write: Submit attestation bundles and Rekor entries.
+            attestor.verify: Invoke attestation verification APIs.
+            attestor.read: Fetch attestation entries and proofs.
+            advisory:ingest: Submit advisory ingestion payloads.
+            advisory:read: Read advisory ingestion data.
+            advisory-ai:view: View Advisory AI artefacts and cached outputs.
+            advisory-ai:operate: Submit Advisory AI inference and remediation requests.
+            advisory-ai:admin: Administer Advisory AI configuration, profiles, and remote execution.
+            aoc:verify: Execute Aggregation-Only Contract verification workflows.
+            airgap:seal: Seal or unseal an air-gapped installation.
+            airgap:import: Import offline bundles and mirror artifacts while air-gapped.
+            airgap:status:read: Read air-gap sealing status and staleness indicators.
+            obs:read: Read observability dashboards, SLO digests, and incident overlays.
+            timeline:read: Read incident timeline entries and annotations.
+            timeline:write: Append deterministic incident timeline events and annotations.
+            evidence:create: Create evidence items, upload artefacts, and link attestations.
+            evidence:read: Read evidence items, artefacts, and linkage metadata.
+            evidence:hold: Apply or release legal holds on evidence items.
+            attest:read: Read attestation records, DSSE bundles, and verification proofs.
+            obs:incident: Toggle incident mode, extend retention, enable emergency telemetry.
+            authority.audit.read: Read Authority audit logs.
+            authority.clients.manage: Manage Authority client registrations.
+            authority.users.manage: Manage Authority users.
+            authority:tenants.read: Read the Authority tenant catalog.
+            concelier.jobs.trigger: Trigger Concelier aggregation jobs.
             concelier.merge: Manage Concelier merge operations.
             effective:write: Write effective findings (Policy Engine service identity only).
             email: Access email claim data.
@@ -72,17 +89,34 @@ components:
             vex:ingest: Submit VEX ingestion payloads.
             vex:read: Read VEX ingestion data.
             vuln:read: Read vulnerability permalinks and overlays.
-        authorizationCode:
-          authorizationUrl: /authorize
-          tokenUrl: /token
-          refreshUrl: /token
-          scopes:
-            advisory:ingest: Submit advisory ingestion payloads.
-            advisory:read: Read advisory ingestion data.
-            aoc:verify: Execute Aggregation-Only Contract verification workflows.
-            authority.audit.read: Read Authority audit logs.
-            authority.clients.manage: Manage Authority client registrations.
-            authority.users.manage: Manage Authority users.
+        authorizationCode:
+          authorizationUrl: /authorize
+          tokenUrl: /token
+          refreshUrl: /token
+          scopes:
+            attestor.write: Submit attestation bundles and Rekor entries.
+            attestor.verify: Invoke attestation verification APIs.
+            attestor.read: Fetch attestation entries and proofs.
+            advisory:ingest: Submit advisory ingestion payloads.
+            advisory:read: Read advisory ingestion data.
+            advisory-ai:view: View Advisory AI artefacts and cached outputs.
+            advisory-ai:operate: Submit Advisory AI inference and remediation requests.
+            advisory-ai:admin: Administer Advisory AI configuration, profiles, and remote execution.
+            aoc:verify: Execute Aggregation-Only Contract verification workflows.
+            airgap:seal: Seal or unseal an air-gapped installation.
+            airgap:import: Import offline bundles and mirror artifacts while air-gapped.
+            airgap:status:read: Read air-gap sealing status and staleness indicators.
+            obs:read: Read observability dashboards, SLO digests, and incident overlays.
+            timeline:read: Read incident timeline entries and annotations.
+            timeline:write: Append deterministic incident timeline events and annotations.
+            evidence:create: Create evidence items, upload artefacts, and link attestations.
+            evidence:read: Read evidence items, artefacts, and linkage metadata.
+            evidence:hold: Apply or release legal holds on evidence items.
+            attest:read: Read attestation records, DSSE bundles, and verification proofs.
+            obs:incident: Toggle incident mode, extend retention, enable emergency telemetry.
+            authority.audit.read: Read Authority audit logs.
+            authority.clients.manage: Manage Authority client registrations.
+            authority.users.manage: Manage Authority users.
             authority:tenants.read: Read the Authority tenant catalog.
             concelier.jobs.trigger: Trigger Concelier aggregation jobs.
             concelier.merge: Manage Concelier merge operations.
@@ -125,11 +159,25 @@ components:
       flows:
         clientCredentials:
           tokenUrl: /token
-          scopes:
-            advisory:ingest: Submit advisory ingestion payloads.
-            advisory:read: Read advisory ingestion data.
-            aoc:verify: Execute Aggregation-Only Contract verification workflows.
-            authority.audit.read: Read Authority audit logs.
+          scopes:
+            attestor.write: Submit attestation bundles and Rekor entries.
+            attestor.verify: Invoke attestation verification APIs.
+            attestor.read: Fetch attestation entries and proofs.
+            advisory:ingest: Submit advisory ingestion payloads.
+            advisory:read: Read advisory ingestion data.
+            advisory-ai:view: View Advisory AI artefacts and cached outputs.
+            advisory-ai:operate: Submit Advisory AI inference and remediation requests.
+            advisory-ai:admin: Administer Advisory AI configuration, profiles, and remote execution.
+            aoc:verify: Execute Aggregation-Only Contract verification workflows.
+            obs:read: Read observability dashboards, SLO digests, and incident overlays.
+            timeline:read: Read incident timeline entries and annotations.
+            timeline:write: Append deterministic incident timeline events and annotations.
+            evidence:create: Create evidence items, upload artefacts, and link attestations.
+            evidence:read: Read evidence items, artefacts, and linkage metadata.
+            evidence:hold: Apply or release legal holds on evidence items.
+            attest:read: Read attestation records, DSSE bundles, and verification proofs.
+            obs:incident: Toggle incident mode, extend retention, enable emergency telemetry.
+            authority.audit.read: Read Authority audit logs.
             authority.clients.manage: Manage Authority client registrations.
             authority.users.manage: Manage Authority users.
             authority:tenants.read: Read the Authority tenant catalog.

src/Attestor/StellaOps.Attestor.Envelope/DsseCompressionAlgorithm.cs

@@ -0,0 +1,8 @@
+namespace StellaOps.Attestor.Envelope;
+
+public enum DsseCompressionAlgorithm
+{
+    None = 0,
+    Gzip = 1,
+    Brotli = 2
+}

src/Attestor/StellaOps.Attestor.Envelope/DsseDetachedPayloadReference.cs

@@ -0,0 +1,32 @@
+using System;
+
+namespace StellaOps.Attestor.Envelope;
+
+public sealed record DsseDetachedPayloadReference
+{
+    public DsseDetachedPayloadReference(string uri, string sha256, long? length = null, string? mediaType = null)
+    {
+        if (string.IsNullOrWhiteSpace(uri))
+        {
+            throw new ArgumentException("Detached payload URI must be provided.", nameof(uri));
+        }
+
+        if (string.IsNullOrWhiteSpace(sha256))
+        {
+            throw new ArgumentException("Detached payload digest must be provided.", nameof(sha256));
+        }
+
+        Uri = uri;
+        Sha256 = sha256.ToLowerInvariant();
+        Length = length;
+        MediaType = mediaType;
+    }
+
+    public string Uri { get; }
+
+    public string Sha256 { get; }
+
+    public long? Length { get; }
+
+    public string? MediaType { get; }
+}

src/Attestor/StellaOps.Attestor.Envelope/DsseEnvelope.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace StellaOps.Attestor.Envelope;
+
+public sealed class DsseEnvelope
+{
+    public DsseEnvelope(
+        string payloadType,
+        ReadOnlyMemory<byte> payload,
+        IEnumerable<DsseSignature> signatures,
+        string? payloadContentType = null,
+        DsseDetachedPayloadReference? detachedPayload = null)
+    {
+        if (string.IsNullOrWhiteSpace(payloadType))
+        {
+            throw new ArgumentException("payloadType must be provided.", nameof(payloadType));
+        }
+
+        PayloadType = payloadType;
+        Payload = payload;
+        PayloadContentType = payloadContentType;
+        DetachedPayload = detachedPayload;
+
+        var normalised = signatures?.ToArray() ?? Array.Empty<DsseSignature>();
+        if (normalised.Length == 0)
+        {
+            throw new ArgumentException("At least one signature must be supplied.", nameof(signatures));
+        }
+
+        // Deterministic ordering (keyid asc, signature asc) for canonical output.
+        Signatures = normalised
+            .OrderBy(static x => x.KeyId ?? string.Empty, StringComparer.Ordinal)
+            .ThenBy(static x => x.Signature, StringComparer.Ordinal)
+            .ToArray();
+    }
+
+    public string PayloadType { get; }
+
+    public ReadOnlyMemory<byte> Payload { get; }
+
+    public string? PayloadContentType { get; }
+
+    public IReadOnlyList<DsseSignature> Signatures { get; }
+
+    public DsseDetachedPayloadReference? DetachedPayload { get; }
+}

src/Attestor/StellaOps.Attestor.Envelope/DsseEnvelopeSerializationOptions.cs

@@ -0,0 +1,14 @@
+namespace StellaOps.Attestor.Envelope;
+
+public sealed class DsseEnvelopeSerializationOptions
+{
+    public bool EmitCompactJson { get; init; } = true;
+
+    public bool EmitExpandedJson { get; init; } = true;
+
+    public bool IndentExpandedJson { get; init; } = true;
+
+    public bool IncludePayloadPreview { get; init; } = true;
+
+    public DsseCompressionAlgorithm CompressionAlgorithm { get; init; } = DsseCompressionAlgorithm.None;
+}

src/Attestor/StellaOps.Attestor.Envelope/DsseEnvelopeSerializationResult.cs

@@ -0,0 +1,38 @@
+using System;
+
+namespace StellaOps.Attestor.Envelope;
+
+public sealed class DsseEnvelopeSerializationResult
+{
+    public DsseEnvelopeSerializationResult(
+        byte[]? compactJson,
+        byte[]? expandedJson,
+        string payloadSha256,
+        int originalPayloadLength,
+        int embeddedPayloadLength,
+        DsseCompressionAlgorithm compression,
+        DsseDetachedPayloadReference? detachedPayload)
+    {
+        CompactJson = compactJson;
+        ExpandedJson = expandedJson;
+        PayloadSha256 = payloadSha256 ?? throw new ArgumentNullException(nameof(payloadSha256));
+        OriginalPayloadLength = originalPayloadLength;
+        EmbeddedPayloadLength = embeddedPayloadLength;
+        Compression = compression;
+        DetachedPayload = detachedPayload;
+    }
+
+    public byte[]? CompactJson { get; }
+
+    public byte[]? ExpandedJson { get; }
+
+    public string PayloadSha256 { get; }
+
+    public int OriginalPayloadLength { get; }
+
+    public int EmbeddedPayloadLength { get; }
+
+    public DsseCompressionAlgorithm Compression { get; }
+
+    public DsseDetachedPayloadReference? DetachedPayload { get; }
+}

src/Attestor/StellaOps.Attestor.Envelope/DsseEnvelopeSerializer.cs

@@ -0,0 +1,331 @@
+using System;
+using System.Buffers;
+using System.Collections.Generic;
+using System.IO;
+using System.IO.Compression;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Encodings.Web;
+using System.Text.Json;
+
+namespace StellaOps.Attestor.Envelope;
+
+public static class DsseEnvelopeSerializer
+{
+    public static DsseEnvelopeSerializationResult Serialize(DsseEnvelope envelope, DsseEnvelopeSerializationOptions? options = null)
+    {
+        ArgumentNullException.ThrowIfNull(envelope);
+
+        options ??= new DsseEnvelopeSerializationOptions();
+
+        var originalPayload = envelope.Payload.ToArray();
+        var processedPayload = ApplyCompression(originalPayload, options.CompressionAlgorithm);
+        var payloadSha256 = Convert.ToHexString(SHA256.HashData(originalPayload)).ToLowerInvariant();
+        var payloadBase64 = Convert.ToBase64String(processedPayload);
+
+        byte[]? compactJson = null;
+        if (options.EmitCompactJson)
+        {
+            compactJson = BuildCompactJson(envelope.PayloadType, payloadBase64, envelope.Signatures);
+        }
+
+        byte[]? expandedJson = null;
+        if (options.EmitExpandedJson)
+        {
+            expandedJson = BuildExpandedJson(
+                envelope,
+                payloadBase64,
+                payloadSha256,
+                originalPayload.Length,
+                processedPayload.Length,
+                options,
+                originalPayload);
+        }
+
+        return new DsseEnvelopeSerializationResult(
+            compactJson,
+            expandedJson,
+            payloadSha256,
+            originalPayload.Length,
+            processedPayload.Length,
+            options.CompressionAlgorithm,
+            envelope.DetachedPayload);
+    }
+
+    private static byte[] BuildCompactJson(string payloadType, string payloadBase64, IReadOnlyList<DsseSignature> signatures)
+    {
+        var buffer = new ArrayBufferWriter<byte>();
+        using var writer = new Utf8JsonWriter(buffer, new JsonWriterOptions
+        {
+            Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
+            Indented = false
+        });
+
+        writer.WriteStartObject();
+        writer.WriteString("payloadType", payloadType);
+        writer.WriteString("payload", payloadBase64);
+        writer.WritePropertyName("signatures");
+        writer.WriteStartArray();
+
+        foreach (var signature in EnumerateCanonicalSignatures(signatures))
+        {
+            writer.WriteStartObject();
+            if (!string.IsNullOrWhiteSpace(signature.KeyId))
+            {
+                writer.WriteString("keyid", signature.KeyId);
+            }
+
+            writer.WriteString("sig", signature.Signature);
+            writer.WriteEndObject();
+        }
+
+        writer.WriteEndArray();
+        writer.WriteEndObject();
+        writer.Flush();
+        return buffer.WrittenSpan.ToArray();
+    }
+
+    private static byte[]? BuildExpandedJson(
+        DsseEnvelope envelope,
+        string payloadBase64,
+        string payloadSha256,
+        int originalPayloadLength,
+        int embeddedPayloadLength,
+        DsseEnvelopeSerializationOptions options,
+        byte[] originalPayload)
+    {
+        var buffer = new ArrayBufferWriter<byte>();
+        using var writer = new Utf8JsonWriter(buffer, new JsonWriterOptions
+        {
+            Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
+            Indented = options.IndentExpandedJson
+        });
+
+        writer.WriteStartObject();
+        writer.WriteString("payloadType", envelope.PayloadType);
+        writer.WriteString("payload", payloadBase64);
+        writer.WritePropertyName("signatures");
+        writer.WriteStartArray();
+
+        foreach (var signature in EnumerateCanonicalSignatures(envelope.Signatures))
+        {
+            writer.WriteStartObject();
+            if (!string.IsNullOrWhiteSpace(signature.KeyId))
+            {
+                writer.WriteString("keyid", signature.KeyId);
+            }
+
+            writer.WriteString("sig", signature.Signature);
+            writer.WriteEndObject();
+        }
+
+        writer.WriteEndArray();
+
+        writer.WritePropertyName("payloadInfo");
+        writer.WriteStartObject();
+        writer.WriteString("sha256", payloadSha256);
+        writer.WriteNumber("length", originalPayloadLength);
+
+        if (options.CompressionAlgorithm != DsseCompressionAlgorithm.None)
+        {
+            writer.WritePropertyName("compression");
+            writer.WriteStartObject();
+            writer.WriteString("algorithm", GetCompressionName(options.CompressionAlgorithm));
+            writer.WriteNumber("compressedLength", embeddedPayloadLength);
+            writer.WriteEndObject();
+        }
+
+        writer.WriteEndObject(); // payloadInfo
+
+        if (options.IncludePayloadPreview && TryWritePayloadPreview(envelope.PayloadContentType, originalPayload, writer))
+        {
+            // preview already written inside helper
+        }
+
+        if (envelope.DetachedPayload is not null)
+        {
+            writer.WritePropertyName("detachedPayload");
+            writer.WriteStartObject();
+            writer.WriteString("uri", envelope.DetachedPayload.Uri);
+            writer.WriteString("sha256", envelope.DetachedPayload.Sha256);
+            if (envelope.DetachedPayload.Length.HasValue)
+            {
+                writer.WriteNumber("length", envelope.DetachedPayload.Length.Value);
+            }
+
+            if (!string.IsNullOrWhiteSpace(envelope.DetachedPayload.MediaType))
+            {
+                writer.WriteString("mediaType", envelope.DetachedPayload.MediaType);
+            }
+
+            writer.WriteEndObject();
+        }
+
+        writer.WriteEndObject();
+        writer.Flush();
+        return buffer.WrittenSpan.ToArray();
+    }
+
+    private static bool TryWritePayloadPreview(string? contentType, byte[] originalPayload, Utf8JsonWriter writer)
+    {
+        if (string.IsNullOrWhiteSpace(contentType))
+        {
+            return false;
+        }
+
+        var lower = contentType.ToLowerInvariant();
+        if (!lower.Contains("json") && !lower.StartsWith("text/", StringComparison.Ordinal))
+        {
+            return false;
+        }
+
+        writer.WritePropertyName("payloadPreview");
+        writer.WriteStartObject();
+        writer.WriteString("mediaType", contentType);
+
+        if (lower.Contains("json") && TryParseJson(originalPayload, out var jsonDocument))
+        {
+            writer.WritePropertyName("json");
+            jsonDocument.WriteTo(writer);
+            jsonDocument.Dispose();
+        }
+        else if (TryDecodeUtf8(originalPayload, out var text))
+        {
+            writer.WriteString("text", text);
+        }
+
+        writer.WriteEndObject();
+        return true;
+    }
+
+    private static bool TryParseJson(byte[] payload, out JsonDocument document)
+    {
+        try
+        {
+            document = JsonDocument.Parse(payload);
+            return true;
+        }
+        catch (JsonException)
+        {
+            document = null!;
+            return false;
+        }
+    }
+
+    private static bool TryDecodeUtf8(byte[] payload, out string text)
+    {
+        var utf8 = new UTF8Encoding(false, true);
+        try
+        {
+            text = utf8.GetString(payload);
+            return true;
+        }
+        catch (DecoderFallbackException)
+        {
+            text = string.Empty;
+            return false;
+        }
+    }
+
+    private static byte[] ApplyCompression(byte[] payload, DsseCompressionAlgorithm algorithm)
+    {
+        return algorithm switch
+        {
+            DsseCompressionAlgorithm.None => payload,
+            DsseCompressionAlgorithm.Gzip => CompressWithStream(payload, static (stream) => new GZipStream(stream, CompressionLevel.SmallestSize, leaveOpen: true)),
+            DsseCompressionAlgorithm.Brotli => CompressWithStream(payload, static (stream) => new BrotliStream(stream, CompressionLevel.SmallestSize, leaveOpen: true)),
+            _ => throw new NotSupportedException($"Compression algorithm '{algorithm}' is not supported.")
+        };
+    }
+
+    private static byte[] CompressWithStream(byte[] payload, Func<Stream, Stream> streamFactory)
+    {
+        if (payload.Length == 0)
+        {
+            return Array.Empty<byte>();
+        }
+
+        using var output = new MemoryStream();
+        using (var compressionStream = streamFactory(output))
+        {
+            compressionStream.Write(payload);
+        }
+
+        return output.ToArray();
+    }
+
+    private static string GetCompressionName(DsseCompressionAlgorithm algorithm)
+    {
+        return algorithm switch
+        {
+            DsseCompressionAlgorithm.Gzip => "gzip",
+            DsseCompressionAlgorithm.Brotli => "brotli",
+            DsseCompressionAlgorithm.None => "none",
+            _ => algorithm.ToString().ToLowerInvariant()
+        };
+    }
+
+    private static IEnumerable<DsseSignature> EnumerateCanonicalSignatures(IReadOnlyList<DsseSignature> signatures)
+    {
+        if (signatures.Count <= 1)
+        {
+            return signatures;
+        }
+
+        var comparer = CanonicalSignatureComparer.Instance;
+        var previous = signatures[0];
+        for (var i = 1; i < signatures.Count; i++)
+        {
+            var current = signatures[i];
+            if (comparer.Compare(previous, current) > 0)
+            {
+                var buffer = new List<DsseSignature>(signatures.Count);
+                for (var j = 0; j < signatures.Count; j++)
+                {
+                    buffer.Add(signatures[j]);
+                }
+
+                buffer.Sort(comparer);
+                return buffer;
+            }
+
+            previous = current;
+        }
+
+        return signatures;
+    }
+
+    private sealed class CanonicalSignatureComparer : IComparer<DsseSignature>
+    {
+        public static CanonicalSignatureComparer Instance { get; } = new();
+
+        public int Compare(DsseSignature? x, DsseSignature? y)
+        {
+            if (ReferenceEquals(x, y))
+            {
+                return 0;
+            }
+
+            ArgumentNullException.ThrowIfNull(x);
+            ArgumentNullException.ThrowIfNull(y);
+
+            var keyComparison = string.Compare(x.KeyId, y.KeyId, StringComparison.Ordinal);
+            if (keyComparison != 0)
+            {
+                if (x.KeyId is null)
+                {
+                    return -1;
+                }
+
+                if (y.KeyId is null)
+                {
+                    return 1;
+                }
+
+                return keyComparison;
+            }
+
+            return string.Compare(x.Signature, y.Signature, StringComparison.Ordinal);
+        }
+    }
+}

src/Attestor/StellaOps.Attestor.Envelope/DsseSignature.cs

@@ -0,0 +1,31 @@
+using System;
+
+namespace StellaOps.Attestor.Envelope;
+
+public sealed record DsseSignature
+{
+    public DsseSignature(string signature, string? keyId = null)
+    {
+        if (string.IsNullOrWhiteSpace(signature))
+        {
+            throw new ArgumentException("Signature must be provided.", nameof(signature));
+        }
+
+        Signature = signature;
+        KeyId = keyId;
+    }
+
+    public string Signature { get; }
+
+    public string? KeyId { get; }
+
+    public static DsseSignature FromBytes(ReadOnlySpan<byte> signature, string? keyId = null)
+    {
+        if (signature.IsEmpty)
+        {
+            throw new ArgumentException("Signature bytes must be provided.", nameof(signature));
+        }
+
+        return new DsseSignature(Convert.ToBase64String(signature), keyId);
+    }
+}

src/Attestor/StellaOps.Attestor.Envelope/EnvelopeKey.cs

@@ -0,0 +1,301 @@
+using System;
+using System.Security.Cryptography;
+using StellaOps.Cryptography;
+
+namespace StellaOps.Attestor.Envelope;
+
+/// <summary>
+/// Describes the underlying key algorithm for DSSE envelope signing.
+/// </summary>
+public enum EnvelopeKeyKind
+{
+    Ed25519,
+    Ecdsa
+}
+
+/// <summary>
+/// Represents signing or verification key material for DSSE envelope operations.
+/// </summary>
+public sealed class EnvelopeKey
+{
+    private const int Ed25519PublicKeyLength = 32;
+    private const int Ed25519PrivateKeySeedLength = 32;
+    private const int Ed25519PrivateKeyExpandedLength = 64;
+
+    private readonly byte[]? ed25519PublicKey;
+    private readonly byte[]? ed25519PrivateKey;
+    private readonly ECParameters? ecdsaPublicParameters;
+    private readonly ECParameters? ecdsaPrivateParameters;
+
+    private EnvelopeKey(
+        EnvelopeKeyKind kind,
+        string algorithmId,
+        string keyId,
+        byte[]? ed25519PublicKey,
+        byte[]? ed25519PrivateKey,
+        ECParameters? ecdsaPublicParameters,
+        ECParameters? ecdsaPrivateParameters)
+    {
+        Kind = kind;
+        AlgorithmId = algorithmId;
+        KeyId = keyId;
+        this.ed25519PublicKey = ed25519PublicKey;
+        this.ed25519PrivateKey = ed25519PrivateKey;
+        this.ecdsaPublicParameters = ecdsaPublicParameters;
+        this.ecdsaPrivateParameters = ecdsaPrivateParameters;
+    }
+
+    /// <summary>
+    /// Gets the key classification.
+    /// </summary>
+    public EnvelopeKeyKind Kind { get; }
+
+    /// <summary>
+    /// Gets the signing algorithm identifier (e.g., ED25519, ES256).
+    /// </summary>
+    public string AlgorithmId { get; }
+
+    /// <summary>
+    /// Gets the deterministic key identifier (RFC7638 JWK thumbprint based).
+    /// </summary>
+    public string KeyId { get; }
+
+    /// <summary>
+    /// Indicates whether the key has private material available.
+    /// </summary>
+    public bool HasPrivateMaterial => Kind switch
+    {
+        EnvelopeKeyKind.Ed25519 => ed25519PrivateKey is not null,
+        EnvelopeKeyKind.Ecdsa => ecdsaPrivateParameters.HasValue,
+        _ => false
+    };
+
+    /// <summary>
+    /// Indicates whether the key has public material available.
+    /// </summary>
+    public bool HasPublicMaterial => Kind switch
+    {
+        EnvelopeKeyKind.Ed25519 => ed25519PublicKey is not null,
+        EnvelopeKeyKind.Ecdsa => ecdsaPublicParameters.HasValue,
+        _ => false
+    };
+
+    internal ReadOnlySpan<byte> GetEd25519PublicKey()
+    {
+        if (Kind != EnvelopeKeyKind.Ed25519 || ed25519PublicKey is null)
+        {
+            throw new InvalidOperationException("Key does not provide Ed25519 public material.");
+        }
+
+        return ed25519PublicKey;
+    }
+
+    internal ReadOnlySpan<byte> GetEd25519PrivateKey()
+    {
+        if (Kind != EnvelopeKeyKind.Ed25519 || ed25519PrivateKey is null)
+        {
+            throw new InvalidOperationException("Key does not provide Ed25519 private material.");
+        }
+
+        return ed25519PrivateKey;
+    }
+
+    internal ECParameters GetEcdsaPublicParameters()
+    {
+        if (Kind != EnvelopeKeyKind.Ecdsa || !ecdsaPublicParameters.HasValue)
+        {
+            throw new InvalidOperationException("Key does not provide ECDSA public parameters.");
+        }
+
+        return CloneParameters(ecdsaPublicParameters.Value, includePrivate: false);
+    }
+
+    internal ECParameters GetEcdsaPrivateParameters()
+    {
+        if (Kind != EnvelopeKeyKind.Ecdsa || !ecdsaPrivateParameters.HasValue)
+        {
+            throw new InvalidOperationException("Key does not provide ECDSA private parameters.");
+        }
+
+        return CloneParameters(ecdsaPrivateParameters.Value, includePrivate: true);
+    }
+
+    /// <summary>
+    /// Creates an Ed25519 signing key (requires private + public material).
+    /// </summary>
+    /// <param name="privateKey">64-byte Ed25519 private key (seed || public key).</param>
+    /// <param name="publicKey">32-byte Ed25519 public key.</param>
+    /// <param name="keyId">Optional external key identifier override.</param>
+    /// <returns>Envelope key instance.</returns>
+    public static EnvelopeKey CreateEd25519Signer(ReadOnlySpan<byte> privateKey, ReadOnlySpan<byte> publicKey, string? keyId = null)
+    {
+        var normalizedPrivate = NormalizeEd25519PrivateKey(privateKey);
+        ValidateEd25519PublicLength(publicKey);
+        var publicCopy = publicKey.ToArray();
+        var resolvedKeyId = string.IsNullOrWhiteSpace(keyId)
+            ? EnvelopeKeyIdCalculator.FromEd25519(publicCopy)
+            : keyId;
+
+        return new EnvelopeKey(
+            EnvelopeKeyKind.Ed25519,
+            SignatureAlgorithms.Ed25519,
+            resolvedKeyId,
+            publicCopy,
+            normalizedPrivate,
+            ecdsaPublicParameters: null,
+            ecdsaPrivateParameters: null);
+    }
+
+    /// <summary>
+    /// Creates an Ed25519 verification key (public material only).
+    /// </summary>
+    /// <param name="publicKey">32-byte Ed25519 public key.</param>
+    /// <param name="keyId">Optional external key identifier override.</param>
+    /// <returns>Envelope key instance.</returns>
+    public static EnvelopeKey CreateEd25519Verifier(ReadOnlySpan<byte> publicKey, string? keyId = null)
+    {
+        ValidateEd25519PublicLength(publicKey);
+
+        var publicCopy = publicKey.ToArray();
+        var resolvedKeyId = string.IsNullOrWhiteSpace(keyId)
+            ? EnvelopeKeyIdCalculator.FromEd25519(publicCopy)
+            : keyId;
+
+        return new EnvelopeKey(
+            EnvelopeKeyKind.Ed25519,
+            SignatureAlgorithms.Ed25519,
+            resolvedKeyId,
+            publicCopy,
+            ed25519PrivateKey: null,
+            ecdsaPublicParameters: null,
+            ecdsaPrivateParameters: null);
+    }
+
+    /// <summary>
+    /// Creates an ECDSA signing key (private + public EC parameters).
+    /// </summary>
+    /// <param name="algorithmId">ECDSA algorithm identifier (ES256, ES384, ES512).</param>
+    /// <param name="privateParameters">EC parameters including private scalar.</param>
+    /// <param name="keyId">Optional external key identifier override.</param>
+    /// <returns>Envelope key instance.</returns>
+    public static EnvelopeKey CreateEcdsaSigner(string algorithmId, in ECParameters privateParameters, string? keyId = null)
+    {
+        ValidateEcdsaAlgorithm(algorithmId);
+
+        if (privateParameters.D is null || privateParameters.D.Length == 0)
+        {
+            throw new ArgumentException("ECDSA private parameters must include the scalar component (D).", nameof(privateParameters));
+        }
+
+        if (privateParameters.Q.X is null || privateParameters.Q.Y is null)
+        {
+            throw new ArgumentException("ECDSA private parameters must include public coordinates.", nameof(privateParameters));
+        }
+
+        var publicClone = CloneParameters(privateParameters, includePrivate: false);
+        var privateClone = CloneParameters(privateParameters, includePrivate: true);
+        var resolvedKeyId = string.IsNullOrWhiteSpace(keyId)
+            ? EnvelopeKeyIdCalculator.FromEcdsa(algorithmId, publicClone)
+            : keyId;
+
+        return new EnvelopeKey(
+            EnvelopeKeyKind.Ecdsa,
+            algorithmId,
+            resolvedKeyId,
+            ed25519PublicKey: null,
+            ed25519PrivateKey: null,
+            ecdsaPublicParameters: publicClone,
+            ecdsaPrivateParameters: privateClone);
+    }
+
+    /// <summary>
+    /// Creates an ECDSA verification key (public EC parameters).
+    /// </summary>
+    /// <param name="algorithmId">ECDSA algorithm identifier (ES256, ES384, ES512).</param>
+    /// <param name="publicParameters">EC parameters containing only public coordinates.</param>
+    /// <param name="keyId">Optional external key identifier override.</param>
+    /// <returns>Envelope key instance.</returns>
+    public static EnvelopeKey CreateEcdsaVerifier(string algorithmId, in ECParameters publicParameters, string? keyId = null)
+    {
+        ValidateEcdsaAlgorithm(algorithmId);
+
+        if (publicParameters.Q.X is null || publicParameters.Q.Y is null)
+        {
+            throw new ArgumentException("ECDSA public parameters must include X and Y coordinates.", nameof(publicParameters));
+        }
+
+        if (publicParameters.D is not null)
+        {
+            throw new ArgumentException("ECDSA verification parameters must not include private scalar data.", nameof(publicParameters));
+        }
+
+        var publicClone = CloneParameters(publicParameters, includePrivate: false);
+        var resolvedKeyId = string.IsNullOrWhiteSpace(keyId)
+            ? EnvelopeKeyIdCalculator.FromEcdsa(algorithmId, publicClone)
+            : keyId;
+
+        return new EnvelopeKey(
+            EnvelopeKeyKind.Ecdsa,
+            algorithmId,
+            resolvedKeyId,
+            ed25519PublicKey: null,
+            ed25519PrivateKey: null,
+            ecdsaPublicParameters: publicClone,
+            ecdsaPrivateParameters: null);
+    }
+
+    private static byte[] NormalizeEd25519PrivateKey(ReadOnlySpan<byte> privateKey)
+    {
+        return privateKey.Length switch
+        {
+            Ed25519PrivateKeySeedLength => privateKey.ToArray(),
+            Ed25519PrivateKeyExpandedLength => privateKey[..Ed25519PrivateKeySeedLength].ToArray(),
+            _ => throw new ArgumentException($"Ed25519 private key must be {Ed25519PrivateKeySeedLength} or {Ed25519PrivateKeyExpandedLength} bytes.", nameof(privateKey))
+        };
+    }
+
+    private static void ValidateEd25519PublicLength(ReadOnlySpan<byte> publicKey)
+    {
+        if (publicKey.Length != Ed25519PublicKeyLength)
+        {
+            throw new ArgumentException($"Ed25519 public key must be {Ed25519PublicKeyLength} bytes.", nameof(publicKey));
+        }
+    }
+
+    private static void ValidateEcdsaAlgorithm(string algorithmId)
+    {
+        if (string.IsNullOrWhiteSpace(algorithmId))
+        {
+            throw new ArgumentException("Algorithm identifier is required.", nameof(algorithmId));
+        }
+
+        var supported = string.Equals(algorithmId, SignatureAlgorithms.Es256, StringComparison.OrdinalIgnoreCase)
+            || string.Equals(algorithmId, SignatureAlgorithms.Es384, StringComparison.OrdinalIgnoreCase)
+            || string.Equals(algorithmId, SignatureAlgorithms.Es512, StringComparison.OrdinalIgnoreCase);
+
+        if (!supported)
+        {
+            throw new ArgumentException($"Unsupported ECDSA algorithm '{algorithmId}'.", nameof(algorithmId));
+        }
+    }
+
+    private static ECParameters CloneParameters(ECParameters source, bool includePrivate)
+    {
+        var clone = new ECParameters
+        {
+            Curve = source.Curve,
+            Q = new ECPoint
+            {
+                X = source.Q.X is null ? null : (byte[])source.Q.X.Clone(),
+                Y = source.Q.Y is null ? null : (byte[])source.Q.Y.Clone()
+            }
+        };
+
+        if (includePrivate && source.D is not null)
+        {
+            clone.D = (byte[])source.D.Clone();
+        }
+
+        return clone;
+    }
+}

src/Attestor/StellaOps.Attestor.Envelope/EnvelopeKeyIdCalculator.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Security.Cryptography;
+using System.Text;
+
+namespace StellaOps.Attestor.Envelope;
+
+internal static class EnvelopeKeyIdCalculator
+{
+    public static string FromEd25519(ReadOnlySpan<byte> publicKey)
+    {
+        if (publicKey.Length != 32)
+        {
+            throw new ArgumentException("Ed25519 public key must be 32 bytes.", nameof(publicKey));
+        }
+
+        var jwk = $"{{\"crv\":\"Ed25519\",\"kty\":\"OKP\",\"x\":\"{ToBase64Url(publicKey)}\"}}";
+        return $"sha256:{ComputeSha256Base64Url(jwk)}";
+    }
+
+    public static string FromEcdsa(string algorithmId, in ECParameters parameters)
+    {
+        var curve = ResolveCurveName(algorithmId);
+        var x = parameters.Q.X ?? throw new ArgumentException("ECDSA public parameters missing X coordinate.", nameof(parameters));
+        var y = parameters.Q.Y ?? throw new ArgumentException("ECDSA public parameters missing Y coordinate.", nameof(parameters));
+
+        var jwk = $"{{\"crv\":\"{curve}\",\"kty\":\"EC\",\"x\":\"{ToBase64Url(x)}\",\"y\":\"{ToBase64Url(y)}\"}}";
+        return $"sha256:{ComputeSha256Base64Url(jwk)}";
+    }
+
+    private static string ResolveCurveName(string algorithmId) => algorithmId?.ToUpperInvariant() switch
+    {
+        "ES256" => "P-256",
+        "ES384" => "P-384",
+        "ES512" => "P-521",
+        _ => throw new ArgumentException($"Unsupported ECDSA algorithm '{algorithmId}'.", nameof(algorithmId))
+    };
+
+    private static string ComputeSha256Base64Url(string value)
+    {
+        using var sha = SHA256.Create();
+        var bytes = Encoding.UTF8.GetBytes(value);
+        var digest = sha.ComputeHash(bytes);
+        return ToBase64Url(digest);
+    }
+
+    private static string ToBase64Url(ReadOnlySpan<byte> value)
+    {
+        var base64 = Convert.ToBase64String(value);
+        return base64
+            .TrimEnd('=')
+            .Replace('+', '-')
+            .Replace('/', '_');
+    }
+}

src/Attestor/StellaOps.Attestor.Envelope/EnvelopeSignature.cs

@@ -0,0 +1,48 @@
+using System;
+
+namespace StellaOps.Attestor.Envelope;
+
+/// <summary>
+/// Represents a DSSE envelope signature (detached from payload).
+/// </summary>
+public sealed class EnvelopeSignature
+{
+    private readonly byte[] signature;
+
+    public EnvelopeSignature(string keyId, string algorithmId, ReadOnlySpan<byte> value)
+    {
+        if (string.IsNullOrWhiteSpace(keyId))
+        {
+            throw new ArgumentException("Key identifier is required.", nameof(keyId));
+        }
+
+        if (string.IsNullOrWhiteSpace(algorithmId))
+        {
+            throw new ArgumentException("Algorithm identifier is required.", nameof(algorithmId));
+        }
+
+        if (value.Length == 0)
+        {
+            throw new ArgumentException("Signature bytes must not be empty.", nameof(value));
+        }
+
+        KeyId = keyId;
+        AlgorithmId = algorithmId;
+        signature = value.ToArray();
+    }
+
+    /// <summary>
+    /// Gets the key identifier associated with the signature.
+    /// </summary>
+    public string KeyId { get; }
+
+    /// <summary>
+    /// Gets the signing algorithm identifier.
+    /// </summary>
+    public string AlgorithmId { get; }
+
+    /// <summary>
+    /// Gets the raw signature bytes.
+    /// </summary>
+    public ReadOnlyMemory<byte> Value => signature;
+}

src/Attestor/StellaOps.Attestor.Envelope/EnvelopeSignatureResult.cs

@@ -0,0 +1,56 @@
+using System;
+
+namespace StellaOps.Attestor.Envelope;
+
+/// <summary>
+/// Error codes returned by envelope signing and verification helpers.
+/// </summary>
+public enum EnvelopeSignatureErrorCode
+{
+    UnsupportedAlgorithm,
+    InvalidKeyMaterial,
+    MissingPrivateKey,
+    MissingPublicKey,
+    AlgorithmMismatch,
+    KeyIdMismatch,
+    InvalidSignatureFormat,
+    SignatureInvalid,
+    SigningFailed,
+    VerificationFailed
+}
+
+/// <summary>
+/// Represents a deterministic error emitted by signature helpers.
+/// </summary>
+public sealed record EnvelopeSignatureError(EnvelopeSignatureErrorCode Code, string Message, Exception? Exception = null);
+
+/// <summary>
+/// Generic result wrapper providing success state and structured errors.
+/// </summary>
+public sealed class EnvelopeResult<T>
+{
+    private EnvelopeResult(bool isSuccess, T? value, EnvelopeSignatureError? error)
+    {
+        IsSuccess = isSuccess;
+        this.value = value;
+        this.error = error;
+    }
+
+    public bool IsSuccess { get; }
+
+    public T Value => IsSuccess
+        ? value ?? throw new InvalidOperationException("Successful result is missing value.")
+        : throw new InvalidOperationException("Cannot access Value when result indicates failure.");
+
+    public EnvelopeSignatureError Error => !IsSuccess
+        ? error ?? throw new InvalidOperationException("Failed result is missing error information.")
+        : throw new InvalidOperationException("Cannot access Error when result indicates success.");
+
+    private readonly T? value;
+
+    private readonly EnvelopeSignatureError? error;
+
+    public static EnvelopeResult<T> Success(T value) => new(true, value, null);
+
+    public static EnvelopeResult<T> Failure(EnvelopeSignatureError error) => new(false, default, error);
+}

src/Attestor/StellaOps.Attestor.Envelope/EnvelopeSignatureService.cs

@@ -0,0 +1,164 @@
+using System;
+using System.Security.Cryptography;
+using System.Threading;
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Crypto.Signers;
+
+namespace StellaOps.Attestor.Envelope;
+
+/// <summary>
+/// Provides Ed25519 and ECDSA helpers for creating and verifying DSSE envelope signatures.
+/// </summary>
+public sealed class EnvelopeSignatureService
+{
+    private const int Ed25519SignatureLength = 64;
+
+    public EnvelopeResult<EnvelopeSignature> Sign(ReadOnlySpan<byte> payload, EnvelopeKey key, CancellationToken cancellationToken = default)
+    {
+        if (key is null)
+        {
+            throw new ArgumentNullException(nameof(key));
+        }
+
+        cancellationToken.ThrowIfCancellationRequested();
+
+        return key.Kind switch
+        {
+            EnvelopeKeyKind.Ed25519 => SignEd25519(payload, key),
+            EnvelopeKeyKind.Ecdsa => SignEcdsa(payload, key),
+            _ => EnvelopeResult<EnvelopeSignature>.Failure(Error(EnvelopeSignatureErrorCode.UnsupportedAlgorithm, $"Unsupported key kind '{key.Kind}'."))
+        };
+    }
+
+    public EnvelopeResult<bool> Verify(ReadOnlySpan<byte> payload, EnvelopeSignature signature, EnvelopeKey key, CancellationToken cancellationToken = default)
+    {
+        if (signature is null)
+        {
+            throw new ArgumentNullException(nameof(signature));
+        }
+
+        if (key is null)
+        {
+            throw new ArgumentNullException(nameof(key));
+        }
+
+        cancellationToken.ThrowIfCancellationRequested();
+
+        if (!key.HasPublicMaterial)
+        {
+            return EnvelopeResult<bool>.Failure(Error(EnvelopeSignatureErrorCode.MissingPublicKey, "Verification requires public key material."));
+        }
+
+        if (!string.Equals(signature.KeyId, key.KeyId, StringComparison.Ordinal))
+        {
+            return EnvelopeResult<bool>.Failure(Error(EnvelopeSignatureErrorCode.KeyIdMismatch, "Signature key identifier does not match the supplied key."));
+        }
+
+        if (!string.Equals(signature.AlgorithmId, key.AlgorithmId, StringComparison.OrdinalIgnoreCase))
+        {
+            return EnvelopeResult<bool>.Failure(Error(EnvelopeSignatureErrorCode.AlgorithmMismatch, "Signature algorithm does not match the supplied key."));
+        }
+
+        return key.Kind switch
+        {
+            EnvelopeKeyKind.Ed25519 => VerifyEd25519(payload, signature, key),
+            EnvelopeKeyKind.Ecdsa => VerifyEcdsa(payload, signature, key),
+            _ => EnvelopeResult<bool>.Failure(Error(EnvelopeSignatureErrorCode.UnsupportedAlgorithm, $"Unsupported key kind '{key.Kind}'."))
+        };
+    }
+
+    private static EnvelopeResult<EnvelopeSignature> SignEd25519(ReadOnlySpan<byte> payload, EnvelopeKey key)
+    {
+        if (!key.HasPrivateMaterial)
+        {
+            return EnvelopeResult<EnvelopeSignature>.Failure(Error(EnvelopeSignatureErrorCode.MissingPrivateKey, "Signing requires Ed25519 private material."));
+        }
+
+        try
+        {
+            var payloadBytes = payload.ToArray();
+            var privateKey = new Ed25519PrivateKeyParameters(key.GetEd25519PrivateKey().ToArray(), 0);
+            var signer = new Ed25519Signer();
+            signer.Init(true, privateKey);
+            signer.BlockUpdate(payloadBytes, 0, payloadBytes.Length);
+            var signatureBytes = signer.GenerateSignature();
+            return EnvelopeResult<EnvelopeSignature>.Success(new EnvelopeSignature(key.KeyId, key.AlgorithmId, signatureBytes));
+        }
+        catch (Exception ex) when (ex is ArgumentException or CryptographicException or InvalidOperationException)
+        {
+            return EnvelopeResult<EnvelopeSignature>.Failure(Error(EnvelopeSignatureErrorCode.SigningFailed, "Failed to produce Ed25519 signature.", ex));
+        }
+    }
+
+    private static EnvelopeResult<EnvelopeSignature> SignEcdsa(ReadOnlySpan<byte> payload, EnvelopeKey key)
+    {
+        if (!key.HasPrivateMaterial)
+        {
+            return EnvelopeResult<EnvelopeSignature>.Failure(Error(EnvelopeSignatureErrorCode.MissingPrivateKey, "Signing requires ECDSA private material."));
+        }
+
+        try
+        {
+            using var ecdsa = ECDsa.Create(key.GetEcdsaPrivateParameters());
+            var signatureBytes = ecdsa.SignData(payload, ResolveHashAlgorithm(key.AlgorithmId));
+            return EnvelopeResult<EnvelopeSignature>.Success(new EnvelopeSignature(key.KeyId, key.AlgorithmId, signatureBytes));
+        }
+        catch (Exception ex) when (ex is ArgumentException or CryptographicException or InvalidOperationException)
+        {
+            return EnvelopeResult<EnvelopeSignature>.Failure(Error(EnvelopeSignatureErrorCode.SigningFailed, "Failed to produce ECDSA signature.", ex));
+        }
+    }
+
+    private static EnvelopeResult<bool> VerifyEd25519(ReadOnlySpan<byte> payload, EnvelopeSignature signature, EnvelopeKey key)
+    {
+        var signatureBytes = signature.Value.Span;
+        if (signatureBytes.Length != Ed25519SignatureLength)
+        {
+            return EnvelopeResult<bool>.Failure(Error(EnvelopeSignatureErrorCode.InvalidSignatureFormat, $"Ed25519 signatures must be {Ed25519SignatureLength} bytes."));
+        }
+
+        try
+        {
+            var payloadBytes = payload.ToArray();
+            var publicKey = new Ed25519PublicKeyParameters(key.GetEd25519PublicKey().ToArray(), 0);
+            var verifier = new Ed25519Signer();
+            verifier.Init(false, publicKey);
+            verifier.BlockUpdate(payloadBytes, 0, payloadBytes.Length);
+            var valid = verifier.VerifySignature(signatureBytes.ToArray());
+            return valid
+                ? EnvelopeResult<bool>.Success(true)
+                : EnvelopeResult<bool>.Failure(Error(EnvelopeSignatureErrorCode.SignatureInvalid, "Ed25519 signature verification failed."));
+        }
+        catch (Exception ex) when (ex is ArgumentException or CryptographicException)
+        {
+            return EnvelopeResult<bool>.Failure(Error(EnvelopeSignatureErrorCode.VerificationFailed, "Failed to verify Ed25519 signature.", ex));
+        }
+    }
+
+    private static EnvelopeResult<bool> VerifyEcdsa(ReadOnlySpan<byte> payload, EnvelopeSignature signature, EnvelopeKey key)
+    {
+        try
+        {
+            using var ecdsa = ECDsa.Create(key.GetEcdsaPublicParameters());
+            var valid = ecdsa.VerifyData(payload, signature.Value.Span, ResolveHashAlgorithm(key.AlgorithmId));
+            return valid
+                ? EnvelopeResult<bool>.Success(true)
+                : EnvelopeResult<bool>.Failure(Error(EnvelopeSignatureErrorCode.SignatureInvalid, "ECDSA signature verification failed."));
+        }
+        catch (Exception ex) when (ex is ArgumentException or CryptographicException)
+        {
+            return EnvelopeResult<bool>.Failure(Error(EnvelopeSignatureErrorCode.VerificationFailed, "Failed to verify ECDSA signature.", ex));
+        }
+    }
+
+    private static HashAlgorithmName ResolveHashAlgorithm(string algorithmId) => algorithmId?.ToUpperInvariant() switch
+    {
+        "ES256" => HashAlgorithmName.SHA256,
+        "ES384" => HashAlgorithmName.SHA384,
+        "ES512" => HashAlgorithmName.SHA512,
+        _ => throw new ArgumentException($"Unsupported ECDSA algorithm '{algorithmId}'.", nameof(algorithmId))
+    };
+
+    private static EnvelopeSignatureError Error(EnvelopeSignatureErrorCode code, string message, Exception? exception = null)
+        => new(code, message, exception);
+}

src/Attestor/StellaOps.Attestor.Envelope/StellaOps.Attestor.Envelope.Tests/DsseEnvelopeSerializerTests.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using FluentAssertions;
+using Xunit;
+using EnvelopeModel = StellaOps.Attestor.Envelope;
+namespace StellaOps.Attestor.Envelope.Tests;
+
+public sealed class DsseEnvelopeSerializerTests
+{
+    private static readonly byte[] SamplePayload = Encoding.UTF8.GetBytes("deterministic-dsse-payload");
+
+    [Fact]
+    public void Serialize_ProducesDeterministicCompactJson_ForSignaturePermutations()
+    {
+        var signatures = new[]
+        {
+            EnvelopeModel.DsseSignature.FromBytes(Convert.FromHexString("0A1B2C3D4E5F60718293A4B5C6D7E8F9"), "tenant-z"),
+            EnvelopeModel.DsseSignature.FromBytes(Convert.FromHexString("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"), null),
+            EnvelopeModel.DsseSignature.FromBytes(Convert.FromHexString("00112233445566778899AABBCCDDEEFF"), "tenant-a"),
+            EnvelopeModel.DsseSignature.FromBytes(Convert.FromHexString("1234567890ABCDEF1234567890ABCDEF"), "tenant-b")
+        };
+
+        var baselineEnvelope = new EnvelopeModel.DsseEnvelope("application/vnd.stellaops.test+json", SamplePayload, signatures);
+        var baseline = EnvelopeModel.DsseEnvelopeSerializer.Serialize(baselineEnvelope);
+        baseline.CompactJson.Should().NotBeNull();
+        var baselineJson = Encoding.UTF8.GetString(baseline.CompactJson!);
+
+        var rng = new Random(12345);
+        for (var iteration = 0; iteration < 32; iteration++)
+        {
+            var shuffled = signatures.OrderBy(_ => rng.Next()).ToArray();
+            var envelope = new EnvelopeModel.DsseEnvelope("application/vnd.stellaops.test+json", SamplePayload, shuffled);
+            var result = EnvelopeModel.DsseEnvelopeSerializer.Serialize(envelope);
+
+            result.CompactJson.Should().NotBeNull();
+            var json = Encoding.UTF8.GetString(result.CompactJson!);
+            json.Should().Be(baselineJson, "canonical JSON must be deterministic regardless of signature insertion order");
+
+            result.PayloadSha256.Should().Be(
+                Convert.ToHexString(SHA256.HashData(SamplePayload)).ToLowerInvariant(),
+                "payload hash must reflect the raw payload bytes");
+
+            using var document = JsonDocument.Parse(result.CompactJson!);
+            var keyIds = document.RootElement
+                .GetProperty("signatures")
+                .EnumerateArray()
+                .Select(element => element.TryGetProperty("keyid", out var key) ? key.GetString() : null)
+                .ToArray();
+
+            keyIds.Should().Equal(new string?[] { null, "tenant-a", "tenant-b", "tenant-z" },
+                "signatures must be ordered by key identifier (null first) for canonical output");
+        }
+    }
+}

src/Attestor/StellaOps.Attestor.Envelope/StellaOps.Attestor.Envelope.Tests/EnvelopeSignatureServiceTests.cs

@@ -0,0 +1,149 @@
+using System;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text;
+using FluentAssertions;
+using StellaOps.Attestor.Envelope;
+using StellaOps.Cryptography;
+using Xunit;
+
+namespace StellaOps.Attestor.Envelope.Tests;
+
+public sealed class EnvelopeSignatureServiceTests
+{
+    private static readonly byte[] SamplePayload = Encoding.UTF8.GetBytes("stella-ops-deterministic");
+
+    private static readonly byte[] Ed25519Seed =
+        Convert.FromHexString("9D61B19DEFFD5A60BA844AF492EC2CC4" +
+                              "4449C5697B326919703BAC031CAE7F60D75A980182B10AB7D54BFED3C964073A" +
+                              "0EE172F3DAA62325AF021A68F707511A");
+
+    private static readonly byte[] Ed25519Public =
+        Convert.FromHexString("D75A980182B10AB7D54BFED3C964073A0EE172F3DAA62325AF021A68F707511A");
+
+    private readonly EnvelopeSignatureService service = new();
+
+    [Fact]
+    public void SignAndVerify_Ed25519_Succeeds()
+    {
+        var signingKey = EnvelopeKey.CreateEd25519Signer(Ed25519Seed, Ed25519Public);
+        var verifyKey = EnvelopeKey.CreateEd25519Verifier(Ed25519Public);
+
+        var signResult = service.Sign(SamplePayload, signingKey);
+
+        signResult.IsSuccess.Should().BeTrue();
+        signResult.Value.AlgorithmId.Should().Be(SignatureAlgorithms.Ed25519);
+        signResult.Value.KeyId.Should().Be(signingKey.KeyId);
+
+        var verifyResult = service.Verify(SamplePayload, signResult.Value, verifyKey);
+
+        verifyResult.IsSuccess.Should().BeTrue();
+        verifyResult.Value.Should().BeTrue();
+
+        var expectedKeyId = ComputeExpectedEd25519KeyId(Ed25519Public);
+        signingKey.KeyId.Should().Be(expectedKeyId);
+    }
+
+    [Fact]
+    public void Verify_Ed25519_InvalidSignature_ReturnsError()
+    {
+        var signingKey = EnvelopeKey.CreateEd25519Signer(Ed25519Seed, Ed25519Public);
+        var signResult = service.Sign(SamplePayload, signingKey);
+        signResult.IsSuccess.Should().BeTrue();
+
+        var tamperedBytes = signResult.Value.Value.ToArray();
+        tamperedBytes[0] ^= 0xFF;
+        var tamperedSignature = new EnvelopeSignature(signResult.Value.KeyId, signResult.Value.AlgorithmId, tamperedBytes);
+        var verifyKey = EnvelopeKey.CreateEd25519Verifier(Ed25519Public);
+
+        var verifyResult = service.Verify(SamplePayload, tamperedSignature, verifyKey);
+
+        verifyResult.IsSuccess.Should().BeFalse();
+        verifyResult.Error.Code.Should().Be(EnvelopeSignatureErrorCode.SignatureInvalid);
+    }
+
+    [Fact]
+    public void SignAndVerify_EcdsaEs256_Succeeds()
+    {
+        using var ecdsa = ECDsa.Create(ECCurve.NamedCurves.nistP256);
+        var privateParameters = ecdsa.ExportParameters(includePrivateParameters: true);
+        var publicParameters = ecdsa.ExportParameters(includePrivateParameters: false);
+
+        var signingKey = EnvelopeKey.CreateEcdsaSigner(SignatureAlgorithms.Es256, in privateParameters);
+        var verifyKey = EnvelopeKey.CreateEcdsaVerifier(SignatureAlgorithms.Es256, in publicParameters);
+
+        var signResult = service.Sign(SamplePayload, signingKey);
+        signResult.IsSuccess.Should().BeTrue();
+
+        var verifyResult = service.Verify(SamplePayload, signResult.Value, verifyKey);
+        verifyResult.IsSuccess.Should().BeTrue();
+        verifyResult.Value.Should().BeTrue();
+    }
+
+    [Fact]
+    public void Sign_WithVerificationOnlyKey_ReturnsMissingPrivateKey()
+    {
+        using var ecdsa = ECDsa.Create(ECCurve.NamedCurves.nistP256);
+        var publicParameters = ecdsa.ExportParameters(includePrivateParameters: false);
+        var verifyOnlyKey = EnvelopeKey.CreateEcdsaVerifier(SignatureAlgorithms.Es256, in publicParameters);
+
+        var signResult = service.Sign(SamplePayload, verifyOnlyKey);
+
+        signResult.IsSuccess.Should().BeFalse();
+        signResult.Error.Code.Should().Be(EnvelopeSignatureErrorCode.MissingPrivateKey);
+    }
+
+    [Fact]
+    public void Verify_WithMismatchedKeyId_ReturnsError()
+    {
+        var signingKey = EnvelopeKey.CreateEd25519Signer(Ed25519Seed, Ed25519Public);
+        var signResult = service.Sign(SamplePayload, signingKey);
+        signResult.IsSuccess.Should().BeTrue();
+
+        var alternateKey = EnvelopeKey.CreateEd25519Verifier(Ed25519Public, "sha256:alternate");
+        var verifyResult = service.Verify(SamplePayload, signResult.Value, alternateKey);
+
+        verifyResult.IsSuccess.Should().BeFalse();
+        verifyResult.Error.Code.Should().Be(EnvelopeSignatureErrorCode.KeyIdMismatch);
+    }
+
+    [Fact]
+    public void Verify_WithInvalidSignatureLength_ReturnsFormatError()
+    {
+        var verifyKey = EnvelopeKey.CreateEd25519Verifier(Ed25519Public);
+        var invalidSignature = new EnvelopeSignature(verifyKey.KeyId, verifyKey.AlgorithmId, new byte[16]);
+
+        var verifyResult = service.Verify(SamplePayload, invalidSignature, verifyKey);
+
+        verifyResult.IsSuccess.Should().BeFalse();
+        verifyResult.Error.Code.Should().Be(EnvelopeSignatureErrorCode.InvalidSignatureFormat);
+    }
+
+    [Fact]
+    public void Verify_WithAlgorithmMismatch_ReturnsError()
+    {
+        using var ecdsa = ECDsa.Create(ECCurve.NamedCurves.nistP256);
+        var privateParameters = ecdsa.ExportParameters(includePrivateParameters: true);
+        var publicParameters = ecdsa.ExportParameters(includePrivateParameters: false);
+        var signingKey = EnvelopeKey.CreateEcdsaSigner(SignatureAlgorithms.Es256, in privateParameters);
+        var signResult = service.Sign(SamplePayload, signingKey);
+        signResult.IsSuccess.Should().BeTrue();
+
+        var mismatchKey = EnvelopeKey.CreateEcdsaVerifier(SignatureAlgorithms.Es384, in publicParameters, signResult.Value.KeyId);
+        var verifyResult = service.Verify(SamplePayload, signResult.Value, mismatchKey);
+
+        verifyResult.IsSuccess.Should().BeFalse();
+        verifyResult.Error.Code.Should().Be(EnvelopeSignatureErrorCode.AlgorithmMismatch);
+    }
+
+    private static string ComputeExpectedEd25519KeyId(byte[] publicKey)
+    {
+        var jwk = $"{{\"crv\":\"Ed25519\",\"kty\":\"OKP\",\"x\":\"{ToBase64Url(publicKey)}\"}}";
+        using var sha = SHA256.Create();
+        var digest = sha.ComputeHash(Encoding.UTF8.GetBytes(jwk));
+        return $"sha256:{ToBase64Url(digest)}";
+    }
+
+    private static string ToBase64Url(byte[] bytes)
+        => Convert.ToBase64String(bytes).TrimEnd('=').Replace('+', '-').Replace('/', '_');
+}

src/Attestor/StellaOps.Attestor.Envelope/StellaOps.Attestor.Envelope.Tests/StellaOps.Attestor.Envelope.Tests.csproj

@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <LangVersion>preview</LangVersion>
+    <IsPackable>false</IsPackable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <WarningsNotAsErrors>NU1504</WarningsNotAsErrors>
+    <UseConcelierTestInfra>false</UseConcelierTestInfra>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="FluentAssertions" Version="6.12.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.0" />
+    <PackageReference Include="xunit" Version="2.9.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
+    <PackageReference Include="coverlet.collector" Version="6.0.4" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\\StellaOps.Attestor.Envelope.csproj" />
+  </ItemGroup>
+</Project>

src/Attestor/StellaOps.Attestor.Envelope/StellaOps.Attestor.Envelope.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <LangVersion>preview</LangVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="BouncyCastle.Cryptography" Version="2.5.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="../../__Libraries/StellaOps.Cryptography/StellaOps.Cryptography.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Remove="__Tests\**\*.cs" />
+    <Compile Remove="StellaOps.Attestor.Envelope.Tests\**\*.cs" />
+  </ItemGroup>
+
+</Project>

src/Attestor/StellaOps.Attestor.Envelope/TASKS.md

@@ -1,13 +1,13 @@
-# Attestation Envelope Task Board — Epic 19: Attestor Console
-
-## Sprint 72 – Foundations
-| ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
-|----|--------|----------|------------|-------------|---------------|
-| ATTEST-ENVELOPE-72-001 | TODO | Envelope Guild | — | Implement DSSE canonicalization, JSON normalization, multi-signature structures, and hashing helpers. | Canonicalization deterministic (property tests); hash matches DSSE spec; unit tests green. |
-| ATTEST-ENVELOPE-72-002 | TODO | Envelope Guild | ATTEST-ENVELOPE-72-001 | Support compact and expanded JSON output, payload compression, and detached payload references. | API returns both variants; payload compression toggles tested; docs updated. |
-
-## Sprint 73 – Crypto Integration
-| ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
-|----|--------|----------|------------|-------------|---------------|
-| ATTEST-ENVELOPE-73-001 | TODO | Envelope Guild, KMS Guild | ATTEST-ENVELOPE-72-001 | Implement Ed25519 & ECDSA signature create/verify helpers, key identification (`keyid`) scheme, and error mapping. | Sign/verify tests pass with fixtures; invalid signatures produce deterministic errors. |
-| ATTEST-ENVELOPE-73-002 | TODO | Envelope Guild | ATTEST-ENVELOPE-73-001 | Add fuzz tests for envelope parsing, signature verification, and canonical JSON round-trips. | Fuzz suite integrated; coverage metrics recorded; no regressions. |
+# Attestation Envelope Task Board — Epic 19: Attestor Console
+
+## Sprint 72 – Foundations
+| ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
+|----|--------|----------|------------|-------------|---------------|
+| ATTEST-ENVELOPE-72-001 | DONE (2025-11-01) | Envelope Guild | — | Implement DSSE canonicalization, JSON normalization, multi-signature structures, and hashing helpers. | Canonicalization deterministic (property tests); hash matches DSSE spec; unit tests green. |
+| ATTEST-ENVELOPE-72-002 | DONE | Envelope Guild | ATTEST-ENVELOPE-72-001 | Support compact and expanded JSON output, payload compression, and detached payload references. | API returns both variants; payload compression toggles tested; docs updated. |
+
+## Sprint 73 – Crypto Integration
+| ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
+|----|--------|----------|------------|-------------|---------------|
+| ATTEST-ENVELOPE-73-001 | DONE | Envelope Guild, KMS Guild | ATTEST-ENVELOPE-72-001 | Implement Ed25519 & ECDSA signature create/verify helpers, key identification (`keyid`) scheme, and error mapping. | Sign/verify tests pass with fixtures; invalid signatures produce deterministic errors. |
+| ATTEST-ENVELOPE-73-002 | DONE | Envelope Guild | ATTEST-ENVELOPE-73-001 | Add fuzz tests for envelope parsing, signature verification, and canonical JSON round-trips. | Fuzz suite integrated; coverage metrics recorded; no regressions. |

src/Attestor/StellaOps.Attestor.Envelope/__Tests/StellaOps.Attestor.Envelope.Tests/DsseEnvelopeSerializerTests.cs

@@ -0,0 +1,139 @@
+using System;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+using System.Text;
+using System.Text.Json;
+using StellaOps.Attestor.Envelope;
+using Xunit;
+
+namespace StellaOps.Attestor.Envelope.Tests;
+
+public sealed class DsseEnvelopeSerializerTests
+{
+    [Fact]
+    public void Serialize_WithDefaultOptions_ProducesCompactAndExpandedJson()
+    {
+        var payload = Encoding.UTF8.GetBytes("{\"foo\":\"bar\"}");
+        var envelope = new DsseEnvelope(
+            "application/vnd.in-toto+json",
+            payload,
+            new[] { new DsseSignature("AQID") },
+            "application/json");
+
+        var result = DsseEnvelopeSerializer.Serialize(envelope);
+
+        Assert.NotNull(result.CompactJson);
+        Assert.NotNull(result.ExpandedJson);
+
+        var compact = Encoding.UTF8.GetString(result.CompactJson!);
+        Assert.Equal("{\"payloadType\":\"application/vnd.in-toto+json\",\"payload\":\"eyJmb28iOiJiYXIifQ==\",\"signatures\":[{\"sig\":\"AQID\"}]}", compact);
+
+        using var expanded = JsonDocument.Parse(result.ExpandedJson!);
+        var root = expanded.RootElement;
+
+        Assert.Equal("application/vnd.in-toto+json", root.GetProperty("payloadType").GetString());
+        Assert.Equal("eyJmb28iOiJiYXIifQ==", root.GetProperty("payload").GetString());
+        Assert.Equal("AQID", root.GetProperty("signatures")[0].GetProperty("sig").GetString());
+
+        var info = root.GetProperty("payloadInfo");
+        Assert.Equal(payload.Length, info.GetProperty("length").GetInt32());
+        Assert.Equal(result.PayloadSha256, info.GetProperty("sha256").GetString());
+        Assert.False(info.TryGetProperty("compression", out _));
+
+        var preview = root.GetProperty("payloadPreview");
+        Assert.Equal("application/json", preview.GetProperty("mediaType").GetString());
+        Assert.Equal("bar", preview.GetProperty("json").GetProperty("foo").GetString());
+    }
+
+    [Fact]
+    public void Serialize_WithCompressionEnabled_EmbedsCompressedPayloadMetadata()
+    {
+        var payload = Encoding.UTF8.GetBytes("{\"foo\":\"bar\",\"count\":1}");
+        var envelope = new DsseEnvelope(
+            "application/vnd.in-toto+json",
+            payload,
+            new[] { new DsseSignature("AQID") },
+            "application/json");
+
+        var options = new DsseEnvelopeSerializationOptions
+        {
+            CompressionAlgorithm = DsseCompressionAlgorithm.Gzip
+        };
+
+        var result = DsseEnvelopeSerializer.Serialize(envelope, options);
+
+        Assert.NotNull(result.CompactJson);
+        var compactDoc = JsonDocument.Parse(result.CompactJson!);
+        var payloadBase64 = compactDoc.RootElement.GetProperty("payload").GetString();
+        Assert.False(string.IsNullOrEmpty(payloadBase64));
+
+        var compressedBytes = Convert.FromBase64String(payloadBase64!);
+        using var compressedStream = new MemoryStream(compressedBytes);
+        using var gzip = new GZipStream(compressedStream, CompressionMode.Decompress);
+        using var decompressed = new MemoryStream();
+        gzip.CopyTo(decompressed);
+        Assert.True(payload.SequenceEqual(decompressed.ToArray()));
+
+        using var expanded = JsonDocument.Parse(result.ExpandedJson!);
+        var info = expanded.RootElement.GetProperty("payloadInfo");
+        Assert.Equal(payload.Length, info.GetProperty("length").GetInt32());
+        var compression = info.GetProperty("compression");
+        Assert.Equal("gzip", compression.GetProperty("algorithm").GetString());
+        Assert.Equal(compressedBytes.Length, compression.GetProperty("compressedLength").GetInt32());
+
+        Assert.Equal(DsseCompressionAlgorithm.Gzip, result.Compression);
+        Assert.Equal(payload.Length, result.OriginalPayloadLength);
+        Assert.Equal(compressedBytes.Length, result.EmbeddedPayloadLength);
+    }
+
+    [Fact]
+    public void Serialize_WithDetachedReference_WritesMetadata()
+    {
+        var payload = Encoding.UTF8.GetBytes("detached payload preview");
+        var reference = new DsseDetachedPayloadReference(
+            "https://evidence.example.com/sbom.json",
+            "abc123",
+            payload.Length,
+            "application/json");
+
+        var envelope = new DsseEnvelope(
+            "application/vnd.in-toto+json",
+            payload,
+            new[] { new DsseSignature("AQID") },
+            "text/plain",
+            reference);
+
+        var result = DsseEnvelopeSerializer.Serialize(envelope);
+
+        Assert.NotNull(result.ExpandedJson);
+
+        using var expanded = JsonDocument.Parse(result.ExpandedJson!);
+        var detached = expanded.RootElement.GetProperty("detachedPayload");
+
+        Assert.Equal(reference.Uri, detached.GetProperty("uri").GetString());
+        Assert.Equal(reference.Sha256, detached.GetProperty("sha256").GetString());
+        Assert.Equal(reference.Length, detached.GetProperty("length").GetInt64());
+        Assert.Equal(reference.MediaType, detached.GetProperty("mediaType").GetString());
+    }
+
+    [Fact]
+    public void Serialize_CompactOnly_SkipsExpandedPayload()
+    {
+        var payload = Encoding.UTF8.GetBytes("payload");
+        var envelope = new DsseEnvelope(
+            "application/vnd.in-toto+json",
+            payload,
+            new[] { new DsseSignature("AQID") });
+
+        var options = new DsseEnvelopeSerializationOptions
+        {
+            EmitExpandedJson = false
+        };
+
+        var result = DsseEnvelopeSerializer.Serialize(envelope, options);
+
+        Assert.NotNull(result.CompactJson);
+        Assert.Null(result.ExpandedJson);
+    }
+}

src/Attestor/StellaOps.Attestor.Envelope/__Tests/StellaOps.Attestor.Envelope.Tests/StellaOps.Attestor.Envelope.Tests.csproj

@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <LangVersion>preview</LangVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <WarningsNotAsErrors>NU1504</WarningsNotAsErrors>
+    <UseConcelierTestInfra>false</UseConcelierTestInfra>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.0" />
+    <PackageReference Include="xunit" Version="2.9.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
+    <PackageReference Include="coverlet.collector" Version="6.0.4" />
+    <PackageReference Include="FsCheck.Xunit" Version="3.3.1" />
+    <PackageReference Include="FsCheck" Version="3.3.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Remove="DsseEnvelopeFuzzTests.cs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\\..\\StellaOps.Attestor.Envelope.csproj" />
+  </ItemGroup>
+
+</Project>

src/Attestor/StellaOps.Attestor.Types/AGENTS.md

@@ -23,3 +23,4 @@ Define strongly typed, versioned schemas for all attestation payloads and provid
 - 3. Keep changes deterministic (stable ordering, timestamps, hashes) and align with offline/air-gap expectations.
 - 4. Coordinate doc updates, tests, and cross-guild communication whenever contracts or workflows change.
 - 5. Revert to `TODO` if you pause the task without shipping changes; leave notes in commit/PR descriptions for context.
+- 6. When schemas or fixtures change, run `npm run docs:attestor:generate` followed by `npm run docs:attestor:validate` to refresh SDKs and guard parity.

src/Attestor/StellaOps.Attestor.Types/TASKS.md

@@ -3,11 +3,11 @@
 ## Sprint 72 – Schema Definition
 | ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
 |----|--------|----------|------------|-------------|---------------|
-| ATTEST-TYPES-72-001 | TODO | Attestation Payloads Guild | — | Draft JSON Schemas for BuildProvenance v1, SBOMAttestation v1, VEXAttestation v1, ScanResults v1, PolicyEvaluation v1, RiskProfileEvidence v1, CustomEvidence v1. | Schemas validated with test fixtures; docs stubbed; versioned under `schemas/`. |
-| ATTEST-TYPES-72-002 | TODO | Attestation Payloads Guild | ATTEST-TYPES-72-001 | Generate Go/TS models from schemas with validation helpers and canonical JSON serialization. | Code generation integrated; lints pass; unit tests cover round-trips. |
+| ATTEST-TYPES-72-001 | DONE | Attestation Payloads Guild | — | Draft JSON Schemas for BuildProvenance v1, SBOMAttestation v1, VEXAttestation v1, ScanResults v1, PolicyEvaluation v1, RiskProfileEvidence v1, CustomEvidence v1. | Schemas validated with test fixtures; docs stubbed; versioned under `schemas/`. |
+| ATTEST-TYPES-72-002 | DONE | Attestation Payloads Guild | ATTEST-TYPES-72-001 | Generate Go/TS models from schemas with validation helpers and canonical JSON serialization. | Code generation integrated; lints pass; unit tests cover round-trips. |
 
 ## Sprint 73 – Fixtures & Docs
 | ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
 |----|--------|----------|------------|-------------|---------------|
-| ATTEST-TYPES-73-001 | TODO | Attestation Payloads Guild | ATTEST-TYPES-72-002 | Create golden payload samples for each type; integrate into tests and documentation. | Golden fixtures stored; tests compare outputs; docs embed examples. |
-| ATTEST-TYPES-73-002 | TODO | Attestation Payloads Guild, Docs Guild | ATTEST-TYPES-73-001 | Publish schema reference docs (`/docs/modules/attestor/payloads.md`) with annotated JSON examples. | Doc merged with banner; examples validated by tests. |
+| ATTEST-TYPES-73-001 | DONE | Attestation Payloads Guild | ATTEST-TYPES-72-002 | Create golden payload samples for each type; integrate into tests and documentation. | Golden fixtures stored; tests compare outputs; docs embed examples. |
+| ATTEST-TYPES-73-002 | DONE | Attestation Payloads Guild, Docs Guild | ATTEST-TYPES-73-001 | Publish schema reference docs (`/docs/modules/attestor/payloads.md`) with annotated JSON examples. | Doc merged with banner; examples validated by tests. |

src/Attestor/StellaOps.Attestor.Types/Tools/StellaOps.Attestor.Types.Generator/StellaOps.Attestor.Types.Generator.csproj

@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+  </PropertyGroup>
+</Project>

src/Attestor/StellaOps.Attestor.Types/fixtures/v1/build-provenance.sample.json

@@ -0,0 +1,107 @@
+{
+  "schemaVersion": "1.0.0",
+  "predicateType": "StellaOps.BuildProvenance@1",
+  "subject": [
+    {
+      "subjectKind": "container-image",
+      "name": "registry.stella-ops.internal/scan/api",
+      "digest": {
+        "sha256": "5f4d4b1e9c2f3a1d7a4e5b6c7d8e9f00112233445566778899aabbccddeeff00"
+      },
+      "imageDigest": "sha256:5f4d4b1e9c2f3a1d7a4e5b6c7d8e9f00112233445566778899aabbccddeeff00",
+      "mediaType": "application/vnd.docker.distribution.manifest.v2+json"
+    }
+  ],
+  "issuer": {
+    "issuerType": "service",
+    "id": "urn:stellaops:svc:builder",
+    "tenantId": "tenant-alpha",
+    "displayName": "StellaOps Build Service",
+    "workload": {
+      "service": "builder-web",
+      "cluster": "prod-us-east",
+      "namespace": "build-system"
+    },
+    "signingKey": {
+      "keyId": "builder-key-01",
+      "mode": "kms",
+      "algorithm": "ed25519",
+      "issuer": "vault.kms.internal"
+    }
+  },
+  "issuedAt": "2025-10-31T18:21:04Z",
+  "materials": [
+    {
+      "uri": "git+https://git.stella-ops.org/scanner.git@refs/heads/main",
+      "digest": {
+        "sha1": "a1b2c3d4e5f6a7b8c9d00112233445566778899a"
+      },
+      "role": "source"
+    },
+    {
+      "uri": "oci://registry.stella-ops.internal/base/node:20-bullseye",
+      "digest": {
+        "sha256": "ab40d8d0734c28f3b60df1e6a4ed3f2c1b5d7e9f0a1b2c3d4e5f66778899aabb"
+      },
+      "role": "base-image"
+    }
+  ],
+  "transparency": [
+    {
+      "logId": "rekor-primary",
+      "logUrl": "https://rekor.stella-ops.internal",
+      "uuid": "cb2a6f2e-353e-4a62-8504-18f741fa0010",
+      "index": 128943,
+      "checkpoint": {
+        "origin": "rekor-primary",
+        "size": 155000,
+        "rootHash": "3rJcAM1b9x1Pcjwo8y9zKg2v1nX8/oe3mY4HhE2bY0g=",
+        "timestamp": "2025-10-31T18:21:06Z"
+      },
+      "witnessed": true
+    }
+  ],
+  "build": {
+    "buildType": "stellaops:buildkit@v1",
+    "builder": {
+      "id": "urn:stellaops:builder:buildkit",
+      "version": "1.9.2",
+      "displayName": "BuildKit Runner"
+    },
+    "invocation": {
+      "configSource": {
+        "uri": "git+https://git.stella-ops.org/scanner.git//.stella/build.yaml",
+        "digest": {
+          "sha256": "1f7e26d668d9fd6bae1a5d0a7a27bf3cdf8b4dd0d9775ad911e6cef0e1edf1d2"
+        }
+      },
+      "parameters": {
+        "target": "release",
+        "platform": "linux/amd64"
+      },
+      "environment": {
+        "GIT_SHA": "9f3e7ad1",
+        "CI_PIPELINE_ID": "build-2045"
+      },
+      "entryPoint": "ci/scripts/build-image.sh"
+    },
+    "metadata": {
+      "startedAt": "2025-10-31T18:19:11Z",
+      "finishedAt": "2025-10-31T18:20:52Z",
+      "reproducible": true,
+      "buildDurationSeconds": 101
+    },
+    "outputs": [
+      {
+        "subjectKind": "artifact",
+        "name": "dist/scanner-api.tar",
+        "digest": {
+          "sha256": "cfe4b9b77b4a90d63ba6c2e5b40e6d9b9724f9a3e0d5b6c7f8e9d0a1b2c3d4e5"
+        },
+        "mediaType": "application/x-tar",
+        "sizeBytes": 31457280
+      }
+    ]
+  },
+  "slsaLevel": "slsa3.0"
+}

src/Attestor/StellaOps.Attestor.Types/fixtures/v1/custom-evidence.sample.json

@@ -0,0 +1,39 @@
+{
+  "schemaVersion": "1.0.0",
+  "predicateType": "StellaOps.CustomEvidence@1",
+  "subject": [
+    {
+      "subjectKind": "artifact",
+      "name": "registry.stella-ops.internal/runtime/api@sha256:d2c3b4a5f6e7d8c9b0a1f2e3d4c5b6a79876543210fedcba9876543210fedcba",
+      "digest": {
+        "sha256": "f3b4c5d6e7f8091a2b3c4d5e6f708192a3b4c5d6e7f8091a2b3c4d5e6f708192"
+      }
+    }
+  ],
+  "issuer": {
+    "issuerType": "automation",
+    "id": "urn:stellaops:automation:evidence-uploader",
+    "tenantId": "tenant-alpha",
+    "signingKey": {
+      "keyId": "automation-key-17",
+      "mode": "offline",
+      "algorithm": "ed25519"
+    }
+  },
+  "issuedAt": "2025-10-31T05:32:28Z",
+  "customSchema": {
+    "uri": "https://schemas.stella-ops.org/custom/runtime-evidence/v1.json",
+    "digest": {
+      "sha256": "aa11bb22cc33dd44ee55ff66aa77bb88cc99ddeeff0011223344556677889900"
+    },
+    "version": "1.0"
+  },
+  "payload": {
+    "controlId": "OPS-RUN-102",
+    "controlStatus": "passed",
+    "auditedBy": "auditor@example.org",
+    "evidenceUri": "s3://compliance-artifacts/runtime/api/2025-10-31/report.pdf",
+    "notes": "Manual security review completed for release 3.14.0."
+  },
+  "notes": "Custom evidence uploaded by compliance automation workflow."
+}

src/Attestor/StellaOps.Attestor.Types/fixtures/v1/policy-evaluation.sample.json

@@ -0,0 +1,77 @@
+{
+  "schemaVersion": "1.0.0",
+  "predicateType": "StellaOps.PolicyEvaluation@1",
+  "subject": [
+    {
+      "subjectKind": "policy-report",
+      "name": "policy-eval/runtime-api@sha256:5f4d4b1e9c2f3a1d7a4e5b6c7d8e9f00112233445566778899aabbccddeeff00",
+      "digest": {
+        "sha256": "21f4b8d7c6e5a4f3b2c1d0e9f8a7b6c5d4e3f2a1b0c9d8e7f6a5b4c3d2e1f0a9"
+      }
+    }
+  ],
+  "issuer": {
+    "issuerType": "service",
+    "id": "urn:stellaops:svc:policy-engine",
+    "tenantId": "tenant-alpha",
+    "signingKey": {
+      "keyId": "policy-engine-key",
+      "mode": "hsm",
+      "algorithm": "ed25519",
+      "issuer": "yubi-hsm"
+    }
+  },
+  "issuedAt": "2025-10-31T02:44:09Z",
+  "policy": {
+    "policyId": "runtime-enforce",
+    "policyVersion": "2025.10.1",
+    "revisionDigest": {
+      "sha256": "aa55bb66cc77dd88ee99ff00112233445566778899aabbccddeeff0011223344"
+    },
+    "mode": "enforce"
+  },
+  "result": {
+    "status": "fail",
+    "summary": "Policy runtime-enforce failed: 1 blocking rule violation.",
+    "violations": [
+      {
+        "ruleId": "RULE-RUNTIME-001",
+        "severity": "high",
+        "message": "Critical KEV vulnerabilities detected without waiver.",
+        "evidence": [
+          {
+            "type": "scan",
+            "id": "CVE-2025-10001"
+          }
+        ],
+        "suggestedRemediation": "Apply patched base image or configure approved waiver."
+      }
+    ],
+    "waiversApplied": [
+      "WAIVER-LICENSE-123"
+    ]
+  },
+  "explain": [
+    {
+      "id": "trace-node-1",
+      "type": "rule",
+      "message": "Evaluated RULE-RUNTIME-001 on scan results"
+    },
+    {
+      "id": "trace-node-1.1",
+      "type": "binding",
+      "message": "Matched vulnerability CVE-2025-10001 with severity critical"
+    }
+  ],
+  "metrics": {
+    "rulesEvaluated": 12,
+    "rulesPassed": 11,
+    "rulesFailed": 1,
+    "evaluationDurationMs": 84
+  },
+  "policyContext": {
+    "policyId": "runtime-enforce",
+    "policyVersion": "2025.10.1",
+    "mode": "enforce"
+  }
+}

src/Attestor/StellaOps.Attestor.Types/fixtures/v1/risk-profile-evidence.sample.json

@@ -0,0 +1,68 @@
+{
+  "schemaVersion": "1.0.0",
+  "predicateType": "StellaOps.RiskProfileEvidence@1",
+  "subject": [
+    {
+      "subjectKind": "risk-profile",
+      "name": "runtime-api@sha256:d2c3b4a5f6e7d8c9b0a1f2e3d4c5b6a79876543210fedcba9876543210fedcba",
+      "digest": {
+        "sha256": "f3c2b1a0e9d8c7b6a5f4e3d2c1b0a9876543210fedcba9876543210fedcba987"
+      }
+    }
+  ],
+  "issuer": {
+    "issuerType": "service",
+    "id": "urn:stellaops:svc:risk-engine",
+    "tenantId": "tenant-alpha",
+    "signingKey": {
+      "keyId": "risk-engine-key",
+      "mode": "kms",
+      "algorithm": "ed25519"
+    }
+  },
+  "issuedAt": "2025-10-31T04:00:00Z",
+  "window": {
+    "startedAt": "2025-10-30T04:00:00Z",
+    "endedAt": "2025-10-31T04:00:00Z"
+  },
+  "riskScores": {
+    "overall": 0.62,
+    "exploitability": 0.74,
+    "impact": 0.51,
+    "epss98Percentile": 0.92,
+    "kevCount": 1
+  },
+  "exposure": {
+    "internetFacing": true,
+    "runtimeEnforced": false,
+    "criticality": "mission-critical",
+    "deployments": 48
+  },
+  "controls": {
+    "sbomAttested": true,
+    "vexCoverage": "partial",
+    "policyStatus": "fail",
+    "lastPolicyEvaluation": "2025-10-31T02:44:09Z"
+  },
+  "findings": [
+    {
+      "category": "vulnerability",
+      "severity": "critical",
+      "summary": "KEV-listed OpenSSL vulnerability present without compensating control.",
+      "detail": "CVE-2025-10001 remained open in production deployments for >24h.",
+      "evidence": [
+        "scan:CVE-2025-10001",
+        "policy:RULE-RUNTIME-001"
+      ]
+    },
+    {
+      "category": "runtime",
+      "severity": "medium",
+      "summary": "No runtime admission control for critical namespaces.",
+      "detail": "Zastava webhook disabled on cluster prod-us-east due to maintenance.",
+      "evidence": [
+        "zastava:event:2025-10-30T21:41Z"
+      ]
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/fixtures/v1/sbom-attestation.sample.json

@@ -0,0 +1,80 @@
+{
+  "schemaVersion": "1.0.0",
+  "predicateType": "StellaOps.SBOMAttestation@1",
+  "subject": [
+    {
+      "subjectKind": "container-image",
+      "name": "registry.stella-ops.internal/policy/engine",
+      "digest": {
+        "sha256": "4d7c3a1b2f9e0d6c5b4a3f2e1d0c9b8a7766554433221100ffaabbccddeeff12"
+      },
+      "imageDigest": "sha256:4d7c3a1b2f9e0d6c5b4a3f2e1d0c9b8a7766554433221100ffaabbccddeeff12"
+    }
+  ],
+  "issuer": {
+    "issuerType": "service",
+    "id": "urn:stellaops:svc:scanner",
+    "tenantId": "tenant-alpha",
+    "signingKey": {
+      "keyId": "scanner-key-01",
+      "mode": "keyless",
+      "algorithm": "ecdsa-p256",
+      "issuer": "fulcio.internal",
+      "certificateChain": [
+        "-----BEGIN CERTIFICATE-----MIIB...==-----END CERTIFICATE-----"
+      ]
+    }
+  },
+  "issuedAt": "2025-10-30T14:05:18Z",
+  "materials": [
+    {
+      "uri": "oci://registry.stella-ops.internal/scanner/sbom-indexer@sha256:1122aa55bb66cc77dd88ee99ff00112233445566778899aabbccddeeff001122",
+      "role": "scanner-runtime"
+    }
+  ],
+  "transparency": [
+    {
+      "logId": "rekor-primary",
+      "logUrl": "https://rekor.stella-ops.internal",
+      "uuid": "11111111-2222-3333-4444-555555555555",
+      "index": 567890
+    }
+  ],
+  "sbom": {
+    "format": "cyclonedx-json",
+    "specVersion": "1.6",
+    "digest": {
+      "sha256": "9a7b6c5d4e3f2a1b0c9d8e7f6a5b4c3d2e1f0a9b8c7d6e5f4a3b2c1d0e9f8a7b"
+    },
+    "contentUri": "cas://sbom/blobs/9a7b6c5d4e3f2a1b0c9d8e7f6a5b4c3d2e1f0a9b8c7d6e5f4a3b2c1d0e9f8a7b",
+    "contentMediaType": "application/vnd.cyclonedx+json;version=1.6",
+    "sizeBytes": 48213,
+    "descriptor": {
+      "bomRef": "urn:uuid:fa8706c2-2d3e-4e74-bc3e-337ca0fdf2f7",
+      "componentName": "policy-engine",
+      "componentVersion": "1.12.0"
+    },
+    "componentCounts": {
+      "packages": 215,
+      "dependencies": 214,
+      "services": 0,
+      "vulnerabilities": 14
+    }
+  },
+  "coverage": {
+    "layers": [
+      "sha256:aa11bb22cc33dd44ee55ff66aa77bb88cc99ddeeff00112233445566778899aa",
+      "sha256:bb22cc33dd44ee55ff66aa77bb88cc99ddeeff00112233445566778899aabbcc"
+    ],
+    "packagesIncluded": true,
+    "licenseScanEnabled": true
+  },
+  "generator": {
+    "name": "StellaOps Scanner",
+    "version": "2.4.3",
+    "buildId": "scanner-build-8897",
+    "configurationDigest": {
+      "sha256": "abc1239f7e6d5c4b3a29181706f5e4d3c2b1a0f99887766554433221100ffeedd"
+    }
+  }
+}

src/Attestor/StellaOps.Attestor.Types/fixtures/v1/scan-results.sample.json

@@ -0,0 +1,126 @@
+{
+  "schemaVersion": "1.0.0",
+  "predicateType": "StellaOps.ScanResults@1",
+  "subject": [
+    {
+      "subjectKind": "scan-report",
+      "name": "registry.stella-ops.internal/runtime/api@sha256:d2c3b4a5f6e7d8c9b0a1f2e3d4c5b6a79876543210fedcba9876543210fedcba",
+      "digest": {
+        "sha256": "deafbeefdeafbeefdeafbeefdeafbeefdeafbeefdeafbeefdeafbeefdeafbeef"
+      },
+      "imageDigest": "sha256:d2c3b4a5f6e7d8c9b0a1f2e3d4c5b6a79876543210fedcba9876543210fedcba"
+    }
+  ],
+  "issuer": {
+    "issuerType": "service",
+    "id": "urn:stellaops:svc:scanner.worker",
+    "tenantId": "tenant-alpha",
+    "signingKey": {
+      "keyId": "scanner-worker-key",
+      "mode": "keyless",
+      "algorithm": "ed25519",
+      "issuer": "fulcio.internal"
+    }
+  },
+  "issuedAt": "2025-10-29T06:14:45Z",
+  "materials": [
+    {
+      "uri": "git+https://git.stella-ops.org/runtime/api.git@refs/tags/v3.14.0",
+      "role": "source"
+    }
+  ],
+  "transparency": [
+    {
+      "logId": "rekor-primary",
+      "logUrl": "https://rekor.stella-ops.internal",
+      "uuid": "33333333-4444-5555-6666-777777777777",
+      "index": 778899
+    }
+  ],
+  "scanner": {
+    "name": "StellaOps Scanner",
+    "version": "2.4.3",
+    "runId": "scan-20251029-0614",
+    "configurationDigest": {
+      "sha256": "f1c2d3e4a5b60718293a4b5c6d7e8f90123456789abcdef0123456789abcdef0"
+    },
+    "mode": "inventory"
+  },
+  "summary": {
+    "totalFindings": 6,
+    "newFindings": 2,
+    "kevFindings": 1,
+    "fixableFindings": 4,
+    "severityCounts": {
+      "critical": 1,
+      "high": 2,
+      "medium": 2,
+      "low": 1,
+      "informational": 0
+    }
+  },
+  "policyContext": {
+    "policyId": "default-runtime-policy",
+    "policyVersion": "42",
+    "mode": "enforce"
+  },
+  "findings": [
+    {
+      "vulnerabilityId": "CVE-2025-10001",
+      "severity": "critical",
+      "status": "detected",
+      "kev": true,
+      "package": {
+        "name": "openssl",
+        "version": "3.0.12-3.el9",
+        "purl": "pkg:rpm/redhat/openssl@3.0.12-3.el9",
+        "type": "rpm"
+      },
+      "fixedVersion": "3.0.13-1.el9",
+      "introducedIn": "sha256:aa99887766554433221100ffeeddccbbaa99887766554433221100ffeeddccbb",
+      "evidence": {
+        "source": "os-packages",
+        "paths": [
+          "/usr/lib64/libssl.so.3"
+        ],
+        "callers": [
+          "policy-engine"
+        ]
+      }
+    },
+    {
+      "vulnerabilityId": "GHSA-1234-abcd-5678",
+      "severity": "high",
+      "status": "detected",
+      "kev": false,
+      "package": {
+        "name": "lodash",
+        "version": "4.17.21",
+        "purl": "pkg:npm/lodash@4.17.21",
+        "type": "npm"
+      },
+      "fixedVersion": "4.17.22",
+      "evidence": {
+        "source": "application-lockfile",
+        "paths": [
+          "/app/package-lock.json"
+        ]
+      },
+      "notes": "Used by metrics exporter."
+    },
+    {
+      "vulnerabilityId": "CVE-2024-50010",
+      "severity": "medium",
+      "status": "remediated",
+      "kev": false,
+      "package": {
+        "name": "glibc",
+        "version": "2.36-60.el9",
+        "purl": "pkg:rpm/redhat/glibc@2.36-60.el9",
+        "type": "rpm"
+      },
+      "fixedVersion": "2.36-62.el9",
+      "notes": "Patched in base image refresh."
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/fixtures/v1/vex-attestation.sample.json

@@ -0,0 +1,75 @@
+{
+  "schemaVersion": "1.0.0",
+  "predicateType": "StellaOps.VEXAttestation@1",
+  "subject": [
+    {
+      "subjectKind": "vex-statement",
+      "name": "registry.stella-ops.internal/runtime/api@sha256:d2c3b4a5f6e7d8c9b0a1f2e3d4c5b6a79876543210fedcba9876543210fedcba",
+      "digest": {
+        "sha256": "8f6e5d4c3b2a190817263544554433221100ffeeddaabbccddeeff0011223344"
+      }
+    }
+  ],
+  "issuer": {
+    "issuerType": "service",
+    "id": "urn:stellaops:svc:excitor",
+    "tenantId": "tenant-alpha",
+    "signingKey": {
+      "keyId": "vex-service-key",
+      "mode": "kms",
+      "algorithm": "ed25519",
+      "issuer": "kms.attestor.internal"
+    }
+  },
+  "issuedAt": "2025-10-30T09:12:03Z",
+  "vexStandard": "openvex-1.0",
+  "generator": {
+    "name": "StellaOps Excititor",
+    "version": "1.8.0"
+  },
+  "statements": [
+    {
+      "id": "stmt-001",
+      "vulnerabilityId": "CVE-2025-10001",
+      "status": "not_affected",
+      "statementType": "analysis",
+      "timestamp": "2025-10-30T09:11:40Z",
+      "justification": "Component not present in the deployed runtime closure.",
+      "impactStatement": "The affected OpenSSL module is unused by the runtime API image entrypoint chain.",
+      "products": [
+        {
+          "productId": "registry.stella-ops.internal/runtime/api@sha256:d2c3b4...",
+          "name": "runtime-api",
+          "version": "3.14.0",
+          "purl": "pkg:oci/runtime-api@sha256:d2c3b4a5f6e7d8c9b0a1f2e3d4c5b6a79876543210fedcba9876543210fedcba"
+        }
+      ],
+      "supplier": {
+        "name": "StellaOps Runtime Guild",
+        "id": "urn:stellaops:guild:runtime"
+      },
+      "references": [
+        "https://kb.stella-ops.org/vex/CVE-2025-10001"
+      ]
+    },
+    {
+      "id": "stmt-002",
+      "vulnerabilityId": "GHSA-1234-abcd-5678",
+      "status": "affected",
+      "statementType": "remediation",
+      "timestamp": "2025-10-30T09:11:55Z",
+      "impactStatement": "Lodash is present in the telemetry plug-in; exploitation requires UID 0 inside the container.",
+      "actionStatement": "Upgrade telemetry plug-in to v2.1.5 or apply policy waiver until patch window.",
+      "products": [
+        {
+          "productId": "registry.stella-ops.internal/runtime/api@sha256:d2c3b4...",
+          "name": "runtime-api",
+          "version": "3.14.0"
+        }
+      ],
+      "references": [
+        "https://github.com/lodash/lodash/security/advisory"
+      ]
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/generated/go/go.mod

@@ -0,0 +1,3 @@
+module github.com/stella-ops/attestor/types
+
+go 1.22

src/Attestor/StellaOps.Attestor.Types/generated/go/types.go

@@ -0,0 +1,628 @@
+// Code generated by StellaOps.Attestor.Types.Generator. DO NOT EDIT.
+package attesttypes
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+)
+
+type FindingStatus string
+
+const (
+	FindingStatusDetected FindingStatus = "detected"
+	FindingStatusConfirmed FindingStatus = "confirmed"
+	FindingStatusFixed FindingStatus = "fixed"
+	FindingStatusNotAffected FindingStatus = "not_affected"
+)
+
+func (v FindingStatus) Validate() error {
+	switch v {
+	case FindingStatusDetected, FindingStatusConfirmed, FindingStatusFixed, FindingStatusNotAffected:
+		return nil
+	default:
+		return fmt.Errorf("invalid value for FindingStatus: %s", string(v))
+	}
+}
+
+type PolicyEffect string
+
+const (
+	PolicyEffectAllow PolicyEffect = "allow"
+	PolicyEffectDeny PolicyEffect = "deny"
+	PolicyEffectWarn PolicyEffect = "warn"
+)
+
+func (v PolicyEffect) Validate() error {
+	switch v {
+	case PolicyEffectAllow, PolicyEffectDeny, PolicyEffectWarn:
+		return nil
+	default:
+		return fmt.Errorf("invalid value for PolicyEffect: %s", string(v))
+	}
+}
+
+type PolicyOutcome string
+
+const (
+	PolicyOutcomePass PolicyOutcome = "pass"
+	PolicyOutcomeFail PolicyOutcome = "fail"
+	PolicyOutcomeWaived PolicyOutcome = "waived"
+)
+
+func (v PolicyOutcome) Validate() error {
+	switch v {
+	case PolicyOutcomePass, PolicyOutcomeFail, PolicyOutcomeWaived:
+		return nil
+	default:
+		return fmt.Errorf("invalid value for PolicyOutcome: %s", string(v))
+	}
+}
+
+type RiskLevel string
+
+const (
+	RiskLevelCritical RiskLevel = "critical"
+	RiskLevelHigh RiskLevel = "high"
+	RiskLevelMedium RiskLevel = "medium"
+	RiskLevelLow RiskLevel = "low"
+	RiskLevelInformational RiskLevel = "informational"
+)
+
+func (v RiskLevel) Validate() error {
+	switch v {
+	case RiskLevelCritical, RiskLevelHigh, RiskLevelMedium, RiskLevelLow, RiskLevelInformational:
+		return nil
+	default:
+		return fmt.Errorf("invalid value for RiskLevel: %s", string(v))
+	}
+}
+
+type SbomFormat string
+
+const (
+	SbomFormatCycloneDx16 SbomFormat = "CycloneDX-1.6"
+	SbomFormatSbom300 SbomFormat = "SBOM-3.0.0"
+)
+
+func (v SbomFormat) Validate() error {
+	switch v {
+	case SbomFormatCycloneDx16, SbomFormatSbom300:
+		return nil
+	default:
+		return fmt.Errorf("invalid value for SbomFormat: %s", string(v))
+	}
+}
+
+type Severity string
+
+const (
+	SeverityCritical Severity = "critical"
+	SeverityHigh Severity = "high"
+	SeverityMedium Severity = "medium"
+	SeverityLow Severity = "low"
+	SeverityInfo Severity = "info"
+)
+
+func (v Severity) Validate() error {
+	switch v {
+	case SeverityCritical, SeverityHigh, SeverityMedium, SeverityLow, SeverityInfo:
+		return nil
+	default:
+		return fmt.Errorf("invalid value for Severity: %s", string(v))
+	}
+}
+
+type VexStatus string
+
+const (
+	VexStatusNotAffected VexStatus = "not_affected"
+	VexStatusAffected VexStatus = "affected"
+	VexStatusUnderInvestigation VexStatus = "under_investigation"
+	VexStatusFixed VexStatus = "fixed"
+)
+
+func (v VexStatus) Validate() error {
+	switch v {
+	case VexStatusNotAffected, VexStatusAffected, VexStatusUnderInvestigation, VexStatusFixed:
+		return nil
+	default:
+		return fmt.Errorf("invalid value for VexStatus: %s", string(v))
+	}
+}
+
+const BuildProvenanceSchemaVersion = "StellaOps.BuildProvenance@1"
+
+const CustomEvidenceSchemaVersion = "StellaOps.CustomEvidence@1"
+
+const PolicyEvaluationSchemaVersion = "StellaOps.PolicyEvaluation@1"
+
+const RiskProfileEvidenceSchemaVersion = "StellaOps.RiskProfileEvidence@1"
+
+const SbomAttestationSchemaVersion = "StellaOps.SBOMAttestation@1"
+
+const ScanResultsSchemaVersion = "StellaOps.ScanResults@1"
+
+const VexAttestationSchemaVersion = "StellaOps.VEXAttestation@1"
+
+type BuildMetadata struct {
+	BuildStartedOn string `json:"buildStartedOn"`
+	BuildFinishedOn string `json:"buildFinishedOn"`
+	Reproducible *bool `json:"reproducible,omitempty"`
+	BuildInvocationId *string `json:"buildInvocationId,omitempty"`
+}
+
+func (value *BuildMetadata) Validate() error {
+	if value == nil {
+		return errors.New("BuildMetadata is nil")
+	}
+	return nil
+}
+
+type BuildProvenance struct {
+	SchemaVersion string `json:"schemaVersion"`
+	BuildType string `json:"buildType"`
+	Builder BuilderIdentity `json:"builder"`
+	Materials []MaterialReference `json:"materials"`
+	Metadata BuildMetadata `json:"metadata"`
+	Environment *EnvironmentMetadata `json:"environment,omitempty"`
+}
+
+func (value *BuildProvenance) Validate() error {
+	if value == nil {
+		return errors.New("BuildProvenance is nil")
+	}
+	if value.SchemaVersion != "StellaOps.BuildProvenance@1" {
+		return fmt.Errorf("BuildProvenance.SchemaVersion must equal StellaOps.BuildProvenance@1")
+	}
+	if err := value.Builder.Validate(); err != nil {
+		return fmt.Errorf("invalid BuildProvenance.Builder: %w", err)
+	}
+	if len(value.Materials) < 1 {
+		return fmt.Errorf("BuildProvenance.Materials must contain at least 1 item(s)")
+	}
+	for i := range value.Materials {
+		if err := value.Materials[i].Validate(); err != nil {
+			return fmt.Errorf("invalid BuildProvenance.Materials[%d]: %w", i, err)
+		}
+	}
+	if err := value.Metadata.Validate(); err != nil {
+		return fmt.Errorf("invalid BuildProvenance.Metadata: %w", err)
+	}
+	if value.Environment != nil {
+		if err := value.Environment.Validate(); err != nil {
+			return fmt.Errorf("invalid BuildProvenance.Environment: %w", err)
+		}
+	}
+	return nil
+}
+
+type BuilderIdentity struct {
+	Id string `json:"id"`
+	Version *string `json:"version,omitempty"`
+	Platform *string `json:"platform,omitempty"`
+}
+
+func (value *BuilderIdentity) Validate() error {
+	if value == nil {
+		return errors.New("BuilderIdentity is nil")
+	}
+	return nil
+}
+
+type CustomEvidence struct {
+	SchemaVersion string `json:"schemaVersion"`
+	SubjectDigest string `json:"subjectDigest"`
+	Kind string `json:"kind"`
+	GeneratedAt string `json:"generatedAt"`
+	Properties []CustomProperty `json:"properties,omitempty"`
+}
+
+func (value *CustomEvidence) Validate() error {
+	if value == nil {
+		return errors.New("CustomEvidence is nil")
+	}
+	if value.SchemaVersion != "StellaOps.CustomEvidence@1" {
+		return fmt.Errorf("CustomEvidence.SchemaVersion must equal StellaOps.CustomEvidence@1")
+	}
+	for i := range value.Properties {
+		if err := value.Properties[i].Validate(); err != nil {
+			return fmt.Errorf("invalid CustomEvidence.Properties[%d]: %w", i, err)
+		}
+	}
+	return nil
+}
+
+type CustomProperty struct {
+	Key string `json:"key"`
+	Value string `json:"value"`
+}
+
+func (value *CustomProperty) Validate() error {
+	if value == nil {
+		return errors.New("CustomProperty is nil")
+	}
+	return nil
+}
+
+type DigestReference struct {
+	Algorithm string `json:"algorithm"`
+	Value string `json:"value"`
+}
+
+func (value *DigestReference) Validate() error {
+	if value == nil {
+		return errors.New("DigestReference is nil")
+	}
+	return nil
+}
+
+type EnvironmentMetadata struct {
+	Platform *string `json:"platform,omitempty"`
+	ImageDigest *DigestReference `json:"imageDigest,omitempty"`
+}
+
+func (value *EnvironmentMetadata) Validate() error {
+	if value == nil {
+		return errors.New("EnvironmentMetadata is nil")
+	}
+	if value.ImageDigest != nil {
+		if err := value.ImageDigest.Validate(); err != nil {
+			return fmt.Errorf("invalid EnvironmentMetadata.ImageDigest: %w", err)
+		}
+	}
+	return nil
+}
+
+type MaterialReference struct {
+	Uri string `json:"uri"`
+	Digests []DigestReference `json:"digests"`
+	Note *string `json:"note,omitempty"`
+}
+
+func (value *MaterialReference) Validate() error {
+	if value == nil {
+		return errors.New("MaterialReference is nil")
+	}
+	if len(value.Digests) < 1 {
+		return fmt.Errorf("MaterialReference.Digests must contain at least 1 item(s)")
+	}
+	for i := range value.Digests {
+		if err := value.Digests[i].Validate(); err != nil {
+			return fmt.Errorf("invalid MaterialReference.Digests[%d]: %w", i, err)
+		}
+	}
+	return nil
+}
+
+type PolicyDecision struct {
+	PolicyId string `json:"policyId"`
+	RuleId string `json:"ruleId"`
+	Effect PolicyEffect `json:"effect"`
+	Reason *string `json:"reason,omitempty"`
+	Remediation *string `json:"remediation,omitempty"`
+}
+
+func (value *PolicyDecision) Validate() error {
+	if value == nil {
+		return errors.New("PolicyDecision is nil")
+	}
+	if err := value.Effect.Validate(); err != nil {
+		return fmt.Errorf("invalid PolicyDecision.Effect: %w", err)
+	}
+	return nil
+}
+
+type PolicyEvaluation struct {
+	SchemaVersion string `json:"schemaVersion"`
+	SubjectDigest string `json:"subjectDigest"`
+	PolicyVersion string `json:"policyVersion"`
+	EvaluatedAt string `json:"evaluatedAt"`
+	Outcome PolicyOutcome `json:"outcome"`
+	Decisions []PolicyDecision `json:"decisions"`
+}
+
+func (value *PolicyEvaluation) Validate() error {
+	if value == nil {
+		return errors.New("PolicyEvaluation is nil")
+	}
+	if value.SchemaVersion != "StellaOps.PolicyEvaluation@1" {
+		return fmt.Errorf("PolicyEvaluation.SchemaVersion must equal StellaOps.PolicyEvaluation@1")
+	}
+	if err := value.Outcome.Validate(); err != nil {
+		return fmt.Errorf("invalid PolicyEvaluation.Outcome: %w", err)
+	}
+	for i := range value.Decisions {
+		if err := value.Decisions[i].Validate(); err != nil {
+			return fmt.Errorf("invalid PolicyEvaluation.Decisions[%d]: %w", i, err)
+		}
+	}
+	return nil
+}
+
+type RiskFactor struct {
+	Name string `json:"name"`
+	Weight float64 `json:"weight"`
+	Description *string `json:"description,omitempty"`
+}
+
+func (value *RiskFactor) Validate() error {
+	if value == nil {
+		return errors.New("RiskFactor is nil")
+	}
+	if value.Weight < 0 {
+		return fmt.Errorf("RiskFactor.Weight must be >= 0")
+	}
+	if value.Weight > 1 {
+		return fmt.Errorf("RiskFactor.Weight must be <= 1")
+	}
+	return nil
+}
+
+type RiskProfileEvidence struct {
+	SchemaVersion string `json:"schemaVersion"`
+	SubjectDigest string `json:"subjectDigest"`
+	GeneratedAt string `json:"generatedAt"`
+	RiskScore float64 `json:"riskScore"`
+	RiskLevel RiskLevel `json:"riskLevel"`
+	Factors []RiskFactor `json:"factors"`
+}
+
+func (value *RiskProfileEvidence) Validate() error {
+	if value == nil {
+		return errors.New("RiskProfileEvidence is nil")
+	}
+	if value.SchemaVersion != "StellaOps.RiskProfileEvidence@1" {
+		return fmt.Errorf("RiskProfileEvidence.SchemaVersion must equal StellaOps.RiskProfileEvidence@1")
+	}
+	if value.RiskScore < 0 {
+		return fmt.Errorf("RiskProfileEvidence.RiskScore must be >= 0")
+	}
+	if value.RiskScore > 100 {
+		return fmt.Errorf("RiskProfileEvidence.RiskScore must be <= 100")
+	}
+	if err := value.RiskLevel.Validate(); err != nil {
+		return fmt.Errorf("invalid RiskProfileEvidence.RiskLevel: %w", err)
+	}
+	for i := range value.Factors {
+		if err := value.Factors[i].Validate(); err != nil {
+			return fmt.Errorf("invalid RiskProfileEvidence.Factors[%d]: %w", i, err)
+		}
+	}
+	return nil
+}
+
+type SbomAttestation struct {
+	SchemaVersion string `json:"schemaVersion"`
+	SubjectDigest string `json:"subjectDigest"`
+	SbomFormat SbomFormat `json:"sbomFormat"`
+	SbomDigest DigestReference `json:"sbomDigest"`
+	SbomUri *string `json:"sbomUri,omitempty"`
+	ComponentCount float64 `json:"componentCount"`
+	Packages []SbomPackage `json:"packages,omitempty"`
+}
+
+func (value *SbomAttestation) Validate() error {
+	if value == nil {
+		return errors.New("SbomAttestation is nil")
+	}
+	if value.SchemaVersion != "StellaOps.SBOMAttestation@1" {
+		return fmt.Errorf("SbomAttestation.SchemaVersion must equal StellaOps.SBOMAttestation@1")
+	}
+	if err := value.SbomFormat.Validate(); err != nil {
+		return fmt.Errorf("invalid SbomAttestation.SbomFormat: %w", err)
+	}
+	if err := value.SbomDigest.Validate(); err != nil {
+		return fmt.Errorf("invalid SbomAttestation.SbomDigest: %w", err)
+	}
+	if value.ComponentCount < 0 {
+		return fmt.Errorf("SbomAttestation.ComponentCount must be >= 0")
+	}
+	for i := range value.Packages {
+		if err := value.Packages[i].Validate(); err != nil {
+			return fmt.Errorf("invalid SbomAttestation.Packages[%d]: %w", i, err)
+		}
+	}
+	return nil
+}
+
+type SbomPackage struct {
+	Purl string `json:"purl"`
+	Version *string `json:"version,omitempty"`
+	Licenses []string `json:"licenses,omitempty"`
+}
+
+func (value *SbomPackage) Validate() error {
+	if value == nil {
+		return errors.New("SbomPackage is nil")
+	}
+	if len(value.Licenses) < 1 {
+		return fmt.Errorf("SbomPackage.Licenses must contain at least 1 item(s)")
+	}
+	return nil
+}
+
+type ScanFinding struct {
+	Id string `json:"id"`
+	Severity Severity `json:"severity"`
+	Status FindingStatus `json:"status"`
+	PackageName string `json:"packageName"`
+	PackageVersion *string `json:"packageVersion,omitempty"`
+	CvssScore *float64 `json:"cvssScore,omitempty"`
+	Description *string `json:"description,omitempty"`
+	References []string `json:"references,omitempty"`
+}
+
+func (value *ScanFinding) Validate() error {
+	if value == nil {
+		return errors.New("ScanFinding is nil")
+	}
+	if err := value.Severity.Validate(); err != nil {
+		return fmt.Errorf("invalid ScanFinding.Severity: %w", err)
+	}
+	if err := value.Status.Validate(); err != nil {
+		return fmt.Errorf("invalid ScanFinding.Status: %w", err)
+	}
+	if value.CvssScore != nil {
+		if *value.CvssScore < 0 {
+			return fmt.Errorf("ScanFinding.CvssScore must be >= 0")
+		}
+		if *value.CvssScore > 10 {
+			return fmt.Errorf("ScanFinding.CvssScore must be <= 10")
+		}
+	}
+	if len(value.References) < 1 {
+		return fmt.Errorf("ScanFinding.References must contain at least 1 item(s)")
+	}
+	return nil
+}
+
+type ScanResults struct {
+	SchemaVersion string `json:"schemaVersion"`
+	SubjectDigest string `json:"subjectDigest"`
+	ScannerName string `json:"scannerName"`
+	ScannerVersion string `json:"scannerVersion"`
+	GeneratedAt string `json:"generatedAt"`
+	Findings []ScanFinding `json:"findings"`
+}
+
+func (value *ScanResults) Validate() error {
+	if value == nil {
+		return errors.New("ScanResults is nil")
+	}
+	if value.SchemaVersion != "StellaOps.ScanResults@1" {
+		return fmt.Errorf("ScanResults.SchemaVersion must equal StellaOps.ScanResults@1")
+	}
+	for i := range value.Findings {
+		if err := value.Findings[i].Validate(); err != nil {
+			return fmt.Errorf("invalid ScanResults.Findings[%d]: %w", i, err)
+		}
+	}
+	return nil
+}
+
+type VexAttestation struct {
+	SchemaVersion string `json:"schemaVersion"`
+	SubjectDigest string `json:"subjectDigest"`
+	GeneratedAt string `json:"generatedAt"`
+	Statements []VexStatement `json:"statements"`
+}
+
+func (value *VexAttestation) Validate() error {
+	if value == nil {
+		return errors.New("VexAttestation is nil")
+	}
+	if value.SchemaVersion != "StellaOps.VEXAttestation@1" {
+		return fmt.Errorf("VexAttestation.SchemaVersion must equal StellaOps.VEXAttestation@1")
+	}
+	if len(value.Statements) < 1 {
+		return fmt.Errorf("VexAttestation.Statements must contain at least 1 item(s)")
+	}
+	for i := range value.Statements {
+		if err := value.Statements[i].Validate(); err != nil {
+			return fmt.Errorf("invalid VexAttestation.Statements[%d]: %w", i, err)
+		}
+	}
+	return nil
+}
+
+type VexStatement struct {
+	VulnerabilityId string `json:"vulnerabilityId"`
+	Status VexStatus `json:"status"`
+	Timestamp string `json:"timestamp"`
+	Justification *string `json:"justification,omitempty"`
+	ImpactStatement *string `json:"impactStatement,omitempty"`
+	ActionStatement *string `json:"actionStatement,omitempty"`
+	References []string `json:"references,omitempty"`
+}
+
+func (value *VexStatement) Validate() error {
+	if value == nil {
+		return errors.New("VexStatement is nil")
+	}
+	if err := value.Status.Validate(); err != nil {
+		return fmt.Errorf("invalid VexStatement.Status: %w", err)
+	}
+	if len(value.References) < 1 {
+		return fmt.Errorf("VexStatement.References must contain at least 1 item(s)")
+	}
+	return nil
+}
+
+func (value *BuildProvenance) CanonicalJSON() ([]byte, error) {
+	if err := value.Validate(); err != nil {
+		return nil, err
+	}
+	buf, err := json.Marshal(value)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal BuildProvenance: %w", err)
+	}
+	return buf, nil
+}
+
+func (value *CustomEvidence) CanonicalJSON() ([]byte, error) {
+	if err := value.Validate(); err != nil {
+		return nil, err
+	}
+	buf, err := json.Marshal(value)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal CustomEvidence: %w", err)
+	}
+	return buf, nil
+}
+
+func (value *PolicyEvaluation) CanonicalJSON() ([]byte, error) {
+	if err := value.Validate(); err != nil {
+		return nil, err
+	}
+	buf, err := json.Marshal(value)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal PolicyEvaluation: %w", err)
+	}
+	return buf, nil
+}
+
+func (value *RiskProfileEvidence) CanonicalJSON() ([]byte, error) {
+	if err := value.Validate(); err != nil {
+		return nil, err
+	}
+	buf, err := json.Marshal(value)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal RiskProfileEvidence: %w", err)
+	}
+	return buf, nil
+}
+
+func (value *SbomAttestation) CanonicalJSON() ([]byte, error) {
+	if err := value.Validate(); err != nil {
+		return nil, err
+	}
+	buf, err := json.Marshal(value)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal SbomAttestation: %w", err)
+	}
+	return buf, nil
+}
+
+func (value *ScanResults) CanonicalJSON() ([]byte, error) {
+	if err := value.Validate(); err != nil {
+		return nil, err
+	}
+	buf, err := json.Marshal(value)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal ScanResults: %w", err)
+	}
+	return buf, nil
+}
+
+func (value *VexAttestation) CanonicalJSON() ([]byte, error) {
+	if err := value.Validate(); err != nil {
+		return nil, err
+	}
+	buf, err := json.Marshal(value)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal VexAttestation: %w", err)
+	}
+	return buf, nil
+}
+

src/Attestor/StellaOps.Attestor.Types/generated/go/types_test.go

@@ -0,0 +1,239 @@
+package attesttypes
+
+import (
+	"fmt"
+	"testing"
+)
+
+func hexString(ch byte) string {
+	buf := make([]byte, 64)
+	for i := range buf {
+		buf[i] = ch
+	}
+	return string(buf)
+}
+
+func sampleBuildProvenance() BuildProvenance {
+	return BuildProvenance{
+		SchemaVersion: BuildProvenanceSchemaVersion,
+		BuildType:     "docker/buildx",
+		Builder: BuilderIdentity{
+			Id:       "builder://stellaops/ci",
+			Version:  stringPtr("2025.10.31"),
+			Platform: stringPtr("linux/amd64"),
+		},
+		Materials: []MaterialReference{
+			{
+				Uri: "git+https://git.stella-ops.org/org/repo@refs/heads/main",
+				Digests: []DigestReference{
+					{Algorithm: "sha256", Value: hexString('a')},
+				},
+				Note: stringPtr("Source repository"),
+			},
+		},
+		Metadata: BuildMetadata{
+			BuildStartedOn:  "2025-10-31T12:00:00Z",
+			BuildFinishedOn: "2025-10-31T12:05:00Z",
+			Reproducible:    boolPtr(true),
+			BuildInvocationId: stringPtr("invocations/123"),
+		},
+		Environment: &EnvironmentMetadata{
+			Platform:    stringPtr("linux/amd64"),
+			ImageDigest: &DigestReference{Algorithm: "sha256", Value: hexString('b')},
+		},
+	}
+}
+
+func sampleSbomAttestation() SbomAttestation {
+	return SbomAttestation{
+		SchemaVersion: SbomAttestationSchemaVersion,
+		SubjectDigest: fmt.Sprintf("sha256:%s", hexString('c')),
+		SbomFormat:    "CycloneDX-1.6",
+		SbomDigest:    DigestReference{Algorithm: "sha256", Value: hexString('d')},
+		SbomUri:       stringPtr("https://example.invalid/sbom.json"),
+		ComponentCount: 2,
+		Packages: []SbomPackage{
+			{
+				Purl:     "pkg:npm/%40stellaops/example@1.0.0",
+				Version:  stringPtr("1.0.0"),
+				Licenses: []string{"MIT"},
+			},
+		},
+	}
+}
+
+func sampleVexAttestation() VexAttestation {
+	return VexAttestation{
+		SchemaVersion: VexAttestationSchemaVersion,
+		SubjectDigest: fmt.Sprintf("sha256:%s", hexString('e')),
+		GeneratedAt:   "2025-10-31T12:10:00Z",
+		Statements: []VexStatement{
+			{
+				VulnerabilityId: "CVE-2025-1234",
+				Status:          VexStatusNotAffected,
+				Timestamp:       "2025-10-31T12:10:00Z",
+				Justification:   stringPtr("component_not_present"),
+				References:      []string{"https://example.invalid/advisory"},
+			},
+		},
+	}
+}
+
+func sampleScanResults() ScanResults {
+	return ScanResults{
+		SchemaVersion: ScanResultsSchemaVersion,
+		SubjectDigest: fmt.Sprintf("sha256:%s", hexString('f')),
+		ScannerName:   "stellaops/scanner",
+		ScannerVersion: "2025.10.31",
+		GeneratedAt:   "2025-10-31T12:15:00Z",
+		Findings: []ScanFinding{
+			{
+				Id:            "FIND-001",
+				Severity:      SeverityMedium,
+				Status:        FindingStatusDetected,
+				PackageName:   "libexample",
+				PackageVersion: stringPtr("1.2.3"),
+				CvssScore:     floatPtr(7.5),
+				Description:   stringPtr("Example vulnerability"),
+				References:    []string{"https://example.invalid/CVE-2025-1234"},
+			},
+		},
+	}
+}
+
+func samplePolicyEvaluation() PolicyEvaluation {
+	return PolicyEvaluation{
+		SchemaVersion: PolicyEvaluationSchemaVersion,
+		SubjectDigest: fmt.Sprintf("sha256:%s", hexString('1')),
+		PolicyVersion: "2025.10.31",
+		EvaluatedAt:   "2025-10-31T12:18:00Z",
+		Outcome:       PolicyOutcomePass,
+		Decisions: []PolicyDecision{
+			{
+				PolicyId: "policy/access-control",
+				RuleId:   "rule/allow-latest",
+				Effect:   PolicyEffectAllow,
+				Reason:   stringPtr("No blocking findings"),
+			},
+		},
+	}
+}
+
+func sampleRiskProfile() RiskProfileEvidence {
+	return RiskProfileEvidence{
+		SchemaVersion: RiskProfileEvidenceSchemaVersion,
+		SubjectDigest: fmt.Sprintf("sha256:%s", hexString('2')),
+		GeneratedAt:   "2025-10-31T12:20:00Z",
+		RiskScore:     42.5,
+		RiskLevel:     RiskLevelMedium,
+		Factors: []RiskFactor{
+			{
+				Name:        "exploitability",
+				Weight:      0.6,
+				Description: stringPtr("No known exploits published"),
+			},
+		},
+	}
+}
+
+func sampleCustomEvidence() CustomEvidence {
+	return CustomEvidence{
+		SchemaVersion: CustomEvidenceSchemaVersion,
+		SubjectDigest: fmt.Sprintf("sha256:%s", hexString('3')),
+		Kind:          "org.stellaops.demo/custom",
+		GeneratedAt:   "2025-10-31T12:25:00Z",
+		Properties: []CustomProperty{
+			{Key: "note", Value: "Custom attestation payload"},
+		},
+	}
+}
+
+func TestBuildProvenanceRoundTrip(t *testing.T) {
+	sample := sampleBuildProvenance()
+	if err := sample.Validate(); err != nil {
+		t.Fatalf("validate: %v", err)
+	}
+	a, err := sample.CanonicalJSON()
+	if err != nil {
+		t.Fatalf("canonical JSON: %v", err)
+	}
+	b, err := sample.CanonicalJSON()
+	if err != nil {
+		t.Fatalf("canonical JSON repeat: %v", err)
+	}
+	if string(a) != string(b) {
+		t.Fatalf("canonical output mismatch:\n%s\n%s", string(a), string(b))
+	}
+}
+
+func TestSbomAttestationRoundTrip(t *testing.T) {
+	sample := sampleSbomAttestation()
+	if err := sample.Validate(); err != nil {
+		t.Fatalf("validate: %v", err)
+	}
+	if _, err := sample.CanonicalJSON(); err != nil {
+		t.Fatalf("canonical JSON: %v", err)
+	}
+}
+
+func TestVexAttestationRoundTrip(t *testing.T) {
+	sample := sampleVexAttestation()
+	if err := sample.Validate(); err != nil {
+		t.Fatalf("validate: %v", err)
+	}
+	if _, err := sample.CanonicalJSON(); err != nil {
+		t.Fatalf("canonical JSON: %v", err)
+	}
+}
+
+func TestScanResultsRoundTrip(t *testing.T) {
+	sample := sampleScanResults()
+	if err := sample.Validate(); err != nil {
+		t.Fatalf("validate: %v", err)
+	}
+	if _, err := sample.CanonicalJSON(); err != nil {
+		t.Fatalf("canonical JSON: %v", err)
+	}
+}
+
+func TestPolicyEvaluationRoundTrip(t *testing.T) {
+	sample := samplePolicyEvaluation()
+	if err := sample.Validate(); err != nil {
+		t.Fatalf("validate: %v", err)
+	}
+	if _, err := sample.CanonicalJSON(); err != nil {
+		t.Fatalf("canonical JSON: %v", err)
+	}
+}
+
+func TestRiskProfileRoundTrip(t *testing.T) {
+	sample := sampleRiskProfile()
+	if err := sample.Validate(); err != nil {
+		t.Fatalf("validate: %v", err)
+	}
+	if _, err := sample.CanonicalJSON(); err != nil {
+		t.Fatalf("canonical JSON: %v", err)
+	}
+}
+
+func TestCustomEvidenceRoundTrip(t *testing.T) {
+	sample := sampleCustomEvidence()
+	if err := sample.Validate(); err != nil {
+		t.Fatalf("validate: %v", err)
+	}
+	if _, err := sample.CanonicalJSON(); err != nil {
+		t.Fatalf("canonical JSON: %v", err)
+	}
+}
+
+func TestCustomEvidenceSchemaVersionMismatch(t *testing.T) {
+	sample := sampleCustomEvidence()
+	sample.SchemaVersion = "StellaOps.CustomEvidence@9"
+	if err := sample.Validate(); err == nil {
+		t.Fatal("expected schemaVersion mismatch to fail validation")
+	}
+}
+
+func stringPtr(v string) *string { return &v }
+func boolPtr(v bool) *bool       { return &v }
+func floatPtr(v float64) *float64 { return &v }

src/Attestor/StellaOps.Attestor.Types/generated/ts/index.test.ts

@@ -0,0 +1,195 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import {
+  canonicalizeBuildProvenance,
+  canonicalizeCustomEvidence,
+  canonicalizePolicyEvaluation,
+  canonicalizeRiskProfileEvidence,
+  canonicalizeSbomAttestation,
+  canonicalizeScanResults,
+  canonicalizeVexAttestation,
+  validateBuildProvenance,
+  validateCustomEvidence,
+  validatePolicyEvaluation,
+  validateRiskProfileEvidence,
+  validateSbomAttestation,
+  validateScanResults,
+  validateVexAttestation
+} from './index.js';
+
+const hex = (char: string): string => char.repeat(64);
+
+const buildProvenanceSample = {
+  schemaVersion: 'StellaOps.BuildProvenance@1' as const,
+  buildType: 'docker/buildx',
+  builder: {
+    id: 'builder://stellaops/ci',
+    version: '2025.10.31',
+    platform: 'linux/amd64'
+  },
+  materials: [
+    {
+      uri: 'git+https://git.stella-ops.org/org/repo@refs/heads/main',
+      digests: [
+        { algorithm: 'sha256', value: hex('a') }
+      ],
+      note: 'Source repository'
+    }
+  ],
+  metadata: {
+    buildStartedOn: '2025-10-31T12:00:00Z',
+    buildFinishedOn: '2025-10-31T12:05:00Z',
+    reproducible: true,
+    buildInvocationId: 'invocations/123'
+  },
+  environment: {
+    platform: 'linux/amd64',
+    imageDigest: { algorithm: 'sha256', value: hex('b') }
+  }
+};
+
+const sbomAttestationSample = {
+  schemaVersion: 'StellaOps.SBOMAttestation@1' as const,
+  subjectDigest: `sha256:${hex('c')}`,
+  sbomFormat: 'CycloneDX-1.6' as const,
+  sbomDigest: { algorithm: 'sha256', value: hex('d') },
+  sbomUri: 'https://example.invalid/sbom.json',
+  componentCount: 2,
+  packages: [
+    {
+      purl: 'pkg:npm/%40stellaops/example@1.0.0',
+      version: '1.0.0',
+      licenses: ['MIT']
+    }
+  ]
+};
+
+const vexAttestationSample = {
+  schemaVersion: 'StellaOps.VEXAttestation@1' as const,
+  subjectDigest: `sha256:${hex('e')}`,
+  generatedAt: '2025-10-31T12:10:00Z',
+  statements: [
+    {
+      vulnerabilityId: 'CVE-2025-1234',
+      status: 'not_affected' as const,
+      timestamp: '2025-10-31T12:10:00Z',
+      justification: 'component_not_present',
+      references: ['https://example.invalid/advisory']
+    }
+  ]
+};
+
+const scanResultsSample = {
+  schemaVersion: 'StellaOps.ScanResults@1' as const,
+  subjectDigest: `sha256:${hex('f')}`,
+  scannerName: 'stellaops/scanner',
+  scannerVersion: '2025.10.31',
+  generatedAt: '2025-10-31T12:15:00Z',
+  findings: [
+    {
+      id: 'FIND-001',
+      severity: 'medium' as const,
+      status: 'detected' as const,
+      packageName: 'libexample',
+      packageVersion: '1.2.3',
+      cvssScore: 7.5,
+      description: 'Example vulnerability',
+      references: ['https://example.invalid/CVE-2025-1234']
+    }
+  ]
+};
+
+const policyEvaluationSample = {
+  schemaVersion: 'StellaOps.PolicyEvaluation@1' as const,
+  subjectDigest: `sha256:${hex('1')}`,
+  policyVersion: '2025.10.31',
+  evaluatedAt: '2025-10-31T12:18:00Z',
+  outcome: 'pass' as const,
+  decisions: [
+    {
+      policyId: 'policy/access-control',
+      ruleId: 'rule/allow-latest',
+      effect: 'allow' as const,
+      reason: 'No blocking findings'
+    }
+  ]
+};
+
+const riskProfileSample = {
+  schemaVersion: 'StellaOps.RiskProfileEvidence@1' as const,
+  subjectDigest: `sha256:${hex('2')}`,
+  generatedAt: '2025-10-31T12:20:00Z',
+  riskScore: 42.5,
+  riskLevel: 'medium' as const,
+  factors: [
+    {
+      name: 'exploitability',
+      weight: 0.6,
+      description: 'No known exploits published'
+    }
+  ]
+};
+
+const customEvidenceSample = {
+  schemaVersion: 'StellaOps.CustomEvidence@1' as const,
+  subjectDigest: `sha256:${hex('3')}`,
+  kind: 'org.stellaops.demo/custom',
+  generatedAt: '2025-10-31T12:25:00Z',
+  properties: [
+    { key: 'note', value: 'Custom attestation payload' }
+  ]
+};
+
+test('BuildProvenance round-trip', () => {
+  const validated = validateBuildProvenance(structuredClone(buildProvenanceSample));
+  assert.deepEqual(validated, buildProvenanceSample);
+  const canonical = canonicalizeBuildProvenance(buildProvenanceSample);
+  assert.equal(canonical, canonicalizeBuildProvenance(structuredClone(buildProvenanceSample)));
+});
+
+test('BuildProvenance validation failure on missing materials', () => {
+  const invalid = structuredClone(buildProvenanceSample);
+  (invalid.materials as unknown[]) = [];
+  assert.throws(() => validateBuildProvenance(invalid as unknown), /must contain at least 1 item/);
+});
+
+test('SBOMAttestation round-trip', () => {
+  const validated = validateSbomAttestation(structuredClone(sbomAttestationSample));
+  assert.deepEqual(validated, sbomAttestationSample);
+  assert.equal(canonicalizeSbomAttestation(sbomAttestationSample), canonicalizeSbomAttestation(structuredClone(sbomAttestationSample)));
+});
+
+test('VexAttestation round-trip', () => {
+  const validated = validateVexAttestation(structuredClone(vexAttestationSample));
+  assert.deepEqual(validated, vexAttestationSample);
+  assert.equal(canonicalizeVexAttestation(vexAttestationSample), canonicalizeVexAttestation(structuredClone(vexAttestationSample)));
+});
+
+test('ScanResults round-trip', () => {
+  const validated = validateScanResults(structuredClone(scanResultsSample));
+  assert.deepEqual(validated, scanResultsSample);
+  assert.equal(canonicalizeScanResults(scanResultsSample), canonicalizeScanResults(structuredClone(scanResultsSample)));
+});
+
+test('PolicyEvaluation round-trip', () => {
+  const validated = validatePolicyEvaluation(structuredClone(policyEvaluationSample));
+  assert.deepEqual(validated, policyEvaluationSample);
+  assert.equal(canonicalizePolicyEvaluation(policyEvaluationSample), canonicalizePolicyEvaluation(structuredClone(policyEvaluationSample)));
+});
+
+test('RiskProfileEvidence round-trip', () => {
+  const validated = validateRiskProfileEvidence(structuredClone(riskProfileSample));
+  assert.deepEqual(validated, riskProfileSample);
+  assert.equal(canonicalizeRiskProfileEvidence(riskProfileSample), canonicalizeRiskProfileEvidence(structuredClone(riskProfileSample)));
+});
+
+test('CustomEvidence round-trip', () => {
+  const validated = validateCustomEvidence(structuredClone(customEvidenceSample));
+  assert.deepEqual(validated, customEvidenceSample);
+  assert.equal(canonicalizeCustomEvidence(customEvidenceSample), canonicalizeCustomEvidence(structuredClone(customEvidenceSample)));
+});
+
+test('CustomEvidence fails when schema version mismatches', () => {
+  const invalid = { ...customEvidenceSample, schemaVersion: 'StellaOps.CustomEvidence@9' as const };
+  assert.throws(() => validateCustomEvidence(invalid as unknown), /must equal 'StellaOps.CustomEvidence@1'/);
+});

src/Attestor/StellaOps.Attestor.Types/generated/ts/index.ts

@@ -0,0 +1,945 @@
+// <auto-generated />
+// Generated by StellaOps.Attestor.Types.Generator
+/* eslint-disable */
+/* prettier-ignore */
+
+export const FindingStatusValues = Object.freeze(['detected', 'confirmed', 'fixed', 'not_affected'] as const);
+export type FindingStatus = typeof FindingStatusValues[number];
+
+export const PolicyEffectValues = Object.freeze(['allow', 'deny', 'warn'] as const);
+export type PolicyEffect = typeof PolicyEffectValues[number];
+
+export const PolicyOutcomeValues = Object.freeze(['pass', 'fail', 'waived'] as const);
+export type PolicyOutcome = typeof PolicyOutcomeValues[number];
+
+export const RiskLevelValues = Object.freeze(['critical', 'high', 'medium', 'low', 'informational'] as const);
+export type RiskLevel = typeof RiskLevelValues[number];
+
+export const SbomFormatValues = Object.freeze(['CycloneDX-1.6', 'SBOM-3.0.0'] as const);
+export type SbomFormat = typeof SbomFormatValues[number];
+
+export const SeverityValues = Object.freeze(['critical', 'high', 'medium', 'low', 'info'] as const);
+export type Severity = typeof SeverityValues[number];
+
+export const VexStatusValues = Object.freeze(['not_affected', 'affected', 'under_investigation', 'fixed'] as const);
+export type VexStatus = typeof VexStatusValues[number];
+
+export interface BuildMetadata {
+  buildStartedOn: string;
+  buildFinishedOn: string;
+  reproducible?: boolean;
+  buildInvocationId?: string;
+}
+
+export interface BuildProvenance {
+  schemaVersion: 'StellaOps.BuildProvenance@1';
+  buildType: string;
+  builder: BuilderIdentity;
+  materials: Array<MaterialReference>;
+  metadata: BuildMetadata;
+  environment?: EnvironmentMetadata;
+}
+
+export interface BuilderIdentity {
+  id: string;
+  version?: string;
+  platform?: string;
+}
+
+export interface CustomEvidence {
+  schemaVersion: 'StellaOps.CustomEvidence@1';
+  subjectDigest: string;
+  kind: string;
+  generatedAt: string;
+  properties?: Array<CustomProperty>;
+}
+
+export interface CustomProperty {
+  key: string;
+  value: string;
+}
+
+export interface DigestReference {
+  algorithm: string;
+  value: string;
+}
+
+export interface EnvironmentMetadata {
+  platform?: string;
+  imageDigest?: DigestReference;
+}
+
+export interface MaterialReference {
+  uri: string;
+  digests: Array<DigestReference>;
+  note?: string;
+}
+
+export interface PolicyDecision {
+  policyId: string;
+  ruleId: string;
+  effect: PolicyEffect;
+  reason?: string;
+  remediation?: string;
+}
+
+export interface PolicyEvaluation {
+  schemaVersion: 'StellaOps.PolicyEvaluation@1';
+  subjectDigest: string;
+  policyVersion: string;
+  evaluatedAt: string;
+  outcome: PolicyOutcome;
+  decisions: Array<PolicyDecision>;
+}
+
+export interface RiskFactor {
+  name: string;
+  weight: number;
+  description?: string;
+}
+
+export interface RiskProfileEvidence {
+  schemaVersion: 'StellaOps.RiskProfileEvidence@1';
+  subjectDigest: string;
+  generatedAt: string;
+  riskScore: number;
+  riskLevel: RiskLevel;
+  factors: Array<RiskFactor>;
+}
+
+export interface SbomAttestation {
+  schemaVersion: 'StellaOps.SBOMAttestation@1';
+  subjectDigest: string;
+  sbomFormat: SbomFormat;
+  sbomDigest: DigestReference;
+  sbomUri?: string;
+  componentCount: number;
+  packages?: Array<SbomPackage>;
+}
+
+export interface SbomPackage {
+  purl: string;
+  version?: string;
+  licenses?: Array<string>;
+}
+
+export interface ScanFinding {
+  id: string;
+  severity: Severity;
+  status: FindingStatus;
+  packageName: string;
+  packageVersion?: string;
+  cvssScore?: number;
+  description?: string;
+  references?: Array<string>;
+}
+
+export interface ScanResults {
+  schemaVersion: 'StellaOps.ScanResults@1';
+  subjectDigest: string;
+  scannerName: string;
+  scannerVersion: string;
+  generatedAt: string;
+  findings: Array<ScanFinding>;
+}
+
+export interface VexAttestation {
+  schemaVersion: 'StellaOps.VEXAttestation@1';
+  subjectDigest: string;
+  generatedAt: string;
+  statements: Array<VexStatement>;
+}
+
+export interface VexStatement {
+  vulnerabilityId: string;
+  status: VexStatus;
+  timestamp: string;
+  justification?: string;
+  impactStatement?: string;
+  actionStatement?: string;
+  references?: Array<string>;
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value);
+}
+
+function pathString(path: string[]): string {
+  return path.length === 0 ? 'value' : `value.${path.join('.')}`;
+}
+
+function assertBuildMetadata(value: unknown, path: string[]): asserts value is BuildMetadata {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.buildStartedOn === undefined) {
+    throw new Error(`${pathString([...path, 'buildStartedOn'])} is required.`);
+  }
+  if (typeof value.buildStartedOn !== 'string') {
+    throw new Error(`${pathString([...path, 'buildStartedOn'])} must be a string.`);
+  }
+  if (value.buildFinishedOn === undefined) {
+    throw new Error(`${pathString([...path, 'buildFinishedOn'])} is required.`);
+  }
+  if (typeof value.buildFinishedOn !== 'string') {
+    throw new Error(`${pathString([...path, 'buildFinishedOn'])} must be a string.`);
+  }
+  if (value.reproducible !== undefined) {
+    if (typeof value.reproducible !== 'boolean') {
+      throw new Error(`${pathString([...path, 'reproducible'])} must be a boolean.`);
+    }
+  }
+  if (value.buildInvocationId !== undefined) {
+    if (typeof value.buildInvocationId !== 'string') {
+      throw new Error(`${pathString([...path, 'buildInvocationId'])} must be a string.`);
+    }
+  }
+}
+
+function assertBuildProvenance(value: unknown, path: string[]): asserts value is BuildProvenance {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.schemaVersion === undefined) {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} is required.`);
+  }
+  if (typeof value.schemaVersion !== 'string') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must be a string.`);
+  }
+  if (value.schemaVersion !== 'StellaOps.BuildProvenance@1') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must equal 'StellaOps.BuildProvenance@1'.`);
+  }
+  if (value.buildType === undefined) {
+    throw new Error(`${pathString([...path, 'buildType'])} is required.`);
+  }
+  if (typeof value.buildType !== 'string') {
+    throw new Error(`${pathString([...path, 'buildType'])} must be a string.`);
+  }
+  if (value.builder === undefined) {
+    throw new Error(`${pathString([...path, 'builder'])} is required.`);
+  }
+  assertBuilderIdentity(value.builder, [...path, 'builder']);
+  if (value.materials === undefined) {
+    throw new Error(`${pathString([...path, 'materials'])} is required.`);
+  }
+  if (!Array.isArray(value.materials)) {
+    throw new Error(`${pathString([...path, 'materials'])} must be an array.`);
+  }
+  if (value.materials.length < 1) {
+    throw new Error(`${pathString([...path, 'materials'])} must contain at least 1 item(s).`);
+  }
+  for (let i = 0; i < value.materials.length; i += 1) {
+    assertMaterialReference(value.materials[i], [...[...path, 'materials'], String(i)]);
+  }
+  if (value.metadata === undefined) {
+    throw new Error(`${pathString([...path, 'metadata'])} is required.`);
+  }
+  assertBuildMetadata(value.metadata, [...path, 'metadata']);
+  if (value.environment !== undefined) {
+    assertEnvironmentMetadata(value.environment, [...path, 'environment']);
+  }
+}
+
+function assertBuilderIdentity(value: unknown, path: string[]): asserts value is BuilderIdentity {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.id === undefined) {
+    throw new Error(`${pathString([...path, 'id'])} is required.`);
+  }
+  if (typeof value.id !== 'string') {
+    throw new Error(`${pathString([...path, 'id'])} must be a string.`);
+  }
+  if (value.version !== undefined) {
+    if (typeof value.version !== 'string') {
+      throw new Error(`${pathString([...path, 'version'])} must be a string.`);
+    }
+  }
+  if (value.platform !== undefined) {
+    if (typeof value.platform !== 'string') {
+      throw new Error(`${pathString([...path, 'platform'])} must be a string.`);
+    }
+  }
+}
+
+function assertCustomEvidence(value: unknown, path: string[]): asserts value is CustomEvidence {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.schemaVersion === undefined) {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} is required.`);
+  }
+  if (typeof value.schemaVersion !== 'string') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must be a string.`);
+  }
+  if (value.schemaVersion !== 'StellaOps.CustomEvidence@1') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must equal 'StellaOps.CustomEvidence@1'.`);
+  }
+  if (value.subjectDigest === undefined) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} is required.`);
+  }
+  if (typeof value.subjectDigest !== 'string') {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} must be a string.`);
+  }
+  if (!/^sha256:[A-Fa-f0-9]{64}$/.test(value.subjectDigest)) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} does not match expected format.`);
+  }
+  if (value.kind === undefined) {
+    throw new Error(`${pathString([...path, 'kind'])} is required.`);
+  }
+  if (typeof value.kind !== 'string') {
+    throw new Error(`${pathString([...path, 'kind'])} must be a string.`);
+  }
+  if (value.generatedAt === undefined) {
+    throw new Error(`${pathString([...path, 'generatedAt'])} is required.`);
+  }
+  if (typeof value.generatedAt !== 'string') {
+    throw new Error(`${pathString([...path, 'generatedAt'])} must be a string.`);
+  }
+  if (value.properties !== undefined) {
+    if (!Array.isArray(value.properties)) {
+      throw new Error(`${pathString([...path, 'properties'])} must be an array.`);
+    }
+    for (let i = 0; i < value.properties.length; i += 1) {
+      assertCustomProperty(value.properties[i], [...[...path, 'properties'], String(i)]);
+    }
+  }
+}
+
+function assertCustomProperty(value: unknown, path: string[]): asserts value is CustomProperty {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.key === undefined) {
+    throw new Error(`${pathString([...path, 'key'])} is required.`);
+  }
+  if (typeof value.key !== 'string') {
+    throw new Error(`${pathString([...path, 'key'])} must be a string.`);
+  }
+  if (value.value === undefined) {
+    throw new Error(`${pathString([...path, 'value'])} is required.`);
+  }
+  if (typeof value.value !== 'string') {
+    throw new Error(`${pathString([...path, 'value'])} must be a string.`);
+  }
+}
+
+function assertDigestReference(value: unknown, path: string[]): asserts value is DigestReference {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.algorithm === undefined) {
+    throw new Error(`${pathString([...path, 'algorithm'])} is required.`);
+  }
+  if (typeof value.algorithm !== 'string') {
+    throw new Error(`${pathString([...path, 'algorithm'])} must be a string.`);
+  }
+  if (value.value === undefined) {
+    throw new Error(`${pathString([...path, 'value'])} is required.`);
+  }
+  if (typeof value.value !== 'string') {
+    throw new Error(`${pathString([...path, 'value'])} must be a string.`);
+  }
+  if (!/^[A-Fa-f0-9]{64}$/.test(value.value)) {
+    throw new Error(`${pathString([...path, 'value'])} does not match expected format.`);
+  }
+}
+
+function assertEnvironmentMetadata(value: unknown, path: string[]): asserts value is EnvironmentMetadata {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.platform !== undefined) {
+    if (typeof value.platform !== 'string') {
+      throw new Error(`${pathString([...path, 'platform'])} must be a string.`);
+    }
+  }
+  if (value.imageDigest !== undefined) {
+    assertDigestReference(value.imageDigest, [...path, 'imageDigest']);
+  }
+}
+
+function assertMaterialReference(value: unknown, path: string[]): asserts value is MaterialReference {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.uri === undefined) {
+    throw new Error(`${pathString([...path, 'uri'])} is required.`);
+  }
+  if (typeof value.uri !== 'string') {
+    throw new Error(`${pathString([...path, 'uri'])} must be a string.`);
+  }
+  if (value.digests === undefined) {
+    throw new Error(`${pathString([...path, 'digests'])} is required.`);
+  }
+  if (!Array.isArray(value.digests)) {
+    throw new Error(`${pathString([...path, 'digests'])} must be an array.`);
+  }
+  if (value.digests.length < 1) {
+    throw new Error(`${pathString([...path, 'digests'])} must contain at least 1 item(s).`);
+  }
+  for (let i = 0; i < value.digests.length; i += 1) {
+    assertDigestReference(value.digests[i], [...[...path, 'digests'], String(i)]);
+  }
+  if (value.note !== undefined) {
+    if (typeof value.note !== 'string') {
+      throw new Error(`${pathString([...path, 'note'])} must be a string.`);
+    }
+  }
+}
+
+function assertPolicyDecision(value: unknown, path: string[]): asserts value is PolicyDecision {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.policyId === undefined) {
+    throw new Error(`${pathString([...path, 'policyId'])} is required.`);
+  }
+  if (typeof value.policyId !== 'string') {
+    throw new Error(`${pathString([...path, 'policyId'])} must be a string.`);
+  }
+  if (value.ruleId === undefined) {
+    throw new Error(`${pathString([...path, 'ruleId'])} is required.`);
+  }
+  if (typeof value.ruleId !== 'string') {
+    throw new Error(`${pathString([...path, 'ruleId'])} must be a string.`);
+  }
+  if (value.effect === undefined) {
+    throw new Error(`${pathString([...path, 'effect'])} is required.`);
+  }
+  if (!PolicyEffectValues.includes(value.effect as PolicyEffect)) {
+    throw new Error(`${pathString([...path, 'effect'])} must be one of ${PolicyEffectValues.join(', ')}`);
+  }
+  if (value.reason !== undefined) {
+    if (typeof value.reason !== 'string') {
+      throw new Error(`${pathString([...path, 'reason'])} must be a string.`);
+    }
+  }
+  if (value.remediation !== undefined) {
+    if (typeof value.remediation !== 'string') {
+      throw new Error(`${pathString([...path, 'remediation'])} must be a string.`);
+    }
+  }
+}
+
+function assertPolicyEvaluation(value: unknown, path: string[]): asserts value is PolicyEvaluation {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.schemaVersion === undefined) {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} is required.`);
+  }
+  if (typeof value.schemaVersion !== 'string') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must be a string.`);
+  }
+  if (value.schemaVersion !== 'StellaOps.PolicyEvaluation@1') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must equal 'StellaOps.PolicyEvaluation@1'.`);
+  }
+  if (value.subjectDigest === undefined) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} is required.`);
+  }
+  if (typeof value.subjectDigest !== 'string') {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} must be a string.`);
+  }
+  if (!/^sha256:[A-Fa-f0-9]{64}$/.test(value.subjectDigest)) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} does not match expected format.`);
+  }
+  if (value.policyVersion === undefined) {
+    throw new Error(`${pathString([...path, 'policyVersion'])} is required.`);
+  }
+  if (typeof value.policyVersion !== 'string') {
+    throw new Error(`${pathString([...path, 'policyVersion'])} must be a string.`);
+  }
+  if (value.evaluatedAt === undefined) {
+    throw new Error(`${pathString([...path, 'evaluatedAt'])} is required.`);
+  }
+  if (typeof value.evaluatedAt !== 'string') {
+    throw new Error(`${pathString([...path, 'evaluatedAt'])} must be a string.`);
+  }
+  if (value.outcome === undefined) {
+    throw new Error(`${pathString([...path, 'outcome'])} is required.`);
+  }
+  if (!PolicyOutcomeValues.includes(value.outcome as PolicyOutcome)) {
+    throw new Error(`${pathString([...path, 'outcome'])} must be one of ${PolicyOutcomeValues.join(', ')}`);
+  }
+  if (value.decisions === undefined) {
+    throw new Error(`${pathString([...path, 'decisions'])} is required.`);
+  }
+  if (!Array.isArray(value.decisions)) {
+    throw new Error(`${pathString([...path, 'decisions'])} must be an array.`);
+  }
+  for (let i = 0; i < value.decisions.length; i += 1) {
+    assertPolicyDecision(value.decisions[i], [...[...path, 'decisions'], String(i)]);
+  }
+}
+
+function assertRiskFactor(value: unknown, path: string[]): asserts value is RiskFactor {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.name === undefined) {
+    throw new Error(`${pathString([...path, 'name'])} is required.`);
+  }
+  if (typeof value.name !== 'string') {
+    throw new Error(`${pathString([...path, 'name'])} must be a string.`);
+  }
+  if (value.weight === undefined) {
+    throw new Error(`${pathString([...path, 'weight'])} is required.`);
+  }
+  if (typeof value.weight !== 'number') {
+    throw new Error(`${pathString([...path, 'weight'])} must be a number.`);
+  }
+  if (value.weight < 0) {
+    throw new Error(`${pathString([...path, 'weight'])} must be >= 0`);
+  }
+  if (value.weight > 1) {
+    throw new Error(`${pathString([...path, 'weight'])} must be <= 1`);
+  }
+  if (value.description !== undefined) {
+    if (typeof value.description !== 'string') {
+      throw new Error(`${pathString([...path, 'description'])} must be a string.`);
+    }
+  }
+}
+
+function assertRiskProfileEvidence(value: unknown, path: string[]): asserts value is RiskProfileEvidence {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.schemaVersion === undefined) {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} is required.`);
+  }
+  if (typeof value.schemaVersion !== 'string') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must be a string.`);
+  }
+  if (value.schemaVersion !== 'StellaOps.RiskProfileEvidence@1') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must equal 'StellaOps.RiskProfileEvidence@1'.`);
+  }
+  if (value.subjectDigest === undefined) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} is required.`);
+  }
+  if (typeof value.subjectDigest !== 'string') {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} must be a string.`);
+  }
+  if (!/^sha256:[A-Fa-f0-9]{64}$/.test(value.subjectDigest)) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} does not match expected format.`);
+  }
+  if (value.generatedAt === undefined) {
+    throw new Error(`${pathString([...path, 'generatedAt'])} is required.`);
+  }
+  if (typeof value.generatedAt !== 'string') {
+    throw new Error(`${pathString([...path, 'generatedAt'])} must be a string.`);
+  }
+  if (value.riskScore === undefined) {
+    throw new Error(`${pathString([...path, 'riskScore'])} is required.`);
+  }
+  if (typeof value.riskScore !== 'number') {
+    throw new Error(`${pathString([...path, 'riskScore'])} must be a number.`);
+  }
+  if (value.riskScore < 0) {
+    throw new Error(`${pathString([...path, 'riskScore'])} must be >= 0`);
+  }
+  if (value.riskScore > 100) {
+    throw new Error(`${pathString([...path, 'riskScore'])} must be <= 100`);
+  }
+  if (value.riskLevel === undefined) {
+    throw new Error(`${pathString([...path, 'riskLevel'])} is required.`);
+  }
+  if (!RiskLevelValues.includes(value.riskLevel as RiskLevel)) {
+    throw new Error(`${pathString([...path, 'riskLevel'])} must be one of ${RiskLevelValues.join(', ')}`);
+  }
+  if (value.factors === undefined) {
+    throw new Error(`${pathString([...path, 'factors'])} is required.`);
+  }
+  if (!Array.isArray(value.factors)) {
+    throw new Error(`${pathString([...path, 'factors'])} must be an array.`);
+  }
+  for (let i = 0; i < value.factors.length; i += 1) {
+    assertRiskFactor(value.factors[i], [...[...path, 'factors'], String(i)]);
+  }
+}
+
+function assertSbomAttestation(value: unknown, path: string[]): asserts value is SbomAttestation {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.schemaVersion === undefined) {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} is required.`);
+  }
+  if (typeof value.schemaVersion !== 'string') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must be a string.`);
+  }
+  if (value.schemaVersion !== 'StellaOps.SBOMAttestation@1') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must equal 'StellaOps.SBOMAttestation@1'.`);
+  }
+  if (value.subjectDigest === undefined) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} is required.`);
+  }
+  if (typeof value.subjectDigest !== 'string') {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} must be a string.`);
+  }
+  if (!/^sha256:[A-Fa-f0-9]{64}$/.test(value.subjectDigest)) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} does not match expected format.`);
+  }
+  if (value.sbomFormat === undefined) {
+    throw new Error(`${pathString([...path, 'sbomFormat'])} is required.`);
+  }
+  if (!SbomFormatValues.includes(value.sbomFormat as SbomFormat)) {
+    throw new Error(`${pathString([...path, 'sbomFormat'])} must be one of ${SbomFormatValues.join(', ')}`);
+  }
+  if (value.sbomDigest === undefined) {
+    throw new Error(`${pathString([...path, 'sbomDigest'])} is required.`);
+  }
+  assertDigestReference(value.sbomDigest, [...path, 'sbomDigest']);
+  if (value.sbomUri !== undefined) {
+    if (typeof value.sbomUri !== 'string') {
+      throw new Error(`${pathString([...path, 'sbomUri'])} must be a string.`);
+    }
+  }
+  if (value.componentCount === undefined) {
+    throw new Error(`${pathString([...path, 'componentCount'])} is required.`);
+  }
+  if (typeof value.componentCount !== 'number') {
+    throw new Error(`${pathString([...path, 'componentCount'])} must be a number.`);
+  }
+  if (value.componentCount < 0) {
+    throw new Error(`${pathString([...path, 'componentCount'])} must be >= 0`);
+  }
+  if (value.packages !== undefined) {
+    if (!Array.isArray(value.packages)) {
+      throw new Error(`${pathString([...path, 'packages'])} must be an array.`);
+    }
+    for (let i = 0; i < value.packages.length; i += 1) {
+      assertSbomPackage(value.packages[i], [...[...path, 'packages'], String(i)]);
+    }
+  }
+}
+
+function assertSbomPackage(value: unknown, path: string[]): asserts value is SbomPackage {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.purl === undefined) {
+    throw new Error(`${pathString([...path, 'purl'])} is required.`);
+  }
+  if (typeof value.purl !== 'string') {
+    throw new Error(`${pathString([...path, 'purl'])} must be a string.`);
+  }
+  if (value.version !== undefined) {
+    if (typeof value.version !== 'string') {
+      throw new Error(`${pathString([...path, 'version'])} must be a string.`);
+    }
+  }
+  if (value.licenses !== undefined) {
+    if (!Array.isArray(value.licenses)) {
+      throw new Error(`${pathString([...path, 'licenses'])} must be an array.`);
+    }
+    if (value.licenses.length < 1) {
+      throw new Error(`${pathString([...path, 'licenses'])} must contain at least 1 item(s).`);
+    }
+    for (let i = 0; i < value.licenses.length; i += 1) {
+      if (typeof value.licenses[i] !== 'string') {
+        throw new Error(`${pathString([...[...path, 'licenses'], String(i)])} must be a string.`);
+      }
+    }
+  }
+}
+
+function assertScanFinding(value: unknown, path: string[]): asserts value is ScanFinding {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.id === undefined) {
+    throw new Error(`${pathString([...path, 'id'])} is required.`);
+  }
+  if (typeof value.id !== 'string') {
+    throw new Error(`${pathString([...path, 'id'])} must be a string.`);
+  }
+  if (value.severity === undefined) {
+    throw new Error(`${pathString([...path, 'severity'])} is required.`);
+  }
+  if (!SeverityValues.includes(value.severity as Severity)) {
+    throw new Error(`${pathString([...path, 'severity'])} must be one of ${SeverityValues.join(', ')}`);
+  }
+  if (value.status === undefined) {
+    throw new Error(`${pathString([...path, 'status'])} is required.`);
+  }
+  if (!FindingStatusValues.includes(value.status as FindingStatus)) {
+    throw new Error(`${pathString([...path, 'status'])} must be one of ${FindingStatusValues.join(', ')}`);
+  }
+  if (value.packageName === undefined) {
+    throw new Error(`${pathString([...path, 'packageName'])} is required.`);
+  }
+  if (typeof value.packageName !== 'string') {
+    throw new Error(`${pathString([...path, 'packageName'])} must be a string.`);
+  }
+  if (value.packageVersion !== undefined) {
+    if (typeof value.packageVersion !== 'string') {
+      throw new Error(`${pathString([...path, 'packageVersion'])} must be a string.`);
+    }
+  }
+  if (value.cvssScore !== undefined) {
+    if (typeof value.cvssScore !== 'number') {
+      throw new Error(`${pathString([...path, 'cvssScore'])} must be a number.`);
+    }
+    if (value.cvssScore < 0) {
+      throw new Error(`${pathString([...path, 'cvssScore'])} must be >= 0`);
+    }
+    if (value.cvssScore > 10) {
+      throw new Error(`${pathString([...path, 'cvssScore'])} must be <= 10`);
+    }
+  }
+  if (value.description !== undefined) {
+    if (typeof value.description !== 'string') {
+      throw new Error(`${pathString([...path, 'description'])} must be a string.`);
+    }
+  }
+  if (value.references !== undefined) {
+    if (!Array.isArray(value.references)) {
+      throw new Error(`${pathString([...path, 'references'])} must be an array.`);
+    }
+    if (value.references.length < 1) {
+      throw new Error(`${pathString([...path, 'references'])} must contain at least 1 item(s).`);
+    }
+    for (let i = 0; i < value.references.length; i += 1) {
+      if (typeof value.references[i] !== 'string') {
+        throw new Error(`${pathString([...[...path, 'references'], String(i)])} must be a string.`);
+      }
+    }
+  }
+}
+
+function assertScanResults(value: unknown, path: string[]): asserts value is ScanResults {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.schemaVersion === undefined) {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} is required.`);
+  }
+  if (typeof value.schemaVersion !== 'string') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must be a string.`);
+  }
+  if (value.schemaVersion !== 'StellaOps.ScanResults@1') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must equal 'StellaOps.ScanResults@1'.`);
+  }
+  if (value.subjectDigest === undefined) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} is required.`);
+  }
+  if (typeof value.subjectDigest !== 'string') {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} must be a string.`);
+  }
+  if (!/^sha256:[A-Fa-f0-9]{64}$/.test(value.subjectDigest)) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} does not match expected format.`);
+  }
+  if (value.scannerName === undefined) {
+    throw new Error(`${pathString([...path, 'scannerName'])} is required.`);
+  }
+  if (typeof value.scannerName !== 'string') {
+    throw new Error(`${pathString([...path, 'scannerName'])} must be a string.`);
+  }
+  if (value.scannerVersion === undefined) {
+    throw new Error(`${pathString([...path, 'scannerVersion'])} is required.`);
+  }
+  if (typeof value.scannerVersion !== 'string') {
+    throw new Error(`${pathString([...path, 'scannerVersion'])} must be a string.`);
+  }
+  if (value.generatedAt === undefined) {
+    throw new Error(`${pathString([...path, 'generatedAt'])} is required.`);
+  }
+  if (typeof value.generatedAt !== 'string') {
+    throw new Error(`${pathString([...path, 'generatedAt'])} must be a string.`);
+  }
+  if (value.findings === undefined) {
+    throw new Error(`${pathString([...path, 'findings'])} is required.`);
+  }
+  if (!Array.isArray(value.findings)) {
+    throw new Error(`${pathString([...path, 'findings'])} must be an array.`);
+  }
+  for (let i = 0; i < value.findings.length; i += 1) {
+    assertScanFinding(value.findings[i], [...[...path, 'findings'], String(i)]);
+  }
+}
+
+function assertVexAttestation(value: unknown, path: string[]): asserts value is VexAttestation {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.schemaVersion === undefined) {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} is required.`);
+  }
+  if (typeof value.schemaVersion !== 'string') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must be a string.`);
+  }
+  if (value.schemaVersion !== 'StellaOps.VEXAttestation@1') {
+    throw new Error(`${pathString([...path, 'schemaVersion'])} must equal 'StellaOps.VEXAttestation@1'.`);
+  }
+  if (value.subjectDigest === undefined) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} is required.`);
+  }
+  if (typeof value.subjectDigest !== 'string') {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} must be a string.`);
+  }
+  if (!/^sha256:[A-Fa-f0-9]{64}$/.test(value.subjectDigest)) {
+    throw new Error(`${pathString([...path, 'subjectDigest'])} does not match expected format.`);
+  }
+  if (value.generatedAt === undefined) {
+    throw new Error(`${pathString([...path, 'generatedAt'])} is required.`);
+  }
+  if (typeof value.generatedAt !== 'string') {
+    throw new Error(`${pathString([...path, 'generatedAt'])} must be a string.`);
+  }
+  if (value.statements === undefined) {
+    throw new Error(`${pathString([...path, 'statements'])} is required.`);
+  }
+  if (!Array.isArray(value.statements)) {
+    throw new Error(`${pathString([...path, 'statements'])} must be an array.`);
+  }
+  if (value.statements.length < 1) {
+    throw new Error(`${pathString([...path, 'statements'])} must contain at least 1 item(s).`);
+  }
+  for (let i = 0; i < value.statements.length; i += 1) {
+    assertVexStatement(value.statements[i], [...[...path, 'statements'], String(i)]);
+  }
+}
+
+function assertVexStatement(value: unknown, path: string[]): asserts value is VexStatement {
+  if (!isRecord(value)) {
+    throw new Error(`${pathString(path)} must be an object.`);
+  }
+  if (value.vulnerabilityId === undefined) {
+    throw new Error(`${pathString([...path, 'vulnerabilityId'])} is required.`);
+  }
+  if (typeof value.vulnerabilityId !== 'string') {
+    throw new Error(`${pathString([...path, 'vulnerabilityId'])} must be a string.`);
+  }
+  if (value.status === undefined) {
+    throw new Error(`${pathString([...path, 'status'])} is required.`);
+  }
+  if (!VexStatusValues.includes(value.status as VexStatus)) {
+    throw new Error(`${pathString([...path, 'status'])} must be one of ${VexStatusValues.join(', ')}`);
+  }
+  if (value.timestamp === undefined) {
+    throw new Error(`${pathString([...path, 'timestamp'])} is required.`);
+  }
+  if (typeof value.timestamp !== 'string') {
+    throw new Error(`${pathString([...path, 'timestamp'])} must be a string.`);
+  }
+  if (value.justification !== undefined) {
+    if (typeof value.justification !== 'string') {
+      throw new Error(`${pathString([...path, 'justification'])} must be a string.`);
+    }
+  }
+  if (value.impactStatement !== undefined) {
+    if (typeof value.impactStatement !== 'string') {
+      throw new Error(`${pathString([...path, 'impactStatement'])} must be a string.`);
+    }
+  }
+  if (value.actionStatement !== undefined) {
+    if (typeof value.actionStatement !== 'string') {
+      throw new Error(`${pathString([...path, 'actionStatement'])} must be a string.`);
+    }
+  }
+  if (value.references !== undefined) {
+    if (!Array.isArray(value.references)) {
+      throw new Error(`${pathString([...path, 'references'])} must be an array.`);
+    }
+    if (value.references.length < 1) {
+      throw new Error(`${pathString([...path, 'references'])} must contain at least 1 item(s).`);
+    }
+    for (let i = 0; i < value.references.length; i += 1) {
+      if (typeof value.references[i] !== 'string') {
+        throw new Error(`${pathString([...[...path, 'references'], String(i)])} must be a string.`);
+      }
+    }
+  }
+}
+
+export function validateBuildProvenance(value: unknown): BuildProvenance {
+  assertBuildProvenance(value, []);
+  return value as BuildProvenance;
+}
+
+export function canonicalizeBuildProvenance(value: BuildProvenance): string {
+  assertBuildProvenance(value, []);
+  return canonicalStringify(value);
+}
+
+export function validateCustomEvidence(value: unknown): CustomEvidence {
+  assertCustomEvidence(value, []);
+  return value as CustomEvidence;
+}
+
+export function canonicalizeCustomEvidence(value: CustomEvidence): string {
+  assertCustomEvidence(value, []);
+  return canonicalStringify(value);
+}
+
+export function validatePolicyEvaluation(value: unknown): PolicyEvaluation {
+  assertPolicyEvaluation(value, []);
+  return value as PolicyEvaluation;
+}
+
+export function canonicalizePolicyEvaluation(value: PolicyEvaluation): string {
+  assertPolicyEvaluation(value, []);
+  return canonicalStringify(value);
+}
+
+export function validateRiskProfileEvidence(value: unknown): RiskProfileEvidence {
+  assertRiskProfileEvidence(value, []);
+  return value as RiskProfileEvidence;
+}
+
+export function canonicalizeRiskProfileEvidence(value: RiskProfileEvidence): string {
+  assertRiskProfileEvidence(value, []);
+  return canonicalStringify(value);
+}
+
+export function validateSbomAttestation(value: unknown): SbomAttestation {
+  assertSbomAttestation(value, []);
+  return value as SbomAttestation;
+}
+
+export function canonicalizeSbomAttestation(value: SbomAttestation): string {
+  assertSbomAttestation(value, []);
+  return canonicalStringify(value);
+}
+
+export function validateScanResults(value: unknown): ScanResults {
+  assertScanResults(value, []);
+  return value as ScanResults;
+}
+
+export function canonicalizeScanResults(value: ScanResults): string {
+  assertScanResults(value, []);
+  return canonicalStringify(value);
+}
+
+export function validateVexAttestation(value: unknown): VexAttestation {
+  assertVexAttestation(value, []);
+  return value as VexAttestation;
+}
+
+export function canonicalizeVexAttestation(value: VexAttestation): string {
+  assertVexAttestation(value, []);
+  return canonicalStringify(value);
+}
+
+function canonicalStringify(input: unknown): string {
+  return JSON.stringify(sortValue(input));
+}
+
+function sortValue(value: unknown): unknown {
+  if (Array.isArray(value)) {
+    return value.map(sortValue);
+  }
+  if (isRecord(value)) {
+    const ordered: Record<string, unknown> = {};
+    const keys = Object.keys(value).sort();
+    for (const key of keys) {
+      ordered[key] = sortValue(value[key]);
+    }
+    return ordered;
+  }
+  return value;
+}
+

src/Attestor/StellaOps.Attestor.Types/generated/ts/package-lock.json

@@ -0,0 +1,237 @@
+{
+  "name": "@stellaops/attestor-types",
+  "version": "0.1.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "@stellaops/attestor-types",
+      "version": "0.1.0",
+      "devDependencies": {
+        "@types/node": "^22.7.4",
+        "ts-node": "^10.9.2",
+        "typescript": "^5.6.3"
+      }
+    },
+    "node_modules/@cspotcode/source-map-support": {
+      "version": "0.8.1",
+      "resolved": "https://registry.npmjs.org/@cspotcode/source-map-support/-/source-map-support-0.8.1.tgz",
+      "integrity": "sha512-IchNf6dN4tHoMFIn/7OE8LWZ19Y6q/67Bmf6vnGREv8RSbBVb9LPJxEcnwrcwX6ixSvaiGoomAUvu4YSxXrVgw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@jridgewell/trace-mapping": "0.3.9"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
+    "node_modules/@jridgewell/resolve-uri": {
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/@jridgewell/resolve-uri/-/resolve-uri-3.1.2.tgz",
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src/Attestor/StellaOps.Attestor.Types/generated/ts/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "@stellaops/attestor-types",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "build": "tsc --project tsconfig.json",
+    "clean": "rm -rf dist",
+    "test": "npm run build && node --test dist/index.test.js"
+  },
+  "devDependencies": {
+    "@types/node": "^22.7.4",
+    "ts-node": "^10.9.2",
+    "typescript": "^5.6.3"
+  }
+}

src/Attestor/StellaOps.Attestor.Types/generated/ts/tsconfig.json

@@ -0,0 +1,19 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ES2022",
+    "moduleResolution": "node",
+    "outDir": "dist",
+    "declaration": true,
+    "declarationMap": false,
+    "sourceMap": false,
+    "strict": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "skipLibCheck": true
+  },
+  "include": [
+    "index.ts",
+    "index.test.ts"
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/samples/README.md

@@ -0,0 +1,23 @@
+# StellaOps Attestation Golden Samples
+
+This directory contains deterministic JSON fixtures used across unit tests, regression checks, and documentation snippets for the Attestor predicate family.
+
+| File | Predicate | Notes |
+| --- | --- | --- |
+| `build-provenance.v1.json` | `StellaOps.BuildProvenance@1` | Mirrors SLSA provenance fields with StellaOps metadata extensions. |
+| `sbom-attestation.v1.json` | `StellaOps.SBOMAttestation@1` | Links to CycloneDX 1.6 BOM data and dependency relationships. |
+| `scan-results.v1.json` | `StellaOps.ScanResults@1` | Captures multi-type findings (vulnerability, policy) with lattice scores. |
+| `policy-evaluation.v1.json` | `StellaOps.PolicyEvaluation@1` | Documents deny verdict trace with digests for inputs and policies. |
+| `vex-attestation.v1.json` | `StellaOps.VEXAttestation@1` | Provides OpenVEX-compatible statements for the Scanner image. |
+| `risk-profile-evidence.v1.json` | `StellaOps.RiskProfileEvidence@1` | Compresses risk matrix outputs from the Risk Engine. |
+| `custom-evidence.v1.json` | `StellaOps.CustomEvidence@1` | Shows a Zastava runtime hardening checklist embedded as custom evidence. |
+
+All fixtures share the same `subject` digest (`ghcr.io/stellaops/scanner@sha256:d5f5…`) so they can be chained together inside multi-artefact verification tests. Keys are alphabetically ordered in every object to keep canonical JSON generation straightforward.
+
+When adding or updating fixtures:
+
+1. Preserve field ordering and avoid timestamps without explicit values.
+2. Update `AttestationGoldenSamplesTests.cs` to assert any new invariants.
+3. Reference the fixture in the relevant module documentation so downstream users can discover it.
+
+Run `npm run docs:attestor:validate` from the repository root to confirm fixtures, schemas, and generated SDKs remain in lock-step.

src/Attestor/StellaOps.Attestor.Types/samples/build-provenance.v1.json

@@ -0,0 +1,71 @@
+{
+  "_type": "https://in-toto.io/Statement/v1",
+  "predicate": {
+    "buildDefinition": {
+      "buildType": "https://stella-ops.org/build/docker-image@v1",
+      "builder": "stellaops://pipelines/scanner-ci",
+      "environment": {
+        "image": "ghcr.io/stellaops/buildkit:2025.10",
+        "platform": "linux/amd64",
+        "workerPool": "us-west-2/buildfarm/a"
+      },
+      "source": {
+        "configDigest": {
+          "sha256": "f135b1eb59b38c46b7c9f95abfa23d8739d9a71717f7ceebf2e0fdf75c9b8d63"
+        },
+        "entryPoint": "scanner/Dockerfile",
+        "uri": "git+https://git.stella-ops.org/stellaops/scanner.git@refs/heads/main"
+      }
+    },
+    "materials": [
+      {
+        "digest": {
+          "sha256": "61e7a7d1d0a64e788d4a32294e7255f2667ef45ef8d358b3f6262e2de3b2c13d"
+        },
+        "uri": "git+https://git.stella-ops.org/stellaops/scanner.git#src"
+      },
+      {
+        "digest": {
+          "sha256": "3f2dc5d957bbf9570da0e7af0fde61ebc9e32b0ad156bea6f3cfa4d94cda740a"
+        },
+        "uri": "oci://ghcr.io/stellaops/base-images/builder:2025.09"
+      }
+    ],
+    "metadata": {
+      "builtOn": "2025-10-29T18:22:14Z",
+      "durationSeconds": 186,
+      "invocationId": "urn:uuid:7ac7b9b4-0f6a-4ad1-9d42-9e0df7bd4a94",
+      "licenseBundle": "stellaops://licenses/enterprise@2025-10"
+    },
+    "runDetails": {
+      "arguments": [
+        "buildx",
+        "bake",
+        "--file",
+        "scanner/docker-bake.hcl",
+        "--set",
+        "sbom.mode=strict"
+      ],
+      "builderImageDigest": "sha256:6ee70a4014258f9c0a40e10b5f5a4b1c6497e5d6b9cd848771c3d79f7f0d91da",
+      "exitCode": 0,
+      "logs": [
+        {
+          "digest": {
+            "sha256": "4b4fd1f46633f475aa1ed58ec0d95af0ed3e4015d9d41fce7883c0e650f730fb"
+          },
+          "uri": "s3://attestor-logs/scanner-ci/2025-10-29/build.log"
+        }
+      ]
+    }
+  },
+  "predicateType": "StellaOps.BuildProvenance@1",
+  "predicateVersion": "1.0.0",
+  "subject": [
+    {
+      "digest": {
+        "sha256": "d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+      },
+      "name": "ghcr.io/stellaops/scanner@sha256:d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/samples/custom-evidence.v1.json

@@ -0,0 +1,48 @@
+{
+  "_type": "https://in-toto.io/Statement/v1",
+  "predicate": {
+    "contentType": "application/json",
+    "description": "Runtime hardening checklist exported from Kubernetes admission controller.",
+    "payload": {
+      "controlResults": [
+        {
+          "control": "NSA-CISA-Kubernetes-1.2.1",
+          "evidence": "pod security baseline profile enforced",
+          "status": "pass"
+        },
+        {
+          "control": "NSA-CISA-Kubernetes-1.3.4",
+          "evidence": "imagePullPolicy set to Always",
+          "status": "pass"
+        },
+        {
+          "control": "NSA-CISA-Kubernetes-1.4.2",
+          "evidence": "no container runs as privileged",
+          "status": "pass"
+        },
+        {
+          "control": "NSA-CISA-Kubernetes-1.5.1",
+          "evidence": "hostPath mounts limited to /var/run/secrets",
+          "status": "warn"
+        }
+      ],
+      "generator": "stellaops://zastava/observer@2025.10.0",
+      "scopedNamespace": "scanner-prod"
+    },
+    "schema": "https://stella-ops.org/custom/nsacisa-runtime-checklist@v1",
+    "tags": [
+      "runtime-hardening",
+      "zastava"
+    ]
+  },
+  "predicateType": "StellaOps.CustomEvidence@1",
+  "predicateVersion": "1.0.0",
+  "subject": [
+    {
+      "digest": {
+        "sha256": "d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+      },
+      "name": "ghcr.io/stellaops/scanner@sha256:d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/samples/policy-evaluation.v1.json

@@ -0,0 +1,69 @@
+{
+  "_type": "https://in-toto.io/Statement/v1",
+  "predicate": {
+    "decision": "deny",
+    "explain": {
+      "failingAssertions": [
+        {
+          "message": "critical vulnerability CVE-2025-30104 lacks mitigating VEX statement",
+          "path": "controls/critical-vulns.rego#L42"
+        },
+        {
+          "message": "policy `runtime-tls` requires TLS 1.3 or higher",
+          "path": "controls/runtime-tls.rego#L18"
+        }
+      ],
+      "inputs": {
+        "policyDigest": "sha256:73acd8cb50ea52b9b98534fada689755fbdb0a12f8bd4f6069276e7ce21a0bd8",
+        "sbomDigest": "sha256:7c8d89e9c5f7ca1be3f75653d3cb4dd511ee1f65c1b9bc606cd19c578b57e9c2",
+        "vexDigest": "sha256:72b3ead4c7de0f65a3be9a9d73b7bc2840f1494de3d1666d4010e23bb1b82768"
+      },
+      "trace": [
+        {
+          "decision": "deny",
+          "policy": "controls/critical-vulns.rego",
+          "rule": "require_vex_or_patch"
+        },
+        {
+          "decision": "warn",
+          "policy": "controls/license.rego",
+          "rule": "allow_mit_or_apache"
+        }
+      ]
+    },
+    "policyDigest": "sha256:73acd8cb50ea52b9b98534fada689755fbdb0a12f8bd4f6069276e7ce21a0bd8",
+    "policyVersion": "2025.10.0",
+    "rules": [
+      {
+        "id": "controls/critical-vulns",
+        "outcome": "deny",
+        "type": "rego"
+      },
+      {
+        "id": "controls/runtime-tls",
+        "outcome": "deny",
+        "type": "rego"
+      },
+      {
+        "id": "controls/license",
+        "outcome": "warn",
+        "type": "rego"
+      }
+    ],
+    "summary": {
+      "decision": "deny",
+      "evaluatedAt": "2025-10-29T18:24:10Z",
+      "inputDigest": "sha256:8f9047f8cb22dafeb8fff2e8e75ef4e93a005f619210d4c4282c86aa2addc81e"
+    }
+  },
+  "predicateType": "StellaOps.PolicyEvaluation@1",
+  "predicateVersion": "1.0.0",
+  "subject": [
+    {
+      "digest": {
+        "sha256": "d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+      },
+      "name": "ghcr.io/stellaops/scanner@sha256:d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/samples/risk-profile-evidence.v1.json

@@ -0,0 +1,50 @@
+{
+  "_type": "https://in-toto.io/Statement/v1",
+  "predicate": {
+    "baseline": {
+      "profile": "stellaops://risk/profiles/container-runtime@2025.10",
+      "source": "RiskEngine 4.2.0",
+      "timestamp": "2025-10-29T18:24:12Z"
+    },
+    "riskMatrix": {
+      "categories": [
+        {
+          "dimension": "attack_surface",
+          "level": "medium",
+          "rationale": "External TCP services restricted to TLS; ephemeral build pods."
+        },
+        {
+          "dimension": "supply_chain",
+          "level": "low",
+          "rationale": "All dependencies pinned with SBOM attestations."
+        },
+        {
+          "dimension": "runtime_controls",
+          "level": "medium",
+          "rationale": "Admission policy enforced; runtime drift monitoring pending rollout."
+        }
+      ]
+    },
+    "scoring": {
+      "method": "stellaops://risk/models/v2",
+      "score": 682,
+      "tier": "moderate"
+    },
+    "vectors": {
+      "cisaKevCoverage": 1.0,
+      "exploitMaturity": "poc_available",
+      "patchLatencyDays": 2,
+      "unknownServiceRatio": 0.08
+    }
+  },
+  "predicateType": "StellaOps.RiskProfileEvidence@1",
+  "predicateVersion": "1.0.0",
+  "subject": [
+    {
+      "digest": {
+        "sha256": "d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+      },
+      "name": "ghcr.io/stellaops/scanner@sha256:d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/samples/sbom-attestation.v1.json

@@ -0,0 +1,80 @@
+{
+  "_type": "https://in-toto.io/Statement/v1",
+  "predicate": {
+    "document": {
+      "bomRef": "urn:uuid:0cda40b3-4e89-4a89-8d94-65011fac1cb1",
+      "created": "2025-10-29T18:22:33Z",
+      "digest": {
+        "sha256": "7c8d89e9c5f7ca1be3f75653d3cb4dd511ee1f65c1b9bc606cd19c578b57e9c2"
+      },
+      "name": "scanner-webservice",
+      "version": "2025.10.29+build.186"
+    },
+    "packages": [
+      {
+        "bomRef": "pkg:docker/alpine@3.19.2?arch=amd64",
+        "licenses": [
+          {
+            "expression": "MIT"
+          }
+        ],
+        "name": "alpine",
+        "purl": "pkg:alpine/alpine-base@3.19.2?arch=amd64",
+        "version": "3.19.2"
+      },
+      {
+        "bomRef": "pkg:nuget/MongoDB.Driver@2.23.0",
+        "licenses": [
+          {
+            "expression": "Apache-2.0"
+          }
+        ],
+        "name": "MongoDB.Driver",
+        "purl": "pkg:nuget/MongoDB.Driver@2.23.0",
+        "version": "2.23.0"
+      },
+      {
+        "bomRef": "pkg:nuget/Serilog@3.1.0",
+        "licenses": [
+          {
+            "expression": "Apache-2.0"
+          }
+        ],
+        "name": "Serilog",
+        "purl": "pkg:nuget/Serilog@3.1.0",
+        "version": "3.1.0"
+      }
+    ],
+    "relationships": [
+      {
+        "source": "pkg:docker/alpine@3.19.2?arch=amd64",
+        "target": "pkg:nuget/MongoDB.Driver@2.23.0",
+        "type": "contains"
+      },
+      {
+        "source": "pkg:docker/alpine@3.19.2?arch=amd64",
+        "target": "pkg:nuget/Serilog@3.1.0",
+        "type": "contains"
+      }
+    ],
+    "sbomFormat": "CycloneDX",
+    "sbomSpecVersion": "1.6.0",
+    "summary": {
+      "componentCount": 143,
+      "dependencyEdges": 212,
+      "metadataDigest": {
+        "sha256": "ba7a324b42d9da408d6c03119f6355bf25cb9f7e1a23355b9ab29cbe588b6e9f"
+      }
+    }
+  },
+  "predicateType": "StellaOps.SBOMAttestation@1",
+  "predicateVersion": "1.0.0",
+  "subject": [
+    {
+      "digest": {
+        "sha256": "d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+      },
+      "name": "ghcr.io/stellaops/scanner@sha256:d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/samples/scan-results.v1.json

@@ -0,0 +1,102 @@
+{
+  "_type": "https://in-toto.io/Statement/v1",
+  "predicate": {
+    "artifacts": [
+      {
+        "digest": {
+          "sha256": "d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+        },
+        "name": "ghcr.io/stellaops/scanner:2025.10.29",
+        "sbomRef": "urn:uuid:0cda40b3-4e89-4a89-8d94-65011fac1cb1"
+      }
+    ],
+    "environment": {
+      "platform": "linux/amd64",
+      "runtime": "stellaops/scanner-worker@2025.10",
+      "tenant": "acme-industries"
+    },
+    "findings": [
+      {
+        "analysis": {
+          "evidence": "library reachable from entry trace",
+          "exploitability": "high",
+          "normalizedScore": 9.1
+        },
+        "id": "CVE-2025-30104",
+        "package": {
+          "name": "openssl",
+          "purl": "pkg:apk/alpine/openssl@3.2.2-r2",
+          "version": "3.2.2-r2"
+        },
+        "references": [
+          "https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-30104"
+        ],
+        "severity": "critical",
+        "status": "affected",
+        "type": "vulnerability"
+      },
+      {
+        "analysis": {
+          "evidence": "policy requires minimum TLS 1.3 support",
+          "exploitability": "medium",
+          "normalizedScore": 6.3
+        },
+        "id": "STELLAOPS-POLICY-2025-0007",
+        "package": {
+          "name": "runtime-config",
+          "purl": "pkg:generic/config/runtime@2025.10.29",
+          "version": "2025.10.29"
+        },
+        "references": [
+          "stellaops://policy/controls/tls-min-version"
+        ],
+        "severity": "medium",
+        "status": "affected",
+        "type": "policy"
+      },
+      {
+        "analysis": {
+          "evidence": "package unused according to entry trace",
+          "exploitability": "none",
+          "normalizedScore": 0.0
+        },
+        "id": "CVE-2023-99999",
+        "package": {
+          "name": "curl",
+          "purl": "pkg:apk/alpine/curl@8.0.1-r0",
+          "version": "8.0.1-r0"
+        },
+        "references": [
+          "https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-99999"
+        ],
+        "severity": "low",
+        "status": "not_affected",
+        "type": "vulnerability"
+      }
+    ],
+    "scanner": {
+      "name": "StellaOps.Scanner",
+      "rulesCommit": "a6dfc9b1f4e64d5e82b6f54b0f2dd1e8b13d1f8a",
+      "version": "2025.10.0"
+    },
+    "summary": {
+      "affected": 2,
+      "critical": 1,
+      "high": 0,
+      "info": 7,
+      "low": 1,
+      "medium": 1,
+      "timestamp": "2025-10-29T18:24:07Z"
+    }
+  },
+  "predicateType": "StellaOps.ScanResults@1",
+  "predicateVersion": "1.0.0",
+  "subject": [
+    {
+      "digest": {
+        "sha256": "d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+      },
+      "name": "ghcr.io/stellaops/scanner@sha256:d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/samples/vex-attestation.v1.json

@@ -0,0 +1,67 @@
+{
+  "_type": "https://in-toto.io/Statement/v1",
+  "predicate": {
+    "context": {
+      "generator": "stellaops://vex/excititor@2025.10",
+      "issuedAt": "2025-10-30T04:05:19Z",
+      "supplier": "StellaOps Security Research"
+    },
+    "statements": [
+      {
+        "analysis": {
+          "detail": "Package not reachable from configured entry trace.",
+          "impact": "not_affected_usage_scope",
+          "lastReviewed": "2025-10-30T03:50:02Z"
+        },
+        "expires": "2026-01-30T00:00:00Z",
+        "justification": "vex:component_not_present",
+        "product": {
+          "cpe": "cpe:2.3:a:stellaops:scanner_webservice:2025.10.29:*:*:*:*:*:*:*",
+          "purl": "pkg:docker/ghcr.io/stellaops/scanner@sha256:d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+        },
+        "status": "not_affected",
+        "subcomponents": [
+          {
+            "path": "/app/bin/StellaOps.Scanner.dll",
+            "ref": "pkg:nuget/Serilog@3.1.0"
+          }
+        ],
+        "timestamp": "2025-10-30T04:05:19Z",
+        "vulnerability": "CVE-2025-21901"
+      },
+      {
+        "analysis": {
+          "detail": "Patched in base image digest specified in SBOM.",
+          "impact": "no_known_exploit",
+          "lastReviewed": "2025-10-29T23:11:44Z"
+        },
+        "expires": "2025-12-15T00:00:00Z",
+        "justification": "vex:fix_available",
+        "product": {
+          "cpe": "cpe:2.3:a:stellaops:scanner_webservice:2025.10.29:*:*:*:*:*:*:*",
+          "purl": "pkg:docker/ghcr.io/stellaops/scanner@sha256:d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+        },
+        "status": "affected",
+        "subcomponents": [
+          {
+            "path": "/usr/lib/libssl.so.3",
+            "ref": "pkg:apk/alpine/openssl@3.2.2-r2"
+          }
+        ],
+        "timestamp": "2025-10-29T23:09:31Z",
+        "vulnerability": "CVE-2025-30104"
+      }
+    ],
+    "vexVersion": "OpenVEX-1.0.0"
+  },
+  "predicateType": "StellaOps.VEXAttestation@1",
+  "predicateVersion": "1.0.0",
+  "subject": [
+    {
+      "digest": {
+        "sha256": "d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+      },
+      "name": "ghcr.io/stellaops/scanner@sha256:d5f5e54d1e1a4c3c7b18961ea7cadb88ec0a93a9f2f40f0e823d9184c83e4d72"
+    }
+  ]
+}

src/Attestor/StellaOps.Attestor.Types/schemas/attestation-common.v1.schema.json

@@ -0,0 +1,372 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://schemas.stella-ops.org/attestations/common/v1",
+  "title": "StellaOps Attestation Common Definitions v1",
+  "type": "object",
+  "description": "Shared schema components reused across StellaOps attestation predicates.",
+  "$defs": {
+    "schemaVersion": {
+      "type": "string",
+      "pattern": "^1\\.0\\.\\d+$",
+      "description": "Semantic version identifier for predicate schema revisions. Initial release is 1.0.x."
+    },
+    "digestSet": {
+      "type": "object",
+      "description": "Map of hashing algorithm to lowercase hexadecimal digest.",
+      "minProperties": 1,
+      "maxProperties": 4,
+      "patternProperties": {
+        "^[A-Za-z0-9]+$": {
+          "type": "string",
+          "pattern": "^[a-f0-9]{32,128}$"
+        }
+      },
+      "additionalProperties": false
+    },
+    "subject": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": [
+        "subjectKind",
+        "digest"
+      ],
+      "properties": {
+        "subjectKind": {
+          "type": "string",
+          "enum": [
+            "container-image",
+            "sbom",
+            "scan-report",
+            "policy-report",
+            "vex-statement",
+            "risk-profile",
+            "artifact"
+          ]
+        },
+        "name": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 512
+        },
+        "uri": {
+          "type": "string",
+          "format": "uri"
+        },
+        "digest": {
+          "$ref": "#/$defs/digestSet"
+        },
+        "annotations": {
+          "type": "object",
+          "additionalProperties": {
+            "type": "string",
+            "maxLength": 256
+          }
+        },
+        "imageDigest": {
+          "type": "string",
+          "pattern": "^sha256:[a-f0-9]{64}$"
+        },
+        "mediaType": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "sizeBytes": {
+          "type": "integer",
+          "minimum": 0
+        }
+      }
+    },
+    "subjectList": {
+      "type": "array",
+      "minItems": 1,
+      "uniqueItems": true,
+      "items": {
+        "$ref": "#/$defs/subject"
+      }
+    },
+    "issuer": {
+      "type": "object",
+      "description": "Identity metadata describing the signer of the attestation predicate.",
+      "additionalProperties": false,
+      "required": [
+        "issuerType",
+        "id",
+        "signingKey"
+      ],
+      "properties": {
+        "issuerType": {
+          "type": "string",
+          "enum": [
+            "service",
+            "user",
+            "automation",
+            "device"
+          ]
+        },
+        "id": {
+          "type": "string",
+          "minLength": 4,
+          "maxLength": 256
+        },
+        "tenantId": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 128
+        },
+        "displayName": {
+          "type": "string",
+          "maxLength": 256
+        },
+        "email": {
+          "type": "string",
+          "format": "email"
+        },
+        "workload": {
+          "type": "object",
+          "additionalProperties": false,
+          "required": [
+            "service"
+          ],
+          "properties": {
+            "service": {
+              "type": "string",
+              "maxLength": 128
+            },
+            "cluster": {
+              "type": "string",
+              "maxLength": 128
+            },
+            "namespace": {
+              "type": "string",
+              "maxLength": 128
+            },
+            "region": {
+              "type": "string",
+              "maxLength": 64
+            }
+          }
+        },
+        "signingKey": {
+          "type": "object",
+          "additionalProperties": false,
+          "required": [
+            "keyId",
+            "mode",
+            "algorithm"
+          ],
+          "properties": {
+            "keyId": {
+              "type": "string",
+              "maxLength": 256
+            },
+            "mode": {
+              "type": "string",
+              "enum": [
+                "keyless",
+                "kms",
+                "hsm",
+                "fido2",
+                "offline"
+              ]
+            },
+            "algorithm": {
+              "type": "string",
+              "maxLength": 64
+            },
+            "issuer": {
+              "type": "string",
+              "maxLength": 256
+            },
+            "certificateChain": {
+              "type": "array",
+              "maxItems": 5,
+              "items": {
+                "type": "string",
+                "minLength": 1
+              }
+            },
+            "proof": {
+              "type": "object",
+              "additionalProperties": false,
+              "properties": {
+                "fulcioIdentity": {
+                  "type": "string",
+                  "maxLength": 256
+                },
+                "hardwareClass": {
+                  "type": "string",
+                  "maxLength": 128
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "material": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": [
+        "uri"
+      ],
+      "properties": {
+        "uri": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 512
+        },
+        "digest": {
+          "$ref": "#/$defs/digestSet"
+        },
+        "mediaType": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "role": {
+          "type": "string",
+          "maxLength": 64
+        },
+        "annotations": {
+          "type": "object",
+          "additionalProperties": {
+            "type": "string",
+            "maxLength": 128
+          }
+        }
+      }
+    },
+    "transparencyLog": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": [
+        "logId",
+        "logUrl",
+        "uuid"
+      ],
+      "properties": {
+        "logId": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "logUrl": {
+          "type": "string",
+          "format": "uri"
+        },
+        "uuid": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "index": {
+          "type": "integer",
+          "minimum": 0
+        },
+        "checkpoint": {
+          "type": "object",
+          "additionalProperties": false,
+          "required": [
+            "origin",
+            "size",
+            "rootHash",
+            "timestamp"
+          ],
+          "properties": {
+            "origin": {
+              "type": "string",
+              "maxLength": 128
+            },
+            "size": {
+              "type": "integer",
+              "minimum": 0
+            },
+            "rootHash": {
+              "type": "string",
+              "pattern": "^[A-Za-z0-9\\+/=]{16,128}$"
+            },
+            "timestamp": {
+              "type": "string",
+              "format": "date-time"
+            }
+          }
+        },
+        "witnessed": {
+          "type": "boolean"
+        }
+      }
+    },
+    "transparencyLogList": {
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/transparencyLog"
+      }
+    },
+    "policyContext": {
+      "type": "object",
+      "additionalProperties": false,
+      "properties": {
+        "policyId": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "policyVersion": {
+          "type": "string",
+          "maxLength": 32
+        },
+        "revisionDigest": {
+          "$ref": "#/$defs/digestSet"
+        },
+        "mode": {
+          "type": "string",
+          "enum": [
+            "enforce",
+            "dry-run"
+          ]
+        }
+      }
+    },
+    "vexStatus": {
+      "type": "string",
+      "enum": [
+        "not_affected",
+        "affected",
+        "fixed",
+        "under_investigation"
+      ]
+    },
+    "severity": {
+      "type": "string",
+      "enum": [
+        "critical",
+        "high",
+        "medium",
+        "low",
+        "informational"
+      ]
+    },
+    "explainReference": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": [
+        "id",
+        "type"
+      ],
+      "properties": {
+        "id": {
+          "type": "string",
+          "maxLength": 128
+        },
+        "type": {
+          "type": "string",
+          "enum": [
+            "rule",
+            "step",
+            "binding"
+          ]
+        },
+        "message": {
+          "type": "string",
+          "maxLength": 2048
+        }
+      }
+    }
+  }
+}

src/Attestor/StellaOps.Attestor.Types/schemas/stellaops-build-provenance.v1.schema.json

@@ -0,0 +1,160 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://stella-ops.org/schemas/attestor/stellaops-build-provenance.v1.json",
+  "title": "Build provenance evidence capturing builder inputs and outputs.",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schemaVersion",
+    "buildType",
+    "builder",
+    "materials",
+    "metadata"
+  ],
+  "properties": {
+    "schemaVersion": {
+      "type": "string",
+      "const": "StellaOps.BuildProvenance@1",
+      "description": "Schema version identifier."
+    },
+    "buildType": {
+      "type": "string",
+      "description": "Build type or workflow identifier."
+    },
+    "builder": {
+      "$ref": "#/$defs/BuilderIdentity",
+      "description": "Builder identity metadata."
+    },
+    "materials": {
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/MaterialReference"
+      },
+      "minItems": 1,
+      "description": "Materials consumed during the build."
+    },
+    "metadata": {
+      "$ref": "#/$defs/BuildMetadata",
+      "description": "Build metadata information."
+    },
+    "environment": {
+      "$ref": "#/$defs/EnvironmentMetadata",
+      "description": "Optional environment details for the build context."
+    }
+  },
+  "$defs": {
+    "BuilderIdentity": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Identifies the builder that produced the artifact.",
+      "required": [
+        "id"
+      ],
+      "properties": {
+        "id": {
+          "type": "string",
+          "description": "Unique builder identity (URI or name)."
+        },
+        "version": {
+          "type": "string",
+          "description": "Builder version identifier."
+        },
+        "platform": {
+          "type": "string",
+          "description": "Execution platform for the build."
+        }
+      }
+    },
+    "DigestReference": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Normalized digest entry containing algorithm and value.",
+      "required": [
+        "algorithm",
+        "value"
+      ],
+      "properties": {
+        "algorithm": {
+          "type": "string",
+          "description": "Digest algorithm identifier (e.g., sha256)."
+        },
+        "value": {
+          "type": "string",
+          "pattern": "^[A-Fa-f0-9]{64}$",
+          "description": "Hex-encoded digest value."
+        }
+      }
+    },
+    "MaterialReference": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Inputs used during build or analysis.",
+      "required": [
+        "uri",
+        "digests"
+      ],
+      "properties": {
+        "uri": {
+          "type": "string",
+          "description": "Material location or identifier."
+        },
+        "digests": {
+          "type": "array",
+          "items": {
+            "$ref": "#/$defs/DigestReference"
+          },
+          "minItems": 1,
+          "description": "Digests associated with the material."
+        },
+        "note": {
+          "type": "string",
+          "description": "Optional annotation about the material."
+        }
+      }
+    },
+    "BuildMetadata": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Metadata describing build timing and reproducibility.",
+      "required": [
+        "buildStartedOn",
+        "buildFinishedOn"
+      ],
+      "properties": {
+        "buildStartedOn": {
+          "type": "string",
+          "format": "date-time",
+          "description": "UTC timestamp for build start."
+        },
+        "buildFinishedOn": {
+          "type": "string",
+          "format": "date-time",
+          "description": "UTC timestamp for build completion."
+        },
+        "reproducible": {
+          "type": "boolean",
+          "description": "Indicates whether the build is reproducible."
+        },
+        "buildInvocationId": {
+          "type": "string",
+          "description": "Unique identifier for the build invocation."
+        }
+      }
+    },
+    "EnvironmentMetadata": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Optional environment metadata for build context.",
+      "properties": {
+        "platform": {
+          "type": "string",
+          "description": "Execution platform or runtime."
+        },
+        "imageDigest": {
+          "$ref": "#/$defs/DigestReference",
+          "description": "Digest for the environment image."
+        }
+      }
+    }
+  }
+}

src/Attestor/StellaOps.Attestor.Types/schemas/stellaops-custom-evidence.v1.schema.json

@@ -0,0 +1,63 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://stella-ops.org/schemas/attestor/stellaops-custom-evidence.v1.json",
+  "title": "Generic evidence payload for bespoke attestations.",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schemaVersion",
+    "subjectDigest",
+    "kind",
+    "generatedAt"
+  ],
+  "properties": {
+    "schemaVersion": {
+      "type": "string",
+      "const": "StellaOps.CustomEvidence@1",
+      "description": "Schema version identifier."
+    },
+    "subjectDigest": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$",
+      "description": "Artifact digest this evidence references."
+    },
+    "kind": {
+      "type": "string",
+      "description": "Custom evidence kind identifier."
+    },
+    "generatedAt": {
+      "type": "string",
+      "format": "date-time",
+      "description": "Timestamp when the evidence was generated."
+    },
+    "properties": {
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/CustomProperty"
+      },
+      "minItems": 0,
+      "description": "Optional key/value properties for additional context."
+    }
+  },
+  "$defs": {
+    "CustomProperty": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Key/value entry for custom evidence.",
+      "required": [
+        "key",
+        "value"
+      ],
+      "properties": {
+        "key": {
+          "type": "string",
+          "description": "Property key."
+        },
+        "value": {
+          "type": "string",
+          "description": "Property value serialized as string."
+        }
+      }
+    }
+  }
+}

src/Attestor/StellaOps.Attestor.Types/schemas/stellaops-policy-evaluation.v1.schema.json

@@ -0,0 +1,100 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://stella-ops.org/schemas/attestor/stellaops-policy-evaluation.v1.json",
+  "title": "Policy evaluation outcome for an artifact.",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schemaVersion",
+    "subjectDigest",
+    "policyVersion",
+    "evaluatedAt",
+    "outcome",
+    "decisions"
+  ],
+  "properties": {
+    "schemaVersion": {
+      "type": "string",
+      "const": "StellaOps.PolicyEvaluation@1",
+      "description": "Schema version identifier."
+    },
+    "subjectDigest": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$",
+      "description": "Artifact digest that was evaluated."
+    },
+    "policyVersion": {
+      "type": "string",
+      "description": "Policy bundle version applied."
+    },
+    "evaluatedAt": {
+      "type": "string",
+      "format": "date-time",
+      "description": "Timestamp when policy evaluation was executed."
+    },
+    "outcome": {
+      "$ref": "#/$defs/PolicyOutcome",
+      "description": "Overall evaluation outcome."
+    },
+    "decisions": {
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/PolicyDecision"
+      },
+      "minItems": 0,
+      "description": "Detailed rule-level decisions."
+    }
+  },
+  "$defs": {
+    "PolicyOutcome": {
+      "type": "string",
+      "description": "Policy evaluation outcome values.",
+      "enum": [
+        "pass",
+        "fail",
+        "waived"
+      ]
+    },
+    "PolicyEffect": {
+      "type": "string",
+      "description": "Policy rule effect values.",
+      "enum": [
+        "allow",
+        "deny",
+        "warn"
+      ]
+    },
+    "PolicyDecision": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Outcome of an individual policy rule evaluation.",
+      "required": [
+        "policyId",
+        "ruleId",
+        "effect"
+      ],
+      "properties": {
+        "policyId": {
+          "type": "string",
+          "description": "Policy identifier."
+        },
+        "ruleId": {
+          "type": "string",
+          "description": "Specific rule identifier."
+        },
+        "effect": {
+          "$ref": "#/$defs/PolicyEffect",
+          "description": "Resulting effect of the rule."
+        },
+        "reason": {
+          "type": "string",
+          "description": "Explanation for the effect."
+        },
+        "remediation": {
+          "type": "string",
+          "description": "Suggested remediation action."
+        }
+      }
+    }
+  }
+}

src/Attestor/StellaOps.Attestor.Types/schemas/stellaops-risk-profile.v1.schema.json

@@ -0,0 +1,88 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://stella-ops.org/schemas/attestor/stellaops-risk-profile.v1.json",
+  "title": "Risk scoring evidence summarising exposure for an artifact.",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schemaVersion",
+    "subjectDigest",
+    "generatedAt",
+    "riskScore",
+    "riskLevel",
+    "factors"
+  ],
+  "properties": {
+    "schemaVersion": {
+      "type": "string",
+      "const": "StellaOps.RiskProfileEvidence@1",
+      "description": "Schema version identifier."
+    },
+    "subjectDigest": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$",
+      "description": "Artifact digest that the risk profile describes."
+    },
+    "generatedAt": {
+      "type": "string",
+      "format": "date-time",
+      "description": "Timestamp when scoring was performed."
+    },
+    "riskScore": {
+      "type": "number",
+      "minimum": 0,
+      "maximum": 100,
+      "description": "Normalized risk score between 0 and 100."
+    },
+    "riskLevel": {
+      "$ref": "#/$defs/RiskLevel",
+      "description": "Risk level classification."
+    },
+    "factors": {
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/RiskFactor"
+      },
+      "minItems": 0,
+      "description": "Factors contributing to the total risk."
+    }
+  },
+  "$defs": {
+    "RiskLevel": {
+      "type": "string",
+      "description": "Risk level indicators.",
+      "enum": [
+        "critical",
+        "high",
+        "medium",
+        "low",
+        "informational"
+      ]
+    },
+    "RiskFactor": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Factor contributing to risk calculation.",
+      "required": [
+        "name",
+        "weight"
+      ],
+      "properties": {
+        "name": {
+          "type": "string",
+          "description": "Risk factor name."
+        },
+        "weight": {
+          "type": "number",
+          "minimum": 0,
+          "maximum": 1,
+          "description": "Relative weight between 0 and 1."
+        },
+        "description": {
+          "type": "string",
+          "description": "Additional context for the factor."
+        }
+      }
+    }
+  }
+}

src/Attestor/StellaOps.Attestor.Types/schemas/stellaops-sbom-attestation.v1.schema.json

@@ -0,0 +1,107 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://stella-ops.org/schemas/attestor/stellaops-sbom-attestation.v1.json",
+  "title": "SBOM attestation linking an SBOM document to an artifact.",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schemaVersion",
+    "subjectDigest",
+    "sbomFormat",
+    "sbomDigest",
+    "componentCount"
+  ],
+  "properties": {
+    "schemaVersion": {
+      "type": "string",
+      "const": "StellaOps.SBOMAttestation@1",
+      "description": "Schema version identifier."
+    },
+    "subjectDigest": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$",
+      "description": "Artifact digest referenced by the SBOM."
+    },
+    "sbomFormat": {
+      "$ref": "#/$defs/SbomFormat",
+      "description": "SBOM format identifier."
+    },
+    "sbomDigest": {
+      "$ref": "#/$defs/DigestReference",
+      "description": "Digest of the SBOM document."
+    },
+    "sbomUri": {
+      "type": "string",
+      "description": "Location where the SBOM can be retrieved."
+    },
+    "componentCount": {
+      "type": "integer",
+      "minimum": 0,
+      "description": "Number of components described by the SBOM."
+    },
+    "packages": {
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/SbomPackage"
+      },
+      "minItems": 0,
+      "description": "Optional package listing for quick lookups."
+    }
+  },
+  "$defs": {
+    "SbomFormat": {
+      "type": "string",
+      "description": "Supported SBOM formats.",
+      "enum": [
+        "CycloneDX-1.6",
+        "SBOM-3.0.0"
+      ]
+    },
+    "DigestReference": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Normalized digest entry containing algorithm and value.",
+      "required": [
+        "algorithm",
+        "value"
+      ],
+      "properties": {
+        "algorithm": {
+          "type": "string",
+          "description": "Digest algorithm identifier (e.g., sha256)."
+        },
+        "value": {
+          "type": "string",
+          "pattern": "^[A-Fa-f0-9]{64}$",
+          "description": "Hex-encoded digest value."
+        }
+      }
+    },
+    "SbomPackage": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "SBOM package entry.",
+      "required": [
+        "purl"
+      ],
+      "properties": {
+        "purl": {
+          "type": "string",
+          "description": "Package URL reference."
+        },
+        "version": {
+          "type": "string",
+          "description": "Resolved package version."
+        },
+        "licenses": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          },
+          "minItems": 1,
+          "description": "Associated license identifiers."
+        }
+      }
+    }
+  }
+}

src/Attestor/StellaOps.Attestor.Types/schemas/stellaops-scan-results.v1.schema.json

@@ -0,0 +1,122 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://stella-ops.org/schemas/attestor/stellaops-scan-results.v1.json",
+  "title": "Scanner findings for an artifact at a point in time.",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schemaVersion",
+    "subjectDigest",
+    "scannerName",
+    "scannerVersion",
+    "generatedAt",
+    "findings"
+  ],
+  "properties": {
+    "schemaVersion": {
+      "type": "string",
+      "const": "StellaOps.ScanResults@1",
+      "description": "Schema version identifier."
+    },
+    "subjectDigest": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$",
+      "description": "Artifact digest that was scanned."
+    },
+    "scannerName": {
+      "type": "string",
+      "description": "Name of the scanner that produced the findings."
+    },
+    "scannerVersion": {
+      "type": "string",
+      "description": "Scanner version string."
+    },
+    "generatedAt": {
+      "type": "string",
+      "format": "date-time",
+      "description": "Timestamp when the scan results were generated."
+    },
+    "findings": {
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/ScanFinding"
+      },
+      "minItems": 0,
+      "description": "List of findings captured during the scan."
+    }
+  },
+  "$defs": {
+    "Severity": {
+      "type": "string",
+      "description": "Finding severity scale.",
+      "enum": [
+        "critical",
+        "high",
+        "medium",
+        "low",
+        "info"
+      ]
+    },
+    "FindingStatus": {
+      "type": "string",
+      "description": "Finding lifecycle status.",
+      "enum": [
+        "detected",
+        "confirmed",
+        "fixed",
+        "not_affected"
+      ]
+    },
+    "ScanFinding": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Individual finding from a scan.",
+      "required": [
+        "id",
+        "severity",
+        "status",
+        "packageName"
+      ],
+      "properties": {
+        "id": {
+          "type": "string",
+          "description": "Scanner-issued identifier."
+        },
+        "severity": {
+          "$ref": "#/$defs/Severity",
+          "description": "Severity classification."
+        },
+        "status": {
+          "$ref": "#/$defs/FindingStatus",
+          "description": "Lifecycle state of the finding."
+        },
+        "packageName": {
+          "type": "string",
+          "description": "Affected package name."
+        },
+        "packageVersion": {
+          "type": "string",
+          "description": "Affected package version."
+        },
+        "cvssScore": {
+          "type": "number",
+          "minimum": 0,
+          "maximum": 10,
+          "description": "CVSS base score if available."
+        },
+        "description": {
+          "type": "string",
+          "description": "Human-readable description of the finding."
+        },
+        "references": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          },
+          "minItems": 1,
+          "description": "Reference links or advisory identifiers."
+        }
+      }
+    }
+  }
+}

src/Attestor/StellaOps.Attestor.Types/schemas/stellaops-vex-attestation.v1.schema.json

@@ -0,0 +1,95 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://stella-ops.org/schemas/attestor/stellaops-vex-attestation.v1.json",
+  "title": "VEX attestation describing vulnerability status for an artifact.",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "schemaVersion",
+    "subjectDigest",
+    "generatedAt",
+    "statements"
+  ],
+  "properties": {
+    "schemaVersion": {
+      "type": "string",
+      "const": "StellaOps.VEXAttestation@1",
+      "description": "Schema version identifier."
+    },
+    "subjectDigest": {
+      "type": "string",
+      "pattern": "^sha256:[A-Fa-f0-9]{64}$",
+      "description": "Artifact digest covered by the VEX statements."
+    },
+    "generatedAt": {
+      "type": "string",
+      "format": "date-time",
+      "description": "Timestamp when the VEX attestation was generated."
+    },
+    "statements": {
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/VexStatement"
+      },
+      "minItems": 1,
+      "description": "Collection of VEX statements."
+    }
+  },
+  "$defs": {
+    "VexStatus": {
+      "type": "string",
+      "description": "VEX statement status values.",
+      "enum": [
+        "not_affected",
+        "affected",
+        "under_investigation",
+        "fixed"
+      ]
+    },
+    "VexStatement": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Single VEX statement covering a vulnerability and status.",
+      "required": [
+        "vulnerabilityId",
+        "status",
+        "timestamp"
+      ],
+      "properties": {
+        "vulnerabilityId": {
+          "type": "string",
+          "description": "Vulnerability identifier (e.g., CVE)."
+        },
+        "status": {
+          "$ref": "#/$defs/VexStatus",
+          "description": "VEX status value."
+        },
+        "timestamp": {
+          "type": "string",
+          "format": "date-time",
+          "description": "UTC timestamp for statement issuance."
+        },
+        "justification": {
+          "type": "string",
+          "description": "Justification for the chosen status."
+        },
+        "impactStatement": {
+          "type": "string",
+          "description": "Impact description for affected systems."
+        },
+        "actionStatement": {
+          "type": "string",
+          "description": "Recommended remediation or action."
+        },
+        "references": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          },
+          "minItems": 1,
+          "description": "Supporting reference URLs."
+        }
+      }
+    }
+  }
+}

src/Attestor/StellaOps.Attestor.Verify/AttestorVerificationEngine.cs

@@ -0,0 +1,960 @@
+using System.Buffers.Binary;
+using System.Collections.Immutable;
+using System.IO;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Security.Cryptography.X509Certificates;
+using System.Text;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using StellaOps.Attestor.Core.Options;
+using StellaOps.Attestor.Core.Storage;
+using StellaOps.Attestor.Core.Submission;
+using StellaOps.Attestor.Core.Verification;
+
+namespace StellaOps.Attestor.Verify;
+
+public sealed class AttestorVerificationEngine : IAttestorVerificationEngine
+{
+    private readonly IDsseCanonicalizer _canonicalizer;
+    private readonly AttestorOptions _options;
+    private readonly ILogger<AttestorVerificationEngine> _logger;
+
+    public AttestorVerificationEngine(
+        IDsseCanonicalizer canonicalizer,
+        IOptions<AttestorOptions> options,
+        ILogger<AttestorVerificationEngine> logger)
+    {
+        _canonicalizer = canonicalizer ?? throw new ArgumentNullException(nameof(canonicalizer));
+        _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public async Task<VerificationReport> EvaluateAsync(
+        AttestorEntry entry,
+        AttestorSubmissionRequest.SubmissionBundle? bundle,
+        DateTimeOffset evaluationTime,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(entry);
+
+        var signatureIssuer = await EvaluateSignatureAndIssuerAsync(entry, bundle, cancellationToken).ConfigureAwait(false);
+        var freshness = EvaluateFreshness(entry, evaluationTime);
+        var transparency = EvaluateTransparency(entry);
+        var policy = EvaluatePolicy(entry, signatureIssuer.Signatures, signatureIssuer.Issuer, freshness, transparency, bundle is not null);
+
+        return new VerificationReport(policy, signatureIssuer.Issuer, freshness, signatureIssuer.Signatures, transparency);
+    }
+
+    private async Task<(SignatureEvaluationResult Signatures, IssuerEvaluationResult Issuer)> EvaluateSignatureAndIssuerAsync(
+        AttestorEntry entry,
+        AttestorSubmissionRequest.SubmissionBundle? bundle,
+        CancellationToken cancellationToken)
+    {
+        var signatureIssues = new List<string>();
+        var issuerIssues = new List<string>();
+
+        if (bundle is null)
+        {
+            var issuerFromEntry = entry.SignerIdentity;
+            return (
+                new SignatureEvaluationResult
+                {
+                    Status = VerificationSectionStatus.Skipped,
+                    BundleProvided = false,
+                    TotalSignatures = 0,
+                    VerifiedSignatures = 0,
+                    RequiredSignatures = Math.Max(1, _options.Verification.MinimumSignatures),
+                    Issues = Array.Empty<string>()
+                },
+                new IssuerEvaluationResult
+                {
+                    Status = VerificationSectionStatus.Skipped,
+                    Mode = issuerFromEntry.Mode ?? "unknown",
+                    Issuer = issuerFromEntry.Issuer,
+                    SubjectAlternativeName = issuerFromEntry.SubjectAlternativeName,
+                    KeyId = issuerFromEntry.KeyId,
+                    Issues = Array.Empty<string>()
+                });
+        }
+
+        var canonicalRequest = new AttestorSubmissionRequest
+        {
+            Bundle = bundle,
+            Meta = new AttestorSubmissionRequest.SubmissionMeta
+            {
+                Artifact = new AttestorSubmissionRequest.ArtifactInfo
+                {
+                    Sha256 = entry.Artifact.Sha256,
+                    Kind = entry.Artifact.Kind,
+                    ImageDigest = entry.Artifact.ImageDigest,
+                    SubjectUri = entry.Artifact.SubjectUri
+                },
+                BundleSha256 = entry.BundleSha256
+            }
+        };
+
+        byte[] canonicalBundle;
+        try
+        {
+            canonicalBundle = await _canonicalizer.CanonicalizeAsync(canonicalRequest, cancellationToken).ConfigureAwait(false);
+        }
+        catch (Exception ex) when (ex is CryptographicException or FormatException)
+        {
+            signatureIssues.Add("bundle_canonicalize_failed");
+            _logger.LogWarning(ex, "Failed to canonicalize DSSE bundle for {Uuid}", entry.RekorUuid);
+
+            var issuerFromEntry = entry.SignerIdentity;
+            return (
+                new SignatureEvaluationResult
+                {
+                    Status = VerificationSectionStatus.Fail,
+                    BundleProvided = true,
+                    TotalSignatures = bundle.Dsse.Signatures.Count,
+                    VerifiedSignatures = 0,
+                    RequiredSignatures = Math.Max(1, _options.Verification.MinimumSignatures),
+                    Issues = signatureIssues.ToArray()
+                },
+                new IssuerEvaluationResult
+                {
+                    Status = VerificationSectionStatus.Warn,
+                    Mode = issuerFromEntry.Mode ?? (bundle.Mode ?? "unknown"),
+                    Issuer = issuerFromEntry.Issuer,
+                    SubjectAlternativeName = issuerFromEntry.SubjectAlternativeName,
+                    KeyId = issuerFromEntry.KeyId,
+                    Issues = new[] { "issuer_verification_skipped" }
+                });
+        }
+
+        var computedHash = Convert.ToHexString(SHA256.HashData(canonicalBundle)).ToLowerInvariant();
+        if (!string.Equals(computedHash, entry.BundleSha256, StringComparison.OrdinalIgnoreCase))
+        {
+            signatureIssues.Add("bundle_hash_mismatch");
+        }
+
+        var mode = (entry.SignerIdentity.Mode ?? bundle.Mode ?? "unknown").ToLowerInvariant();
+        var requiredSignatures = Math.Max(1, _options.Verification.MinimumSignatures);
+        var totalSignatures = bundle.Dsse.Signatures.Count;
+        var verifiedSignatures = 0;
+        string? subjectAlternativeName = null;
+
+        if (!TryDecodeBase64(bundle.Dsse.PayloadBase64, out var payloadBytes))
+        {
+            signatureIssues.Add("bundle_payload_invalid_base64");
+
+            return (
+                new SignatureEvaluationResult
+                {
+                    Status = VerificationSectionStatus.Fail,
+                    BundleProvided = true,
+                    TotalSignatures = bundle.Dsse.Signatures.Count,
+                    VerifiedSignatures = 0,
+                    RequiredSignatures = requiredSignatures,
+                    Issues = signatureIssues.ToArray()
+                },
+                new IssuerEvaluationResult
+                {
+                    Status = VerificationSectionStatus.Warn,
+                    Mode = mode,
+                    Issuer = entry.SignerIdentity.Issuer,
+                    SubjectAlternativeName = entry.SignerIdentity.SubjectAlternativeName,
+                    KeyId = entry.SignerIdentity.KeyId,
+                    Issues = issuerIssues.ToArray()
+                });
+        }
+
+        var preAuth = ComputePreAuthEncoding(bundle.Dsse.PayloadType, payloadBytes);
+
+        switch (mode)
+        {
+            case "kms":
+                verifiedSignatures = EvaluateKmsSignature(bundle, preAuth, signatureIssues, issuerIssues);
+                break;
+
+            case "keyless":
+                var keylessResult = EvaluateKeylessSignature(entry, bundle, preAuth, signatureIssues, issuerIssues);
+                verifiedSignatures = keylessResult.VerifiedSignatures;
+                subjectAlternativeName = keylessResult.SubjectAlternativeName;
+                break;
+
+            default:
+                issuerIssues.Add(string.IsNullOrWhiteSpace(mode) ? "signer_mode_unknown" : $"signer_mode_unsupported:{mode}");
+                break;
+        }
+
+        var signatureStatus = DetermineSignatureStatus(signatureIssues, verifiedSignatures, requiredSignatures, totalSignatures);
+        var issuerStatus = DetermineIssuerStatus(issuerIssues, mode, verifiedSignatures > 0);
+
+        return (
+            new SignatureEvaluationResult
+            {
+                Status = signatureStatus,
+                BundleProvided = true,
+                TotalSignatures = totalSignatures,
+                VerifiedSignatures = verifiedSignatures,
+                RequiredSignatures = requiredSignatures,
+                Issues = signatureIssues.ToArray()
+            },
+            new IssuerEvaluationResult
+            {
+                Status = issuerStatus,
+                Mode = mode,
+                Issuer = entry.SignerIdentity.Issuer,
+                SubjectAlternativeName = subjectAlternativeName ?? entry.SignerIdentity.SubjectAlternativeName,
+                KeyId = entry.SignerIdentity.KeyId,
+                Issues = issuerIssues.ToArray()
+            });
+    }
+
+    private int EvaluateKmsSignature(
+        AttestorSubmissionRequest.SubmissionBundle bundle,
+        byte[] preAuthEncoding,
+        List<string> signatureIssues,
+        List<string> issuerIssues)
+    {
+        if (_options.Security.SignerIdentity.KmsKeys.Count == 0)
+        {
+            issuerIssues.Add("kms_key_missing");
+            return 0;
+        }
+
+        var signatures = new List<byte[]>();
+        foreach (var signature in bundle.Dsse.Signatures)
+        {
+            if (!TryDecodeBase64(signature.Signature, out var signatureBytes))
+            {
+                signatureIssues.Add("signature_invalid_base64");
+                return 0;
+            }
+
+            signatures.Add(signatureBytes);
+        }
+
+        var verified = 0;
+
+        foreach (var secret in _options.Security.SignerIdentity.KmsKeys)
+        {
+            if (!TryDecodeSecret(secret, out var secretBytes))
+            {
+                continue;
+            }
+
+            using var hmac = new HMACSHA256(secretBytes);
+            var computed = hmac.ComputeHash(preAuthEncoding);
+
+            foreach (var candidate in signatures)
+            {
+                if (CryptographicOperations.FixedTimeEquals(computed, candidate))
+                {
+                    verified++;
+                }
+            }
+        }
+
+        if (verified == 0)
+        {
+            signatureIssues.Add("signature_invalid");
+        }
+
+        return verified;
+    }
+
+    private (int VerifiedSignatures, string? SubjectAlternativeName) EvaluateKeylessSignature(
+        AttestorEntry entry,
+        AttestorSubmissionRequest.SubmissionBundle bundle,
+        byte[] preAuthEncoding,
+        List<string> signatureIssues,
+        List<string> issuerIssues)
+    {
+        if (bundle.CertificateChain.Count == 0)
+        {
+            issuerIssues.Add("certificate_chain_missing");
+            return (0, null);
+        }
+
+        var certificates = new List<X509Certificate2>();
+        try
+        {
+            foreach (var pem in bundle.CertificateChain)
+            {
+                certificates.Add(X509Certificate2.CreateFromPem(pem));
+            }
+        }
+        catch (Exception ex) when (ex is CryptographicException or ArgumentException)
+        {
+            issuerIssues.Add("certificate_chain_invalid");
+            _logger.LogWarning(ex, "Failed to parse certificate chain for {Uuid}", entry.RekorUuid);
+            return (0, null);
+        }
+
+        var leafCertificate = certificates[0];
+        var subjectAltName = GetSubjectAlternativeNames(leafCertificate).FirstOrDefault();
+
+        if (_options.Security.SignerIdentity.FulcioRoots.Count > 0)
+        {
+            using var chain = new X509Chain
+            {
+                ChainPolicy =
+                {
+                    RevocationMode = X509RevocationMode.NoCheck,
+                    VerificationFlags = X509VerificationFlags.NoFlag,
+                    TrustMode = X509ChainTrustMode.CustomRootTrust
+                }
+            };
+
+            foreach (var rootPath in _options.Security.SignerIdentity.FulcioRoots)
+            {
+                try
+                {
+                    if (File.Exists(rootPath))
+                    {
+                        var rootCertificate = X509CertificateLoader.LoadCertificateFromFile(rootPath);
+                        chain.ChainPolicy.CustomTrustStore.Add(rootCertificate);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogWarning(ex, "Failed to load Fulcio root {Root}", rootPath);
+                }
+            }
+
+            if (!chain.Build(leafCertificate))
+            {
+                var status = string.Join(";", chain.ChainStatus.Select(s => s.StatusInformation.Trim())).Trim(';');
+                issuerIssues.Add(string.IsNullOrEmpty(status) ? "certificate_chain_untrusted" : $"certificate_chain_untrusted:{status}");
+            }
+        }
+
+        if (_options.Security.SignerIdentity.AllowedSans.Count > 0)
+        {
+            var sans = GetSubjectAlternativeNames(leafCertificate);
+            if (!sans.Any(san => _options.Security.SignerIdentity.AllowedSans.Contains(san, StringComparer.OrdinalIgnoreCase)))
+            {
+                issuerIssues.Add("certificate_san_untrusted");
+            }
+        }
+
+        var verified = 0;
+        foreach (var signature in bundle.Dsse.Signatures)
+        {
+            if (!TryDecodeBase64(signature.Signature, out var signatureBytes))
+            {
+                signatureIssues.Add("signature_invalid_base64");
+                return (0, subjectAltName);
+            }
+
+            if (TryVerifyWithCertificate(leafCertificate, preAuthEncoding, signatureBytes))
+            {
+                verified++;
+            }
+        }
+
+        if (verified == 0)
+        {
+            signatureIssues.Add("signature_invalid");
+        }
+
+        return (verified, subjectAltName);
+    }
+
+    private FreshnessEvaluationResult EvaluateFreshness(AttestorEntry entry, DateTimeOffset evaluationTime)
+    {
+        if (entry.CreatedAt == default)
+        {
+            return new FreshnessEvaluationResult
+            {
+                Status = VerificationSectionStatus.Warn,
+                CreatedAt = entry.CreatedAt,
+                EvaluatedAt = evaluationTime,
+                Age = TimeSpan.Zero,
+                MaxAge = null,
+                Issues = new[] { "freshness_unknown" }
+            };
+        }
+
+        var age = evaluationTime - entry.CreatedAt;
+        var maxAgeMinutes = _options.Verification.FreshnessMaxAgeMinutes;
+        var warnAgeMinutes = _options.Verification.FreshnessWarnAgeMinutes;
+
+        if (maxAgeMinutes is null)
+        {
+            return new FreshnessEvaluationResult
+            {
+                Status = VerificationSectionStatus.Skipped,
+                CreatedAt = entry.CreatedAt,
+                EvaluatedAt = evaluationTime,
+                Age = age,
+                MaxAge = null,
+                Issues = Array.Empty<string>()
+            };
+        }
+
+        var maxAge = TimeSpan.FromMinutes(maxAgeMinutes.Value);
+        VerificationSectionStatus status;
+        var issues = new List<string>();
+
+        if (age > maxAge)
+        {
+            status = VerificationSectionStatus.Fail;
+            issues.Add("freshness_stale");
+        }
+        else if (warnAgeMinutes is not null && age > TimeSpan.FromMinutes(warnAgeMinutes.Value))
+        {
+            status = VerificationSectionStatus.Warn;
+            issues.Add("freshness_warning");
+        }
+        else
+        {
+            status = VerificationSectionStatus.Pass;
+        }
+
+        return new FreshnessEvaluationResult
+        {
+            Status = status,
+            CreatedAt = entry.CreatedAt,
+            EvaluatedAt = evaluationTime,
+            Age = age,
+            MaxAge = maxAge,
+            Issues = issues.ToArray()
+        };
+    }
+
+    private TransparencyEvaluationResult EvaluateTransparency(AttestorEntry entry)
+    {
+        var issues = new List<string>();
+
+        TransparencyEvaluationResult Finalize(VerificationSectionStatus finalStatus, bool proofPresent, bool checkpointPresent, bool inclusionPresent)
+        {
+            var witness = entry.Witness;
+            var witnessPresent = witness is not null;
+            var witnessMatches = false;
+            var witnessAggregator = witness?.Aggregator;
+            var witnessStatus = witness?.Status ?? "missing";
+
+            if (witness is null)
+            {
+                issues.Add("witness_missing");
+                if (_options.Verification.RequireWitnessEndorsement)
+                {
+                    finalStatus = VerificationSectionStatus.Fail;
+                }
+                else if (finalStatus != VerificationSectionStatus.Fail)
+                {
+                    finalStatus = VerificationSectionStatus.Warn;
+                }
+            }
+            else
+            {
+                var normalizedStatus = string.IsNullOrWhiteSpace(witness.Status) ? "unknown" : witness.Status!;
+                if (!string.Equals(normalizedStatus, "endorsed", StringComparison.OrdinalIgnoreCase))
+                {
+                    issues.Add("witness_status_" + normalizedStatus.ToLowerInvariant());
+                    if (_options.Verification.RequireWitnessEndorsement)
+                    {
+                        finalStatus = VerificationSectionStatus.Fail;
+                    }
+                    else if (finalStatus != VerificationSectionStatus.Fail)
+                    {
+                        finalStatus = VerificationSectionStatus.Warn;
+                    }
+                }
+
+                if (!string.IsNullOrWhiteSpace(witness.RootHash) && entry.Proof?.Checkpoint?.RootHash is not null)
+                {
+                    if (string.Equals(witness.RootHash, entry.Proof.Checkpoint.RootHash, StringComparison.OrdinalIgnoreCase))
+                    {
+                        witnessMatches = true;
+                    }
+                    else
+                    {
+                        issues.Add("witness_root_mismatch");
+                        if (_options.Verification.RequireWitnessEndorsement)
+                        {
+                            finalStatus = VerificationSectionStatus.Fail;
+                        }
+                        else if (finalStatus != VerificationSectionStatus.Fail)
+                        {
+                            finalStatus = VerificationSectionStatus.Warn;
+                        }
+                    }
+                }
+            }
+
+            return BuildTransparencyResult(finalStatus, issues, proofPresent, checkpointPresent, inclusionPresent, witnessPresent, witnessMatches, witnessAggregator, witnessStatus);
+        }
+
+        if (entry.Proof is null)
+        {
+            issues.Add("proof_missing");
+            var finalStatus = _options.Verification.RequireTransparencyInclusion ? VerificationSectionStatus.Fail : VerificationSectionStatus.Warn;
+            return Finalize(finalStatus, false, false, false);
+        }
+
+        if (!TryDecodeHash(entry.BundleSha256, out var bundleHash))
+        {
+            issues.Add("bundle_hash_decode_failed");
+            return Finalize(VerificationSectionStatus.Fail, true, entry.Proof.Checkpoint is not null, entry.Proof.Inclusion is not null);
+        }
+
+        if (entry.Proof.Inclusion is null)
+        {
+            issues.Add("proof_inclusion_missing");
+            var finalStatus = _options.Verification.RequireTransparencyInclusion ? VerificationSectionStatus.Fail : VerificationSectionStatus.Warn;
+            return Finalize(finalStatus, true, entry.Proof.Checkpoint is not null, false);
+        }
+
+        if (entry.Proof.Inclusion.LeafHash is not null)
+        {
+            if (!TryDecodeHash(entry.Proof.Inclusion.LeafHash, out var proofLeaf))
+            {
+                issues.Add("proof_leafhash_decode_failed");
+                return Finalize(VerificationSectionStatus.Fail, true, entry.Proof.Checkpoint is not null, true);
+            }
+
+            if (!CryptographicOperations.FixedTimeEquals(bundleHash, proofLeaf))
+            {
+                issues.Add("proof_leafhash_mismatch");
+            }
+        }
+
+        var current = bundleHash;
+        var inclusionNodesPresent = entry.Proof.Inclusion.Path.Count > 0;
+
+        if (inclusionNodesPresent)
+        {
+            var nodes = new List<ProofPathNode>();
+            foreach (var element in entry.Proof.Inclusion.Path)
+            {
+                if (!ProofPathNode.TryParse(element, out var node))
+                {
+                    issues.Add("proof_path_decode_failed");
+                    return Finalize(VerificationSectionStatus.Fail, true, entry.Proof.Checkpoint is not null, true);
+                }
+
+                if (!node.HasOrientation)
+                {
+                    issues.Add("proof_path_orientation_missing");
+                    return Finalize(VerificationSectionStatus.Fail, true, entry.Proof.Checkpoint is not null, true);
+                }
+
+                nodes.Add(node);
+            }
+
+            foreach (var node in nodes)
+            {
+                current = node.Left ? HashInternal(node.Hash, current) : HashInternal(current, node.Hash);
+            }
+        }
+
+        if (entry.Proof.Checkpoint is null)
+        {
+            issues.Add("checkpoint_missing");
+            var finalStatus = _options.Verification.RequireCheckpoint ? VerificationSectionStatus.Fail : VerificationSectionStatus.Warn;
+            return Finalize(finalStatus, true, false, inclusionNodesPresent);
+        }
+
+        if (!TryDecodeHash(entry.Proof.Checkpoint.RootHash, out var rootHash))
+        {
+            issues.Add("checkpoint_root_decode_failed");
+            return Finalize(VerificationSectionStatus.Fail, true, true, inclusionNodesPresent);
+        }
+
+        if (!CryptographicOperations.FixedTimeEquals(current, rootHash))
+        {
+            issues.Add("proof_root_mismatch");
+        }
+
+        var status = issues.Count == 0 ? VerificationSectionStatus.Pass : VerificationSectionStatus.Fail;
+        return Finalize(status, true, true, inclusionNodesPresent);
+    }
+
+    private PolicyEvaluationResult EvaluatePolicy(
+        AttestorEntry entry,
+        SignatureEvaluationResult signatures,
+        IssuerEvaluationResult issuer,
+        FreshnessEvaluationResult freshness,
+        TransparencyEvaluationResult transparency,
+        bool bundleProvided)
+    {
+        var issues = new List<string>();
+        var status = VerificationSectionStatus.Pass;
+
+        if (!string.Equals(entry.Status, "included", StringComparison.OrdinalIgnoreCase))
+        {
+            issues.Add($"log_status_{entry.Status.ToLowerInvariant()}");
+            status = VerificationSectionStatus.Fail;
+        }
+
+        if (_options.Verification.RequireBundleForSignatureValidation && !bundleProvided)
+        {
+            issues.Add("bundle_required");
+            status = VerificationSectionStatus.Fail;
+        }
+
+        status = CombinePolicyStatus(status, signatures.Status, "signatures", issues);
+        status = CombinePolicyStatus(status, issuer.Status, "issuer", issues);
+        status = CombinePolicyStatus(status, freshness.Status, "freshness", issues, warnOnly: true);
+        status = CombinePolicyStatus(status, transparency.Status, "transparency", issues);
+
+        var verdict = status switch
+        {
+            VerificationSectionStatus.Fail => "fail",
+            VerificationSectionStatus.Warn => "warn",
+            VerificationSectionStatus.Pass => "pass",
+            _ => "unknown"
+        };
+
+        var attributes = ImmutableDictionary<string, string>.Empty
+            .Add("status", entry.Status ?? "unknown")
+            .Add("logBackend", entry.Log.Backend ?? "primary")
+            .Add("logUrl", entry.Log.Url ?? string.Empty);
+
+        if (entry.Index.HasValue)
+        {
+            attributes = attributes.Add("index", entry.Index.Value.ToString());
+        }
+
+        if (entry.Proof?.Checkpoint?.Timestamp is not null)
+        {
+            attributes = attributes.Add("checkpointTs", entry.Proof.Checkpoint.Timestamp.Value.ToString("O"));
+        }
+
+        return new PolicyEvaluationResult
+        {
+            Status = status,
+            PolicyId = _options.Verification.PolicyId,
+            PolicyVersion = _options.Verification.PolicyVersion,
+            Verdict = verdict,
+            Issues = issues.Distinct(StringComparer.OrdinalIgnoreCase).ToArray(),
+            Attributes = attributes
+        };
+    }
+
+    private static VerificationSectionStatus DetermineSignatureStatus(
+        IReadOnlyCollection<string> issues,
+        int verified,
+        int required,
+        int total)
+    {
+        if (total == 0)
+        {
+            return VerificationSectionStatus.Fail;
+        }
+
+        if (issues.Count > 0)
+        {
+            return issues.Contains("signature_invalid", StringComparer.OrdinalIgnoreCase)
+                || issues.Contains("bundle_payload_invalid_base64", StringComparer.OrdinalIgnoreCase)
+                || issues.Contains("bundle_hash_mismatch", StringComparer.OrdinalIgnoreCase)
+                ? VerificationSectionStatus.Fail
+                : VerificationSectionStatus.Warn;
+        }
+
+        return verified >= required ? VerificationSectionStatus.Pass : VerificationSectionStatus.Fail;
+    }
+
+    private static VerificationSectionStatus DetermineIssuerStatus(
+        IReadOnlyCollection<string> issues,
+        string mode,
+        bool signatureVerified)
+    {
+        if (issues.Count == 0)
+        {
+            return signatureVerified ? VerificationSectionStatus.Pass : VerificationSectionStatus.Warn;
+        }
+
+        if (issues.Any(issue => issue.StartsWith("certificate_", StringComparison.OrdinalIgnoreCase) || issue.StartsWith("kms_", StringComparison.OrdinalIgnoreCase)))
+        {
+            return VerificationSectionStatus.Fail;
+        }
+
+        if (issues.Any(issue => issue.StartsWith("signer_mode", StringComparison.OrdinalIgnoreCase)))
+        {
+            return VerificationSectionStatus.Fail;
+        }
+
+        return VerificationSectionStatus.Warn;
+    }
+
+    private static VerificationSectionStatus CombinePolicyStatus(
+        VerificationSectionStatus current,
+        VerificationSectionStatus next,
+        string component,
+        List<string> issues,
+        bool warnOnly = false)
+    {
+        if (next == VerificationSectionStatus.Fail)
+        {
+            issues.Add($"policy_blocked:{component}");
+            return VerificationSectionStatus.Fail;
+        }
+
+        if (next == VerificationSectionStatus.Warn && !warnOnly)
+        {
+            issues.Add($"policy_warn:{component}");
+            return current == VerificationSectionStatus.Fail ? current : VerificationSectionStatus.Warn;
+        }
+
+        if (next == VerificationSectionStatus.Warn && warnOnly)
+        {
+            issues.Add($"policy_warn:{component}");
+            return current;
+        }
+
+        return current;
+    }
+
+    private static TransparencyEvaluationResult BuildTransparencyResult(
+        VerificationSectionStatus status,
+        List<string> issues,
+        bool proofPresent,
+        bool checkpointPresent,
+        bool inclusionPresent,
+        bool witnessPresent,
+        bool witnessMatches,
+        string? witnessAggregator,
+        string witnessStatus)
+    {
+        return new TransparencyEvaluationResult
+        {
+            Status = status,
+            ProofPresent = proofPresent,
+            CheckpointPresent = checkpointPresent,
+            InclusionPathPresent = inclusionPresent,
+            WitnessPresent = witnessPresent,
+            WitnessMatchesRoot = witnessMatches,
+            WitnessAggregator = witnessAggregator,
+            WitnessStatus = witnessStatus,
+            Issues = issues.ToArray()
+        };
+    }
+
+    private static bool TryVerifyWithCertificate(X509Certificate2 certificate, byte[] preAuthEncoding, byte[] signature)
+    {
+        try
+        {
+            var ecdsa = certificate.GetECDsaPublicKey();
+            if (ecdsa is not null)
+            {
+                using (ecdsa)
+                {
+                    if (ecdsa.VerifyData(preAuthEncoding, signature, HashAlgorithmName.SHA256))
+                    {
+                        return true;
+                    }
+                }
+            }
+
+            var rsa = certificate.GetRSAPublicKey();
+            if (rsa is not null)
+            {
+                using (rsa)
+                {
+                    if (rsa.VerifyData(preAuthEncoding, signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1))
+                    {
+                        return true;
+                    }
+                }
+            }
+        }
+        catch (CryptographicException)
+        {
+            return false;
+        }
+
+        return false;
+    }
+
+    private static IEnumerable<string> GetSubjectAlternativeNames(X509Certificate2 certificate)
+    {
+        foreach (var extension in certificate.Extensions)
+        {
+            if (string.Equals(extension.Oid?.Value, "2.5.29.17", StringComparison.Ordinal))
+            {
+                var formatted = extension.Format(true);
+                var lines = formatted.Split(new[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries);
+                foreach (var line in lines)
+                {
+                    var parts = line.Split('=');
+                    if (parts.Length == 2)
+                    {
+                        yield return parts[1].Trim();
+                    }
+                }
+            }
+        }
+    }
+
+    private static byte[] ComputePreAuthEncoding(string payloadType, byte[] payload)
+    {
+        var headerBytes = Encoding.UTF8.GetBytes(payloadType ?? string.Empty);
+        var buffer = new byte[6 + 8 + headerBytes.Length + 8 + payload.Length];
+        var offset = 0;
+
+        Encoding.ASCII.GetBytes("DSSEv1", 0, 6, buffer, offset);
+        offset += 6;
+
+        BinaryPrimitives.WriteUInt64BigEndian(buffer.AsSpan(offset, 8), (ulong)headerBytes.Length);
+        offset += 8;
+        Buffer.BlockCopy(headerBytes, 0, buffer, offset, headerBytes.Length);
+        offset += headerBytes.Length;
+
+        BinaryPrimitives.WriteUInt64BigEndian(buffer.AsSpan(offset, 8), (ulong)payload.Length);
+        offset += 8;
+        Buffer.BlockCopy(payload, 0, buffer, offset, payload.Length);
+
+        return buffer;
+    }
+
+    private static byte[] HashInternal(byte[] left, byte[] right)
+    {
+        using var sha = SHA256.Create();
+        var buffer = new byte[1 + left.Length + right.Length];
+        buffer[0] = 0x01;
+        Buffer.BlockCopy(left, 0, buffer, 1, left.Length);
+        Buffer.BlockCopy(right, 0, buffer, 1 + left.Length, right.Length);
+        return sha.ComputeHash(buffer);
+    }
+
+    private static bool TryDecodeSecret(string value, out byte[] bytes)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            bytes = Array.Empty<byte>();
+            return false;
+        }
+
+        value = value.Trim();
+
+        if (value.StartsWith("base64:", StringComparison.OrdinalIgnoreCase))
+        {
+            return TryDecodeBase64(value[7..], out bytes);
+        }
+
+        if (value.StartsWith("hex:", StringComparison.OrdinalIgnoreCase))
+        {
+            return TryDecodeHex(value[4..], out bytes);
+        }
+
+        if (TryDecodeBase64(value, out bytes))
+        {
+            return true;
+        }
+
+        if (TryDecodeHex(value, out bytes))
+        {
+            return true;
+        }
+
+        bytes = Array.Empty<byte>();
+        return false;
+    }
+
+    private static bool TryDecodeBase64(string value, out byte[] bytes)
+    {
+        try
+        {
+            bytes = Convert.FromBase64String(value);
+            return true;
+        }
+        catch (FormatException)
+        {
+            bytes = Array.Empty<byte>();
+            return false;
+        }
+    }
+
+    private static bool TryDecodeHex(string value, out byte[] bytes)
+    {
+        try
+        {
+            bytes = Convert.FromHexString(value);
+            return true;
+        }
+        catch (FormatException)
+        {
+            bytes = Array.Empty<byte>();
+            return false;
+        }
+    }
+
+    private static bool TryDecodeHash(string? value, out byte[] bytes)
+    {
+        bytes = Array.Empty<byte>();
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            return false;
+        }
+
+        var trimmed = value.Trim();
+
+        if (TryDecodeHex(trimmed, out bytes))
+        {
+            return true;
+        }
+
+        if (TryDecodeBase64(trimmed, out bytes))
+        {
+            return true;
+        }
+
+        bytes = Array.Empty<byte>();
+        return false;
+    }
+
+    private readonly struct ProofPathNode
+    {
+        private ProofPathNode(bool hasOrientation, bool left, byte[] hash)
+        {
+            HasOrientation = hasOrientation;
+            Left = left;
+            Hash = hash;
+        }
+
+        public bool HasOrientation { get; }
+
+        public bool Left { get; }
+
+        public byte[] Hash { get; }
+
+        public static bool TryParse(string value, out ProofPathNode node)
+        {
+            node = default;
+            if (string.IsNullOrWhiteSpace(value))
+            {
+                return false;
+            }
+
+            var trimmed = value.Trim();
+            var parts = trimmed.Split(':', 2);
+            bool hasOrientation = false;
+            bool left = false;
+            string hashPart = trimmed;
+
+            if (parts.Length == 2)
+            {
+                var prefix = parts[0].Trim().ToLowerInvariant();
+                if (prefix is "l" or "left")
+                {
+                    hasOrientation = true;
+                    left = true;
+                }
+                else if (prefix is "r" or "right")
+                {
+                    hasOrientation = true;
+                    left = false;
+                }
+
+                hashPart = parts[1].Trim();
+            }
+
+            if (!TryDecodeHash(hashPart, out var hash))
+            {
+                return false;
+            }
+
+            node = new ProofPathNode(hasOrientation, left, hash);
+            return true;
+        }
+    }
+}

src/Attestor/StellaOps.Attestor.Verify/IAttestorVerificationEngine.cs

@@ -0,0 +1,14 @@
+using StellaOps.Attestor.Core.Storage;
+using StellaOps.Attestor.Core.Submission;
+using StellaOps.Attestor.Core.Verification;
+
+namespace StellaOps.Attestor.Verify;
+
+public interface IAttestorVerificationEngine
+{
+    Task<VerificationReport> EvaluateAsync(
+        AttestorEntry entry,
+        AttestorSubmissionRequest.SubmissionBundle? bundle,
+        DateTimeOffset evaluationTime,
+        CancellationToken cancellationToken = default);
+}

src/Attestor/StellaOps.Attestor.Verify/StellaOps.Attestor.Verify.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <LangVersion>preview</LangVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\\StellaOps.Attestor\\StellaOps.Attestor.Core\\StellaOps.Attestor.Core.csproj" />
+  </ItemGroup>
+</Project>

src/Attestor/StellaOps.Attestor.Verify/TASKS.md

@@ -3,11 +3,11 @@
 ## Sprint 73 – Policy Integration
 | ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
 |----|--------|----------|------------|-------------|---------------|
-| ATTEST-VERIFY-73-001 | TODO | Verification Guild, Policy Guild | VERPOL-73-001, ATTESTOR-73-002 | Implement verification engine: policy evaluation, issuer trust resolution, freshness, signature count, transparency checks; produce structured reports. | Engine returns report DTOs; policy rules honored; unit tests cover pass/fail scenarios. |
-| ATTEST-VERIFY-73-002 | TODO | Verification Guild | ATTEST-VERIFY-73-001 | Add caching layer keyed by `(subject, envelope_id, policy_version)` with TTL and invalidation on new evidence. | Cache reduces repeated verification cost; tests cover cache hits/misses. |
+| ATTEST-VERIFY-73-001 | DONE | Verification Guild, Policy Guild | VERPOL-73-001, ATTESTOR-73-002 | Implement verification engine: policy evaluation, issuer trust resolution, freshness, signature count, transparency checks; produce structured reports. | Engine returns report DTOs; policy rules honored; unit tests cover pass/fail scenarios. |
+| ATTEST-VERIFY-73-002 | DONE | Verification Guild | ATTEST-VERIFY-73-001 | Add caching layer keyed by `(subject, envelope_id, policy_version)` with TTL and invalidation on new evidence. | Cache reduces repeated verification cost; tests cover cache hits/misses. |
 
 ## Sprint 74 – Explainability & Observability
 | ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
 |----|--------|----------|------------|-------------|---------------|
-| ATTEST-VERIFY-74-001 | TODO | Verification Guild, Observability Guild | ATTEST-VERIFY-73-001 | Emit telemetry (spans/metrics) tagged by subject, issuer, policy, result; integrate with dashboards. | Metrics visible; spans present; SLO thresholds defined. |
-| ATTEST-VERIFY-74-002 | TODO | Verification Guild, Docs Guild | ATTEST-VERIFY-73-001 | Document verification report schema and explainability in `/docs/modules/attestor/workflows.md`. | Documentation merged; examples verified via tests. |
+| ATTEST-VERIFY-74-001 | DONE | Verification Guild, Observability Guild | ATTEST-VERIFY-73-001 | Emit telemetry (spans/metrics) tagged by subject, issuer, policy, result; integrate with dashboards. | Metrics visible; spans present; SLO thresholds defined. |
+| ATTEST-VERIFY-74-002 | DONE (2025-11-01) | Verification Guild, Docs Guild | ATTEST-VERIFY-73-001 | Document verification report schema and explainability in `/docs/modules/attestor/workflows.md`. | Documentation merged; examples verified via tests. |

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Bulk/BulkVerificationModels.cs

@@ -0,0 +1,94 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using StellaOps.Attestor.Core.Verification;
+
+namespace StellaOps.Attestor.Core.Bulk;
+
+public sealed class BulkVerificationJob
+{
+    public string Id { get; set; } = Guid.NewGuid().ToString("N");
+
+    public int Version { get; set; }
+
+    public BulkVerificationJobStatus Status { get; set; } = BulkVerificationJobStatus.Queued;
+
+    public DateTimeOffset CreatedAt { get; set; } = DateTimeOffset.UtcNow;
+
+    public DateTimeOffset? StartedAt { get; set; }
+
+    public DateTimeOffset? CompletedAt { get; set; }
+
+    public BulkVerificationJobContext Context { get; set; } = new();
+
+    public IList<BulkVerificationJobItem> Items { get; set; } = new List<BulkVerificationJobItem>();
+
+    public int ProcessedCount { get; set; }
+
+    public int SucceededCount { get; set; }
+
+    public int FailedCount { get; set; }
+
+    public string? FailureReason { get; set; }
+
+    public bool AllCompleted => Items.Count > 0 && Items.All(i => i.Status is BulkVerificationItemStatus.Succeeded or BulkVerificationItemStatus.Failed);
+}
+
+public sealed class BulkVerificationJobItem
+{
+    public int Index { get; set; }
+
+    public BulkVerificationItemRequest Request { get; set; } = new();
+
+    public BulkVerificationItemStatus Status { get; set; } = BulkVerificationItemStatus.Pending;
+
+    public DateTimeOffset? StartedAt { get; set; }
+
+    public DateTimeOffset? CompletedAt { get; set; }
+
+    public AttestorVerificationResult? Result { get; set; }
+
+    public string? Error { get; set; }
+}
+
+public sealed class BulkVerificationItemRequest
+{
+    public string? Uuid { get; set; }
+
+    public string? ArtifactSha256 { get; set; }
+
+    public string? Subject { get; set; }
+
+    public string? EnvelopeId { get; set; }
+
+    public string? PolicyVersion { get; set; }
+
+    public bool RefreshProof { get; set; }
+}
+
+public sealed class BulkVerificationJobContext
+{
+    public string? Tenant { get; set; }
+
+    public string? RequestedBy { get; set; }
+
+    public string? ClientId { get; set; }
+
+    public IList<string> Scopes { get; set; } = new List<string>();
+}
+
+public enum BulkVerificationJobStatus
+{
+    Queued,
+    Running,
+    Completed,
+    Failed
+}
+
+public enum BulkVerificationItemStatus
+{
+    Pending,
+    Running,
+    Succeeded,
+    Failed
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Bulk/IBulkVerificationJobStore.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Attestor.Core.Bulk;
+
+public interface IBulkVerificationJobStore
+{
+    Task<BulkVerificationJob> CreateAsync(BulkVerificationJob job, CancellationToken cancellationToken = default);
+
+    Task<BulkVerificationJob?> GetAsync(string jobId, CancellationToken cancellationToken = default);
+
+    Task<BulkVerificationJob?> TryAcquireAsync(CancellationToken cancellationToken = default);
+
+    Task<bool> TryUpdateAsync(BulkVerificationJob job, CancellationToken cancellationToken = default);
+
+    Task<int> CountQueuedAsync(CancellationToken cancellationToken = default);
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Observability/AttestorActivitySource.cs

@@ -0,0 +1,59 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+
+namespace StellaOps.Attestor.Core.Observability;
+
+public sealed class AttestorActivitySource : IDisposable
+{
+    public const string Name = "StellaOps.Attestor";
+
+    private readonly ActivitySource _source = new(Name);
+    private bool _disposed;
+
+    public Activity? StartVerification(string subject, string issuer, string policy)
+    {
+        var tags = new ActivityTagsCollection
+        {
+            { AttestorTelemetryTags.Subject, subject },
+            { AttestorTelemetryTags.Issuer, issuer },
+            { AttestorTelemetryTags.Policy, policy }
+        };
+
+        return _source.StartActivity("attestor.verify", ActivityKind.Internal, default(ActivityContext), tags);
+    }
+
+    public Activity? StartProofRefresh(string backend, string policy)
+    {
+        var tags = new ActivityTagsCollection
+        {
+            { "attestor.log.backend", backend },
+            { AttestorTelemetryTags.Policy, policy }
+        };
+
+        return _source.StartActivity("attestor.verify.refresh_proof", ActivityKind.Internal, default(ActivityContext), tags);
+    }
+
+    public Activity? StartWitnessFetch(string aggregator)
+    {
+        var tags = new ActivityTagsCollection
+        {
+            { AttestorTelemetryTags.WitnessAggregator, string.IsNullOrWhiteSpace(aggregator) ? "unknown" : aggregator }
+        };
+
+        return _source.StartActivity("attestor.verify.fetch_witness", ActivityKind.Internal, default(ActivityContext), tags);
+    }
+
+    public ActivitySource Source => _source;
+
+    public void Dispose()
+    {
+        if (_disposed)
+        {
+            return;
+        }
+
+        _source.Dispose();
+        _disposed = true;
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Observability/AttestorMetrics.cs

@@ -1,45 +1,75 @@
-using System.Diagnostics.Metrics;
-
-namespace StellaOps.Attestor.Core.Observability;
-
-public sealed class AttestorMetrics : IDisposable
-{
-    public const string MeterName = "StellaOps.Attestor";
-
-    private readonly Meter _meter;
-    private bool _disposed;
-
-    public AttestorMetrics()
-    {
-        _meter = new Meter(MeterName);
-        SubmitTotal = _meter.CreateCounter<long>("attestor.submit_total", description: "Total submission attempts grouped by result and backend.");
-        SubmitLatency = _meter.CreateHistogram<double>("attestor.submit_latency_seconds", unit: "s", description: "Submission latency in seconds per backend.");
-        ProofFetchTotal = _meter.CreateCounter<long>("attestor.proof_fetch_total", description: "Proof fetch attempts grouped by result.");
-        VerifyTotal = _meter.CreateCounter<long>("attestor.verify_total", description: "Verification attempts grouped by result.");
-        DedupeHitsTotal = _meter.CreateCounter<long>("attestor.dedupe_hits_total", description: "Number of dedupe hits by outcome.");
-        ErrorTotal = _meter.CreateCounter<long>("attestor.errors_total", description: "Total errors grouped by type.");
-    }
-
-    public Counter<long> SubmitTotal { get; }
-
-    public Histogram<double> SubmitLatency { get; }
-
-    public Counter<long> ProofFetchTotal { get; }
-
-    public Counter<long> VerifyTotal { get; }
-
-    public Counter<long> DedupeHitsTotal { get; }
-
-    public Counter<long> ErrorTotal { get; }
-
-    public void Dispose()
-    {
-        if (_disposed)
-        {
-            return;
-        }
-
-        _meter.Dispose();
-        _disposed = true;
-    }
-}
+using System.Diagnostics.Metrics;
+
+namespace StellaOps.Attestor.Core.Observability;
+
+public sealed class AttestorMetrics : IDisposable
+{
+    public const string MeterName = "StellaOps.Attestor";
+
+    private readonly Meter _meter;
+    private bool _disposed;
+
+    public AttestorMetrics()
+    {
+        _meter = new Meter(MeterName);
+        SubmitTotal = _meter.CreateCounter<long>("attestor.submit_total", description: "Total submission attempts grouped by result and backend.");
+        SubmitLatency = _meter.CreateHistogram<double>("attestor.submit_latency_seconds", unit: "s", description: "Submission latency in seconds per backend.");
+        SignTotal = _meter.CreateCounter<long>("attestor.sign_total", description: "Total signing attempts grouped by result/algorithm/provider.");
+        SignLatency = _meter.CreateHistogram<double>("attestor.sign_latency_seconds", unit: "s", description: "Signing latency in seconds grouped by algorithm/provider.");
+        ProofFetchTotal = _meter.CreateCounter<long>("attestor.proof_fetch_total", description: "Proof fetch attempts grouped by result.");
+        WitnessFetchTotal = _meter.CreateCounter<long>("attestor.witness_fetch_total", description: "Transparency witness fetch attempts grouped by result and aggregator.");
+        WitnessFetchLatency = _meter.CreateHistogram<double>("attestor.witness_fetch_latency_seconds", unit: "s", description: "Transparency witness fetch latency grouped by aggregator.");
+        VerifyTotal = _meter.CreateCounter<long>("attestor.verify_total", description: "Verification attempts grouped by subject, issuer, policy, and result.");
+        VerifyLatency = _meter.CreateHistogram<double>("attestor.verify_latency_seconds", unit: "s", description: "Verification latency in seconds grouped by subject, issuer, policy, and result.");
+        VerifyCacheLookupTotal = _meter.CreateCounter<long>("attestor.verify_cache_lookup_total", description: "Verification cache lookups.");
+        VerifyCacheHitTotal = _meter.CreateCounter<long>("attestor.verify_cache_hit_total", description: "Verification cache hits.");
+        DedupeHitsTotal = _meter.CreateCounter<long>("attestor.dedupe_hits_total", description: "Number of dedupe hits by outcome.");
+        BulkJobsTotal = _meter.CreateCounter<long>("attestor.bulk_jobs_total", description: "Bulk verification jobs processed grouped by status.");
+        BulkItemsTotal = _meter.CreateCounter<long>("attestor.bulk_items_total", description: "Bulk verification items processed grouped by result.");
+        BulkJobDuration = _meter.CreateHistogram<double>("attestor.bulk_job_duration_seconds", unit: "s", description: "Bulk verification job duration in seconds grouped by status.");
+        ErrorTotal = _meter.CreateCounter<long>("attestor.errors_total", description: "Total errors grouped by type.");
+    }
+
+    public Counter<long> SubmitTotal { get; }
+
+    public Histogram<double> SubmitLatency { get; }
+
+    public Counter<long> SignTotal { get; }
+
+    public Histogram<double> SignLatency { get; }
+
+    public Counter<long> ProofFetchTotal { get; }
+
+    public Counter<long> WitnessFetchTotal { get; }
+
+    public Histogram<double> WitnessFetchLatency { get; }
+
+    public Counter<long> VerifyTotal { get; }
+
+    public Histogram<double> VerifyLatency { get; }
+
+    public Counter<long> VerifyCacheLookupTotal { get; }
+
+    public Counter<long> VerifyCacheHitTotal { get; }
+
+    public Counter<long> DedupeHitsTotal { get; }
+
+    public Counter<long> BulkJobsTotal { get; }
+
+    public Counter<long> BulkItemsTotal { get; }
+
+    public Histogram<double> BulkJobDuration { get; }
+
+    public Counter<long> ErrorTotal { get; }
+
+    public void Dispose()
+    {
+        if (_disposed)
+        {
+            return;
+        }
+
+        _meter.Dispose();
+        _disposed = true;
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Observability/AttestorTelemetryTags.cs

@@ -0,0 +1,10 @@
+namespace StellaOps.Attestor.Core.Observability;
+
+public static class AttestorTelemetryTags
+{
+    public const string Subject = "attestor.subject";
+    public const string Issuer = "attestor.issuer";
+    public const string Policy = "attestor.policy";
+    public const string Result = "result";
+    public const string WitnessAggregator = "attestor.witness.aggregator";
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Offline/AttestorOfflineBundle.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+using StellaOps.Attestor.Core.Storage;
+
+namespace StellaOps.Attestor.Core.Offline;
+
+public static class AttestorBundleVersions
+{
+    public const string V1 = "stellaops.attestor.bundle/1";
+
+    public const string Current = V1;
+}
+
+public sealed class AttestorBundlePackage
+{
+    public string Version { get; init; } = AttestorBundleVersions.Current;
+
+    public DateTimeOffset GeneratedAt { get; init; }
+
+    public IReadOnlyList<AttestorBundleItem> Items { get; init; } = Array.Empty<AttestorBundleItem>();
+
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    public string? ContinuationToken { get; init; }
+}
+
+public sealed class AttestorBundleItem
+{
+    public AttestorEntry Entry { get; init; } = new();
+
+    /// <summary>
+    /// Canonical DSSE envelope encoded as base64 (UTF-8 JSON).
+    /// </summary>
+    public string CanonicalBundle { get; init; } = string.Empty;
+
+    /// <summary>
+    /// Optional Rekor proof payload encoded as base64 (UTF-8 JSON).
+    /// </summary>
+    public string? Proof { get; init; }
+
+    public IReadOnlyDictionary<string, string>? Metadata { get; init; }
+}
+
+public sealed class AttestorBundleExportRequest
+{
+    public IReadOnlyList<string> Uuids { get; init; } = Array.Empty<string>();
+
+    public string? Subject { get; init; }
+
+    public string? Type { get; init; }
+
+    public string? Issuer { get; init; }
+
+    public string? Scope { get; init; }
+
+    public DateTimeOffset? CreatedAfter { get; init; }
+
+    public DateTimeOffset? CreatedBefore { get; init; }
+
+    public int? Limit { get; init; }
+
+    public string? ContinuationToken { get; init; }
+}
+
+public sealed class AttestorBundleImportResult
+{
+    public int Imported { get; init; }
+
+    public int Updated { get; init; }
+
+    public int Skipped { get; init; }
+
+    public IReadOnlyList<string> Issues { get; init; } = Array.Empty<string>();
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Offline/IAttestorBundleService.cs

@@ -0,0 +1,11 @@
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Attestor.Core.Offline;
+
+public interface IAttestorBundleService
+{
+    Task<AttestorBundlePackage> ExportAsync(AttestorBundleExportRequest request, CancellationToken cancellationToken = default);
+
+    Task<AttestorBundleImportResult> ImportAsync(AttestorBundlePackage package, CancellationToken cancellationToken = default);
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Options/AttestorOptions.cs

@@ -1,148 +1,301 @@
-using System.Collections.Generic;
-
-namespace StellaOps.Attestor.Core.Options;
-
-/// <summary>
-/// Strongly typed configuration for the Attestor service.
-/// </summary>
-public sealed class AttestorOptions
-{
-    public string Listen { get; set; } = "https://0.0.0.0:8444";
-
-    public SecurityOptions Security { get; set; } = new();
-
-    public RekorOptions Rekor { get; set; } = new();
-
-    public MongoOptions Mongo { get; set; } = new();
-
-    public RedisOptions Redis { get; set; } = new();
-
-    public S3Options S3 { get; set; } = new();
-
-    public QuotaOptions Quotas { get; set; } = new();
-
-    public TelemetryOptions Telemetry { get; set; } = new();
-
-    public sealed class SecurityOptions
-    {
-        public MtlsOptions Mtls { get; set; } = new();
-
-        public AuthorityOptions Authority { get; set; } = new();
-
-        public SignerIdentityOptions SignerIdentity { get; set; } = new();
-    }
-
-    public sealed class MtlsOptions
-    {
-        public bool RequireClientCertificate { get; set; } = true;
-
-        public string? CaBundle { get; set; }
-
-        public IList<string> AllowedSubjects { get; set; } = new List<string>();
-
-        public IList<string> AllowedThumbprints { get; set; } = new List<string>();
-    }
-
-    public sealed class AuthorityOptions
-    {
-        public string? Issuer { get; set; }
-
-        public string? JwksUrl { get; set; }
-
-        public string? RequireSenderConstraint { get; set; }
-
-        public bool RequireHttpsMetadata { get; set; } = true;
-
-        public IList<string> Audiences { get; set; } = new List<string>();
-
-        public IList<string> RequiredScopes { get; set; } = new List<string>();
-    }
-
-    public sealed class SignerIdentityOptions
-    {
-        public IList<string> Mode { get; set; } = new List<string> { "keyless", "kms" };
-
-        public IList<string> FulcioRoots { get; set; } = new List<string>();
-
-        public IList<string> AllowedSans { get; set; } = new List<string>();
-
-        public IList<string> KmsKeys { get; set; } = new List<string>();
-    }
-
-    public sealed class RekorOptions
-    {
-        public RekorBackendOptions Primary { get; set; } = new();
-
-        public RekorMirrorOptions Mirror { get; set; } = new();
-    }
-
-    public class RekorBackendOptions
-    {
-        public string? Url { get; set; }
-
-        public int ProofTimeoutMs { get; set; } = 15_000;
-
-        public int PollIntervalMs { get; set; } = 250;
-
-        public int MaxAttempts { get; set; } = 60;
-    }
-
-    public sealed class RekorMirrorOptions : RekorBackendOptions
-    {
-        public bool Enabled { get; set; }
-    }
-
-    public sealed class MongoOptions
-    {
-        public string? Uri { get; set; }
-
-        public string Database { get; set; } = "attestor";
-
-        public string EntriesCollection { get; set; } = "entries";
-
-        public string DedupeCollection { get; set; } = "dedupe";
-
-        public string AuditCollection { get; set; } = "audit";
-    }
-
-    public sealed class RedisOptions
-    {
-        public string? Url { get; set; }
-
-        public string? DedupePrefix { get; set; } = "attestor:dedupe:";
-    }
-
-    public sealed class S3Options
-    {
-        public bool Enabled { get; set; }
-
-        public string? Endpoint { get; set; }
-
-        public string? Bucket { get; set; }
-
-        public string? Prefix { get; set; }
-
-        public string? ObjectLockMode { get; set; }
-
-        public bool UseTls { get; set; } = true;
-    }
-
-    public sealed class QuotaOptions
-    {
-        public PerCallerQuotaOptions PerCaller { get; set; } = new();
-    }
-
-    public sealed class PerCallerQuotaOptions
-    {
-        public int Qps { get; set; } = 50;
-
-        public int Burst { get; set; } = 100;
-    }
-
-    public sealed class TelemetryOptions
-    {
-        public bool EnableLogging { get; set; } = true;
-
-        public bool EnableTracing { get; set; } = false;
-    }
-}
+using System.Collections.Generic;
+using StellaOps.Cryptography;
+
+namespace StellaOps.Attestor.Core.Options;
+
+/// <summary>
+/// Strongly typed configuration for the Attestor service.
+/// </summary>
+public sealed class AttestorOptions
+{
+    public string Listen { get; set; } = "https://0.0.0.0:8444";
+
+    public SecurityOptions Security { get; set; } = new();
+
+    public RekorOptions Rekor { get; set; } = new();
+
+    public SigningOptions Signing { get; set; } = new();
+
+    public MongoOptions Mongo { get; set; } = new();
+
+    public RedisOptions Redis { get; set; } = new();
+
+    public S3Options S3 { get; set; } = new();
+
+    public QuotaOptions Quotas { get; set; } = new();
+
+    public BulkVerificationOptions BulkVerification { get; set; } = new();
+
+    public CacheOptions Cache { get; set; } = new();
+
+    public TelemetryOptions Telemetry { get; set; } = new();
+    public TransparencyWitnessOptions TransparencyWitness { get; set; } = new();
+    public VerificationOptions Verification { get; set; } = new();
+
+
+    public sealed class SecurityOptions
+    {
+        public MtlsOptions Mtls { get; set; } = new();
+
+        public AuthorityOptions Authority { get; set; } = new();
+
+        public SignerIdentityOptions SignerIdentity { get; set; } = new();
+
+        public SubmissionLimitOptions SubmissionLimits { get; set; } = new();
+    }
+
+    public sealed class MtlsOptions
+    {
+        public bool RequireClientCertificate { get; set; } = true;
+
+        public string? CaBundle { get; set; }
+
+        public IList<string> AllowedSubjects { get; set; } = new List<string>();
+
+        public IList<string> AllowedThumbprints { get; set; } = new List<string>();
+    }
+
+    public sealed class AuthorityOptions
+    {
+        public string? Issuer { get; set; }
+
+        public string? JwksUrl { get; set; }
+
+        public string? RequireSenderConstraint { get; set; }
+
+        public bool RequireHttpsMetadata { get; set; } = true;
+
+        public IList<string> Audiences { get; set; } = new List<string>();
+
+        public IList<string> RequiredScopes { get; set; } = new List<string>();
+    }
+
+    public sealed class SignerIdentityOptions
+    {
+        public IList<string> Mode { get; set; } = new List<string> { "keyless", "kms" };
+
+        public IList<string> FulcioRoots { get; set; } = new List<string>();
+
+        public IList<string> AllowedSans { get; set; } = new List<string>();
+
+        public IList<string> KmsKeys { get; set; } = new List<string>();
+    }
+
+    public sealed class SubmissionLimitOptions
+    {
+        /// <summary>
+        /// Maximum allowed DSSE payload size, in bytes, after base64 decoding.
+        /// </summary>
+        public int MaxPayloadBytes { get; set; } = 2 * 1024 * 1024;
+
+        /// <summary>
+        /// Maximum number of DSSE signatures accepted per submission.
+        /// </summary>
+        public int MaxSignatures { get; set; } = 6;
+
+        /// <summary>
+        /// Maximum number of certificates allowed in the leaf-to-root chain.
+        /// </summary>
+        public int MaxCertificateChainEntries { get; set; } = 6;
+    }
+
+    public sealed class RekorOptions
+    {
+        public RekorBackendOptions Primary { get; set; } = new();
+
+        public RekorMirrorOptions Mirror { get; set; } = new();
+    }
+
+    public class RekorBackendOptions
+    {
+        public string? Url { get; set; }
+
+        public int ProofTimeoutMs { get; set; } = 15_000;
+
+        public int PollIntervalMs { get; set; } = 250;
+
+        public int MaxAttempts { get; set; } = 60;
+    }
+
+    public sealed class RekorMirrorOptions : RekorBackendOptions
+    {
+        public bool Enabled { get; set; }
+    }
+
+    public sealed class MongoOptions
+    {
+        public string? Uri { get; set; }
+
+        public string Database { get; set; } = "attestor";
+
+        public string EntriesCollection { get; set; } = "entries";
+
+        public string DedupeCollection { get; set; } = "dedupe";
+
+        public string AuditCollection { get; set; } = "audit";
+
+        public string BulkJobsCollection { get; set; } = "bulk_jobs";
+    }
+
+    public sealed class RedisOptions
+    {
+        public string? Url { get; set; }
+
+        public string? DedupePrefix { get; set; } = "attestor:dedupe:";
+    }
+
+    public sealed class S3Options
+    {
+        public bool Enabled { get; set; }
+
+        public string? Endpoint { get; set; }
+
+        public string? Bucket { get; set; }
+
+        public string? Prefix { get; set; }
+
+        public string? ObjectLockMode { get; set; }
+
+        public bool UseTls { get; set; } = true;
+    }
+
+    public sealed class QuotaOptions
+    {
+        public PerCallerQuotaOptions PerCaller { get; set; } = new();
+
+        public BulkVerificationQuotaOptions Bulk { get; set; } = new();
+    }
+
+    public sealed class PerCallerQuotaOptions
+    {
+        public int Qps { get; set; } = 50;
+
+        public int Burst { get; set; } = 100;
+    }
+
+    public sealed class BulkVerificationQuotaOptions
+    {
+        public int RequestsPerMinute { get; set; } = 6;
+
+        public int MaxItemsPerJob { get; set; } = 100;
+
+        public int MaxQueuedJobs { get; set; } = 20;
+
+        public int MaxConcurrentJobs { get; set; } = 1;
+    }
+
+    public sealed class CacheOptions
+    {
+        public VerificationCacheOptions Verification { get; set; } = new();
+    }
+
+    public sealed class VerificationCacheOptions
+    {
+        public bool Enabled { get; set; } = true;
+
+        public int TtlSeconds { get; set; } = 300;
+    }
+
+    public sealed class TelemetryOptions
+    {
+        public bool EnableLogging { get; set; } = true;
+
+        public bool EnableTracing { get; set; } = false;
+    }
+
+    public sealed class BulkVerificationOptions
+    {
+        public int WorkerPollSeconds { get; set; } = 1;
+
+        public int ItemDelayMilliseconds { get; set; } = 10;
+
+        public int MaxAttemptsPerItem { get; set; } = 1;
+    }
+
+    public sealed class VerificationOptions
+    {
+        public string PolicyId { get; set; } = "default";
+
+        public string PolicyVersion { get; set; } = "1.0.0";
+
+        public int MinimumSignatures { get; set; } = 1;
+
+        public int? FreshnessMaxAgeMinutes { get; set; }
+
+        public int? FreshnessWarnAgeMinutes { get; set; }
+
+        public bool RequireTransparencyInclusion { get; set; } = true;
+
+        public bool RequireCheckpoint { get; set; } = true;
+
+        public bool RequireBundleForSignatureValidation { get; set; } = false;
+
+        public bool RequireWitnessEndorsement { get; set; } = false;
+    }
+
+    public sealed class TransparencyWitnessOptions
+    {
+        public bool Enabled { get; set; }
+
+        public string? BaseUrl { get; set; }
+
+        public string? ApiKey { get; set; }
+
+        public int RequestTimeoutMs { get; set; } = 15_000;
+
+        public int CacheTtlSeconds { get; set; } = 900;
+
+        public string? AggregatorId { get; set; }
+    }
+
+    public sealed class SigningOptions
+    {
+        public IList<string> PreferredProviders { get; set; } = new List<string>();
+
+        public IList<SigningKeyOptions> Keys { get; set; } = new List<SigningKeyOptions>();
+
+        public SigningKmsOptions? Kms { get; set; }
+    }
+
+    public sealed class SigningKmsOptions
+    {
+        public bool Enabled { get; set; } = true;
+
+        public string? RootPath { get; set; }
+
+        public string? Password { get; set; }
+
+        public string Algorithm { get; set; } = "ES256K";
+
+        public int? KeyDerivationIterations { get; set; }
+    }
+
+    public sealed class SigningKeyOptions
+    {
+        public bool Enabled { get; set; } = true;
+
+        public string KeyId { get; set; } = string.Empty;
+
+        public string? ProviderKeyId { get; set; }
+
+        public string? Provider { get; set; }
+
+        public string? Mode { get; set; }
+
+        public string? Algorithm { get; set; }
+
+        public string? MaterialFormat { get; set; }
+
+        public string? Material { get; set; }
+
+        public string? MaterialPath { get; set; }
+
+        public string? MaterialPassphrase { get; set; }
+
+        public string? KmsKey { get; set; }
+
+        public string? KmsVersionId { get; set; }
+
+        public IList<string> CertificateChain { get; set; } = new List<string>();
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Signing/AttestationSignRequest.cs

@@ -0,0 +1,50 @@
+using System.Collections.Generic;
+using StellaOps.Attestor.Core.Submission;
+
+namespace StellaOps.Attestor.Core.Signing;
+
+/// <summary>
+/// Input contract for attestation signing requests.
+/// </summary>
+public sealed class AttestationSignRequest
+{
+    /// <summary>
+    /// Identifier of the signing key to use.
+    /// </summary>
+    public string KeyId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// DSSE payload type (MIME).
+    /// </summary>
+    public string PayloadType { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Base64 encoded payload.
+    /// </summary>
+    public string PayloadBase64 { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Optional signing mode override (e.g. keyless, kms).
+    /// </summary>
+    public string? Mode { get; set; }
+
+    /// <summary>
+    /// Optional certificate chain for keyless signatures.
+    /// </summary>
+    public IList<string> CertificateChain { get; set; } = new List<string>();
+
+    /// <summary>
+    /// Artifact metadata that will be embedded in the submission meta.
+    /// </summary>
+    public AttestorSubmissionRequest.ArtifactInfo Artifact { get; set; } = new();
+
+    /// <summary>
+    /// Preferred transparency log backend ("primary", "mirror", "both").
+    /// </summary>
+    public string LogPreference { get; set; } = "primary";
+
+    /// <summary>
+    /// Whether the resulting bundle should be archived.
+    /// </summary>
+    public bool Archive { get; set; } = true;
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Signing/AttestationSignResult.cs

@@ -0,0 +1,24 @@
+using System;
+using StellaOps.Attestor.Core.Submission;
+
+namespace StellaOps.Attestor.Core.Signing;
+
+/// <summary>
+/// Represents the signed DSSE bundle ready for Rekor submission.
+/// </summary>
+public sealed class AttestationSignResult
+{
+    public AttestorSubmissionRequest.SubmissionBundle Bundle { get; init; } = new();
+
+    public AttestorSubmissionRequest.SubmissionMeta Meta { get; init; } = new();
+
+    public string KeyId { get; init; } = string.Empty;
+
+    public string Algorithm { get; init; } = string.Empty;
+
+    public string Mode { get; init; } = string.Empty;
+
+    public string Provider { get; init; } = string.Empty;
+
+    public DateTimeOffset SignedAt { get; init; } = DateTimeOffset.UtcNow;
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Signing/AttestorSigningException.cs

@@ -0,0 +1,20 @@
+using System;
+
+namespace StellaOps.Attestor.Core.Signing;
+
+public sealed class AttestorSigningException : Exception
+{
+    public AttestorSigningException(string code, string message)
+        : base(message)
+    {
+        Code = string.IsNullOrWhiteSpace(code) ? "signing_error" : code;
+    }
+
+    public AttestorSigningException(string code, string message, Exception innerException)
+        : base(message, innerException)
+    {
+        Code = string.IsNullOrWhiteSpace(code) ? "signing_error" : code;
+    }
+
+    public string Code { get; }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Signing/DssePreAuthenticationEncoding.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Buffers.Binary;
+using System.Text;
+
+namespace StellaOps.Attestor.Core.Signing;
+
+/// <summary>
+/// Computes DSSE pre-authentication encoding (PAE) for payload signing.
+/// </summary>
+public static class DssePreAuthenticationEncoding
+{
+    private static readonly byte[] Prefix = Encoding.ASCII.GetBytes("DSSEv1");
+
+    public static byte[] Compute(string payloadType, ReadOnlySpan<byte> payload)
+    {
+        var header = Encoding.UTF8.GetBytes(payloadType ?? string.Empty);
+        var buffer = new byte[Prefix.Length + sizeof(long) + header.Length + sizeof(long) + payload.Length];
+        var offset = 0;
+
+        Prefix.CopyTo(buffer, offset);
+        offset += Prefix.Length;
+
+        BinaryPrimitives.WriteUInt64BigEndian(buffer.AsSpan(offset, sizeof(long)), (ulong)header.Length);
+        offset += sizeof(long);
+
+        header.CopyTo(buffer, offset);
+        offset += header.Length;
+
+        BinaryPrimitives.WriteUInt64BigEndian(buffer.AsSpan(offset, sizeof(long)), (ulong)payload.Length);
+        offset += sizeof(long);
+
+        payload.CopyTo(buffer.AsSpan(offset));
+
+        return buffer;
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Signing/IAttestationSigningService.cs

@@ -0,0 +1,13 @@
+using System.Threading;
+using System.Threading.Tasks;
+using StellaOps.Attestor.Core.Submission;
+
+namespace StellaOps.Attestor.Core.Signing;
+
+public interface IAttestationSigningService
+{
+    Task<AttestationSignResult> SignAsync(
+        AttestationSignRequest request,
+        SubmissionContext context,
+        CancellationToken cancellationToken = default);
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/StellaOps.Attestor.Core.csproj

@@ -1,9 +1,13 @@
-<Project Sdk="Microsoft.NET.Sdk">
-  <PropertyGroup>
-    <TargetFramework>net10.0</TargetFramework>
-    <LangVersion>preview</LangVersion>
-    <Nullable>enable</Nullable>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
-  </PropertyGroup>
-</Project>
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <LangVersion>preview</LangVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\__Libraries\StellaOps.Cryptography\StellaOps.Cryptography.csproj" />
+    <ProjectReference Include="..\..\..\__Libraries\StellaOps.Cryptography.Kms\StellaOps.Cryptography.Kms.csproj" />
+  </ItemGroup>
+</Project>

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Storage/AttestorEntry.cs

@@ -1,105 +1,128 @@
-using System;
-using System.Collections.Generic;
-
-namespace StellaOps.Attestor.Core.Storage;
-
-/// <summary>
-/// Canonical representation of a Rekor entry persisted in Mongo.
-/// </summary>
-public sealed class AttestorEntry
-{
-    public string RekorUuid { get; init; } = string.Empty;
-
-    public ArtifactDescriptor Artifact { get; init; } = new();
-
-    public string BundleSha256 { get; init; } = string.Empty;
-
-    public long? Index { get; init; }
-
-    public ProofDescriptor? Proof { get; init; }
-
-    public LogDescriptor Log { get; init; } = new();
-
-    public DateTimeOffset CreatedAt { get; init; }
-
-    public string Status { get; init; } = "pending";
-
-    public SignerIdentityDescriptor SignerIdentity { get; init; } = new();
-
-    public LogReplicaDescriptor? Mirror { get; init; }
-
-    public sealed class ArtifactDescriptor
-    {
-        public string Sha256 { get; init; } = string.Empty;
-
-        public string Kind { get; init; } = string.Empty;
-
-        public string? ImageDigest { get; init; }
-
-        public string? SubjectUri { get; init; }
-    }
-
-    public sealed class ProofDescriptor
-    {
-        public CheckpointDescriptor? Checkpoint { get; init; }
-
-        public InclusionDescriptor? Inclusion { get; init; }
-    }
-
-    public sealed class CheckpointDescriptor
-    {
-        public string? Origin { get; init; }
-
-        public long Size { get; init; }
-
-        public string? RootHash { get; init; }
-
-        public DateTimeOffset? Timestamp { get; init; }
-    }
-
-    public sealed class InclusionDescriptor
-    {
-        public string? LeafHash { get; init; }
-
-        public IReadOnlyList<string> Path { get; init; } = Array.Empty<string>();
-    }
-
-    public sealed class LogDescriptor
-    {
-        public string Backend { get; init; } = "primary";
-
-        public string Url { get; init; } = string.Empty;
-
-        public string? LogId { get; init; }
-    }
-
-    public sealed class SignerIdentityDescriptor
-    {
-        public string Mode { get; init; } = string.Empty;
-
-        public string? Issuer { get; init; }
-
-        public string? SubjectAlternativeName { get; init; }
-
-        public string? KeyId { get; init; }
-    }
-
-    public sealed class LogReplicaDescriptor
-    {
-        public string Backend { get; init; } = string.Empty;
-
-        public string Url { get; init; } = string.Empty;
-
-        public string? Uuid { get; init; }
-
-        public long? Index { get; init; }
-
-        public string Status { get; init; } = "pending";
-
-        public ProofDescriptor? Proof { get; init; }
-
-        public string? LogId { get; init; }
-
-        public string? Error { get; init; }
-    }
-}
+using System;
+using System.Collections.Generic;
+
+namespace StellaOps.Attestor.Core.Storage;
+
+/// <summary>
+/// Canonical representation of a Rekor entry persisted in Mongo.
+/// </summary>
+public sealed class AttestorEntry
+{
+    public string RekorUuid { get; init; } = string.Empty;
+
+    public ArtifactDescriptor Artifact { get; init; } = new();
+
+    public string BundleSha256 { get; init; } = string.Empty;
+
+    public long? Index { get; init; }
+
+    public ProofDescriptor? Proof { get; init; }
+
+    public WitnessDescriptor? Witness { get; init; }
+
+    public LogDescriptor Log { get; init; } = new();
+
+    public DateTimeOffset CreatedAt { get; init; }
+
+    public string Status { get; init; } = "pending";
+
+    public SignerIdentityDescriptor SignerIdentity { get; init; } = new();
+
+    public LogReplicaDescriptor? Mirror { get; init; }
+
+    public sealed class ArtifactDescriptor
+    {
+        public string Sha256 { get; init; } = string.Empty;
+
+        public string Kind { get; init; } = string.Empty;
+
+        public string? ImageDigest { get; init; }
+
+        public string? SubjectUri { get; init; }
+    }
+
+    public sealed class ProofDescriptor
+    {
+        public CheckpointDescriptor? Checkpoint { get; init; }
+
+        public InclusionDescriptor? Inclusion { get; init; }
+    }
+
+    public sealed class WitnessDescriptor
+    {
+        public string Aggregator { get; init; } = string.Empty;
+
+        public string Status { get; init; } = "unknown";
+
+        public string? RootHash { get; init; }
+
+        public DateTimeOffset RetrievedAt { get; init; }
+
+        public string? Statement { get; init; }
+
+        public string? Signature { get; init; }
+
+        public string? KeyId { get; init; }
+
+        public string? Error { get; init; }
+    }
+
+    public sealed class CheckpointDescriptor
+    {
+        public string? Origin { get; init; }
+
+        public long Size { get; init; }
+
+        public string? RootHash { get; init; }
+
+        public DateTimeOffset? Timestamp { get; init; }
+    }
+
+    public sealed class InclusionDescriptor
+    {
+        public string? LeafHash { get; init; }
+
+        public IReadOnlyList<string> Path { get; init; } = Array.Empty<string>();
+    }
+
+    public sealed class LogDescriptor
+    {
+        public string Backend { get; init; } = "primary";
+
+        public string Url { get; init; } = string.Empty;
+
+        public string? LogId { get; init; }
+    }
+
+    public sealed class SignerIdentityDescriptor
+    {
+        public string Mode { get; init; } = string.Empty;
+
+        public string? Issuer { get; init; }
+
+        public string? SubjectAlternativeName { get; init; }
+
+        public string? KeyId { get; init; }
+    }
+
+    public sealed class LogReplicaDescriptor
+    {
+        public string Backend { get; init; } = string.Empty;
+
+        public string Url { get; init; } = string.Empty;
+
+        public string? Uuid { get; init; }
+
+        public long? Index { get; init; }
+
+        public string Status { get; init; } = "pending";
+
+        public ProofDescriptor? Proof { get; init; }
+
+        public string? LogId { get; init; }
+
+        public string? Error { get; init; }
+
+        public WitnessDescriptor? Witness { get; init; }
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Storage/AttestorEntryContinuationToken.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Globalization;
+using System.Text;
+
+namespace StellaOps.Attestor.Core.Storage;
+
+/// <summary>
+/// Encodes and decodes pagination state for attestor entry listings.
+/// </summary>
+public static class AttestorEntryContinuationToken
+{
+    private const char Separator = '|';
+
+    public readonly record struct Cursor(DateTimeOffset CreatedAt, string RekorUuid);
+
+    public static string Encode(DateTimeOffset createdAt, string rekorUuid)
+    {
+        ArgumentException.ThrowIfNullOrEmpty(rekorUuid);
+
+        var ticksText = createdAt.UtcTicks.ToString(CultureInfo.InvariantCulture);
+        var payload = string.Concat(ticksText, Separator, rekorUuid);
+        return Convert.ToBase64String(Encoding.UTF8.GetBytes(payload));
+    }
+
+    public static Cursor Parse(string token)
+    {
+        if (!TryParse(token, out var cursor))
+        {
+            throw new FormatException("Invalid attestor continuation token.");
+        }
+
+        return cursor;
+    }
+
+    public static bool TryParse(string? token, out Cursor cursor)
+    {
+        cursor = default;
+        if (string.IsNullOrWhiteSpace(token))
+        {
+            return false;
+        }
+
+        byte[] data;
+        try
+        {
+            data = Convert.FromBase64String(token);
+        }
+        catch (FormatException)
+        {
+            return false;
+        }
+
+        var decoded = Encoding.UTF8.GetString(data);
+        var separatorIndex = decoded.IndexOf(Separator, StringComparison.Ordinal);
+        if (separatorIndex <= 0 || separatorIndex == decoded.Length - 1)
+        {
+            return false;
+        }
+
+        var ticksSpan = decoded.AsSpan(0, separatorIndex);
+        if (!long.TryParse(ticksSpan, NumberStyles.Integer, CultureInfo.InvariantCulture, out var ticks))
+        {
+            return false;
+        }
+
+        var uuid = decoded[(separatorIndex + 1)..];
+        if (string.IsNullOrEmpty(uuid))
+        {
+            return false;
+        }
+
+        try
+        {
+            var createdAt = new DateTimeOffset(ticks, TimeSpan.Zero);
+            cursor = new Cursor(createdAt, uuid);
+            return true;
+        }
+        catch (ArgumentOutOfRangeException)
+        {
+            return false;
+        }
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Storage/AttestorEntryQuery.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+
+namespace StellaOps.Attestor.Core.Storage;
+
+/// <summary>
+/// Query parameters for listing attestor entries.
+/// </summary>
+public sealed class AttestorEntryQuery
+{
+    public string? Subject { get; init; }
+
+    public string? Type { get; init; }
+
+    public string? Issuer { get; init; }
+
+    public string? Scope { get; init; }
+
+    public DateTimeOffset? CreatedAfter { get; init; }
+
+    public DateTimeOffset? CreatedBefore { get; init; }
+
+    public int PageSize { get; init; } = 50;
+
+    public string? ContinuationToken { get; init; }
+}
+
+/// <summary>
+/// Represents a paginated page of attestor entries.
+/// </summary>
+public sealed class AttestorEntryQueryResult
+{
+    public IReadOnlyList<AttestorEntry> Items { get; init; } = Array.Empty<AttestorEntry>();
+
+    public string? ContinuationToken { get; init; }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Storage/IAttestorArchiveStore.cs

@@ -3,7 +3,9 @@ using System.Threading.Tasks;
 
 namespace StellaOps.Attestor.Core.Storage;
 
-public interface IAttestorArchiveStore
-{
-    Task ArchiveBundleAsync(AttestorArchiveBundle bundle, CancellationToken cancellationToken = default);
-}
+public interface IAttestorArchiveStore
+{
+    Task ArchiveBundleAsync(AttestorArchiveBundle bundle, CancellationToken cancellationToken = default);
+
+    Task<AttestorArchiveBundle?> GetBundleAsync(string bundleSha256, string rekorUuid, CancellationToken cancellationToken = default);
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Storage/IAttestorEntryRepository.cs

@@ -8,9 +8,11 @@ public interface IAttestorEntryRepository
 {
     Task<AttestorEntry?> GetByBundleShaAsync(string bundleSha256, CancellationToken cancellationToken = default);
 
-    Task<AttestorEntry?> GetByUuidAsync(string rekorUuid, CancellationToken cancellationToken = default);
-
-    Task<IReadOnlyList<AttestorEntry>> GetByArtifactShaAsync(string artifactSha256, CancellationToken cancellationToken = default);
-
-    Task SaveAsync(AttestorEntry entry, CancellationToken cancellationToken = default);
-}
+    Task<AttestorEntry?> GetByUuidAsync(string rekorUuid, CancellationToken cancellationToken = default);
+
+    Task<IReadOnlyList<AttestorEntry>> GetByArtifactShaAsync(string artifactSha256, CancellationToken cancellationToken = default);
+
+    Task SaveAsync(AttestorEntry entry, CancellationToken cancellationToken = default);
+
+    Task<AttestorEntryQueryResult> QueryAsync(AttestorEntryQuery query, CancellationToken cancellationToken = default);
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Submission/AttestorSubmissionResult.cs

@@ -1,83 +1,116 @@
-using System;
-using System.Collections.Generic;
-using System.Text.Json.Serialization;
-
-namespace StellaOps.Attestor.Core.Submission;
-
-/// <summary>
-/// Result returned to callers after processing a submission.
-/// </summary>
-public sealed class AttestorSubmissionResult
-{
-    [JsonPropertyName("uuid")]
-    public string? Uuid { get; set; }
-
-    [JsonPropertyName("index")]
-    public long? Index { get; set; }
-
-    [JsonPropertyName("proof")]
-    public RekorProof? Proof { get; set; }
-
-    [JsonPropertyName("logURL")]
-    public string? LogUrl { get; set; }
-
-    [JsonPropertyName("status")]
-    public string Status { get; set; } = "pending";
-
-    [JsonPropertyName("mirror")]
-    public MirrorLog? Mirror { get; set; }
-
-    public sealed class RekorProof
-    {
-        [JsonPropertyName("checkpoint")]
-        public Checkpoint? Checkpoint { get; set; }
-
-        [JsonPropertyName("inclusion")]
-        public InclusionProof? Inclusion { get; set; }
-    }
-
-    public sealed class Checkpoint
-    {
-        [JsonPropertyName("origin")]
-        public string? Origin { get; set; }
-
-        [JsonPropertyName("size")]
-        public long Size { get; set; }
-
-        [JsonPropertyName("rootHash")]
-        public string? RootHash { get; set; }
-
-        [JsonPropertyName("timestamp")]
-        public string? Timestamp { get; set; }
-    }
-
-    public sealed class InclusionProof
-    {
-        [JsonPropertyName("leafHash")]
-        public string? LeafHash { get; set; }
-
-        [JsonPropertyName("path")]
-        public IReadOnlyList<string> Path { get; init; } = Array.Empty<string>();
-    }
-
-    public sealed class MirrorLog
-    {
-        [JsonPropertyName("uuid")]
-        public string? Uuid { get; set; }
-
-        [JsonPropertyName("index")]
-        public long? Index { get; set; }
-
-        [JsonPropertyName("logURL")]
-        public string? LogUrl { get; set; }
-
-        [JsonPropertyName("status")]
-        public string Status { get; set; } = "pending";
-
-        [JsonPropertyName("proof")]
-        public RekorProof? Proof { get; set; }
-
-        [JsonPropertyName("error")]
-        public string? Error { get; set; }
-    }
-}
+using System;
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Attestor.Core.Submission;
+
+/// <summary>
+/// Result returned to callers after processing a submission.
+/// </summary>
+public sealed class AttestorSubmissionResult
+{
+    [JsonPropertyName("uuid")]
+    public string? Uuid { get; set; }
+
+    [JsonPropertyName("index")]
+    public long? Index { get; set; }
+
+    [JsonPropertyName("proof")]
+    public RekorProof? Proof { get; set; }
+
+    [JsonPropertyName("logURL")]
+    public string? LogUrl { get; set; }
+
+    [JsonPropertyName("status")]
+    public string Status { get; set; } = "pending";
+
+    [JsonPropertyName("mirror")]
+    public MirrorLog? Mirror { get; set; }
+
+    [JsonPropertyName("witness")]
+    public WitnessStatement? Witness { get; set; }
+
+    public sealed class RekorProof
+    {
+        [JsonPropertyName("checkpoint")]
+        public Checkpoint? Checkpoint { get; set; }
+
+        [JsonPropertyName("inclusion")]
+        public InclusionProof? Inclusion { get; set; }
+    }
+
+    public sealed class Checkpoint
+    {
+        [JsonPropertyName("origin")]
+        public string? Origin { get; set; }
+
+        [JsonPropertyName("size")]
+        public long Size { get; set; }
+
+        [JsonPropertyName("rootHash")]
+        public string? RootHash { get; set; }
+
+        [JsonPropertyName("timestamp")]
+        public string? Timestamp { get; set; }
+    }
+
+    public sealed class InclusionProof
+    {
+        [JsonPropertyName("leafHash")]
+        public string? LeafHash { get; set; }
+
+        [JsonPropertyName("path")]
+        public IReadOnlyList<string> Path { get; init; } = Array.Empty<string>();
+    }
+
+    public sealed class MirrorLog
+    {
+        [JsonPropertyName("uuid")]
+        public string? Uuid { get; set; }
+
+        [JsonPropertyName("index")]
+        public long? Index { get; set; }
+
+        [JsonPropertyName("logURL")]
+        public string? LogUrl { get; set; }
+
+        [JsonPropertyName("status")]
+        public string Status { get; set; } = "pending";
+
+        [JsonPropertyName("proof")]
+        public RekorProof? Proof { get; set; }
+
+        [JsonPropertyName("error")]
+        public string? Error { get; set; }
+
+        [JsonPropertyName("witness")]
+        public WitnessStatement? Witness { get; set; }
+    }
+
+    public sealed class WitnessStatement
+    {
+        [JsonPropertyName("aggregator")]
+        public string? Aggregator { get; set; }
+
+        [JsonPropertyName("status")]
+        public string Status { get; set; } = "unknown";
+
+        [JsonPropertyName("rootHash")]
+        public string? RootHash { get; set; }
+
+        [JsonPropertyName("retrievedAt")]
+        public string? RetrievedAt { get; set; }
+
+        [JsonPropertyName("statement")]
+        public string? Statement { get; set; }
+
+        [JsonPropertyName("signature")]
+        public string? Signature { get; set; }
+
+        [JsonPropertyName("keyId")]
+        public string? KeyId { get; set; }
+
+        [JsonPropertyName("error")]
+        public string? Error { get; set; }
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Submission/AttestorSubmissionValidator.cs

@@ -12,19 +12,24 @@ public sealed class AttestorSubmissionValidator
     private static readonly string[] AllowedKinds = ["sbom", "report", "vex-export"];
 
     private readonly IDsseCanonicalizer _canonicalizer;
-    private readonly HashSet<string> _allowedModes;
-
-    public AttestorSubmissionValidator(IDsseCanonicalizer canonicalizer, IEnumerable<string>? allowedModes = null)
-    {
-        _canonicalizer = canonicalizer ?? throw new ArgumentNullException(nameof(canonicalizer));
-        _allowedModes = allowedModes is null
-            ? new HashSet<string>(StringComparer.OrdinalIgnoreCase)
-            : new HashSet<string>(allowedModes, StringComparer.OrdinalIgnoreCase);
-    }
-
-    public async Task<AttestorSubmissionValidationResult> ValidateAsync(AttestorSubmissionRequest request, CancellationToken cancellationToken = default)
-    {
-        ArgumentNullException.ThrowIfNull(request);
+    private readonly HashSet<string> _allowedModes;
+    private readonly AttestorSubmissionConstraints _constraints;
+
+    public AttestorSubmissionValidator(
+        IDsseCanonicalizer canonicalizer,
+        IEnumerable<string>? allowedModes = null,
+        AttestorSubmissionConstraints? constraints = null)
+    {
+        _canonicalizer = canonicalizer ?? throw new ArgumentNullException(nameof(canonicalizer));
+        _allowedModes = allowedModes is null
+            ? new HashSet<string>(StringComparer.OrdinalIgnoreCase)
+            : new HashSet<string>(allowedModes, StringComparer.OrdinalIgnoreCase);
+        _constraints = constraints ?? AttestorSubmissionConstraints.Default;
+    }
+
+    public async Task<AttestorSubmissionValidationResult> ValidateAsync(AttestorSubmissionRequest request, CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(request);
 
         if (request.Bundle is null)
         {
@@ -42,20 +47,25 @@ public sealed class AttestorSubmissionValidator
         }
 
         if (string.IsNullOrWhiteSpace(request.Bundle.Dsse.PayloadBase64))
-        {
-            throw new AttestorValidationException("payload_missing", "DSSE payload must be provided.");
-        }
-
-        if (request.Bundle.Dsse.Signatures.Count == 0)
-        {
-            throw new AttestorValidationException("signature_missing", "At least one DSSE signature is required.");
-        }
-
-        if (_allowedModes.Count > 0 && !string.IsNullOrWhiteSpace(request.Bundle.Mode) && !_allowedModes.Contains(request.Bundle.Mode))
-        {
-            throw new AttestorValidationException("mode_not_allowed", $"Submission mode '{request.Bundle.Mode}' is not permitted.");
-        }
-
+        {
+            throw new AttestorValidationException("payload_missing", "DSSE payload must be provided.");
+        }
+
+        if (request.Bundle.Dsse.Signatures.Count == 0)
+        {
+            throw new AttestorValidationException("signature_missing", "At least one DSSE signature is required.");
+        }
+
+        if (request.Bundle.Dsse.Signatures.Count > _constraints.MaxSignatures)
+        {
+            throw new AttestorValidationException("signature_limit_exceeded", $"A maximum of {_constraints.MaxSignatures} DSSE signatures is permitted per submission.");
+        }
+
+        if (_allowedModes.Count > 0 && !string.IsNullOrWhiteSpace(request.Bundle.Mode) && !_allowedModes.Contains(request.Bundle.Mode))
+        {
+            throw new AttestorValidationException("mode_not_allowed", $"Submission mode '{request.Bundle.Mode}' is not permitted.");
+        }
+
         if (request.Meta is null)
         {
             throw new AttestorValidationException("meta_missing", "Submission metadata is required.");
@@ -86,21 +96,31 @@ public sealed class AttestorSubmissionValidator
             throw new AttestorValidationException("bundle_sha_invalid", "bundleSha256 must be a 64-character hex string.");
         }
 
-        if (Array.IndexOf(AllowedKinds, request.Meta.Artifact.Kind) < 0)
-        {
-            throw new AttestorValidationException("artifact_kind_invalid", $"Artifact kind '{request.Meta.Artifact.Kind}' is not supported.");
-        }
-
-        if (!Base64UrlDecode(request.Bundle.Dsse.PayloadBase64, out _))
-        {
-            throw new AttestorValidationException("payload_invalid_base64", "DSSE payload must be valid base64.");
-        }
-
-        var canonical = await _canonicalizer.CanonicalizeAsync(request, cancellationToken).ConfigureAwait(false);
-        Span<byte> hash = stackalloc byte[32];
-        if (!SHA256.TryHashData(canonical, hash, out _))
-        {
-            throw new AttestorValidationException("bundle_sha_failure", "Failed to compute canonical bundle hash.");
+        if (Array.IndexOf(AllowedKinds, request.Meta.Artifact.Kind) < 0)
+        {
+            throw new AttestorValidationException("artifact_kind_invalid", $"Artifact kind '{request.Meta.Artifact.Kind}' is not supported.");
+        }
+
+        if (request.Bundle.CertificateChain.Count > _constraints.MaxCertificateChainEntries)
+        {
+            throw new AttestorValidationException("certificate_chain_too_long", $"Certificate chain length exceeds {_constraints.MaxCertificateChainEntries} entries.");
+        }
+
+        if (!Base64UrlDecode(request.Bundle.Dsse.PayloadBase64, out var payloadBytes))
+        {
+            throw new AttestorValidationException("payload_invalid_base64", "DSSE payload must be valid base64.");
+        }
+
+        if (payloadBytes.Length > _constraints.MaxPayloadBytes)
+        {
+            throw new AttestorValidationException("payload_too_large", $"DSSE payload exceeds {_constraints.MaxPayloadBytes} bytes limit.");
+        }
+
+        var canonical = await _canonicalizer.CanonicalizeAsync(request, cancellationToken).ConfigureAwait(false);
+        Span<byte> hash = stackalloc byte[32];
+        if (!SHA256.TryHashData(canonical, hash, out _))
+        {
+            throw new AttestorValidationException("bundle_sha_failure", "Failed to compute canonical bundle hash.");
         }
 
         var hashHex = Convert.ToHexString(hash).ToLowerInvariant();
@@ -172,5 +192,41 @@ public sealed class AttestorSubmissionValidator
         }
 
         return value;
-    }
-}
+    }
+}
+
+public sealed class AttestorSubmissionConstraints
+{
+    public static AttestorSubmissionConstraints Default { get; } = new();
+
+    public AttestorSubmissionConstraints(
+        int maxPayloadBytes = 2 * 1024 * 1024,
+        int maxSignatures = 6,
+        int maxCertificateChainEntries = 6)
+    {
+        if (maxPayloadBytes <= 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(maxPayloadBytes), "Max payload bytes must be positive.");
+        }
+
+        if (maxSignatures <= 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(maxSignatures), "Max signatures must be positive.");
+        }
+
+        if (maxCertificateChainEntries <= 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(maxCertificateChainEntries), "Max certificate chain entries must be positive.");
+        }
+
+        MaxPayloadBytes = maxPayloadBytes;
+        MaxSignatures = maxSignatures;
+        MaxCertificateChainEntries = maxCertificateChainEntries;
+    }
+
+    public int MaxPayloadBytes { get; }
+
+    public int MaxSignatures { get; }
+
+    public int MaxCertificateChainEntries { get; }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Transparency/ITransparencyWitnessClient.cs

@@ -0,0 +1,9 @@
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Attestor.Core.Transparency;
+
+public interface ITransparencyWitnessClient
+{
+    Task<TransparencyWitnessObservation?> GetObservationAsync(TransparencyWitnessRequest request, CancellationToken cancellationToken = default);
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Transparency/TransparencyWitnessObservation.cs

@@ -0,0 +1,22 @@
+using System;
+
+namespace StellaOps.Attestor.Core.Transparency;
+
+public sealed class TransparencyWitnessObservation
+{
+    public string Aggregator { get; init; } = string.Empty;
+
+    public string Status { get; init; } = "unknown";
+
+    public string? RootHash { get; init; }
+
+    public DateTimeOffset RetrievedAt { get; init; } = DateTimeOffset.UtcNow;
+
+    public string? Statement { get; init; }
+
+    public string? Signature { get; init; }
+
+    public string? KeyId { get; init; }
+
+    public string? Error { get; init; }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Transparency/TransparencyWitnessRequest.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace StellaOps.Attestor.Core.Transparency;
+
+public sealed record TransparencyWitnessRequest(
+    string Uuid,
+    string Backend,
+    Uri BackendUrl,
+    string? CheckpointRootHash);

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Verification/AttestorVerificationRequest.cs

@@ -5,11 +5,23 @@ namespace StellaOps.Attestor.Core.Verification;
 /// </summary>
 public sealed class AttestorVerificationRequest
 {
-    public string? Uuid { get; set; }
-
-    public Submission.AttestorSubmissionRequest.SubmissionBundle? Bundle { get; set; }
-
-    public string? ArtifactSha256 { get; set; }
-
-    public bool RefreshProof { get; set; }
-}
+    public string? Uuid { get; set; }
+
+    public Submission.AttestorSubmissionRequest.SubmissionBundle? Bundle { get; set; }
+
+    public string? ArtifactSha256 { get; set; }
+
+    public string? Subject { get; set; }
+
+    public string? EnvelopeId { get; set; }
+
+    public string? PolicyVersion { get; set; }
+
+    public bool RefreshProof { get; set; }
+
+    /// <summary>
+    /// When true, verification does not attempt to contact external transparency logs and
+    /// surfaces issues for missing proofs instead.
+    /// </summary>
+    public bool Offline { get; set; }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Verification/AttestorVerificationResult.cs

@@ -11,11 +11,13 @@ public sealed class AttestorVerificationResult
 
     public long? Index { get; init; }
 
-    public string? LogUrl { get; init; }
-
-    public DateTimeOffset CheckedAt { get; init; } = DateTimeOffset.UtcNow;
-
-    public string Status { get; init; } = "unknown";
-
-    public IReadOnlyList<string> Issues { get; init; } = Array.Empty<string>();
-}
+    public string? LogUrl { get; init; }
+
+    public DateTimeOffset CheckedAt { get; init; } = DateTimeOffset.UtcNow;
+
+    public string Status { get; init; } = "unknown";
+
+    public IReadOnlyList<string> Issues { get; init; } = Array.Empty<string>();
+
+    public VerificationReport? Report { get; init; }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Verification/IAttestorVerificationCache.cs

@@ -0,0 +1,13 @@
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace StellaOps.Attestor.Core.Verification;
+
+public interface IAttestorVerificationCache
+{
+    Task<AttestorVerificationResult?> GetAsync(string subject, string envelopeId, string policyVersion, CancellationToken cancellationToken = default);
+
+    Task SetAsync(string subject, string envelopeId, string policyVersion, AttestorVerificationResult result, CancellationToken cancellationToken = default);
+
+    Task InvalidateSubjectAsync(string subject, CancellationToken cancellationToken = default);
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Verification/VerificationReport.cs

@@ -0,0 +1,185 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+
+namespace StellaOps.Attestor.Core.Verification;
+
+public sealed class PolicyEvaluationResult
+{
+    public VerificationSectionStatus Status { get; init; } = VerificationSectionStatus.Skipped;
+
+    public string PolicyId { get; init; } = "default";
+
+    public string PolicyVersion { get; init; } = "0.0.0";
+
+    public string Verdict { get; init; } = "unknown";
+
+    public IReadOnlyList<string> Issues { get; init; } = Array.Empty<string>();
+
+    public IReadOnlyDictionary<string, string> Attributes { get; init; } =
+        ImmutableDictionary<string, string>.Empty;
+}
+
+public sealed class IssuerEvaluationResult
+{
+    public VerificationSectionStatus Status { get; init; } = VerificationSectionStatus.Skipped;
+
+    public string Mode { get; init; } = "unknown";
+
+    public string? Issuer { get; init; }
+
+    public string? SubjectAlternativeName { get; init; }
+
+    public string? KeyId { get; init; }
+
+    public IReadOnlyList<string> Issues { get; init; } = Array.Empty<string>();
+}
+
+public sealed class FreshnessEvaluationResult
+{
+    public VerificationSectionStatus Status { get; init; } = VerificationSectionStatus.Skipped;
+
+    public DateTimeOffset CreatedAt { get; init; }
+
+    public DateTimeOffset EvaluatedAt { get; init; }
+
+    public TimeSpan Age { get; init; }
+
+    public TimeSpan? MaxAge { get; init; }
+
+    public IReadOnlyList<string> Issues { get; init; } = Array.Empty<string>();
+}
+
+public sealed class SignatureEvaluationResult
+{
+    public VerificationSectionStatus Status { get; init; } = VerificationSectionStatus.Skipped;
+
+    public bool BundleProvided { get; init; }
+
+    public int TotalSignatures { get; init; }
+
+    public int VerifiedSignatures { get; init; }
+
+    public int RequiredSignatures { get; init; }
+
+    public IReadOnlyList<string> Issues { get; init; } = Array.Empty<string>();
+}
+
+public sealed class TransparencyEvaluationResult
+{
+    public VerificationSectionStatus Status { get; init; } = VerificationSectionStatus.Skipped;
+
+    public bool ProofPresent { get; init; }
+
+    public bool CheckpointPresent { get; init; }
+
+    public bool InclusionPathPresent { get; init; }
+
+    public bool WitnessPresent { get; init; }
+
+    public bool WitnessMatchesRoot { get; init; }
+
+    public string? WitnessAggregator { get; init; }
+
+    public string WitnessStatus { get; init; } = "missing";
+
+    public IReadOnlyList<string> Issues { get; init; } = Array.Empty<string>();
+}
+
+public sealed class VerificationReport
+{
+    public VerificationSectionStatus OverallStatus { get; }
+
+    public PolicyEvaluationResult Policy { get; }
+
+    public IssuerEvaluationResult Issuer { get; }
+
+    public FreshnessEvaluationResult Freshness { get; }
+
+    public SignatureEvaluationResult Signatures { get; }
+
+    public TransparencyEvaluationResult Transparency { get; }
+
+    public IReadOnlyList<string> Issues { get; }
+
+    public VerificationReport(
+        PolicyEvaluationResult policy,
+        IssuerEvaluationResult issuer,
+        FreshnessEvaluationResult freshness,
+        SignatureEvaluationResult signatures,
+        TransparencyEvaluationResult transparency)
+    {
+        Policy = policy ?? throw new ArgumentNullException(nameof(policy));
+        Issuer = issuer ?? throw new ArgumentNullException(nameof(issuer));
+        Freshness = freshness ?? throw new ArgumentNullException(nameof(freshness));
+        Signatures = signatures ?? throw new ArgumentNullException(nameof(signatures));
+        Transparency = transparency ?? throw new ArgumentNullException(nameof(transparency));
+
+        OverallStatus = DetermineOverallStatus(policy, issuer, freshness, signatures, transparency);
+        Issues = AggregateIssues(policy, issuer, freshness, signatures, transparency);
+    }
+
+    public bool Succeeded => OverallStatus == VerificationSectionStatus.Pass || OverallStatus == VerificationSectionStatus.Warn;
+
+    private static VerificationSectionStatus DetermineOverallStatus(params object[] sections)
+    {
+        var statuses = sections
+            .OfType<object>()
+            .Select(section => section switch
+            {
+                PolicyEvaluationResult p => p.Status,
+                IssuerEvaluationResult i => i.Status,
+                FreshnessEvaluationResult f => f.Status,
+                SignatureEvaluationResult s => s.Status,
+                TransparencyEvaluationResult t => t.Status,
+                _ => VerificationSectionStatus.Skipped
+            })
+            .ToArray();
+
+        if (statuses.Any(status => status == VerificationSectionStatus.Fail))
+        {
+            return VerificationSectionStatus.Fail;
+        }
+
+        if (statuses.Any(status => status == VerificationSectionStatus.Warn))
+        {
+            return VerificationSectionStatus.Warn;
+        }
+
+        if (statuses.All(status => status == VerificationSectionStatus.Skipped))
+        {
+            return VerificationSectionStatus.Skipped;
+        }
+
+        return VerificationSectionStatus.Pass;
+    }
+
+    private static IReadOnlyList<string> AggregateIssues(params object[] sections)
+    {
+        var set = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+        foreach (var section in sections)
+        {
+            var issues = section switch
+            {
+                PolicyEvaluationResult p => p.Issues,
+                IssuerEvaluationResult i => i.Issues,
+                FreshnessEvaluationResult f => f.Issues,
+                SignatureEvaluationResult s => s.Issues,
+                TransparencyEvaluationResult t => t.Issues,
+                _ => Array.Empty<string>()
+            };
+
+            foreach (var issue in issues)
+            {
+                if (!string.IsNullOrWhiteSpace(issue))
+                {
+                    set.Add(issue);
+                }
+            }
+        }
+
+        return set.ToArray();
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Core/Verification/VerificationSectionStatus.cs

@@ -0,0 +1,12 @@
+namespace StellaOps.Attestor.Core.Verification;
+
+/// <summary>
+/// Represents the evaluation status of an individual verification section.
+/// </summary>
+public enum VerificationSectionStatus
+{
+    Pass,
+    Warn,
+    Fail,
+    Skipped
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Bulk/BulkVerificationWorker.cs

@@ -0,0 +1,240 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using StellaOps.Attestor.Core.Bulk;
+using StellaOps.Attestor.Core.Options;
+using StellaOps.Attestor.Core.Observability;
+using StellaOps.Attestor.Core.Verification;
+
+namespace StellaOps.Attestor.Infrastructure.Bulk;
+
+internal sealed class BulkVerificationWorker : BackgroundService
+{
+    private readonly IBulkVerificationJobStore _jobStore;
+    private readonly IAttestorVerificationService _verificationService;
+    private readonly AttestorMetrics _metrics;
+    private readonly AttestorOptions _options;
+    private readonly ILogger<BulkVerificationWorker> _logger;
+    private readonly TimeProvider _timeProvider;
+
+    public BulkVerificationWorker(
+        IBulkVerificationJobStore jobStore,
+        IAttestorVerificationService verificationService,
+        AttestorMetrics metrics,
+        IOptions<AttestorOptions> options,
+        TimeProvider timeProvider,
+        ILogger<BulkVerificationWorker> logger)
+    {
+        _jobStore = jobStore ?? throw new ArgumentNullException(nameof(jobStore));
+        _verificationService = verificationService ?? throw new ArgumentNullException(nameof(verificationService));
+        _metrics = metrics ?? throw new ArgumentNullException(nameof(metrics));
+        _options = options?.Value ?? throw new ArgumentNullException(nameof(options));
+        _timeProvider = timeProvider ?? throw new ArgumentNullException(nameof(timeProvider));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        var pollDelay = TimeSpan.FromSeconds(Math.Max(1, _options.BulkVerification.WorkerPollSeconds));
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                var job = await _jobStore.TryAcquireAsync(stoppingToken).ConfigureAwait(false);
+                if (job is null)
+                {
+                    await Task.Delay(pollDelay, stoppingToken).ConfigureAwait(false);
+                    continue;
+                }
+
+                await ProcessJobAsync(job, stoppingToken).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+            {
+                break;
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Bulk verification worker loop failed.");
+                await Task.Delay(pollDelay, stoppingToken).ConfigureAwait(false);
+            }
+        }
+    }
+
+    internal async Task ProcessJobAsync(BulkVerificationJob job, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(job);
+
+        _logger.LogInformation("Processing bulk verification job {JobId} with {ItemCount} items.", job.Id, job.Items.Count);
+
+        job.StartedAt ??= _timeProvider.GetUtcNow();
+        if (!await PersistAsync(job, cancellationToken).ConfigureAwait(false))
+        {
+            _logger.LogWarning("Failed to persist initial state for job {JobId}.", job.Id);
+        }
+
+        var itemDelay = _options.BulkVerification.ItemDelayMilliseconds > 0
+            ? TimeSpan.FromMilliseconds(_options.BulkVerification.ItemDelayMilliseconds)
+            : TimeSpan.Zero;
+
+        foreach (var item in job.Items.OrderBy(i => i.Index))
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            if (item.Status is not BulkVerificationItemStatus.Pending)
+            {
+                continue;
+            }
+
+            await ExecuteItemAsync(job, item, cancellationToken).ConfigureAwait(false);
+
+            if (itemDelay > TimeSpan.Zero)
+            {
+                try
+                {
+                    await Task.Delay(itemDelay, cancellationToken).ConfigureAwait(false);
+                }
+                catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+                {
+                    break;
+                }
+            }
+        }
+
+        job.CompletedAt = _timeProvider.GetUtcNow();
+        job.Status = job.FailureReason is null ? BulkVerificationJobStatus.Completed : BulkVerificationJobStatus.Failed;
+
+        if (!await PersistAsync(job, cancellationToken).ConfigureAwait(false))
+        {
+            _logger.LogWarning("Failed to persist completion state for job {JobId}.", job.Id);
+        }
+
+        var durationSeconds = (job.CompletedAt - job.StartedAt)?.TotalSeconds ?? 0;
+        var statusTag = job.Status == BulkVerificationJobStatus.Completed && job.FailedCount == 0 ? "succeeded" :
+            job.Status == BulkVerificationJobStatus.Completed ? "completed_with_failures" : "failed";
+
+        _metrics.BulkJobsTotal.Add(1, new KeyValuePair<string, object?>("status", statusTag));
+        _metrics.BulkJobDuration.Record(durationSeconds, new KeyValuePair<string, object?>("status", statusTag));
+
+        _logger.LogInformation("Finished bulk verification job {JobId}. Ran {Processed} items (success: {Success}, failed: {Failed}).",
+            job.Id, job.ProcessedCount, job.SucceededCount, job.FailedCount);
+    }
+
+    private async Task ExecuteItemAsync(BulkVerificationJob job, BulkVerificationJobItem item, CancellationToken cancellationToken)
+    {
+        item.Status = BulkVerificationItemStatus.Running;
+        item.StartedAt = _timeProvider.GetUtcNow();
+        await PersistAsync(job, cancellationToken).ConfigureAwait(false);
+
+        var statusTag = "failed";
+        try
+        {
+            var request = new AttestorVerificationRequest
+            {
+                Uuid = item.Request.Uuid,
+                ArtifactSha256 = item.Request.ArtifactSha256,
+                Subject = item.Request.Subject,
+                EnvelopeId = item.Request.EnvelopeId,
+                PolicyVersion = item.Request.PolicyVersion,
+                RefreshProof = item.Request.RefreshProof
+            };
+
+            var result = await _verificationService.VerifyAsync(request, cancellationToken).ConfigureAwait(false);
+            item.Result = result;
+            item.CompletedAt = _timeProvider.GetUtcNow();
+            item.Status = result.Ok ? BulkVerificationItemStatus.Succeeded : BulkVerificationItemStatus.Failed;
+            statusTag = item.Status == BulkVerificationItemStatus.Succeeded ? "succeeded" : "verification_failed";
+
+            job.ProcessedCount++;
+            if (item.Status == BulkVerificationItemStatus.Succeeded)
+            {
+                job.SucceededCount++;
+            }
+            else
+            {
+                job.FailedCount++;
+            }
+        }
+        catch (AttestorVerificationException verificationEx)
+        {
+            item.CompletedAt = _timeProvider.GetUtcNow();
+            item.Status = BulkVerificationItemStatus.Failed;
+            item.Error = $"{verificationEx.Code}:{verificationEx.Message}";
+            job.ProcessedCount++;
+            job.FailedCount++;
+            job.FailureReason ??= "item_failure";
+            statusTag = "verification_error";
+        }
+        catch (Exception ex)
+        {
+            item.CompletedAt = _timeProvider.GetUtcNow();
+            item.Status = BulkVerificationItemStatus.Failed;
+            item.Error = ex.Message;
+            job.ProcessedCount++;
+            job.FailedCount++;
+            job.FailureReason ??= "worker_exception";
+            _logger.LogError(ex, "Bulk verification item {ItemIndex} failed for job {JobId}.", item.Index, job.Id);
+            statusTag = "exception";
+        }
+
+        if (!await PersistAsync(job, cancellationToken).ConfigureAwait(false))
+        {
+            _logger.LogWarning("Failed to persist progress for job {JobId} item {ItemIndex}.", job.Id, item.Index);
+        }
+
+        _metrics.BulkItemsTotal.Add(1, new KeyValuePair<string, object?>("status", statusTag));
+    }
+
+    private async Task<bool> PersistAsync(BulkVerificationJob job, CancellationToken cancellationToken)
+    {
+        for (var attempt = 0; attempt < 3; attempt++)
+        {
+            if (await _jobStore.TryUpdateAsync(job, cancellationToken).ConfigureAwait(false))
+            {
+                return true;
+            }
+
+            var refreshed = await _jobStore.GetAsync(job.Id, cancellationToken).ConfigureAwait(false);
+            if (refreshed is null)
+            {
+                return false;
+            }
+
+            Synchronize(job, refreshed);
+        }
+
+        return false;
+    }
+
+    private static void Synchronize(BulkVerificationJob target, BulkVerificationJob source)
+    {
+        target.Version = source.Version;
+        target.Status = source.Status;
+        target.CreatedAt = source.CreatedAt;
+        target.StartedAt = source.StartedAt;
+        target.CompletedAt = source.CompletedAt;
+        target.ProcessedCount = source.ProcessedCount;
+        target.SucceededCount = source.SucceededCount;
+        target.FailedCount = source.FailedCount;
+        target.FailureReason = source.FailureReason;
+
+        var sourceItems = source.Items.ToDictionary(i => i.Index);
+        foreach (var item in target.Items)
+        {
+            if (sourceItems.TryGetValue(item.Index, out var updated))
+            {
+                item.Status = updated.Status;
+                item.StartedAt = updated.StartedAt;
+                item.CompletedAt = updated.CompletedAt;
+                item.Result = updated.Result;
+                item.Error = updated.Error;
+            }
+        }
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Bulk/MongoBulkVerificationJobStore.cs

@@ -0,0 +1,343 @@
+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using MongoDB.Bson;
+using MongoDB.Bson.Serialization.Attributes;
+using MongoDB.Driver;
+using StellaOps.Attestor.Core.Bulk;
+using StellaOps.Attestor.Core.Verification;
+
+namespace StellaOps.Attestor.Infrastructure.Bulk;
+
+internal sealed class MongoBulkVerificationJobStore : IBulkVerificationJobStore
+{
+    private static readonly JsonSerializerOptions SerializerOptions = new(JsonSerializerDefaults.Web);
+
+    private readonly IMongoCollection<JobDocument> _collection;
+
+    public MongoBulkVerificationJobStore(IMongoCollection<JobDocument> collection)
+    {
+        _collection = collection ?? throw new ArgumentNullException(nameof(collection));
+    }
+
+    public async Task<BulkVerificationJob> CreateAsync(BulkVerificationJob job, CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(job);
+
+        job.Version = 0;
+        var document = JobDocument.FromDomain(job, SerializerOptions);
+        await _collection.InsertOneAsync(document, cancellationToken: cancellationToken).ConfigureAwait(false);
+        job.Version = document.Version;
+        return job;
+    }
+
+    public async Task<BulkVerificationJob?> GetAsync(string jobId, CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(jobId))
+        {
+            return null;
+        }
+
+        var filter = Builders<JobDocument>.Filter.Eq(doc => doc.Id, jobId);
+        var document = await _collection.Find(filter).FirstOrDefaultAsync(cancellationToken).ConfigureAwait(false);
+        return document?.ToDomain(SerializerOptions);
+    }
+
+    public async Task<BulkVerificationJob?> TryAcquireAsync(CancellationToken cancellationToken = default)
+    {
+        var filter = Builders<JobDocument>.Filter.Eq(doc => doc.Status, BulkVerificationJobStatus.Queued);
+        var update = Builders<JobDocument>.Update
+            .Set(doc => doc.Status, BulkVerificationJobStatus.Running)
+            .Set(doc => doc.StartedAt, DateTimeOffset.UtcNow.UtcDateTime)
+            .Inc(doc => doc.Version, 1);
+
+        var options = new FindOneAndUpdateOptions<JobDocument>
+        {
+            Sort = Builders<JobDocument>.Sort.Ascending(doc => doc.CreatedAt),
+            ReturnDocument = ReturnDocument.After
+        };
+
+        var document = await _collection.FindOneAndUpdateAsync(filter, update, options, cancellationToken).ConfigureAwait(false);
+        return document?.ToDomain(SerializerOptions);
+    }
+
+    public async Task<bool> TryUpdateAsync(BulkVerificationJob job, CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(job);
+
+        var currentVersion = job.Version;
+        var replacement = JobDocument.FromDomain(job, SerializerOptions);
+        replacement.Version = currentVersion + 1;
+
+        var filter = Builders<JobDocument>.Filter.Where(doc => doc.Id == job.Id && doc.Version == currentVersion);
+        var result = await _collection.ReplaceOneAsync(filter, replacement, cancellationToken: cancellationToken).ConfigureAwait(false);
+
+        if (result.ModifiedCount == 0)
+        {
+            return false;
+        }
+
+        job.Version = replacement.Version;
+        return true;
+    }
+
+    public async Task<int> CountQueuedAsync(CancellationToken cancellationToken = default)
+    {
+        var filter = Builders<JobDocument>.Filter.Eq(doc => doc.Status, BulkVerificationJobStatus.Queued);
+        var count = await _collection.CountDocumentsAsync(filter, cancellationToken: cancellationToken).ConfigureAwait(false);
+        return Convert.ToInt32(count);
+    }
+
+    internal sealed class JobDocument
+    {
+        [BsonId]
+        [BsonElement("_id")]
+        public string Id { get; set; } = string.Empty;
+
+        [BsonElement("version")]
+        public int Version { get; set; }
+
+        [BsonElement("status")]
+        [BsonRepresentation(BsonType.String)]
+        public BulkVerificationJobStatus Status { get; set; }
+
+        [BsonElement("createdAt")]
+        public DateTime CreatedAt { get; set; }
+
+        [BsonElement("startedAt")]
+        [BsonIgnoreIfNull]
+        public DateTime? StartedAt { get; set; }
+
+        [BsonElement("completedAt")]
+        [BsonIgnoreIfNull]
+        public DateTime? CompletedAt { get; set; }
+
+        [BsonElement("context")]
+        public JobContextDocument Context { get; set; } = new();
+
+        [BsonElement("items")]
+        public List<JobItemDocument> Items { get; set; } = new();
+
+        [BsonElement("processed")]
+        public int ProcessedCount { get; set; }
+
+        [BsonElement("succeeded")]
+        public int SucceededCount { get; set; }
+
+        [BsonElement("failed")]
+        public int FailedCount { get; set; }
+
+        [BsonElement("failureReason")]
+        [BsonIgnoreIfNull]
+        public string? FailureReason { get; set; }
+
+        public static JobDocument FromDomain(BulkVerificationJob job, JsonSerializerOptions serializerOptions)
+        {
+            return new JobDocument
+            {
+                Id = job.Id,
+                Version = job.Version,
+                Status = job.Status,
+                CreatedAt = job.CreatedAt.UtcDateTime,
+                StartedAt = job.StartedAt?.UtcDateTime,
+                CompletedAt = job.CompletedAt?.UtcDateTime,
+                Context = JobContextDocument.FromDomain(job.Context),
+                Items = JobItemDocument.FromDomain(job.Items, serializerOptions),
+                ProcessedCount = job.ProcessedCount,
+                SucceededCount = job.SucceededCount,
+                FailedCount = job.FailedCount,
+                FailureReason = job.FailureReason
+            };
+        }
+
+        public BulkVerificationJob ToDomain(JsonSerializerOptions serializerOptions)
+        {
+            return new BulkVerificationJob
+            {
+                Id = Id,
+                Version = Version,
+                Status = Status,
+                CreatedAt = DateTime.SpecifyKind(CreatedAt, DateTimeKind.Utc),
+                StartedAt = StartedAt is null ? null : DateTime.SpecifyKind(StartedAt.Value, DateTimeKind.Utc),
+                CompletedAt = CompletedAt is null ? null : DateTime.SpecifyKind(CompletedAt.Value, DateTimeKind.Utc),
+                Context = Context.ToDomain(),
+                Items = JobItemDocument.ToDomain(Items, serializerOptions),
+                ProcessedCount = ProcessedCount,
+                SucceededCount = SucceededCount,
+                FailedCount = FailedCount,
+                FailureReason = FailureReason
+            };
+        }
+    }
+
+    internal sealed class JobContextDocument
+    {
+        [BsonElement("tenant")]
+        [BsonIgnoreIfNull]
+        public string? Tenant { get; set; }
+
+        [BsonElement("requestedBy")]
+        [BsonIgnoreIfNull]
+        public string? RequestedBy { get; set; }
+
+        [BsonElement("clientId")]
+        [BsonIgnoreIfNull]
+        public string? ClientId { get; set; }
+
+        [BsonElement("scopes")]
+        public List<string> Scopes { get; set; } = new();
+
+        public static JobContextDocument FromDomain(BulkVerificationJobContext context)
+        {
+            return new JobContextDocument
+            {
+                Tenant = context.Tenant,
+                RequestedBy = context.RequestedBy,
+                ClientId = context.ClientId,
+                Scopes = new List<string>(context.Scopes)
+            };
+        }
+
+        public BulkVerificationJobContext ToDomain()
+        {
+            return new BulkVerificationJobContext
+            {
+                Tenant = Tenant,
+                RequestedBy = RequestedBy,
+                ClientId = ClientId,
+                Scopes = new List<string>(Scopes ?? new List<string>())
+            };
+        }
+    }
+
+    internal sealed class JobItemDocument
+    {
+        [BsonElement("index")]
+        public int Index { get; set; }
+
+        [BsonElement("request")]
+        public ItemRequestDocument Request { get; set; } = new();
+
+        [BsonElement("status")]
+        [BsonRepresentation(BsonType.String)]
+        public BulkVerificationItemStatus Status { get; set; }
+
+        [BsonElement("startedAt")]
+        [BsonIgnoreIfNull]
+        public DateTime? StartedAt { get; set; }
+
+        [BsonElement("completedAt")]
+        [BsonIgnoreIfNull]
+        public DateTime? CompletedAt { get; set; }
+
+        [BsonElement("result")]
+        [BsonIgnoreIfNull]
+        public string? ResultJson { get; set; }
+
+        [BsonElement("error")]
+        [BsonIgnoreIfNull]
+        public string? Error { get; set; }
+
+        public static List<JobItemDocument> FromDomain(IEnumerable<BulkVerificationJobItem> items, JsonSerializerOptions serializerOptions)
+        {
+            var list = new List<JobItemDocument>();
+
+            foreach (var item in items)
+            {
+                list.Add(new JobItemDocument
+                {
+                    Index = item.Index,
+                    Request = ItemRequestDocument.FromDomain(item.Request),
+                    Status = item.Status,
+                    StartedAt = item.StartedAt?.UtcDateTime,
+                    CompletedAt = item.CompletedAt?.UtcDateTime,
+                    ResultJson = item.Result is null ? null : JsonSerializer.Serialize(item.Result, serializerOptions),
+                    Error = item.Error
+                });
+            }
+
+            return list;
+        }
+
+        public static IList<BulkVerificationJobItem> ToDomain(IEnumerable<JobItemDocument> documents, JsonSerializerOptions serializerOptions)
+        {
+            var list = new List<BulkVerificationJobItem>();
+
+            foreach (var document in documents)
+            {
+                AttestorVerificationResult? result = null;
+                if (!string.IsNullOrWhiteSpace(document.ResultJson))
+                {
+                    result = JsonSerializer.Deserialize<AttestorVerificationResult>(document.ResultJson, serializerOptions);
+                }
+
+                list.Add(new BulkVerificationJobItem
+                {
+                    Index = document.Index,
+                    Request = document.Request.ToDomain(),
+                    Status = document.Status,
+                    StartedAt = document.StartedAt is null ? null : DateTime.SpecifyKind(document.StartedAt.Value, DateTimeKind.Utc),
+                    CompletedAt = document.CompletedAt is null ? null : DateTime.SpecifyKind(document.CompletedAt.Value, DateTimeKind.Utc),
+                    Result = result,
+                    Error = document.Error
+                });
+            }
+
+            return list;
+        }
+    }
+
+    internal sealed class ItemRequestDocument
+    {
+        [BsonElement("uuid")]
+        [BsonIgnoreIfNull]
+        public string? Uuid { get; set; }
+
+        [BsonElement("artifactSha256")]
+        [BsonIgnoreIfNull]
+        public string? ArtifactSha256 { get; set; }
+
+        [BsonElement("subject")]
+        [BsonIgnoreIfNull]
+        public string? Subject { get; set; }
+
+        [BsonElement("envelopeId")]
+        [BsonIgnoreIfNull]
+        public string? EnvelopeId { get; set; }
+
+        [BsonElement("policyVersion")]
+        [BsonIgnoreIfNull]
+        public string? PolicyVersion { get; set; }
+
+        [BsonElement("refreshProof")]
+        public bool RefreshProof { get; set; }
+
+        public static ItemRequestDocument FromDomain(BulkVerificationItemRequest request)
+        {
+            return new ItemRequestDocument
+            {
+                Uuid = request.Uuid,
+                ArtifactSha256 = request.ArtifactSha256,
+                Subject = request.Subject,
+                EnvelopeId = request.EnvelopeId,
+                PolicyVersion = request.PolicyVersion,
+                RefreshProof = request.RefreshProof
+            };
+        }
+
+        public BulkVerificationItemRequest ToDomain()
+        {
+            return new BulkVerificationItemRequest
+            {
+                Uuid = Uuid,
+                ArtifactSha256 = ArtifactSha256,
+                Subject = Subject,
+                EnvelopeId = EnvelopeId,
+                PolicyVersion = PolicyVersion,
+                RefreshProof = RefreshProof
+            };
+        }
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Offline/AttestorBundleService.cs

@@ -0,0 +1,269 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using StellaOps.Attestor.Core.Offline;
+using StellaOps.Attestor.Core.Options;
+using StellaOps.Attestor.Core.Storage;
+using StellaOps.Attestor.Infrastructure.Storage;
+
+namespace StellaOps.Attestor.Infrastructure.Offline;
+
+internal sealed class AttestorBundleService : IAttestorBundleService
+{
+    private readonly IAttestorEntryRepository _repository;
+    private readonly IAttestorArchiveStore _archiveStore;
+    private readonly TimeProvider _timeProvider;
+    private readonly AttestorOptions _options;
+    private readonly ILogger<AttestorBundleService> _logger;
+
+    public AttestorBundleService(
+        IAttestorEntryRepository repository,
+        IAttestorArchiveStore archiveStore,
+        TimeProvider timeProvider,
+        IOptions<AttestorOptions> options,
+        ILogger<AttestorBundleService> logger)
+    {
+        _repository = repository;
+        _archiveStore = archiveStore;
+        _timeProvider = timeProvider;
+        _options = options.Value;
+        _logger = logger;
+    }
+
+    public async Task<AttestorBundlePackage> ExportAsync(AttestorBundleExportRequest request, CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(request);
+
+        var (entries, continuationToken) = await ResolveEntriesAsync(request, cancellationToken).ConfigureAwait(false);
+        var items = new List<AttestorBundleItem>(entries.Count);
+
+        foreach (var entry in entries
+            .OrderBy(e => e.CreatedAt)
+            .ThenBy(e => e.RekorUuid, StringComparer.Ordinal))
+        {
+            var archiveBundle = await _archiveStore.GetBundleAsync(entry.BundleSha256, entry.RekorUuid, cancellationToken).ConfigureAwait(false);
+            if (archiveBundle is null)
+            {
+                _logger.LogWarning("Archive bundle for {Uuid} ({BundleSha}) unavailable; exporting metadata only.", entry.RekorUuid, entry.BundleSha256);
+                items.Add(new AttestorBundleItem
+                {
+                    Entry = entry,
+                    CanonicalBundle = string.Empty,
+                    Metadata = new Dictionary<string, string>
+                    {
+                        ["archive.missing"] = "true"
+                    }
+                });
+
+                continue;
+            }
+
+            var metadata = archiveBundle.Metadata ?? new Dictionary<string, string>();
+            if (!metadata.ContainsKey("logUrl"))
+            {
+                metadata = new Dictionary<string, string>(metadata)
+                {
+                    ["logUrl"] = entry.Log.Url
+                };
+            }
+
+            items.Add(new AttestorBundleItem
+            {
+                Entry = entry,
+                CanonicalBundle = Convert.ToBase64String(archiveBundle.CanonicalBundleJson),
+                Proof = archiveBundle.ProofJson.Length > 0 ? Convert.ToBase64String(archiveBundle.ProofJson) : null,
+                Metadata = metadata
+            });
+        }
+
+        return new AttestorBundlePackage
+        {
+            Version = AttestorBundleVersions.Current,
+            GeneratedAt = _timeProvider.GetUtcNow(),
+            Items = items,
+            ContinuationToken = continuationToken
+        };
+    }
+
+    public async Task<AttestorBundleImportResult> ImportAsync(AttestorBundlePackage package, CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(package);
+
+        if (!_options.S3.Enabled || _archiveStore is NullAttestorArchiveStore)
+        {
+            var skippedCount = package.Items?.Count ?? 0;
+            _logger.LogWarning("Attestor archive store disabled; skipping import for {Count} bundle item(s).", skippedCount);
+            return new AttestorBundleImportResult
+            {
+                Imported = 0,
+                Updated = 0,
+                Skipped = skippedCount,
+                Issues = new[] { "archive_disabled" }
+            };
+        }
+
+        if (package.Items is null || package.Items.Count == 0)
+        {
+            return new AttestorBundleImportResult
+            {
+                Imported = 0,
+                Updated = 0,
+                Skipped = 0,
+                Issues = Array.Empty<string>()
+            };
+        }
+
+        var imported = 0;
+        var updated = 0;
+        var skipped = 0;
+        var issues = new List<string>();
+
+        foreach (var item in package.Items)
+        {
+            if (item.Entry is null)
+            {
+                skipped++;
+                issues.Add("entry_missing");
+                continue;
+            }
+
+            if (string.IsNullOrWhiteSpace(item.Entry.RekorUuid))
+            {
+                skipped++;
+                issues.Add("uuid_missing");
+                continue;
+            }
+
+            if (string.IsNullOrWhiteSpace(item.Entry.BundleSha256))
+            {
+                skipped++;
+                issues.Add($"bundle_sha_missing:{item.Entry.RekorUuid}");
+                continue;
+            }
+
+            if (string.IsNullOrWhiteSpace(item.CanonicalBundle))
+            {
+                skipped++;
+                issues.Add($"bundle_payload_missing:{item.Entry.RekorUuid}");
+                continue;
+            }
+
+            byte[] canonicalBytes;
+            try
+            {
+                canonicalBytes = Convert.FromBase64String(item.CanonicalBundle);
+            }
+            catch (FormatException)
+            {
+                skipped++;
+                issues.Add($"bundle_payload_invalid_base64:{item.Entry.RekorUuid}");
+                continue;
+            }
+
+            var computedSha = Convert.ToHexString(SHA256.HashData(canonicalBytes)).ToLowerInvariant();
+            if (!string.Equals(computedSha, item.Entry.BundleSha256, StringComparison.OrdinalIgnoreCase))
+            {
+                skipped++;
+                issues.Add($"bundle_hash_mismatch:{item.Entry.RekorUuid}");
+                continue;
+            }
+
+            byte[] proofBytes = Array.Empty<byte>();
+            if (!string.IsNullOrEmpty(item.Proof))
+            {
+                try
+                {
+                    proofBytes = Convert.FromBase64String(item.Proof);
+                }
+                catch (FormatException)
+                {
+                    issues.Add($"proof_invalid_base64:{item.Entry.RekorUuid}");
+                }
+            }
+
+            var archiveBundle = new AttestorArchiveBundle
+            {
+                RekorUuid = item.Entry.RekorUuid,
+                ArtifactSha256 = item.Entry.Artifact.Sha256,
+                BundleSha256 = item.Entry.BundleSha256,
+                CanonicalBundleJson = canonicalBytes,
+                ProofJson = proofBytes,
+                Metadata = item.Metadata ?? new Dictionary<string, string>()
+            };
+
+            await _archiveStore.ArchiveBundleAsync(archiveBundle, cancellationToken).ConfigureAwait(false);
+
+            var existing = await _repository.GetByUuidAsync(item.Entry.RekorUuid, cancellationToken).ConfigureAwait(false);
+            if (existing is null)
+            {
+                imported++;
+            }
+            else
+            {
+                updated++;
+            }
+
+            await _repository.SaveAsync(item.Entry, cancellationToken).ConfigureAwait(false);
+        }
+
+        return new AttestorBundleImportResult
+        {
+            Imported = imported,
+            Updated = updated,
+            Skipped = skipped,
+            Issues = issues
+        };
+    }
+
+    private async Task<(List<AttestorEntry> Entries, string? ContinuationToken)> ResolveEntriesAsync(AttestorBundleExportRequest request, CancellationToken cancellationToken)
+    {
+        var entries = new List<AttestorEntry>();
+
+        if (request.Uuids is { Count: > 0 })
+        {
+            foreach (var uuid in request.Uuids.Where(u => !string.IsNullOrWhiteSpace(u)).Distinct(StringComparer.OrdinalIgnoreCase))
+            {
+                var entry = await _repository.GetByUuidAsync(uuid, cancellationToken).ConfigureAwait(false);
+                if (entry is null)
+                {
+                    _logger.LogWarning("Attestation {Uuid} not found; skipping export entry.", uuid);
+                    continue;
+                }
+
+                entries.Add(entry);
+            }
+
+            return (entries, null);
+        }
+
+        var limit = request.Limit.HasValue
+            ? Math.Clamp(request.Limit.Value, 1, 200)
+            : 100;
+
+        var query = new AttestorEntryQuery
+        {
+            Subject = request.Subject,
+            Type = request.Type,
+            Issuer = request.Issuer,
+            Scope = request.Scope,
+            CreatedAfter = request.CreatedAfter,
+            CreatedBefore = request.CreatedBefore,
+            PageSize = limit,
+            ContinuationToken = request.ContinuationToken
+        };
+
+        var result = await _repository.QueryAsync(query, cancellationToken).ConfigureAwait(false);
+        if (result.Items.Count == 0)
+        {
+            _logger.LogInformation("No attestor entries matched export query.");
+        }
+
+        entries.AddRange(result.Items.Take(limit));
+        return (entries, result.ContinuationToken);
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/ServiceCollectionExtensions.cs

@@ -1,21 +1,24 @@
 using System;
-using Amazon.Runtime;
-using Amazon.S3;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Options;
-using MongoDB.Driver;
-using StackExchange.Redis;
-using StellaOps.Attestor.Core.Options;
-using StellaOps.Attestor.Core.Observability;
-using StellaOps.Attestor.Core.Rekor;
-using StellaOps.Attestor.Core.Storage;
-using StellaOps.Attestor.Core.Submission;
-using StellaOps.Attestor.Infrastructure.Rekor;
-using StellaOps.Attestor.Infrastructure.Storage;
-using StellaOps.Attestor.Infrastructure.Submission;
-using StellaOps.Attestor.Core.Verification;
-using StellaOps.Attestor.Infrastructure.Verification;
+using Amazon.Runtime;
+using Amazon.S3;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using MongoDB.Driver;
+using StackExchange.Redis;
+using StellaOps.Attestor.Core.Options;
+using StellaOps.Attestor.Core.Observability;
+using StellaOps.Attestor.Core.Rekor;
+using StellaOps.Attestor.Core.Storage;
+using StellaOps.Attestor.Core.Submission;
+using StellaOps.Attestor.Core.Transparency;
+using StellaOps.Attestor.Core.Verification;
+using StellaOps.Attestor.Infrastructure.Rekor;
+using StellaOps.Attestor.Infrastructure.Storage;
+using StellaOps.Attestor.Infrastructure.Submission;
+using StellaOps.Attestor.Infrastructure.Transparency;
+using StellaOps.Attestor.Infrastructure.Verification;
 
 namespace StellaOps.Attestor.Infrastructure;
 
@@ -23,7 +26,9 @@ public static class ServiceCollectionExtensions
 {
     public static IServiceCollection AddAttestorInfrastructure(this IServiceCollection services)
     {
-        services.AddSingleton<IDsseCanonicalizer, DefaultDsseCanonicalizer>();
+        services.AddMemoryCache();
+
+        services.AddSingleton<IDsseCanonicalizer, DefaultDsseCanonicalizer>();
         services.AddSingleton(sp =>
         {
             var canonicalizer = sp.GetRequiredService<IDsseCanonicalizer>();
@@ -33,11 +38,34 @@ public static class ServiceCollectionExtensions
         services.AddSingleton<AttestorMetrics>();
         services.AddSingleton<IAttestorSubmissionService, AttestorSubmissionService>();
         services.AddSingleton<IAttestorVerificationService, AttestorVerificationService>();
-        services.AddHttpClient<HttpRekorClient>(client =>
-        {
-            client.Timeout = TimeSpan.FromSeconds(30);
-        });
-        services.AddSingleton<IRekorClient>(sp => sp.GetRequiredService<HttpRekorClient>());
+        services.AddHttpClient<HttpRekorClient>(client =>
+        {
+            client.Timeout = TimeSpan.FromSeconds(30);
+        });
+        services.AddSingleton<IRekorClient>(sp => sp.GetRequiredService<HttpRekorClient>());
+
+        services.AddHttpClient<HttpTransparencyWitnessClient>((sp, client) =>
+        {
+            var options = sp.GetRequiredService<IOptions<AttestorOptions>>().Value;
+            var timeoutMs = options.TransparencyWitness.RequestTimeoutMs;
+            if (timeoutMs <= 0)
+            {
+                timeoutMs = 15_000;
+            }
+
+            client.Timeout = TimeSpan.FromMilliseconds(timeoutMs);
+        });
+
+        services.AddSingleton<ITransparencyWitnessClient>(sp =>
+        {
+            var options = sp.GetRequiredService<IOptions<AttestorOptions>>().Value;
+            if (!options.TransparencyWitness.Enabled || string.IsNullOrWhiteSpace(options.TransparencyWitness.BaseUrl))
+            {
+                return new NullTransparencyWitnessClient();
+            }
+
+            return sp.GetRequiredService<HttpTransparencyWitnessClient>();
+        });
 
         services.AddSingleton<IMongoClient>(sp =>
         {

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Signing/AttestorSigningKeyRegistry.cs

@@ -0,0 +1,347 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Security.Cryptography;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using Org.BouncyCastle.Crypto.Parameters;
+using StellaOps.Attestor.Core.Options;
+using StellaOps.Attestor.Core.Signing;
+using StellaOps.Cryptography;
+using StellaOps.Cryptography.Kms;
+using StellaOps.Cryptography.Plugin.BouncyCastle;
+
+namespace StellaOps.Attestor.Infrastructure.Signing;
+
+internal sealed class AttestorSigningKeyRegistry : IDisposable
+{
+    private readonly Dictionary<string, SigningKeyEntry> _keys;
+    private readonly FileKmsClient? _kmsClient;
+    private readonly ILogger<AttestorSigningKeyRegistry> _logger;
+
+    public AttestorSigningKeyRegistry(
+        IOptions<AttestorOptions> options,
+        TimeProvider timeProvider,
+        ILogger<AttestorSigningKeyRegistry> logger)
+    {
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        var attestorOptions = options?.Value ?? new AttestorOptions();
+        var signingOptions = attestorOptions.Signing ?? new AttestorOptions.SigningOptions();
+
+        var providers = new List<ICryptoProvider>();
+        var providerMap = new Dictionary<string, ICryptoProvider>(StringComparer.OrdinalIgnoreCase);
+
+        void RegisterProvider(ICryptoProvider provider)
+        {
+            providers.Add(provider);
+            providerMap[provider.Name] = provider;
+        }
+
+        var defaultProvider = new DefaultCryptoProvider();
+        RegisterProvider(defaultProvider);
+
+        var edProvider = new BouncyCastleEd25519CryptoProvider();
+        RegisterProvider(edProvider);
+
+        KmsCryptoProvider? kmsProvider = null;
+        if (RequiresKms(signingOptions))
+        {
+            var kmsOptions = signingOptions.Kms ?? throw new InvalidOperationException("attestor.signing.kms is required when a signing key declares mode 'kms'.");
+            if (string.IsNullOrWhiteSpace(kmsOptions.RootPath))
+            {
+                throw new InvalidOperationException("attestor.signing.kms.rootPath must be provided when using KMS-backed signing keys.");
+            }
+
+            if (string.IsNullOrWhiteSpace(kmsOptions.Password))
+            {
+                throw new InvalidOperationException("attestor.signing.kms.password must be provided when using KMS-backed signing keys.");
+            }
+
+            var fileOptions = new FileKmsOptions
+            {
+                RootPath = Path.GetFullPath(kmsOptions.RootPath!),
+                Password = kmsOptions.Password!,
+                Algorithm = kmsOptions.Algorithm,
+                KeyDerivationIterations = kmsOptions.KeyDerivationIterations ?? 600_000
+            };
+
+            _kmsClient = new FileKmsClient(fileOptions);
+            kmsProvider = new KmsCryptoProvider(_kmsClient);
+            RegisterProvider(kmsProvider);
+        }
+
+        Registry = new CryptoProviderRegistry(providers, signingOptions.PreferredProviders);
+        _keys = new Dictionary<string, SigningKeyEntry>(StringComparer.OrdinalIgnoreCase);
+
+        foreach (var key in signingOptions.Keys ?? Array.Empty<AttestorOptions.SigningKeyOptions>())
+        {
+            if (key is null || !key.Enabled)
+            {
+                continue;
+            }
+
+            var entry = CreateEntry(
+                key,
+                providerMap,
+                defaultProvider,
+                edProvider,
+                kmsProvider,
+                _kmsClient,
+                timeProvider);
+
+            if (_keys.ContainsKey(entry.KeyId))
+            {
+                throw new InvalidOperationException($"Duplicate signing key id '{entry.KeyId}' configured.");
+            }
+
+            _keys[entry.KeyId] = entry;
+            _logger.LogInformation("Registered attestor signing key {KeyId} using provider {Provider} and algorithm {Algorithm}.", entry.KeyId, entry.ProviderName, entry.Algorithm);
+        }
+    }
+
+    public ICryptoProviderRegistry Registry { get; }
+
+    public SigningKeyEntry GetRequired(string keyId)
+    {
+        if (string.IsNullOrWhiteSpace(keyId))
+        {
+            throw new AttestorSigningException("key_missing", "Signing key id must be provided.");
+        }
+
+        if (_keys.TryGetValue(keyId, out var entry))
+        {
+            return entry;
+        }
+
+        throw new AttestorSigningException("key_not_found", $"Signing key '{keyId}' is not configured.");
+    }
+
+    public void Dispose()
+    {
+        _kmsClient?.Dispose();
+    }
+
+    private static bool RequiresKms(AttestorOptions.SigningOptions signingOptions)
+        => signingOptions.Keys?.Any(static key =>
+            string.Equals(key?.Mode, "kms", StringComparison.OrdinalIgnoreCase)) == true;
+
+    private SigningKeyEntry CreateEntry(
+        AttestorOptions.SigningKeyOptions key,
+        IReadOnlyDictionary<string, ICryptoProvider> providers,
+        DefaultCryptoProvider defaultProvider,
+        BouncyCastleEd25519CryptoProvider edProvider,
+        KmsCryptoProvider? kmsProvider,
+        FileKmsClient? kmsClient,
+        TimeProvider timeProvider)
+    {
+        var providerName = ResolveProviderName(key);
+        if (!providers.TryGetValue(providerName, out var provider))
+        {
+            throw new InvalidOperationException($"Signing provider '{providerName}' is not registered for key '{key.KeyId}'.");
+        }
+
+        var providerKeyId = string.IsNullOrWhiteSpace(key.ProviderKeyId) ? key.KeyId : key.ProviderKeyId!;
+        if (string.IsNullOrWhiteSpace(providerKeyId))
+        {
+            throw new InvalidOperationException($"Signing key '{key.KeyId}' must specify a provider key identifier.");
+        }
+
+        var now = timeProvider.GetUtcNow();
+        var normalizedAlgorithm = NormalizeAlgorithm(key.Algorithm ?? string.Empty);
+
+        if (string.Equals(providerName, "kms", StringComparison.OrdinalIgnoreCase))
+        {
+            if (kmsProvider is null || kmsClient is null)
+            {
+                throw new InvalidOperationException($"KMS signing provider is not configured but signing key '{key.KeyId}' requests mode 'kms'.");
+            }
+
+            var versionId = key.KmsVersionId;
+            if (string.IsNullOrWhiteSpace(versionId))
+            {
+                throw new InvalidOperationException($"Signing key '{key.KeyId}' must specify kmsVersionId when using mode 'kms'.");
+            }
+
+            var material = kmsClient.ExportAsync(providerKeyId, versionId, default).GetAwaiter().GetResult();
+            var parameters = new ECParameters
+            {
+                Curve = ECCurve.NamedCurves.nistP256,
+                D = material.D,
+                Q = new ECPoint
+                {
+                    X = material.Qx,
+                    Y = material.Qy
+                }
+            };
+
+            var metadata = new Dictionary<string, string?>(StringComparer.OrdinalIgnoreCase)
+            {
+                ["kms.version"] = material.VersionId
+            };
+
+            var signingKey = new CryptoSigningKey(
+                new CryptoKeyReference(providerKeyId, providerName),
+                normalizedAlgorithm,
+                in parameters,
+                now,
+                expiresAt: null,
+                metadata: metadata);
+
+            kmsProvider.UpsertSigningKey(signingKey);
+        }
+        else if (string.Equals(providerName, "bouncycastle.ed25519", StringComparison.OrdinalIgnoreCase))
+        {
+            var privateKeyBytes = LoadPrivateKeyBytes(key);
+            var privateKeyParameters = new Ed25519PrivateKeyParameters(privateKeyBytes, 0);
+            var publicKeyBytes = privateKeyParameters.GeneratePublicKey().GetEncoded();
+
+            var signingKey = new CryptoSigningKey(
+                new CryptoKeyReference(providerKeyId, providerName),
+                normalizedAlgorithm,
+                privateKeyBytes,
+                now,
+                publicKey: publicKeyBytes);
+
+            edProvider.UpsertSigningKey(signingKey);
+        }
+        else
+        {
+            var parameters = LoadEcParameters(key);
+            var signingKey = new CryptoSigningKey(
+                new CryptoKeyReference(providerKeyId, providerName),
+                normalizedAlgorithm,
+                in parameters,
+                now);
+
+            defaultProvider.UpsertSigningKey(signingKey);
+        }
+
+        var mode = string.IsNullOrWhiteSpace(key.Mode)
+            ? (string.Equals(providerName, "kms", StringComparison.OrdinalIgnoreCase) ? "kms" : "keyful")
+            : key.Mode!;
+
+        var certificateChain = key.CertificateChain?.Count > 0
+            ? key.CertificateChain.ToArray()
+            : Array.Empty<string>();
+
+        return new SigningKeyEntry(
+            key.KeyId,
+            providerKeyId,
+            providerName,
+            normalizedAlgorithm,
+            mode,
+            certificateChain);
+    }
+
+    private static string ResolveProviderName(AttestorOptions.SigningKeyOptions key)
+    {
+        if (!string.IsNullOrWhiteSpace(key.Provider))
+        {
+            return key.Provider!;
+        }
+
+        if (string.Equals(key.Mode, "kms", StringComparison.OrdinalIgnoreCase))
+        {
+            return "kms";
+        }
+
+        if (string.Equals(key.Algorithm, SignatureAlgorithms.Ed25519, StringComparison.OrdinalIgnoreCase) ||
+            string.Equals(key.Algorithm, SignatureAlgorithms.EdDsa, StringComparison.OrdinalIgnoreCase))
+        {
+            return "bouncycastle.ed25519";
+        }
+
+        return "default";
+    }
+
+    private static string NormalizeAlgorithm(string algorithm)
+    {
+        if (string.IsNullOrWhiteSpace(algorithm))
+        {
+            return SignatureAlgorithms.Es256;
+        }
+
+        if (string.Equals(algorithm, SignatureAlgorithms.EdDsa, StringComparison.OrdinalIgnoreCase))
+        {
+            return SignatureAlgorithms.Ed25519;
+        }
+
+        return algorithm.ToUpperInvariant();
+    }
+
+    private static byte[] LoadPrivateKeyBytes(AttestorOptions.SigningKeyOptions key)
+    {
+        var material = ReadMaterial(key);
+        return key.MaterialFormat?.ToLowerInvariant() switch
+        {
+            "base64" or null => Convert.FromBase64String(material),
+            "hex" => Convert.FromHexString(material),
+            _ => throw new InvalidOperationException($"Unsupported materialFormat '{key.MaterialFormat}' for Ed25519 signing key '{key.KeyId}'. Supported formats: base64, hex.")
+        };
+    }
+
+    private static ECParameters LoadEcParameters(AttestorOptions.SigningKeyOptions key)
+    {
+        var material = ReadMaterial(key);
+        using var ecdsa = ECDsa.Create();
+
+        switch (key.MaterialFormat?.ToLowerInvariant())
+        {
+            case null:
+            case "pem":
+                ecdsa.ImportFromPem(material);
+                break;
+            case "base64":
+                {
+                    var pkcs8 = Convert.FromBase64String(material);
+                    ecdsa.ImportPkcs8PrivateKey(pkcs8, out _);
+                    break;
+                }
+            case "hex":
+                {
+                    var pkcs8 = Convert.FromHexString(material);
+                    ecdsa.ImportPkcs8PrivateKey(pkcs8, out _);
+                    break;
+                }
+            default:
+                throw new InvalidOperationException($"Unsupported materialFormat '{key.MaterialFormat}' for signing key '{key.KeyId}'. Supported formats: pem, base64, hex.");
+        }
+
+        return ecdsa.ExportParameters(true);
+    }
+
+    private static string ReadMaterial(AttestorOptions.SigningKeyOptions key)
+    {
+        if (!string.IsNullOrWhiteSpace(key.MaterialPassphrase))
+        {
+            throw new InvalidOperationException($"Signing key '{key.KeyId}' specifies a materialPassphrase but encrypted keys are not yet supported.");
+        }
+
+        if (!string.IsNullOrWhiteSpace(key.Material))
+        {
+            return key.Material.Trim();
+        }
+
+        if (!string.IsNullOrWhiteSpace(key.MaterialPath))
+        {
+            var path = Path.GetFullPath(key.MaterialPath);
+            if (!File.Exists(path))
+            {
+                throw new InvalidOperationException($"Signing key material file '{path}' for key '{key.KeyId}' does not exist.");
+            }
+
+            return File.ReadAllText(path).Trim();
+        }
+
+        throw new InvalidOperationException($"Signing key '{key.KeyId}' must provide either inline material or a materialPath.");
+    }
+
+    internal sealed record SigningKeyEntry(
+        string KeyId,
+        string ProviderKeyId,
+        string ProviderName,
+        string Algorithm,
+        string Mode,
+        IReadOnlyList<string> CertificateChain);
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Signing/AttestorSigningService.cs

@@ -0,0 +1,260 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Security.Cryptography;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using StellaOps.Attestor.Core.Audit;
+using StellaOps.Attestor.Core.Observability;
+using StellaOps.Attestor.Core.Signing;
+using StellaOps.Attestor.Core.Submission;
+using StellaOps.Cryptography;
+
+namespace StellaOps.Attestor.Infrastructure.Signing;
+
+internal sealed class AttestorSigningService : IAttestationSigningService
+{
+    private readonly AttestorSigningKeyRegistry _registry;
+    private readonly IDsseCanonicalizer _canonicalizer;
+    private readonly StellaOps.Attestor.Core.Storage.IAttestorAuditSink _auditSink;
+    private readonly AttestorMetrics _metrics;
+    private readonly ILogger<AttestorSigningService> _logger;
+    private readonly TimeProvider _timeProvider;
+
+    public AttestorSigningService(
+        AttestorSigningKeyRegistry registry,
+        IDsseCanonicalizer canonicalizer,
+        StellaOps.Attestor.Core.Storage.IAttestorAuditSink auditSink,
+        AttestorMetrics metrics,
+        ILogger<AttestorSigningService> logger,
+        TimeProvider timeProvider)
+    {
+        _registry = registry ?? throw new ArgumentNullException(nameof(registry));
+        _canonicalizer = canonicalizer ?? throw new ArgumentNullException(nameof(canonicalizer));
+        _auditSink = auditSink ?? throw new ArgumentNullException(nameof(auditSink));
+        _metrics = metrics ?? throw new ArgumentNullException(nameof(metrics));
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        _timeProvider = timeProvider ?? TimeProvider.System;
+    }
+
+    public async Task<AttestationSignResult> SignAsync(
+        AttestationSignRequest request,
+        SubmissionContext context,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(request);
+        ArgumentNullException.ThrowIfNull(context);
+
+        var stopwatch = Stopwatch.StartNew();
+        try
+        {
+            if (string.IsNullOrWhiteSpace(request.KeyId))
+            {
+                throw new AttestorSigningException("key_missing", "Signing key id is required.");
+            }
+
+            if (string.IsNullOrWhiteSpace(request.PayloadType))
+            {
+                throw new AttestorSigningException("payload_type_missing", "payloadType must be provided.");
+            }
+
+            if (string.IsNullOrWhiteSpace(request.PayloadBase64))
+            {
+                throw new AttestorSigningException("payload_missing", "payload must be provided as base64.");
+            }
+
+            var entry = _registry.GetRequired(request.KeyId);
+            byte[] payloadBytes;
+            try
+            {
+                payloadBytes = Convert.FromBase64String(request.PayloadBase64.Trim());
+            }
+            catch (FormatException)
+            {
+                throw new AttestorSigningException("payload_invalid_base64", "payload must be valid base64.");
+            }
+
+            var normalizedPayload = Convert.ToBase64String(payloadBytes);
+            var preAuth = DssePreAuthenticationEncoding.Compute(request.PayloadType, payloadBytes);
+
+            var signerResolution = _registry.Registry.ResolveSigner(
+                CryptoCapability.Signing,
+                entry.Algorithm,
+                new CryptoKeyReference(entry.ProviderKeyId, entry.ProviderName),
+                entry.ProviderName);
+
+            var signatureBytes = await signerResolution.Signer.SignAsync(preAuth, cancellationToken).ConfigureAwait(false);
+            var signatureBase64 = Convert.ToBase64String(signatureBytes);
+
+            var bundle = BuildBundle(request, entry, normalizedPayload, signatureBase64);
+            var meta = BuildMeta(request);
+
+            var canonicalRequest = new AttestorSubmissionRequest
+            {
+                Bundle = bundle,
+                Meta = meta
+            };
+
+            var canonical = await _canonicalizer.CanonicalizeAsync(canonicalRequest, cancellationToken).ConfigureAwait(false);
+            meta.BundleSha256 = Convert.ToHexString(SHA256.HashData(canonical)).ToLowerInvariant();
+
+            var elapsedSeconds = stopwatch.Elapsed.TotalSeconds;
+            RecordSuccessMetrics(entry, elapsedSeconds);
+            await WriteAuditAsync(context, entry, meta, elapsedSeconds, result: "signed", error: null, cancellationToken).ConfigureAwait(false);
+
+            return new AttestationSignResult
+            {
+                Bundle = bundle,
+                Meta = meta,
+                KeyId = request.KeyId,
+                Algorithm = entry.Algorithm,
+                Mode = bundle.Mode,
+                Provider = entry.ProviderName,
+                SignedAt = _timeProvider.GetUtcNow()
+            };
+        }
+        catch (AttestorSigningException)
+        {
+            var elapsedSeconds = stopwatch.Elapsed.TotalSeconds;
+            RecordFailureMetrics(elapsedSeconds);
+            await WriteAuditAsync(context, null, null, elapsedSeconds, "failed", error: "validation", cancellationToken).ConfigureAwait(false);
+            throw;
+        }
+        catch (Exception ex)
+        {
+            var elapsedSeconds = stopwatch.Elapsed.TotalSeconds;
+            RecordFailureMetrics(elapsedSeconds);
+            _metrics.ErrorTotal.Add(1, new KeyValuePair<string, object?>("type", "sign"));
+            _logger.LogError(ex, "Unexpected error while signing attestation.");
+            await WriteAuditAsync(context, null, null, elapsedSeconds, "failed", error: "unexpected", cancellationToken).ConfigureAwait(false);
+            throw new AttestorSigningException("signing_failed", "Signing failed due to an internal error.", ex);
+        }
+    }
+
+    private static AttestorSubmissionRequest.SubmissionBundle BuildBundle(
+        AttestationSignRequest request,
+        AttestorSigningKeyRegistry.SigningKeyEntry entry,
+        string normalizedPayload,
+        string signatureBase64)
+    {
+        var mode = string.IsNullOrWhiteSpace(request.Mode) ? entry.Mode : request.Mode!;
+        var certificateChain = new List<string>(entry.CertificateChain.Count + (request.CertificateChain?.Count ?? 0));
+        certificateChain.AddRange(entry.CertificateChain);
+        if (request.CertificateChain is not null)
+        {
+            foreach (var cert in request.CertificateChain)
+            {
+                if (!string.IsNullOrWhiteSpace(cert) &&
+                    !certificateChain.Contains(cert, StringComparer.Ordinal))
+                {
+                    certificateChain.Add(cert);
+                }
+            }
+        }
+
+        var bundle = new AttestorSubmissionRequest.SubmissionBundle
+        {
+            Mode = mode,
+            Dsse = new AttestorSubmissionRequest.DsseEnvelope
+            {
+                PayloadType = request.PayloadType,
+                PayloadBase64 = normalizedPayload,
+                Signatures =
+                {
+                    new AttestorSubmissionRequest.DsseSignature
+                    {
+                        KeyId = request.KeyId,
+                        Signature = signatureBase64
+                    }
+                }
+            },
+            CertificateChain = certificateChain
+        };
+
+        return bundle;
+    }
+
+    private static AttestorSubmissionRequest.SubmissionMeta BuildMeta(AttestationSignRequest request)
+    {
+        var artifact = request.Artifact ?? new AttestorSubmissionRequest.ArtifactInfo();
+        return new AttestorSubmissionRequest.SubmissionMeta
+        {
+            Artifact = new AttestorSubmissionRequest.ArtifactInfo
+            {
+                Sha256 = artifact.Sha256,
+                Kind = artifact.Kind,
+                ImageDigest = artifact.ImageDigest,
+                SubjectUri = artifact.SubjectUri
+            },
+            Archive = request.Archive,
+            LogPreference = string.IsNullOrWhiteSpace(request.LogPreference)
+                ? "primary"
+                : request.LogPreference.Trim()
+        };
+    }
+
+    private void RecordSuccessMetrics(AttestorSigningKeyRegistry.SigningKeyEntry entry, double elapsedSeconds)
+    {
+        _metrics.SignTotal.Add(1,
+            new KeyValuePair<string, object?>("result", "success"),
+            new KeyValuePair<string, object?>("algorithm", entry.Algorithm),
+            new KeyValuePair<string, object?>("provider", entry.ProviderName));
+
+        _metrics.SignLatency.Record(elapsedSeconds,
+            new KeyValuePair<string, object?>("algorithm", entry.Algorithm),
+            new KeyValuePair<string, object?>("provider", entry.ProviderName));
+    }
+
+    private void RecordFailureMetrics(double elapsedSeconds)
+    {
+        _metrics.SignTotal.Add(1, new KeyValuePair<string, object?>("result", "failure"));
+        _metrics.SignLatency.Record(elapsedSeconds);
+    }
+
+    private async Task WriteAuditAsync(
+        SubmissionContext context,
+        AttestorSigningKeyRegistry.SigningKeyEntry? entry,
+        AttestorSubmissionRequest.SubmissionMeta? meta,
+        double elapsedSeconds,
+        string result,
+        string? error,
+        CancellationToken cancellationToken)
+    {
+        var metadata = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        if (entry is not null)
+        {
+            metadata["algorithm"] = entry.Algorithm;
+            metadata["provider"] = entry.ProviderName;
+            metadata["mode"] = entry.Mode;
+            metadata["keyId"] = entry.KeyId;
+        }
+
+        if (!string.IsNullOrWhiteSpace(error))
+        {
+            metadata["error"] = error!;
+        }
+
+        var record = new AttestorAuditRecord
+        {
+            Action = "sign",
+            Result = result,
+            ArtifactSha256 = meta?.Artifact?.Sha256 ?? string.Empty,
+            BundleSha256 = meta?.BundleSha256 ?? string.Empty,
+            Backend = entry?.ProviderName ?? string.Empty,
+            LatencyMs = (long)(elapsedSeconds * 1000),
+            Timestamp = _timeProvider.GetUtcNow(),
+            Caller = new AttestorAuditRecord.CallerDescriptor
+            {
+                Subject = context.CallerSubject,
+                Audience = context.CallerAudience,
+                ClientId = context.CallerClientId,
+                MtlsThumbprint = context.MtlsThumbprint,
+                Tenant = context.CallerTenant
+            },
+            Metadata = metadata
+        };
+
+        await _auditSink.WriteAsync(record, cancellationToken).ConfigureAwait(false);
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/StellaOps.Attestor.Infrastructure.csproj

@@ -1,21 +1,28 @@
-<Project Sdk="Microsoft.NET.Sdk">
-  <PropertyGroup>
-    <TargetFramework>net10.0</TargetFramework>
-    <LangVersion>preview</LangVersion>
-    <Nullable>enable</Nullable>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
-  </PropertyGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\StellaOps.Attestor.Core\StellaOps.Attestor.Core.csproj" />
-  </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.0-rc.2.25502.107" />
-    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.0-rc.2.25502.107" />
-    <PackageReference Include="Microsoft.Extensions.Options" Version="10.0.0-rc.2.25502.107" />
-    <PackageReference Include="Microsoft.Extensions.Http" Version="10.0.0-rc.2.25502.107" />
-    <PackageReference Include="MongoDB.Driver" Version="3.5.0" />
-    <PackageReference Include="StackExchange.Redis" Version="2.8.24" />
-    <PackageReference Include="AWSSDK.S3" Version="3.7.307.6" />
-  </ItemGroup>
-</Project>
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <LangVersion>preview</LangVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\StellaOps.Attestor.Core\StellaOps.Attestor.Core.csproj" />
+    <ProjectReference Include="..\..\StellaOps.Attestor.Verify\StellaOps.Attestor.Verify.csproj" />
+    <ProjectReference Include="..\..\..\__Libraries\StellaOps.Cryptography\StellaOps.Cryptography.csproj" />
+    <ProjectReference Include="..\..\..\__Libraries\StellaOps.Cryptography.Plugin.BouncyCastle\StellaOps.Cryptography.Plugin.BouncyCastle.csproj" />
+    <ProjectReference Include="..\..\..\__Libraries\StellaOps.Cryptography.Kms\StellaOps.Cryptography.Kms.csproj" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.0-rc.2.25502.107" />
+    <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="10.0.0-rc.2.25502.107" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.0-rc.2.25502.107" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="10.0.0-rc.2.25502.107" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.0-rc.2.25502.107" />
+    <PackageReference Include="Microsoft.Extensions.Options" Version="10.0.0-rc.2.25502.107" />
+    <PackageReference Include="Microsoft.Extensions.Http" Version="10.0.0-rc.2.25502.107" />
+    <PackageReference Include="MongoDB.Driver" Version="3.5.0" />
+    <PackageReference Include="StackExchange.Redis" Version="2.8.24" />
+    <PackageReference Include="AWSSDK.S3" Version="3.7.307.6" />
+  </ItemGroup>
+</Project>

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Storage/CachingAttestorDedupeStore.cs

@@ -0,0 +1,56 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using StellaOps.Attestor.Core.Storage;
+
+namespace StellaOps.Attestor.Infrastructure.Storage;
+
+internal sealed class CachingAttestorDedupeStore : IAttestorDedupeStore
+{
+    private readonly IAttestorDedupeStore _cache;
+    private readonly IAttestorDedupeStore _inner;
+    private readonly ILogger<CachingAttestorDedupeStore> _logger;
+
+    public CachingAttestorDedupeStore(
+        IAttestorDedupeStore cache,
+        IAttestorDedupeStore inner,
+        ILogger<CachingAttestorDedupeStore> logger)
+    {
+        _cache = cache;
+        _inner = inner;
+        _logger = logger;
+    }
+
+    public async Task<string?> TryGetExistingAsync(string bundleSha256, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            var cached = await _cache.TryGetExistingAsync(bundleSha256, cancellationToken).ConfigureAwait(false);
+            if (!string.IsNullOrWhiteSpace(cached))
+            {
+                return cached;
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogDebug(ex, "Dedupe cache lookup failed for bundle {BundleSha}", bundleSha256);
+        }
+
+        return await _inner.TryGetExistingAsync(bundleSha256, cancellationToken).ConfigureAwait(false);
+    }
+
+    public async Task SetAsync(string bundleSha256, string rekorUuid, TimeSpan ttl, CancellationToken cancellationToken = default)
+    {
+        await _inner.SetAsync(bundleSha256, rekorUuid, ttl, cancellationToken).ConfigureAwait(false);
+
+        try
+        {
+            await _cache.SetAsync(bundleSha256, rekorUuid, ttl, cancellationToken).ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Failed to update dedupe cache for bundle {BundleSha}", bundleSha256);
+        }
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Storage/MongoAttestorAuditSink.cs

@@ -9,20 +9,36 @@ using StellaOps.Attestor.Core.Storage;
 
 namespace StellaOps.Attestor.Infrastructure.Storage;
 
-internal sealed class MongoAttestorAuditSink : IAttestorAuditSink
-{
-    private readonly IMongoCollection<AttestorAuditDocument> _collection;
-
-    public MongoAttestorAuditSink(IMongoCollection<AttestorAuditDocument> collection)
-    {
-        _collection = collection;
-    }
-
-    public Task WriteAsync(AttestorAuditRecord record, CancellationToken cancellationToken = default)
-    {
-        var document = AttestorAuditDocument.FromRecord(record);
-        return _collection.InsertOneAsync(document, cancellationToken: cancellationToken);
-    }
+internal sealed class MongoAttestorAuditSink : IAttestorAuditSink
+{
+    private readonly IMongoCollection<AttestorAuditDocument> _collection;
+    private static int _indexesInitialized;
+
+    public MongoAttestorAuditSink(IMongoCollection<AttestorAuditDocument> collection)
+    {
+        _collection = collection;
+        EnsureIndexes();
+    }
+
+    public Task WriteAsync(AttestorAuditRecord record, CancellationToken cancellationToken = default)
+    {
+        var document = AttestorAuditDocument.FromRecord(record);
+        return _collection.InsertOneAsync(document, cancellationToken: cancellationToken);
+    }
+
+    private void EnsureIndexes()
+    {
+        if (Interlocked.Exchange(ref _indexesInitialized, 1) == 1)
+        {
+            return;
+        }
+
+        var index = new CreateIndexModel<AttestorAuditDocument>(
+            Builders<AttestorAuditDocument>.IndexKeys.Descending(x => x.Timestamp),
+            new CreateIndexOptions { Name = "ts_desc" });
+
+        _collection.Indexes.CreateOne(index);
+    }
 
     internal sealed class AttestorAuditDocument
     {

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Storage/MongoAttestorDedupeStore.cs

@@ -0,0 +1,111 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using MongoDB.Bson;
+using MongoDB.Bson.Serialization.Attributes;
+using MongoDB.Driver;
+using StellaOps.Attestor.Core.Storage;
+
+namespace StellaOps.Attestor.Infrastructure.Storage;
+
+internal sealed class MongoAttestorDedupeStore : IAttestorDedupeStore
+{
+    private readonly IMongoCollection<AttestorDedupeDocument> _collection;
+    private readonly TimeProvider _timeProvider;
+    private static int _indexesInitialized;
+
+    public MongoAttestorDedupeStore(
+        IMongoCollection<AttestorDedupeDocument> collection,
+        TimeProvider timeProvider)
+    {
+        _collection = collection;
+        _timeProvider = timeProvider;
+        EnsureIndexes();
+    }
+
+    public async Task<string?> TryGetExistingAsync(string bundleSha256, CancellationToken cancellationToken = default)
+    {
+        var key = BuildKey(bundleSha256);
+        var now = _timeProvider.GetUtcNow().UtcDateTime;
+        var filter = Builders<AttestorDedupeDocument>.Filter.Eq(x => x.Key, key);
+
+        var document = await _collection
+            .Find(filter)
+            .FirstOrDefaultAsync(cancellationToken)
+            .ConfigureAwait(false);
+
+        if (document is null)
+        {
+            return null;
+        }
+
+        if (document.TtlAt <= now)
+        {
+            await _collection.DeleteOneAsync(filter, cancellationToken).ConfigureAwait(false);
+            return null;
+        }
+
+        return document.RekorUuid;
+    }
+
+    public Task SetAsync(string bundleSha256, string rekorUuid, TimeSpan ttl, CancellationToken cancellationToken = default)
+    {
+        var now = _timeProvider.GetUtcNow().UtcDateTime;
+        var expiresAt = now.Add(ttl);
+        var key = BuildKey(bundleSha256);
+        var filter = Builders<AttestorDedupeDocument>.Filter.Eq(x => x.Key, key);
+
+        var update = Builders<AttestorDedupeDocument>.Update
+            .SetOnInsert(x => x.Key, key)
+            .Set(x => x.RekorUuid, rekorUuid)
+            .Set(x => x.CreatedAt, now)
+            .Set(x => x.TtlAt, expiresAt);
+
+        return _collection.UpdateOneAsync(
+            filter,
+            update,
+            new UpdateOptions { IsUpsert = true },
+            cancellationToken);
+    }
+
+    private static string BuildKey(string bundleSha256) => $"bundle:{bundleSha256}";
+
+    private void EnsureIndexes()
+    {
+        if (Interlocked.Exchange(ref _indexesInitialized, 1) == 1)
+        {
+            return;
+        }
+
+        var indexes = new[]
+        {
+            new CreateIndexModel<AttestorDedupeDocument>(
+                Builders<AttestorDedupeDocument>.IndexKeys.Ascending(x => x.Key),
+                new CreateIndexOptions { Unique = true, Name = "dedupe_key_unique" }),
+            new CreateIndexModel<AttestorDedupeDocument>(
+                Builders<AttestorDedupeDocument>.IndexKeys.Ascending(x => x.TtlAt),
+                new CreateIndexOptions { ExpireAfter = TimeSpan.Zero, Name = "dedupe_ttl" })
+        };
+
+        _collection.Indexes.CreateMany(indexes);
+    }
+
+    [BsonIgnoreExtraElements]
+    internal sealed class AttestorDedupeDocument
+    {
+        [BsonId]
+        public ObjectId Id { get; set; }
+
+        [BsonElement("key")]
+        public string Key { get; set; } = string.Empty;
+
+        [BsonElement("rekorUuid")]
+        public string RekorUuid { get; set; } = string.Empty;
+
+        [BsonElement("createdAt")]
+        public DateTime CreatedAt { get; set; }
+
+        [BsonElement("ttlAt")]
+        public DateTime TtlAt { get; set; }
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Storage/MongoAttestorEntryRepository.cs

@@ -1,342 +1,609 @@
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using MongoDB.Bson;
-using MongoDB.Bson.Serialization.Attributes;
-using MongoDB.Driver;
-using StellaOps.Attestor.Core.Storage;
-
-namespace StellaOps.Attestor.Infrastructure.Storage;
-
-internal sealed class MongoAttestorEntryRepository : IAttestorEntryRepository
-{
-    private readonly IMongoCollection<AttestorEntryDocument> _entries;
-
-    public MongoAttestorEntryRepository(IMongoCollection<AttestorEntryDocument> entries)
-    {
-        _entries = entries;
-    }
-
-    public async Task<AttestorEntry?> GetByBundleShaAsync(string bundleSha256, CancellationToken cancellationToken = default)
-    {
-        var filter = Builders<AttestorEntryDocument>.Filter.Eq(x => x.BundleSha256, bundleSha256);
-        var document = await _entries.Find(filter).FirstOrDefaultAsync(cancellationToken).ConfigureAwait(false);
-        return document?.ToDomain();
-    }
-
-    public async Task<AttestorEntry?> GetByUuidAsync(string rekorUuid, CancellationToken cancellationToken = default)
-    {
-        var filter = Builders<AttestorEntryDocument>.Filter.Eq(x => x.Id, rekorUuid);
-        var document = await _entries.Find(filter).FirstOrDefaultAsync(cancellationToken).ConfigureAwait(false);
-        return document?.ToDomain();
-    }
-
-    public async Task<IReadOnlyList<AttestorEntry>> GetByArtifactShaAsync(string artifactSha256, CancellationToken cancellationToken = default)
-    {
-        var filter = Builders<AttestorEntryDocument>.Filter.Eq(x => x.Artifact.Sha256, artifactSha256);
-        var documents = await _entries.Find(filter).ToListAsync(cancellationToken).ConfigureAwait(false);
-        return documents.ConvertAll(static doc => doc.ToDomain());
-    }
-
-    public async Task SaveAsync(AttestorEntry entry, CancellationToken cancellationToken = default)
-    {
-        var document = AttestorEntryDocument.FromDomain(entry);
-        var filter = Builders<AttestorEntryDocument>.Filter.Eq(x => x.Id, document.Id);
-        await _entries.ReplaceOneAsync(filter, document, new ReplaceOptions { IsUpsert = true }, cancellationToken).ConfigureAwait(false);
-    }
-
-    [BsonIgnoreExtraElements]
-    internal sealed class AttestorEntryDocument
-    {
-        [BsonId]
-        public string Id { get; set; } = string.Empty;
-
-        [BsonElement("artifact")]
-        public ArtifactDocument Artifact { get; set; } = new();
-
-        [BsonElement("bundleSha256")]
-        public string BundleSha256 { get; set; } = string.Empty;
-
-        [BsonElement("index")]
-        public long? Index { get; set; }
-
-        [BsonElement("proof")]
-        public ProofDocument? Proof { get; set; }
-
-        [BsonElement("log")]
-        public LogDocument Log { get; set; } = new();
-
-        [BsonElement("createdAt")]
-        public BsonDateTime CreatedAt { get; set; } = BsonDateTime.Create(System.DateTimeOffset.UtcNow);
-
-        [BsonElement("status")]
-        public string Status { get; set; } = "pending";
-
-        [BsonElement("signerIdentity")]
-        public SignerIdentityDocument SignerIdentity { get; set; } = new();
-
-        [BsonElement("mirror")]
-        public MirrorDocument? Mirror { get; set; }
-
-        public static AttestorEntryDocument FromDomain(AttestorEntry entry)
-        {
-            return new AttestorEntryDocument
-            {
-                Id = entry.RekorUuid,
-                Artifact = new ArtifactDocument
-                {
-                    Sha256 = entry.Artifact.Sha256,
-                    Kind = entry.Artifact.Kind,
-                    ImageDigest = entry.Artifact.ImageDigest,
-                    SubjectUri = entry.Artifact.SubjectUri
-                },
-                BundleSha256 = entry.BundleSha256,
-                Index = entry.Index,
-                Proof = entry.Proof is null ? null : new ProofDocument
-                {
-                    Checkpoint = entry.Proof.Checkpoint is null ? null : new CheckpointDocument
-                    {
-                        Origin = entry.Proof.Checkpoint.Origin,
-                        Size = entry.Proof.Checkpoint.Size,
-                        RootHash = entry.Proof.Checkpoint.RootHash,
-                        Timestamp = entry.Proof.Checkpoint.Timestamp is null
-                            ? null
-                            : BsonDateTime.Create(entry.Proof.Checkpoint.Timestamp.Value)
-                    },
-                    Inclusion = entry.Proof.Inclusion is null ? null : new InclusionDocument
-                    {
-                        LeafHash = entry.Proof.Inclusion.LeafHash,
-                        Path = entry.Proof.Inclusion.Path
-                    }
-                },
-                Log = new LogDocument
-                {
-                    Backend = entry.Log.Backend,
-                    Url = entry.Log.Url,
-                    LogId = entry.Log.LogId
-                },
-                CreatedAt = BsonDateTime.Create(entry.CreatedAt.UtcDateTime),
-                Status = entry.Status,
-                SignerIdentity = new SignerIdentityDocument
-                {
-                    Mode = entry.SignerIdentity.Mode,
-                    Issuer = entry.SignerIdentity.Issuer,
-                    SubjectAlternativeName = entry.SignerIdentity.SubjectAlternativeName,
-                    KeyId = entry.SignerIdentity.KeyId
-                },
-                Mirror = entry.Mirror is null ? null : MirrorDocument.FromDomain(entry.Mirror)
-            };
-        }
-
-        public AttestorEntry ToDomain()
-        {
-            return new AttestorEntry
-            {
-                RekorUuid = Id,
-                Artifact = new AttestorEntry.ArtifactDescriptor
-                {
-                    Sha256 = Artifact.Sha256,
-                    Kind = Artifact.Kind,
-                    ImageDigest = Artifact.ImageDigest,
-                    SubjectUri = Artifact.SubjectUri
-                },
-                BundleSha256 = BundleSha256,
-                Index = Index,
-                Proof = Proof is null ? null : new AttestorEntry.ProofDescriptor
-                {
-                    Checkpoint = Proof.Checkpoint is null ? null : new AttestorEntry.CheckpointDescriptor
-                    {
-                        Origin = Proof.Checkpoint.Origin,
-                        Size = Proof.Checkpoint.Size,
-                        RootHash = Proof.Checkpoint.RootHash,
-                        Timestamp = Proof.Checkpoint.Timestamp?.ToUniversalTime()
-                    },
-                    Inclusion = Proof.Inclusion is null ? null : new AttestorEntry.InclusionDescriptor
-                    {
-                        LeafHash = Proof.Inclusion.LeafHash,
-                        Path = Proof.Inclusion.Path
-                    }
-                },
-                Log = new AttestorEntry.LogDescriptor
-                {
-                    Backend = Log.Backend,
-                    Url = Log.Url,
-                    LogId = Log.LogId
-                },
-                CreatedAt = CreatedAt.ToUniversalTime(),
-                Status = Status,
-                SignerIdentity = new AttestorEntry.SignerIdentityDescriptor
-                {
-                    Mode = SignerIdentity.Mode,
-                    Issuer = SignerIdentity.Issuer,
-                    SubjectAlternativeName = SignerIdentity.SubjectAlternativeName,
-                    KeyId = SignerIdentity.KeyId
-                },
-                Mirror = Mirror?.ToDomain()
-            };
-        }
-
-        internal sealed class ArtifactDocument
-        {
-            [BsonElement("sha256")]
-            public string Sha256 { get; set; } = string.Empty;
-
-            [BsonElement("kind")]
-            public string Kind { get; set; } = string.Empty;
-
-            [BsonElement("imageDigest")]
-            public string? ImageDigest { get; set; }
-
-            [BsonElement("subjectUri")]
-            public string? SubjectUri { get; set; }
-        }
-
-        internal sealed class ProofDocument
-        {
-            [BsonElement("checkpoint")]
-            public CheckpointDocument? Checkpoint { get; set; }
-
-            [BsonElement("inclusion")]
-            public InclusionDocument? Inclusion { get; set; }
-        }
-
-        internal sealed class CheckpointDocument
-        {
-            [BsonElement("origin")]
-            public string? Origin { get; set; }
-
-            [BsonElement("size")]
-            public long Size { get; set; }
-
-            [BsonElement("rootHash")]
-            public string? RootHash { get; set; }
-
-            [BsonElement("timestamp")]
-            public BsonDateTime? Timestamp { get; set; }
-        }
-
-        internal sealed class InclusionDocument
-        {
-            [BsonElement("leafHash")]
-            public string? LeafHash { get; set; }
-
-            [BsonElement("path")]
-            public IReadOnlyList<string> Path { get; set; } = System.Array.Empty<string>();
-        }
-
-        internal sealed class LogDocument
-        {
-            [BsonElement("backend")]
-            public string Backend { get; set; } = "primary";
-
-            [BsonElement("url")]
-            public string Url { get; set; } = string.Empty;
-
-            [BsonElement("logId")]
-            public string? LogId { get; set; }
-        }
-
-        internal sealed class SignerIdentityDocument
-        {
-            [BsonElement("mode")]
-            public string Mode { get; set; } = string.Empty;
-
-            [BsonElement("issuer")]
-            public string? Issuer { get; set; }
-
-            [BsonElement("san")]
-            public string? SubjectAlternativeName { get; set; }
-
-            [BsonElement("kid")]
-            public string? KeyId { get; set; }
-        }
-
-        internal sealed class MirrorDocument
-        {
-            [BsonElement("backend")]
-            public string Backend { get; set; } = string.Empty;
-
-            [BsonElement("url")]
-            public string Url { get; set; } = string.Empty;
-
-            [BsonElement("uuid")]
-            public string? Uuid { get; set; }
-
-            [BsonElement("index")]
-            public long? Index { get; set; }
-
-            [BsonElement("status")]
-            public string Status { get; set; } = "pending";
-
-            [BsonElement("proof")]
-            public ProofDocument? Proof { get; set; }
-
-            [BsonElement("logId")]
-            public string? LogId { get; set; }
-
-            [BsonElement("error")]
-            public string? Error { get; set; }
-
-            public static MirrorDocument FromDomain(AttestorEntry.LogReplicaDescriptor mirror)
-            {
-                return new MirrorDocument
-                {
-                    Backend = mirror.Backend,
-                    Url = mirror.Url,
-                    Uuid = mirror.Uuid,
-                    Index = mirror.Index,
-                    Status = mirror.Status,
-                    Proof = mirror.Proof is null ? null : new ProofDocument
-                    {
-                        Checkpoint = mirror.Proof.Checkpoint is null ? null : new CheckpointDocument
-                        {
-                            Origin = mirror.Proof.Checkpoint.Origin,
-                            Size = mirror.Proof.Checkpoint.Size,
-                            RootHash = mirror.Proof.Checkpoint.RootHash,
-                            Timestamp = mirror.Proof.Checkpoint.Timestamp is null
-                                ? null
-                                : BsonDateTime.Create(mirror.Proof.Checkpoint.Timestamp.Value)
-                        },
-                        Inclusion = mirror.Proof.Inclusion is null ? null : new InclusionDocument
-                        {
-                            LeafHash = mirror.Proof.Inclusion.LeafHash,
-                            Path = mirror.Proof.Inclusion.Path
-                        }
-                    },
-                    LogId = mirror.LogId,
-                    Error = mirror.Error
-                };
-            }
-
-            public AttestorEntry.LogReplicaDescriptor ToDomain()
-            {
-                return new AttestorEntry.LogReplicaDescriptor
-                {
-                    Backend = Backend,
-                    Url = Url,
-                    Uuid = Uuid,
-                    Index = Index,
-                    Status = Status,
-                    Proof = Proof is null ? null : new AttestorEntry.ProofDescriptor
-                    {
-                        Checkpoint = Proof.Checkpoint is null ? null : new AttestorEntry.CheckpointDescriptor
-                        {
-                            Origin = Proof.Checkpoint.Origin,
-                            Size = Proof.Checkpoint.Size,
-                            RootHash = Proof.Checkpoint.RootHash,
-                            Timestamp = Proof.Checkpoint.Timestamp?.ToUniversalTime()
-                        },
-                        Inclusion = Proof.Inclusion is null ? null : new AttestorEntry.InclusionDescriptor
-                        {
-                            LeafHash = Proof.Inclusion.LeafHash,
-                            Path = Proof.Inclusion.Path
-                        }
-                    },
-                    LogId = LogId,
-                    Error = Error
-                };
-            }
-        }
-    }
-}
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using MongoDB.Bson.Serialization.Attributes;
+using MongoDB.Driver;
+using StellaOps.Attestor.Core.Storage;
+
+namespace StellaOps.Attestor.Infrastructure.Storage;
+
+internal sealed class MongoAttestorEntryRepository : IAttestorEntryRepository
+{
+    private const int DefaultPageSize = 50;
+    private const int MaxPageSize = 200;
+
+    private readonly IMongoCollection<AttestorEntryDocument> _entries;
+
+    public MongoAttestorEntryRepository(IMongoCollection<AttestorEntryDocument> entries)
+    {
+        _entries = entries ?? throw new ArgumentNullException(nameof(entries));
+        EnsureIndexes();
+    }
+
+    public async Task<AttestorEntry?> GetByBundleShaAsync(string bundleSha256, CancellationToken cancellationToken = default)
+    {
+        var filter = Builders<AttestorEntryDocument>.Filter.Eq(x => x.BundleSha256, bundleSha256);
+        var document = await _entries.Find(filter).FirstOrDefaultAsync(cancellationToken).ConfigureAwait(false);
+        return document?.ToDomain();
+    }
+
+    public async Task<AttestorEntry?> GetByUuidAsync(string rekorUuid, CancellationToken cancellationToken = default)
+    {
+        var filter = Builders<AttestorEntryDocument>.Filter.Eq(x => x.Id, rekorUuid);
+        var document = await _entries.Find(filter).FirstOrDefaultAsync(cancellationToken).ConfigureAwait(false);
+        return document?.ToDomain();
+    }
+
+    public async Task<IReadOnlyList<AttestorEntry>> GetByArtifactShaAsync(string artifactSha256, CancellationToken cancellationToken = default)
+    {
+        var filter = Builders<AttestorEntryDocument>.Filter.Eq(x => x.Artifact.Sha256, artifactSha256);
+        var documents = await _entries.Find(filter)
+            .Sort(Builders<AttestorEntryDocument>.Sort.Descending(x => x.CreatedAt))
+            .ToListAsync(cancellationToken)
+            .ConfigureAwait(false);
+
+        return documents.ConvertAll(static doc => doc.ToDomain());
+    }
+
+    public async Task SaveAsync(AttestorEntry entry, CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(entry);
+
+        var document = AttestorEntryDocument.FromDomain(entry);
+        var filter = Builders<AttestorEntryDocument>.Filter.Eq(x => x.Id, document.Id);
+        await _entries.ReplaceOneAsync(filter, document, new ReplaceOptions { IsUpsert = true }, cancellationToken).ConfigureAwait(false);
+    }
+
+    public async Task<AttestorEntryQueryResult> QueryAsync(AttestorEntryQuery query, CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(query);
+
+        var pageSize = query.PageSize <= 0 ? DefaultPageSize : Math.Min(query.PageSize, MaxPageSize);
+        var filterBuilder = Builders<AttestorEntryDocument>.Filter;
+        var filter = filterBuilder.Empty;
+
+        if (!string.IsNullOrWhiteSpace(query.Subject))
+        {
+            var subject = query.Subject;
+            var subjectFilter = filterBuilder.Or(
+                filterBuilder.Eq(x => x.Artifact.Sha256, subject),
+                filterBuilder.Eq(x => x.Artifact.ImageDigest, subject),
+                filterBuilder.Eq(x => x.Artifact.SubjectUri, subject));
+            filter &= subjectFilter;
+        }
+
+        if (!string.IsNullOrWhiteSpace(query.Type))
+        {
+            filter &= filterBuilder.Eq(x => x.Artifact.Kind, query.Type);
+        }
+
+        if (!string.IsNullOrWhiteSpace(query.Issuer))
+        {
+            filter &= filterBuilder.Eq(x => x.SignerIdentity.SubjectAlternativeName, query.Issuer);
+        }
+
+        if (!string.IsNullOrWhiteSpace(query.Scope))
+        {
+            filter &= filterBuilder.Eq(x => x.SignerIdentity.Issuer, query.Scope);
+        }
+
+        if (query.CreatedAfter is { } createdAfter)
+        {
+            filter &= filterBuilder.Gte(x => x.CreatedAt, createdAfter.UtcDateTime);
+        }
+
+        if (query.CreatedBefore is { } createdBefore)
+        {
+            filter &= filterBuilder.Lte(x => x.CreatedAt, createdBefore.UtcDateTime);
+        }
+
+        if (!string.IsNullOrWhiteSpace(query.ContinuationToken))
+        {
+            if (!AttestorEntryContinuationToken.TryParse(query.ContinuationToken, out var cursor))
+            {
+                throw new FormatException("Invalid continuation token.");
+            }
+
+            var cursorInstant = cursor.CreatedAt.UtcDateTime;
+            var continuationFilter = filterBuilder.Or(
+                filterBuilder.Lt(x => x.CreatedAt, cursorInstant),
+                filterBuilder.And(
+                    filterBuilder.Eq(x => x.CreatedAt, cursorInstant),
+                    filterBuilder.Gt(x => x.Id, cursor.RekorUuid)));
+
+            filter &= continuationFilter;
+        }
+
+        var sort = Builders<AttestorEntryDocument>.Sort
+            .Descending(x => x.CreatedAt)
+            .Ascending(x => x.Id);
+
+        var documents = await _entries.Find(filter)
+            .Sort(sort)
+            .Limit(pageSize + 1)
+            .ToListAsync(cancellationToken)
+            .ConfigureAwait(false);
+
+        string? continuation = null;
+        if (documents.Count > pageSize)
+        {
+            var cursorDocument = documents[pageSize];
+            var nextCreatedAt = DateTime.SpecifyKind(cursorDocument.CreatedAt, DateTimeKind.Utc);
+            continuation = AttestorEntryContinuationToken.Encode(new DateTimeOffset(nextCreatedAt), cursorDocument.Id);
+
+            documents.RemoveRange(pageSize, documents.Count - pageSize);
+        }
+
+        var items = documents.ConvertAll(static doc => doc.ToDomain());
+
+        return new AttestorEntryQueryResult
+        {
+            Items = items,
+            ContinuationToken = continuation
+        };
+    }
+
+    private void EnsureIndexes()
+    {
+        var keys = Builders<AttestorEntryDocument>.IndexKeys;
+
+        var models = new[]
+        {
+            new CreateIndexModel<AttestorEntryDocument>(
+                keys.Ascending(x => x.BundleSha256),
+                new CreateIndexOptions { Name = "bundle_sha_unique", Unique = true }),
+            new CreateIndexModel<AttestorEntryDocument>(
+                keys.Descending(x => x.CreatedAt).Ascending(x => x.Id),
+                new CreateIndexOptions { Name = "created_at_uuid" }),
+            new CreateIndexModel<AttestorEntryDocument>(
+                keys.Ascending(x => x.Artifact.Sha256),
+                new CreateIndexOptions { Name = "artifact_sha" }),
+            new CreateIndexModel<AttestorEntryDocument>(
+                keys.Ascending(x => x.Artifact.ImageDigest),
+                new CreateIndexOptions { Name = "artifact_image_digest" }),
+            new CreateIndexModel<AttestorEntryDocument>(
+                keys.Ascending(x => x.Artifact.SubjectUri),
+                new CreateIndexOptions { Name = "artifact_subject_uri" }),
+            new CreateIndexModel<AttestorEntryDocument>(
+                keys.Ascending(x => x.SignerIdentity.Issuer)
+                    .Ascending(x => x.Artifact.Kind)
+                    .Descending(x => x.CreatedAt)
+                    .Ascending(x => x.Id),
+                new CreateIndexOptions { Name = "scope_kind_created_at" }),
+            new CreateIndexModel<AttestorEntryDocument>(
+                keys.Ascending(x => x.SignerIdentity.SubjectAlternativeName),
+                new CreateIndexOptions { Name = "issuer_san" })
+        };
+
+        _entries.Indexes.CreateMany(models);
+    }
+
+    [BsonIgnoreExtraElements]
+    internal sealed class AttestorEntryDocument
+    {
+        [BsonId]
+        public string Id { get; set; } = string.Empty;
+
+        [BsonElement("artifact")]
+        public ArtifactDocument Artifact { get; set; } = new();
+
+        [BsonElement("bundleSha256")]
+        public string BundleSha256 { get; set; } = string.Empty;
+
+        [BsonElement("index")]
+        public long? Index { get; set; }
+
+        [BsonElement("proof")]
+        public ProofDocument? Proof { get; set; }
+
+        [BsonElement("witness")]
+        public WitnessDocument? Witness { get; set; }
+
+        [BsonElement("log")]
+        public LogDocument Log { get; set; } = new();
+
+        [BsonElement("createdAt")]
+        [BsonDateTimeOptions(Kind = DateTimeKind.Utc)]
+        public DateTime CreatedAt { get; set; }
+
+        [BsonElement("status")]
+        public string Status { get; set; } = "pending";
+
+        [BsonElement("signer")]
+        public SignerIdentityDocument SignerIdentity { get; set; } = new();
+
+        [BsonElement("mirror")]
+        public MirrorDocument? Mirror { get; set; }
+
+        public static AttestorEntryDocument FromDomain(AttestorEntry entry)
+        {
+            ArgumentNullException.ThrowIfNull(entry);
+
+            return new AttestorEntryDocument
+            {
+                Id = entry.RekorUuid,
+                Artifact = ArtifactDocument.FromDomain(entry.Artifact),
+                BundleSha256 = entry.BundleSha256,
+                Index = entry.Index,
+                Proof = ProofDocument.FromDomain(entry.Proof),
+                Witness = WitnessDocument.FromDomain(entry.Witness),
+                Log = LogDocument.FromDomain(entry.Log),
+                CreatedAt = entry.CreatedAt.UtcDateTime,
+                Status = entry.Status,
+                SignerIdentity = SignerIdentityDocument.FromDomain(entry.SignerIdentity),
+                Mirror = MirrorDocument.FromDomain(entry.Mirror)
+            };
+        }
+
+        public AttestorEntry ToDomain()
+        {
+            var createdAtUtc = DateTime.SpecifyKind(CreatedAt, DateTimeKind.Utc);
+
+            return new AttestorEntry
+            {
+                RekorUuid = Id,
+                Artifact = Artifact.ToDomain(),
+                BundleSha256 = BundleSha256,
+                Index = Index,
+                Proof = Proof?.ToDomain(),
+                Witness = Witness?.ToDomain(),
+                Log = Log.ToDomain(),
+                CreatedAt = new DateTimeOffset(createdAtUtc),
+                Status = Status,
+                SignerIdentity = SignerIdentity.ToDomain(),
+                Mirror = Mirror?.ToDomain()
+            };
+        }
+    }
+
+    internal sealed class ArtifactDocument
+    {
+        [BsonElement("sha256")]
+        public string Sha256 { get; set; } = string.Empty;
+
+        [BsonElement("kind")]
+        public string Kind { get; set; } = string.Empty;
+
+        [BsonElement("imageDigest")]
+        public string? ImageDigest { get; set; }
+
+        [BsonElement("subjectUri")]
+        public string? SubjectUri { get; set; }
+
+        public static ArtifactDocument FromDomain(AttestorEntry.ArtifactDescriptor artifact)
+        {
+            ArgumentNullException.ThrowIfNull(artifact);
+
+            return new ArtifactDocument
+            {
+                Sha256 = artifact.Sha256,
+                Kind = artifact.Kind,
+                ImageDigest = artifact.ImageDigest,
+                SubjectUri = artifact.SubjectUri
+            };
+        }
+
+        public AttestorEntry.ArtifactDescriptor ToDomain()
+        {
+            return new AttestorEntry.ArtifactDescriptor
+            {
+                Sha256 = Sha256,
+                Kind = Kind,
+                ImageDigest = ImageDigest,
+                SubjectUri = SubjectUri
+            };
+        }
+    }
+
+    internal sealed class ProofDocument
+    {
+        [BsonElement("checkpoint")]
+        public CheckpointDocument? Checkpoint { get; set; }
+
+        [BsonElement("inclusion")]
+        public InclusionDocument? Inclusion { get; set; }
+
+        public static ProofDocument? FromDomain(AttestorEntry.ProofDescriptor? proof)
+        {
+            if (proof is null)
+            {
+                return null;
+            }
+
+            return new ProofDocument
+            {
+                Checkpoint = CheckpointDocument.FromDomain(proof.Checkpoint),
+                Inclusion = InclusionDocument.FromDomain(proof.Inclusion)
+            };
+        }
+
+        public AttestorEntry.ProofDescriptor ToDomain()
+        {
+            return new AttestorEntry.ProofDescriptor
+            {
+                Checkpoint = Checkpoint?.ToDomain(),
+                Inclusion = Inclusion?.ToDomain()
+            };
+        }
+    }
+
+    internal sealed class WitnessDocument
+    {
+        [BsonElement("aggregator")]
+        public string? Aggregator { get; set; }
+
+        [BsonElement("status")]
+        public string Status { get; set; } = "unknown";
+
+        [BsonElement("rootHash")]
+        public string? RootHash { get; set; }
+
+        [BsonElement("retrievedAt")]
+        [BsonDateTimeOptions(Kind = DateTimeKind.Utc)]
+        public DateTime RetrievedAt { get; set; }
+
+        [BsonElement("statement")]
+        public string? Statement { get; set; }
+
+        [BsonElement("signature")]
+        public string? Signature { get; set; }
+
+        [BsonElement("keyId")]
+        public string? KeyId { get; set; }
+
+        [BsonElement("error")]
+        public string? Error { get; set; }
+
+        public static WitnessDocument? FromDomain(AttestorEntry.WitnessDescriptor? witness)
+        {
+            if (witness is null)
+            {
+                return null;
+            }
+
+            return new WitnessDocument
+            {
+                Aggregator = witness.Aggregator,
+                Status = witness.Status,
+                RootHash = witness.RootHash,
+                RetrievedAt = witness.RetrievedAt.UtcDateTime,
+                Statement = witness.Statement,
+                Signature = witness.Signature,
+                KeyId = witness.KeyId,
+                Error = witness.Error
+            };
+        }
+
+        public AttestorEntry.WitnessDescriptor ToDomain()
+        {
+            return new AttestorEntry.WitnessDescriptor
+            {
+                Aggregator = Aggregator ?? string.Empty,
+                Status = string.IsNullOrWhiteSpace(Status) ? "unknown" : Status,
+                RootHash = RootHash,
+                RetrievedAt = new DateTimeOffset(DateTime.SpecifyKind(RetrievedAt, DateTimeKind.Utc)),
+                Statement = Statement,
+                Signature = Signature,
+                KeyId = KeyId,
+                Error = Error
+            };
+        }
+    }
+
+    internal sealed class CheckpointDocument
+    {
+        [BsonElement("origin")]
+        public string? Origin { get; set; }
+
+        [BsonElement("size")]
+        public long Size { get; set; }
+
+        [BsonElement("rootHash")]
+        public string? RootHash { get; set; }
+
+        [BsonElement("timestamp")]
+        [BsonDateTimeOptions(Kind = DateTimeKind.Utc)]
+        public DateTime? Timestamp { get; set; }
+
+        public static CheckpointDocument? FromDomain(AttestorEntry.CheckpointDescriptor? checkpoint)
+        {
+            if (checkpoint is null)
+            {
+                return null;
+            }
+
+            return new CheckpointDocument
+            {
+                Origin = checkpoint.Origin,
+                Size = checkpoint.Size,
+                RootHash = checkpoint.RootHash,
+                Timestamp = checkpoint.Timestamp?.UtcDateTime
+            };
+        }
+
+        public AttestorEntry.CheckpointDescriptor ToDomain()
+        {
+            return new AttestorEntry.CheckpointDescriptor
+            {
+                Origin = Origin,
+                Size = Size,
+                RootHash = RootHash,
+                Timestamp = Timestamp is null ? null : new DateTimeOffset(DateTime.SpecifyKind(Timestamp.Value, DateTimeKind.Utc))
+            };
+        }
+    }
+
+    internal sealed class InclusionDocument
+    {
+        [BsonElement("leafHash")]
+        public string? LeafHash { get; set; }
+
+        [BsonElement("path")]
+        public IReadOnlyList<string> Path { get; set; } = Array.Empty<string>();
+
+        public static InclusionDocument? FromDomain(AttestorEntry.InclusionDescriptor? inclusion)
+        {
+            if (inclusion is null)
+            {
+                return null;
+            }
+
+            return new InclusionDocument
+            {
+                LeafHash = inclusion.LeafHash,
+                Path = inclusion.Path
+            };
+        }
+
+        public AttestorEntry.InclusionDescriptor ToDomain()
+        {
+            return new AttestorEntry.InclusionDescriptor
+            {
+                LeafHash = LeafHash,
+                Path = Path
+            };
+        }
+    }
+
+    internal sealed class LogDocument
+    {
+        [BsonElement("backend")]
+        public string Backend { get; set; } = "primary";
+
+        [BsonElement("url")]
+        public string Url { get; set; } = string.Empty;
+
+        [BsonElement("logId")]
+        public string? LogId { get; set; }
+
+        public static LogDocument FromDomain(AttestorEntry.LogDescriptor log)
+        {
+            ArgumentNullException.ThrowIfNull(log);
+
+            return new LogDocument
+            {
+                Backend = log.Backend,
+                Url = log.Url,
+                LogId = log.LogId
+            };
+        }
+
+        public AttestorEntry.LogDescriptor ToDomain()
+        {
+            return new AttestorEntry.LogDescriptor
+            {
+                Backend = Backend,
+                Url = Url,
+                LogId = LogId
+            };
+        }
+    }
+
+    internal sealed class SignerIdentityDocument
+    {
+        [BsonElement("mode")]
+        public string Mode { get; set; } = string.Empty;
+
+        [BsonElement("issuer")]
+        public string? Issuer { get; set; }
+
+        [BsonElement("san")]
+        public string? SubjectAlternativeName { get; set; }
+
+        [BsonElement("kid")]
+        public string? KeyId { get; set; }
+
+        public static SignerIdentityDocument FromDomain(AttestorEntry.SignerIdentityDescriptor signer)
+        {
+            ArgumentNullException.ThrowIfNull(signer);
+
+            return new SignerIdentityDocument
+            {
+                Mode = signer.Mode,
+                Issuer = signer.Issuer,
+                SubjectAlternativeName = signer.SubjectAlternativeName,
+                KeyId = signer.KeyId
+            };
+        }
+
+        public AttestorEntry.SignerIdentityDescriptor ToDomain()
+        {
+            return new AttestorEntry.SignerIdentityDescriptor
+            {
+                Mode = Mode,
+                Issuer = Issuer,
+                SubjectAlternativeName = SubjectAlternativeName,
+                KeyId = KeyId
+            };
+        }
+    }
+
+    internal sealed class MirrorDocument
+    {
+        [BsonElement("backend")]
+        public string Backend { get; set; } = string.Empty;
+
+        [BsonElement("url")]
+        public string Url { get; set; } = string.Empty;
+
+        [BsonElement("uuid")]
+        public string? Uuid { get; set; }
+
+        [BsonElement("index")]
+        public long? Index { get; set; }
+
+        [BsonElement("status")]
+        public string Status { get; set; } = "pending";
+
+        [BsonElement("proof")]
+        public ProofDocument? Proof { get; set; }
+
+        [BsonElement("witness")]
+        public WitnessDocument? Witness { get; set; }
+
+        [BsonElement("logId")]
+        public string? LogId { get; set; }
+
+        [BsonElement("error")]
+        public string? Error { get; set; }
+
+        public static MirrorDocument? FromDomain(AttestorEntry.LogReplicaDescriptor? mirror)
+        {
+            if (mirror is null)
+            {
+                return null;
+            }
+
+            return new MirrorDocument
+            {
+                Backend = mirror.Backend,
+                Url = mirror.Url,
+                Uuid = mirror.Uuid,
+                Index = mirror.Index,
+                Status = mirror.Status,
+                Proof = ProofDocument.FromDomain(mirror.Proof),
+                Witness = WitnessDocument.FromDomain(mirror.Witness),
+                LogId = mirror.LogId,
+                Error = mirror.Error
+            };
+        }
+
+        public AttestorEntry.LogReplicaDescriptor ToDomain()
+        {
+            return new AttestorEntry.LogReplicaDescriptor
+            {
+                Backend = Backend,
+                Url = Url,
+                Uuid = Uuid,
+                Index = Index,
+                Status = Status,
+                Proof = Proof?.ToDomain(),
+                Witness = Witness?.ToDomain(),
+                LogId = LogId,
+                Error = Error
+            };
+        }
+    }
+}

src/Attestor/StellaOps.Attestor/StellaOps.Attestor.Infrastructure/Storage/NullAttestorArchiveStore.cs

@@ -14,9 +14,15 @@ internal sealed class NullAttestorArchiveStore : IAttestorArchiveStore
         _logger = logger;
     }
 
-    public Task ArchiveBundleAsync(AttestorArchiveBundle bundle, CancellationToken cancellationToken = default)
-    {
-        _logger.LogDebug("Archive disabled; skipping bundle {BundleSha}", bundle.BundleSha256);
-        return Task.CompletedTask;
-    }
-}
+    public Task ArchiveBundleAsync(AttestorArchiveBundle bundle, CancellationToken cancellationToken = default)
+    {
+        _logger.LogDebug("Archive disabled; skipping bundle {BundleSha}", bundle.BundleSha256);
+        return Task.CompletedTask;
+    }
+
+    public Task<AttestorArchiveBundle?> GetBundleAsync(string bundleSha256, string rekorUuid, CancellationToken cancellationToken = default)
+    {
+        _logger.LogDebug("Archive disabled; bundle {BundleSha} ({RekorUuid}) cannot be retrieved", bundleSha256, rekorUuid);
+        return Task.FromResult<AttestorArchiveBundle?>(null);
+    }
+}