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src/Cli/StellaOps.Cli/Services/AttestationBundleVerifier.cs

@@ -0,0 +1,533 @@
+using System.Formats.Tar;
+using System.IO.Compression;
+using System.Security.Cryptography;
+using System.Text.Json;
+using Microsoft.Extensions.Logging;
+using StellaOps.Cli.Services.Models;
+
+namespace StellaOps.Cli.Services;
+
+/// <summary>
+/// Verifier for attestation bundles exported from the Export Center.
+/// Per EXPORT-ATTEST-75-001.
+/// </summary>
+internal sealed class AttestationBundleVerifier : IAttestationBundleVerifier
+{
+    private const string DsseEnvelopeFileName = "attestation.dsse.json";
+    private const string StatementFileName = "statement.json";
+    private const string TransparencyFileName = "transparency.ndjson";
+    private const string MetadataFileName = "metadata.json";
+    private const string ChecksumsFileName = "checksums.txt";
+
+    private static readonly JsonSerializerOptions SerializerOptions = new(JsonSerializerDefaults.Web)
+    {
+        PropertyNameCaseInsensitive = true,
+        WriteIndented = true,
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+    };
+
+    private readonly ILogger<AttestationBundleVerifier> _logger;
+
+    public AttestationBundleVerifier(ILogger<AttestationBundleVerifier> logger)
+    {
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public async Task<AttestationBundleVerifyResult> VerifyAsync(
+        AttestationBundleVerifyOptions options,
+        CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+        ArgumentException.ThrowIfNullOrWhiteSpace(options.FilePath);
+
+        _logger.LogDebug("Verifying attestation bundle at {FilePath}, offline={Offline}",
+            options.FilePath, options.Offline);
+
+        // Step 1: Check bundle exists
+        if (!File.Exists(options.FilePath))
+        {
+            return CreateFailedResult(
+                AttestationBundleExitCodes.FileNotFound,
+                "Bundle file not found",
+                options.FilePath);
+        }
+
+        // Step 2: Verify SHA-256 against .sha256 file if present
+        var sha256Path = options.FilePath + ".sha256";
+        if (File.Exists(sha256Path))
+        {
+            var checksumResult = await VerifyBundleChecksumAsync(options.FilePath, sha256Path, cancellationToken)
+                .ConfigureAwait(false);
+            if (!checksumResult.IsValid)
+            {
+                return CreateFailedResult(
+                    AttestationBundleExitCodes.ChecksumMismatch,
+                    "SHA-256 checksum mismatch",
+                    options.FilePath,
+                    $"Expected: {checksumResult.ExpectedHash}, Computed: {checksumResult.ActualHash}");
+            }
+        }
+        else
+        {
+            _logger.LogDebug("No co-located .sha256 file found for external checksum verification");
+        }
+
+        // Step 3: Extract and parse bundle contents
+        BundleContents contents;
+        try
+        {
+            contents = await ExtractBundleContentsAsync(options.FilePath, cancellationToken).ConfigureAwait(false);
+        }
+        catch (Exception ex) when (ex is InvalidDataException or JsonException or IOException)
+        {
+            _logger.LogError(ex, "Failed to extract bundle contents");
+            return CreateFailedResult(
+                AttestationBundleExitCodes.FormatError,
+                "Failed to extract bundle contents",
+                options.FilePath,
+                ex.Message);
+        }
+
+        // Step 4: Verify internal checksums from checksums.txt
+        if (contents.ChecksumsText is not null)
+        {
+            var internalCheckResult = VerifyInternalChecksums(contents);
+            if (!internalCheckResult.Success)
+            {
+                return CreateFailedResult(
+                    AttestationBundleExitCodes.ChecksumMismatch,
+                    "Internal checksum verification failed",
+                    options.FilePath,
+                    internalCheckResult.ErrorMessage);
+            }
+        }
+
+        // Step 5: Verify DSSE signature
+        var signatureValid = VerifyDsseSignature(contents, options.Offline, out var signatureError);
+        if (!signatureValid && !string.IsNullOrEmpty(signatureError))
+        {
+            return CreateFailedResult(
+                AttestationBundleExitCodes.SignatureFailure,
+                "DSSE signature verification failed",
+                options.FilePath,
+                signatureError);
+        }
+
+        // Step 6: Check transparency entries (only if not offline and verifyTransparency is true)
+        if (!options.Offline && options.VerifyTransparency)
+        {
+            if (string.IsNullOrWhiteSpace(contents.TransparencyNdjson))
+            {
+                return CreateFailedResult(
+                    AttestationBundleExitCodes.MissingTransparency,
+                    "Transparency log entry missing",
+                    options.FilePath,
+                    "Bundle requires transparency.ndjson when not in offline mode");
+            }
+        }
+
+        // Step 7: Build success result
+        var metadata = contents.Metadata;
+        var subjects = ExtractSubjects(contents);
+
+        return new AttestationBundleVerifyResult(
+            Success: true,
+            Status: "verified",
+            ExportId: metadata?.ExportId,
+            AttestationId: metadata?.AttestationId,
+            RootHash: FormatRootHash(metadata?.RootHash),
+            Subjects: subjects,
+            PredicateType: ExtractPredicateType(contents),
+            StatementVersion: metadata?.StatementVersion,
+            BundlePath: options.FilePath,
+            ExitCode: AttestationBundleExitCodes.Success);
+    }
+
+    public async Task<AttestationBundleImportResult> ImportAsync(
+        AttestationBundleImportOptions options,
+        CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+        ArgumentException.ThrowIfNullOrWhiteSpace(options.FilePath);
+
+        _logger.LogDebug("Importing attestation bundle from {FilePath}", options.FilePath);
+
+        // First verify the bundle
+        var verifyOptions = new AttestationBundleVerifyOptions(
+            options.FilePath,
+            options.Offline,
+            options.VerifyTransparency,
+            options.TrustRootPath);
+
+        var verifyResult = await VerifyAsync(verifyOptions, cancellationToken).ConfigureAwait(false);
+        if (!verifyResult.Success)
+        {
+            return new AttestationBundleImportResult(
+                Success: false,
+                Status: "verification_failed",
+                AttestationId: verifyResult.AttestationId,
+                TenantId: null,
+                Namespace: options.Namespace,
+                RootHash: verifyResult.RootHash,
+                ErrorMessage: verifyResult.ErrorMessage,
+                ExitCode: verifyResult.ExitCode);
+        }
+
+        // Extract metadata for import
+        BundleContents contents;
+        try
+        {
+            contents = await ExtractBundleContentsAsync(options.FilePath, cancellationToken).ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            return new AttestationBundleImportResult(
+                Success: false,
+                Status: "extraction_failed",
+                AttestationId: null,
+                TenantId: null,
+                Namespace: options.Namespace,
+                RootHash: null,
+                ErrorMessage: ex.Message,
+                ExitCode: AttestationBundleExitCodes.ImportFailed);
+        }
+
+        var metadata = contents.Metadata;
+        var tenantId = options.Tenant ?? metadata?.TenantId;
+
+        // Import is a local-only operation for air-gap scenarios
+        // The actual import to backend would happen via separate API call
+        _logger.LogInformation("Attestation bundle imported: {AttestationId} for tenant {TenantId}",
+            metadata?.AttestationId, tenantId);
+
+        return new AttestationBundleImportResult(
+            Success: true,
+            Status: "imported",
+            AttestationId: metadata?.AttestationId,
+            TenantId: tenantId,
+            Namespace: options.Namespace,
+            RootHash: FormatRootHash(metadata?.RootHash),
+            ExitCode: AttestationBundleExitCodes.Success);
+    }
+
+    private async Task<(bool IsValid, string? ExpectedHash, string? ActualHash)> VerifyBundleChecksumAsync(
+        string bundlePath,
+        string sha256Path,
+        CancellationToken cancellationToken)
+    {
+        // Read expected hash from .sha256 file
+        var content = await File.ReadAllTextAsync(sha256Path, cancellationToken).ConfigureAwait(false);
+        var expectedHash = content.Split(' ', StringSplitOptions.RemoveEmptyEntries).FirstOrDefault()?.Trim()?.ToLowerInvariant();
+
+        if (string.IsNullOrEmpty(expectedHash))
+        {
+            return (false, null, null);
+        }
+
+        // Compute actual hash
+        await using var stream = File.OpenRead(bundlePath);
+        var hashBytes = await SHA256.HashDataAsync(stream, cancellationToken).ConfigureAwait(false);
+        var actualHash = Convert.ToHexString(hashBytes).ToLowerInvariant();
+
+        return (string.Equals(expectedHash, actualHash, StringComparison.OrdinalIgnoreCase), expectedHash, actualHash);
+    }
+
+    private async Task<BundleContents> ExtractBundleContentsAsync(
+        string bundlePath,
+        CancellationToken cancellationToken)
+    {
+        var contents = new BundleContents();
+
+        await using var fileStream = File.OpenRead(bundlePath);
+        await using var gzipStream = new GZipStream(fileStream, CompressionMode.Decompress);
+        using var tarReader = new TarReader(gzipStream);
+
+        TarEntry? entry;
+        while ((entry = await tarReader.GetNextEntryAsync(cancellationToken: cancellationToken).ConfigureAwait(false)) is not null)
+        {
+            if (entry.EntryType != TarEntryType.RegularFile || entry.DataStream is null)
+            {
+                continue;
+            }
+
+            using var memoryStream = new MemoryStream();
+            await entry.DataStream.CopyToAsync(memoryStream, cancellationToken).ConfigureAwait(false);
+            var data = memoryStream.ToArray();
+            var text = System.Text.Encoding.UTF8.GetString(data);
+
+            switch (entry.Name)
+            {
+                case DsseEnvelopeFileName:
+                    contents.DsseEnvelopeJson = text;
+                    contents.DsseEnvelopeBytes = data;
+                    contents.DsseEnvelope = JsonSerializer.Deserialize<DsseEnvelope>(text, SerializerOptions);
+                    break;
+                case StatementFileName:
+                    contents.StatementJson = text;
+                    contents.StatementBytes = data;
+                    contents.Statement = JsonSerializer.Deserialize<InTotoStatement>(text, SerializerOptions);
+                    break;
+                case TransparencyFileName:
+                    contents.TransparencyNdjson = text;
+                    contents.TransparencyBytes = data;
+                    break;
+                case MetadataFileName:
+                    contents.MetadataJson = text;
+                    contents.MetadataBytes = data;
+                    contents.Metadata = JsonSerializer.Deserialize<AttestationBundleMetadata>(text, SerializerOptions);
+                    break;
+                case ChecksumsFileName:
+                    contents.ChecksumsText = text;
+                    break;
+            }
+        }
+
+        return contents;
+    }
+
+    private (bool Success, string? ErrorMessage) VerifyInternalChecksums(BundleContents contents)
+    {
+        if (string.IsNullOrWhiteSpace(contents.ChecksumsText))
+        {
+            return (true, null);
+        }
+
+        var lines = contents.ChecksumsText.Split('\n', StringSplitOptions.RemoveEmptyEntries);
+        foreach (var line in lines)
+        {
+            // Skip comments
+            if (line.TrimStart().StartsWith('#'))
+            {
+                continue;
+            }
+
+            // Parse "hash  filename" format
+            var parts = line.Split(new[] { ' ' }, 2, StringSplitOptions.RemoveEmptyEntries);
+            if (parts.Length != 2)
+            {
+                continue;
+            }
+
+            var expectedHash = parts[0].Trim().ToLowerInvariant();
+            var fileName = parts[1].Trim();
+
+            byte[]? fileBytes = fileName switch
+            {
+                DsseEnvelopeFileName => contents.DsseEnvelopeBytes,
+                StatementFileName => contents.StatementBytes,
+                TransparencyFileName => contents.TransparencyBytes,
+                MetadataFileName => contents.MetadataBytes,
+                _ => null
+            };
+
+            if (fileBytes is null)
+            {
+                // File not found in bundle - could be optional
+                if (fileName == TransparencyFileName)
+                {
+                    continue; // transparency.ndjson is optional
+                }
+
+                return (false, $"File '{fileName}' referenced in checksums but not found in bundle");
+            }
+
+            var actualHash = Convert.ToHexString(SHA256.HashData(fileBytes)).ToLowerInvariant();
+            if (!string.Equals(expectedHash, actualHash, StringComparison.OrdinalIgnoreCase))
+            {
+                return (false, $"Checksum mismatch for '{fileName}': expected {expectedHash}, got {actualHash}");
+            }
+        }
+
+        return (true, null);
+    }
+
+    private bool VerifyDsseSignature(BundleContents contents, bool offline, out string? error)
+    {
+        error = null;
+
+        if (contents.DsseEnvelope is null || string.IsNullOrEmpty(contents.DsseEnvelope.Payload))
+        {
+            error = "DSSE envelope not found or has no payload";
+            return false;
+        }
+
+        // Verify payload matches statement
+        if (contents.StatementJson is not null)
+        {
+            try
+            {
+                var payloadBytes = Convert.FromBase64String(contents.DsseEnvelope.Payload);
+                var payloadJson = System.Text.Encoding.UTF8.GetString(payloadBytes);
+
+                // Compare parsed JSON to handle whitespace differences
+                using var statementDoc = JsonDocument.Parse(contents.StatementJson);
+                using var payloadDoc = JsonDocument.Parse(payloadJson);
+
+                // Check _type field matches
+                var statementType = statementDoc.RootElement.TryGetProperty("_type", out var sType)
+                    ? sType.GetString()
+                    : null;
+                var payloadType = payloadDoc.RootElement.TryGetProperty("_type", out var pType)
+                    ? pType.GetString()
+                    : null;
+
+                if (!string.Equals(statementType, payloadType, StringComparison.Ordinal))
+                {
+                    error = "DSSE payload does not match statement _type";
+                    return false;
+                }
+            }
+            catch (FormatException ex)
+            {
+                error = $"Invalid DSSE payload encoding: {ex.Message}";
+                return false;
+            }
+            catch (JsonException ex)
+            {
+                error = $"Invalid DSSE payload JSON: {ex.Message}";
+                return false;
+            }
+        }
+
+        // In offline mode, we don't verify the actual cryptographic signature
+        // (would require access to signing keys/certificates)
+        if (offline)
+        {
+            _logger.LogDebug("Offline mode: skipping cryptographic signature verification");
+            return true;
+        }
+
+        // Check that signatures exist
+        if (contents.DsseEnvelope.Signatures is null || contents.DsseEnvelope.Signatures.Count == 0)
+        {
+            error = "DSSE envelope has no signatures";
+            return false;
+        }
+
+        // Online signature verification would require access to trust roots
+        // For now, we trust the signature if payload matches and signatures exist
+        return true;
+    }
+
+    private static IReadOnlyList<string>? ExtractSubjects(BundleContents contents)
+    {
+        if (contents.Statement?.Subject is null || contents.Statement.Subject.Count == 0)
+        {
+            // Fall back to metadata subjects
+            if (contents.Metadata?.SubjectDigests is not null)
+            {
+                return contents.Metadata.SubjectDigests
+                    .Select(s => $"{s.Name}@{s.Algorithm}:{s.Digest}")
+                    .ToList();
+            }
+            return null;
+        }
+
+        return contents.Statement.Subject
+            .Select(s =>
+            {
+                var digest = s.Digest?.FirstOrDefault();
+                return digest.HasValue
+                    ? $"{s.Name}@{digest.Value.Key}:{digest.Value.Value}"
+                    : s.Name ?? "unknown";
+            })
+            .ToList();
+    }
+
+    private static string? ExtractPredicateType(BundleContents contents)
+    {
+        return contents.Statement?.PredicateType ?? contents.DsseEnvelope?.PayloadType;
+    }
+
+    private static string? FormatRootHash(string? rootHash)
+    {
+        if (string.IsNullOrWhiteSpace(rootHash))
+        {
+            return null;
+        }
+
+        return rootHash.StartsWith("sha256:", StringComparison.OrdinalIgnoreCase)
+            ? rootHash
+            : $"sha256:{rootHash}";
+    }
+
+    private static AttestationBundleVerifyResult CreateFailedResult(
+        int exitCode,
+        string message,
+        string bundlePath,
+        string? detail = null)
+        => new(
+            Success: false,
+            Status: "failed",
+            ExportId: null,
+            AttestationId: null,
+            RootHash: null,
+            Subjects: null,
+            PredicateType: null,
+            StatementVersion: null,
+            BundlePath: bundlePath,
+            ErrorMessage: detail ?? message,
+            ExitCode: exitCode);
+
+    private sealed class BundleContents
+    {
+        public string? DsseEnvelopeJson { get; set; }
+        public byte[]? DsseEnvelopeBytes { get; set; }
+        public DsseEnvelope? DsseEnvelope { get; set; }
+
+        public string? StatementJson { get; set; }
+        public byte[]? StatementBytes { get; set; }
+        public InTotoStatement? Statement { get; set; }
+
+        public string? TransparencyNdjson { get; set; }
+        public byte[]? TransparencyBytes { get; set; }
+
+        public string? MetadataJson { get; set; }
+        public byte[]? MetadataBytes { get; set; }
+        public AttestationBundleMetadata? Metadata { get; set; }
+
+        public string? ChecksumsText { get; set; }
+    }
+
+    private sealed class DsseEnvelope
+    {
+        public string? PayloadType { get; set; }
+        public string? Payload { get; set; }
+        public IReadOnlyList<DsseSignature>? Signatures { get; set; }
+    }
+
+    private sealed class DsseSignature
+    {
+        public string? KeyId { get; set; }
+        public string? Sig { get; set; }
+    }
+
+    private sealed class InTotoStatement
+    {
+        public string? Type { get; set; }
+        public string? PredicateType { get; set; }
+        public IReadOnlyList<InTotoSubject>? Subject { get; set; }
+    }
+
+    private sealed class InTotoSubject
+    {
+        public string? Name { get; set; }
+        public Dictionary<string, string>? Digest { get; set; }
+    }
+
+    private sealed record AttestationBundleMetadata(
+        string? Version,
+        string? ExportId,
+        string? AttestationId,
+        string? TenantId,
+        DateTimeOffset? CreatedAtUtc,
+        string? RootHash,
+        string? SourceUri,
+        string? StatementVersion,
+        IReadOnlyList<AttestationSubjectDigest>? SubjectDigests);
+
+    private sealed record AttestationSubjectDigest(
+        string? Name,
+        string? Digest,
+        string? Algorithm);
+}

src/Cli/StellaOps.Cli/Services/DevPortalBundleVerifier.cs

@@ -0,0 +1,380 @@
+using System.Formats.Tar;
+using System.IO.Compression;
+using System.Security.Cryptography;
+using System.Text.Json;
+using Microsoft.Extensions.Logging;
+
+namespace StellaOps.Cli.Services;
+
+/// <summary>
+/// Verifier for EvidenceLocker sealed bundles used in DevPortal offline verification.
+/// Per DVOFF-64-002.
+/// </summary>
+internal sealed class DevPortalBundleVerifier : IDevPortalBundleVerifier
+{
+    private static readonly JsonSerializerOptions SerializerOptions = new(JsonSerializerDefaults.Web)
+    {
+        PropertyNameCaseInsensitive = true,
+        WriteIndented = true,
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+    };
+
+    private readonly ILogger<DevPortalBundleVerifier> _logger;
+
+    public DevPortalBundleVerifier(ILogger<DevPortalBundleVerifier> logger)
+    {
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+    }
+
+    public async Task<DevPortalBundleVerificationResult> VerifyBundleAsync(
+        string bundlePath,
+        bool offline,
+        CancellationToken cancellationToken)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(bundlePath);
+
+        _logger.LogDebug("Verifying DevPortal bundle at {BundlePath}, offline={Offline}", bundlePath, offline);
+
+        // Step 1: Check bundle exists
+        if (!File.Exists(bundlePath))
+        {
+            return DevPortalBundleVerificationResult.Failed(
+                DevPortalVerifyExitCode.Unexpected,
+                "Bundle file not found",
+                bundlePath);
+        }
+
+        // Step 2: Validate SHA-256 against .sha256 file if present
+        var sha256Path = bundlePath + ".sha256";
+        if (File.Exists(sha256Path))
+        {
+            var checksumResult = await VerifyBundleChecksumAsync(bundlePath, sha256Path, cancellationToken)
+                .ConfigureAwait(false);
+            if (!checksumResult.IsValid)
+            {
+                return DevPortalBundleVerificationResult.Failed(
+                    DevPortalVerifyExitCode.ChecksumMismatch,
+                    "SHA-256 checksum mismatch",
+                    $"Expected: {checksumResult.ExpectedHash}, Computed: {checksumResult.ActualHash}");
+            }
+        }
+        else
+        {
+            _logger.LogDebug("No .sha256 file found, skipping checksum verification");
+        }
+
+        // Step 3: Extract and parse bundle contents
+        BundleContents contents;
+        try
+        {
+            contents = await ExtractBundleContentsAsync(bundlePath, cancellationToken).ConfigureAwait(false);
+        }
+        catch (Exception ex) when (ex is InvalidDataException or JsonException or IOException)
+        {
+            _logger.LogError(ex, "Failed to extract bundle contents");
+            return DevPortalBundleVerificationResult.Failed(
+                DevPortalVerifyExitCode.Unexpected,
+                "Failed to extract bundle contents",
+                ex.Message);
+        }
+
+        // Step 4: Verify DSSE signature
+        var signatureValid = VerifyDsseSignature(contents, offline, out var signatureError);
+        if (!signatureValid && !string.IsNullOrEmpty(signatureError))
+        {
+            return DevPortalBundleVerificationResult.Failed(
+                DevPortalVerifyExitCode.SignatureFailure,
+                "DSSE signature verification failed",
+                signatureError);
+        }
+
+        // Step 5: Verify TSA (only if not offline)
+        if (!offline && contents.Signature is not null)
+        {
+            if (string.IsNullOrEmpty(contents.Signature.TimestampAuthority) ||
+                string.IsNullOrEmpty(contents.Signature.TimestampToken))
+            {
+                return DevPortalBundleVerificationResult.Failed(
+                    DevPortalVerifyExitCode.TsaMissing,
+                    "RFC3161 timestamp missing",
+                    "Bundle requires timestamping when not in offline mode");
+            }
+        }
+
+        // Step 6: Build success result
+        return new DevPortalBundleVerificationResult
+        {
+            Status = "verified",
+            BundleId = contents.Manifest?.BundleId ?? contents.BundleMetadata?.BundleId,
+            RootHash = contents.BundleMetadata?.RootHash is not null
+                ? $"sha256:{contents.BundleMetadata.RootHash}"
+                : null,
+            Entries = contents.Manifest?.Entries?.Count ?? 0,
+            CreatedAt = contents.Manifest?.CreatedAt ?? contents.BundleMetadata?.CreatedAt,
+            Portable = contents.BundleMetadata?.PortableGeneratedAt is not null,
+            ExitCode = DevPortalVerifyExitCode.Success
+        };
+    }
+
+    private async Task<(bool IsValid, string? ExpectedHash, string? ActualHash)> VerifyBundleChecksumAsync(
+        string bundlePath,
+        string sha256Path,
+        CancellationToken cancellationToken)
+    {
+        // Read expected hash from .sha256 file
+        var content = await File.ReadAllTextAsync(sha256Path, cancellationToken).ConfigureAwait(false);
+        var expectedHash = content.Split(' ', StringSplitOptions.RemoveEmptyEntries).FirstOrDefault()?.Trim()?.ToLowerInvariant();
+
+        if (string.IsNullOrEmpty(expectedHash))
+        {
+            return (false, null, null);
+        }
+
+        // Compute actual hash
+        await using var stream = File.OpenRead(bundlePath);
+        var hashBytes = await SHA256.HashDataAsync(stream, cancellationToken).ConfigureAwait(false);
+        var actualHash = Convert.ToHexString(hashBytes).ToLowerInvariant();
+
+        return (string.Equals(expectedHash, actualHash, StringComparison.OrdinalIgnoreCase), expectedHash, actualHash);
+    }
+
+    private async Task<BundleContents> ExtractBundleContentsAsync(
+        string bundlePath,
+        CancellationToken cancellationToken)
+    {
+        var contents = new BundleContents();
+
+        await using var fileStream = File.OpenRead(bundlePath);
+        await using var gzipStream = new GZipStream(fileStream, CompressionMode.Decompress);
+        using var tarReader = new TarReader(gzipStream);
+
+        TarEntry? entry;
+        while ((entry = await tarReader.GetNextEntryAsync(cancellationToken: cancellationToken).ConfigureAwait(false)) is not null)
+        {
+            if (entry.EntryType != TarEntryType.RegularFile || entry.DataStream is null)
+            {
+                continue;
+            }
+
+            using var memoryStream = new MemoryStream();
+            await entry.DataStream.CopyToAsync(memoryStream, cancellationToken).ConfigureAwait(false);
+            var json = System.Text.Encoding.UTF8.GetString(memoryStream.ToArray());
+
+            switch (entry.Name)
+            {
+                case "manifest.json":
+                    contents.ManifestJson = json;
+                    contents.Manifest = JsonSerializer.Deserialize<BundleManifest>(json, SerializerOptions);
+                    break;
+                case "signature.json":
+                    contents.SignatureJson = json;
+                    contents.Signature = JsonSerializer.Deserialize<BundleSignature>(json, SerializerOptions);
+                    break;
+                case "bundle.json":
+                    contents.BundleMetadataJson = json;
+                    contents.BundleMetadata = JsonSerializer.Deserialize<BundleMetadataDocument>(json, SerializerOptions);
+                    break;
+                case "checksums.txt":
+                    contents.ChecksumsText = json;
+                    break;
+            }
+        }
+
+        return contents;
+    }
+
+    private bool VerifyDsseSignature(BundleContents contents, bool offline, out string? error)
+    {
+        error = null;
+
+        if (contents.Signature is null || string.IsNullOrEmpty(contents.Signature.Payload))
+        {
+            error = "Signature not found in bundle";
+            return false;
+        }
+
+        // Verify payload matches manifest
+        if (contents.ManifestJson is not null)
+        {
+            try
+            {
+                var payloadBytes = Convert.FromBase64String(contents.Signature.Payload);
+                var payloadJson = System.Text.Encoding.UTF8.GetString(payloadBytes);
+
+                // Compare parsed JSON to handle whitespace differences
+                using var manifestDoc = JsonDocument.Parse(contents.ManifestJson);
+                using var payloadDoc = JsonDocument.Parse(payloadJson);
+
+                var manifestBundleId = manifestDoc.RootElement.TryGetProperty("bundleId", out var mId)
+                    ? mId.GetString()
+                    : null;
+                var payloadBundleId = payloadDoc.RootElement.TryGetProperty("bundleId", out var pId)
+                    ? pId.GetString()
+                    : null;
+
+                if (!string.Equals(manifestBundleId, payloadBundleId, StringComparison.OrdinalIgnoreCase))
+                {
+                    error = "Signature payload does not match manifest bundleId";
+                    return false;
+                }
+            }
+            catch (FormatException ex)
+            {
+                error = $"Invalid signature payload encoding: {ex.Message}";
+                return false;
+            }
+            catch (JsonException ex)
+            {
+                error = $"Invalid signature payload JSON: {ex.Message}";
+                return false;
+            }
+        }
+
+        // In offline mode, we don't verify the actual cryptographic signature
+        // (would require access to signing keys/certificates)
+        if (offline)
+        {
+            _logger.LogDebug("Offline mode: skipping cryptographic signature verification");
+            return true;
+        }
+
+        // Online signature verification would go here
+        // For now, we trust the signature if payload matches
+        return true;
+    }
+
+    private sealed class BundleContents
+    {
+        public string? ManifestJson { get; set; }
+        public BundleManifest? Manifest { get; set; }
+        public string? SignatureJson { get; set; }
+        public BundleSignature? Signature { get; set; }
+        public string? BundleMetadataJson { get; set; }
+        public BundleMetadataDocument? BundleMetadata { get; set; }
+        public string? ChecksumsText { get; set; }
+    }
+
+    private sealed class BundleManifest
+    {
+        public string? BundleId { get; set; }
+        public string? TenantId { get; set; }
+        public int Kind { get; set; }
+        public DateTimeOffset? CreatedAt { get; set; }
+        public Dictionary<string, string>? Metadata { get; set; }
+        public List<BundleManifestEntry>? Entries { get; set; }
+    }
+
+    private sealed class BundleManifestEntry
+    {
+        public string? Section { get; set; }
+        public string? CanonicalPath { get; set; }
+        public string? Sha256 { get; set; }
+        public long SizeBytes { get; set; }
+        public string? MediaType { get; set; }
+    }
+
+    private sealed class BundleSignature
+    {
+        public string? PayloadType { get; set; }
+        public string? Payload { get; set; }
+        public string? Signature { get; set; }
+        public string? KeyId { get; set; }
+        public string? Algorithm { get; set; }
+        public string? Provider { get; set; }
+        public DateTimeOffset? SignedAt { get; set; }
+        public DateTimeOffset? TimestampedAt { get; set; }
+        public string? TimestampAuthority { get; set; }
+        public string? TimestampToken { get; set; }
+    }
+
+    private sealed class BundleMetadataDocument
+    {
+        public string? BundleId { get; set; }
+        public string? TenantId { get; set; }
+        public int Kind { get; set; }
+        public int Status { get; set; }
+        public string? RootHash { get; set; }
+        public string? StorageKey { get; set; }
+        public DateTimeOffset? CreatedAt { get; set; }
+        public DateTimeOffset? SealedAt { get; set; }
+        public DateTimeOffset? PortableGeneratedAt { get; set; }
+    }
+}
+
+/// <summary>
+/// Exit codes for DevPortal bundle verification per DVOFF-64-002.
+/// </summary>
+public enum DevPortalVerifyExitCode
+{
+    /// <summary>Verification successful.</summary>
+    Success = 0,
+
+    /// <summary>SHA-256 checksum mismatch.</summary>
+    ChecksumMismatch = 2,
+
+    /// <summary>DSSE signature verification failed.</summary>
+    SignatureFailure = 3,
+
+    /// <summary>RFC3161 timestamp missing (when not offline).</summary>
+    TsaMissing = 4,
+
+    /// <summary>Unexpected error.</summary>
+    Unexpected = 5
+}
+
+/// <summary>
+/// Result of DevPortal bundle verification.
+/// </summary>
+public sealed class DevPortalBundleVerificationResult
+{
+    public string Status { get; set; } = "failed";
+    public string? BundleId { get; set; }
+    public string? RootHash { get; set; }
+    public int Entries { get; set; }
+    public DateTimeOffset? CreatedAt { get; set; }
+    public bool Portable { get; set; }
+    public DevPortalVerifyExitCode ExitCode { get; set; } = DevPortalVerifyExitCode.Unexpected;
+    public string? ErrorMessage { get; set; }
+    public string? ErrorDetail { get; set; }
+
+    public static DevPortalBundleVerificationResult Failed(
+        DevPortalVerifyExitCode exitCode,
+        string message,
+        string? detail = null)
+        => new()
+        {
+            Status = "failed",
+            ExitCode = exitCode,
+            ErrorMessage = message,
+            ErrorDetail = detail
+        };
+
+    public string ToJson()
+    {
+        var options = new JsonSerializerOptions
+        {
+            WriteIndented = false,
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+            DefaultIgnoreCondition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull
+        };
+
+        // Build output with sorted keys
+        var output = new SortedDictionary<string, object?>(StringComparer.Ordinal);
+
+        if (BundleId is not null)
+            output["bundleId"] = BundleId;
+        if (CreatedAt.HasValue)
+            output["createdAt"] = CreatedAt.Value.ToString("O");
+        output["entries"] = Entries;
+        if (ErrorDetail is not null)
+            output["errorDetail"] = ErrorDetail;
+        if (ErrorMessage is not null)
+            output["errorMessage"] = ErrorMessage;
+        output["portable"] = Portable;
+        if (RootHash is not null)
+            output["rootHash"] = RootHash;
+        output["status"] = Status;
+
+        return JsonSerializer.Serialize(output, options);
+    }
+}

src/Cli/StellaOps.Cli/Services/IAttestationBundleVerifier.cs

@@ -0,0 +1,29 @@
+using StellaOps.Cli.Services.Models;
+
+namespace StellaOps.Cli.Services;
+
+/// <summary>
+/// Interface for attestation bundle verification.
+/// </summary>
+public interface IAttestationBundleVerifier
+{
+    /// <summary>
+    /// Verifies an attestation bundle exported from the Export Center.
+    /// </summary>
+    /// <param name="options">Verification options.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Verification result with status and exit code.</returns>
+    Task<AttestationBundleVerifyResult> VerifyAsync(
+        AttestationBundleVerifyOptions options,
+        CancellationToken cancellationToken);
+
+    /// <summary>
+    /// Imports an attestation bundle into the local system.
+    /// </summary>
+    /// <param name="options">Import options.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Import result with status and exit code.</returns>
+    Task<AttestationBundleImportResult> ImportAsync(
+        AttestationBundleImportOptions options,
+        CancellationToken cancellationToken);
+}

src/Cli/StellaOps.Cli/Services/IDevPortalBundleVerifier.cs

@@ -0,0 +1,19 @@
+namespace StellaOps.Cli.Services;
+
+/// <summary>
+/// Interface for DevPortal bundle verification.
+/// </summary>
+public interface IDevPortalBundleVerifier
+{
+    /// <summary>
+    /// Verifies a DevPortal/EvidenceLocker sealed bundle.
+    /// </summary>
+    /// <param name="bundlePath">Path to the bundle .tgz file.</param>
+    /// <param name="offline">If true, skip TSA verification and online checks.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Verification result with status and exit code.</returns>
+    Task<DevPortalBundleVerificationResult> VerifyBundleAsync(
+        string bundlePath,
+        bool offline,
+        CancellationToken cancellationToken);
+}

src/Cli/StellaOps.Cli/Services/Models/AttestationBundleModels.cs

@@ -0,0 +1,126 @@
+using System.Text.Json.Serialization;
+
+namespace StellaOps.Cli.Services.Models;
+
+/// <summary>
+/// Options for attestation bundle verification.
+/// </summary>
+public sealed record AttestationBundleVerifyOptions(
+    string FilePath,
+    bool Offline = false,
+    bool VerifyTransparency = true,
+    string? TrustRootPath = null);
+
+/// <summary>
+/// Options for attestation bundle import.
+/// </summary>
+public sealed record AttestationBundleImportOptions(
+    string FilePath,
+    string? Tenant = null,
+    string? Namespace = null,
+    bool Offline = false,
+    bool VerifyTransparency = true,
+    string? TrustRootPath = null);
+
+/// <summary>
+/// Result of attestation bundle verification.
+/// </summary>
+public sealed record AttestationBundleVerifyResult(
+    bool Success,
+    string Status,
+    string? ExportId,
+    string? AttestationId,
+    string? RootHash,
+    IReadOnlyList<string>? Subjects,
+    string? PredicateType,
+    string? StatementVersion,
+    string BundlePath,
+    string? ErrorMessage = null,
+    int ExitCode = 0);
+
+/// <summary>
+/// Result of attestation bundle import.
+/// </summary>
+public sealed record AttestationBundleImportResult(
+    bool Success,
+    string Status,
+    string? AttestationId,
+    string? TenantId,
+    string? Namespace,
+    string? RootHash,
+    string? ErrorMessage = null,
+    int ExitCode = 0);
+
+/// <summary>
+/// JSON output for attestation bundle verify command.
+/// </summary>
+public sealed record AttestationBundleVerifyJson(
+    [property: JsonPropertyName("status")] string Status,
+    [property: JsonPropertyName("exportId")] string? ExportId,
+    [property: JsonPropertyName("attestationId")] string? AttestationId,
+    [property: JsonPropertyName("rootHash")] string? RootHash,
+    [property: JsonPropertyName("subjects")] IReadOnlyList<string>? Subjects,
+    [property: JsonPropertyName("predicateType")] string? PredicateType,
+    [property: JsonPropertyName("bundlePath")] string BundlePath);
+
+/// <summary>
+/// JSON output for attestation bundle import command.
+/// </summary>
+public sealed record AttestationBundleImportJson(
+    [property: JsonPropertyName("status")] string Status,
+    [property: JsonPropertyName("attestationId")] string? AttestationId,
+    [property: JsonPropertyName("tenantId")] string? TenantId,
+    [property: JsonPropertyName("namespace")] string? Namespace,
+    [property: JsonPropertyName("rootHash")] string? RootHash);
+
+/// <summary>
+/// Exit codes for attestation bundle commands.
+/// </summary>
+public static class AttestationBundleExitCodes
+{
+    /// <summary>Success.</summary>
+    public const int Success = 0;
+
+    /// <summary>General failure.</summary>
+    public const int GeneralFailure = 1;
+
+    /// <summary>Checksum mismatch.</summary>
+    public const int ChecksumMismatch = 2;
+
+    /// <summary>DSSE signature verification failure.</summary>
+    public const int SignatureFailure = 3;
+
+    /// <summary>Missing required TSA/CT log entry.</summary>
+    public const int MissingTransparency = 4;
+
+    /// <summary>Archive or file format error.</summary>
+    public const int FormatError = 5;
+
+    /// <summary>File not found.</summary>
+    public const int FileNotFound = 6;
+
+    /// <summary>Import failed.</summary>
+    public const int ImportFailed = 7;
+}
+
+/// <summary>
+/// Metadata parsed from an attestation bundle.
+/// </summary>
+internal sealed record AttestationBundleMetadata(
+    string? Version,
+    string? ExportId,
+    string? AttestationId,
+    string? TenantId,
+    DateTimeOffset? CreatedAtUtc,
+    string? RootHash,
+    string? SourceUri,
+    string? StatementVersion,
+    IReadOnlyList<AttestationBundleSubjectDigest>? SubjectDigests);
+
+/// <summary>
+/// Subject digest from attestation bundle metadata.
+/// </summary>
+internal sealed record AttestationBundleSubjectDigest(
+    string? Name,
+    string? Digest,
+    string? Algorithm);