Resolve Concelier/Excititor merge conflicts

src/StellaOps.Policy/PolicyDigest.cs

@@ -0,0 +1,211 @@
+using System;
+using System.Buffers;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text.Json;
+
+namespace StellaOps.Policy;
+
+public static class PolicyDigest
+{
+    public static string Compute(PolicyDocument document)
+    {
+        if (document is null)
+        {
+            throw new ArgumentNullException(nameof(document));
+        }
+
+        var buffer = new ArrayBufferWriter<byte>();
+        using (var writer = new Utf8JsonWriter(buffer, new JsonWriterOptions
+        {
+            SkipValidation = true,
+        }))
+        {
+            WriteDocument(writer, document);
+        }
+
+        var hash = SHA256.HashData(buffer.WrittenSpan);
+        return Convert.ToHexString(hash).ToLowerInvariant();
+    }
+
+    private static void WriteDocument(Utf8JsonWriter writer, PolicyDocument document)
+    {
+        writer.WriteStartObject();
+        writer.WriteString("version", document.Version);
+
+        if (!document.Metadata.IsEmpty)
+        {
+            writer.WritePropertyName("metadata");
+            writer.WriteStartObject();
+            foreach (var pair in document.Metadata.OrderBy(static kvp => kvp.Key, StringComparer.Ordinal))
+            {
+                writer.WriteString(pair.Key, pair.Value);
+            }
+            writer.WriteEndObject();
+        }
+
+        writer.WritePropertyName("rules");
+        writer.WriteStartArray();
+        foreach (var rule in document.Rules)
+        {
+            WriteRule(writer, rule);
+        }
+        writer.WriteEndArray();
+
+        writer.WriteEndObject();
+        writer.Flush();
+    }
+
+    private static void WriteRule(Utf8JsonWriter writer, PolicyRule rule)
+    {
+        writer.WriteStartObject();
+        writer.WriteString("name", rule.Name);
+
+        if (!string.IsNullOrWhiteSpace(rule.Identifier))
+        {
+            writer.WriteString("id", rule.Identifier);
+        }
+
+        if (!string.IsNullOrWhiteSpace(rule.Description))
+        {
+            writer.WriteString("description", rule.Description);
+        }
+
+        WriteMetadata(writer, rule.Metadata);
+        WriteSeverities(writer, rule.Severities);
+        WriteStringArray(writer, "environments", rule.Environments);
+        WriteStringArray(writer, "sources", rule.Sources);
+        WriteStringArray(writer, "vendors", rule.Vendors);
+        WriteStringArray(writer, "licenses", rule.Licenses);
+        WriteStringArray(writer, "tags", rule.Tags);
+
+        if (!rule.Match.IsEmpty)
+        {
+            writer.WritePropertyName("match");
+            writer.WriteStartObject();
+            WriteStringArray(writer, "images", rule.Match.Images);
+            WriteStringArray(writer, "repositories", rule.Match.Repositories);
+            WriteStringArray(writer, "packages", rule.Match.Packages);
+            WriteStringArray(writer, "purls", rule.Match.Purls);
+            WriteStringArray(writer, "cves", rule.Match.Cves);
+            WriteStringArray(writer, "paths", rule.Match.Paths);
+            WriteStringArray(writer, "layerDigests", rule.Match.LayerDigests);
+            WriteStringArray(writer, "usedByEntrypoint", rule.Match.UsedByEntrypoint);
+            writer.WriteEndObject();
+        }
+
+        WriteAction(writer, rule.Action);
+
+        if (rule.Expires is DateTimeOffset expires)
+        {
+            writer.WriteString("expires", expires.ToUniversalTime().ToString("O"));
+        }
+
+        if (!string.IsNullOrWhiteSpace(rule.Justification))
+        {
+            writer.WriteString("justification", rule.Justification);
+        }
+
+        writer.WriteEndObject();
+    }
+
+    private static void WriteAction(Utf8JsonWriter writer, PolicyAction action)
+    {
+        writer.WritePropertyName("action");
+        writer.WriteStartObject();
+        writer.WriteString("type", action.Type.ToString().ToLowerInvariant());
+
+        if (action.Quiet)
+        {
+            writer.WriteBoolean("quiet", true);
+        }
+
+        if (action.Ignore is { } ignore)
+        {
+            if (ignore.Until is DateTimeOffset until)
+            {
+                writer.WriteString("until", until.ToUniversalTime().ToString("O"));
+            }
+
+            if (!string.IsNullOrWhiteSpace(ignore.Justification))
+            {
+                writer.WriteString("justification", ignore.Justification);
+            }
+        }
+
+        if (action.Escalate is { } escalate)
+        {
+            if (escalate.MinimumSeverity is { } severity)
+            {
+                writer.WriteString("severity", severity.ToString());
+            }
+
+            if (escalate.RequireKev)
+            {
+                writer.WriteBoolean("kev", true);
+            }
+
+            if (escalate.MinimumEpss is double epss)
+            {
+                writer.WriteNumber("epss", epss);
+            }
+        }
+
+        if (action.RequireVex is { } requireVex)
+        {
+            WriteStringArray(writer, "vendors", requireVex.Vendors);
+            WriteStringArray(writer, "justifications", requireVex.Justifications);
+        }
+
+        writer.WriteEndObject();
+    }
+
+    private static void WriteMetadata(Utf8JsonWriter writer, ImmutableDictionary<string, string> metadata)
+    {
+        if (metadata.IsEmpty)
+        {
+            return;
+        }
+
+        writer.WritePropertyName("metadata");
+        writer.WriteStartObject();
+        foreach (var pair in metadata.OrderBy(static kvp => kvp.Key, StringComparer.Ordinal))
+        {
+            writer.WriteString(pair.Key, pair.Value);
+        }
+        writer.WriteEndObject();
+    }
+
+    private static void WriteSeverities(Utf8JsonWriter writer, ImmutableArray<PolicySeverity> severities)
+    {
+        if (severities.IsDefaultOrEmpty)
+        {
+            return;
+        }
+
+        writer.WritePropertyName("severity");
+        writer.WriteStartArray();
+        foreach (var severity in severities)
+        {
+            writer.WriteStringValue(severity.ToString());
+        }
+        writer.WriteEndArray();
+    }
+
+    private static void WriteStringArray(Utf8JsonWriter writer, string propertyName, ImmutableArray<string> values)
+    {
+        if (values.IsDefaultOrEmpty)
+        {
+            return;
+        }
+
+        writer.WritePropertyName(propertyName);
+        writer.WriteStartArray();
+        foreach (var value in values)
+        {
+            writer.WriteStringValue(value);
+        }
+        writer.WriteEndArray();
+    }
+}