audit work, fixed StellaOps.sln warnings/errors, fixed tests, sprints work, new advisories

src/__Libraries/StellaOps.Eventing/Internal/EventIdGenerator.cs

@@ -0,0 +1,56 @@
+// Copyright (c) StellaOps. Licensed under the AGPL-3.0-or-later.
+
+using System.Security.Cryptography;
+using System.Text;
+using StellaOps.HybridLogicalClock;
+
+namespace StellaOps.Eventing.Internal;
+
+/// <summary>
+/// Generates deterministic event IDs from event content.
+/// </summary>
+internal static class EventIdGenerator
+{
+    /// <summary>
+    /// Generates a deterministic event ID using SHA-256 hash of inputs.
+    /// </summary>
+    /// <param name="correlationId">The correlation ID.</param>
+    /// <param name="tHlc">The HLC timestamp.</param>
+    /// <param name="service">The service name.</param>
+    /// <param name="kind">The event kind.</param>
+    /// <returns>First 32 hex characters of SHA-256 hash (128 bits).</returns>
+    public static string Generate(
+        string correlationId,
+        HlcTimestamp tHlc,
+        string service,
+        string kind)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(correlationId);
+        ArgumentException.ThrowIfNullOrWhiteSpace(service);
+        ArgumentException.ThrowIfNullOrWhiteSpace(kind);
+
+        using var hasher = IncrementalHash.CreateHash(HashAlgorithmName.SHA256);
+
+        // Append all inputs in deterministic order
+        hasher.AppendData(Encoding.UTF8.GetBytes(correlationId));
+        hasher.AppendData(Encoding.UTF8.GetBytes(tHlc.ToSortableString()));
+        hasher.AppendData(Encoding.UTF8.GetBytes(service));
+        hasher.AppendData(Encoding.UTF8.GetBytes(kind));
+
+        var hash = hasher.GetHashAndReset();
+
+        // Return first 16 bytes (128 bits) as lowercase hex (32 chars)
+        return Convert.ToHexString(hash.AsSpan(0, 16)).ToLowerInvariant();
+    }
+
+    /// <summary>
+    /// Computes SHA-256 digest of the payload.
+    /// </summary>
+    /// <param name="payload">The canonicalized JSON payload.</param>
+    /// <returns>SHA-256 digest bytes.</returns>
+    public static byte[] ComputePayloadDigest(string payload)
+    {
+        ArgumentNullException.ThrowIfNull(payload);
+        return SHA256.HashData(Encoding.UTF8.GetBytes(payload));
+    }
+}