Add unit tests for RabbitMq and Udp transport servers and clients

- Implemented comprehensive unit tests for RabbitMqTransportServer, covering constructor, disposal, connection management, event handlers, and exception handling.
- Added configuration tests for RabbitMqTransportServer to validate SSL, durable queues, auto-recovery, and custom virtual host options.
- Created unit tests for UdpFrameProtocol, including frame parsing and serialization, header size validation, and round-trip data preservation.
- Developed tests for UdpTransportClient, focusing on connection handling, event subscriptions, and exception scenarios.
- Established tests for UdpTransportServer, ensuring proper start/stop behavior, connection state management, and event handling.
- Included tests for UdpTransportOptions to verify default values and modification capabilities.
- Enhanced service registration tests for Udp transport services in the dependency injection container.

src/Findings/StellaOps.Findings.Ledger/Infrastructure/Merkle/LedgerMerkleAnchorWorker.cs

@@ -3,6 +3,7 @@ using System.Diagnostics;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
+using StellaOps.Cryptography;
 using StellaOps.Findings.Ledger.Domain;
 using StellaOps.Findings.Ledger.Observability;
 using StellaOps.Findings.Ledger.Options;
@@ -14,6 +15,7 @@ public sealed class LedgerMerkleAnchorWorker : BackgroundService
 {
     private readonly LedgerAnchorQueue _queue;
     private readonly IMerkleAnchorRepository _repository;
+    private readonly ICryptoHash _cryptoHash;
     private readonly TimeProvider _timeProvider;
     private readonly LedgerServiceOptions.MerkleOptions _options;
     private readonly ILogger<LedgerMerkleAnchorWorker> _logger;
@@ -22,12 +24,14 @@ public sealed class LedgerMerkleAnchorWorker : BackgroundService
     public LedgerMerkleAnchorWorker(
         LedgerAnchorQueue queue,
         IMerkleAnchorRepository repository,
+        ICryptoHash cryptoHash,
         IOptions<LedgerServiceOptions> options,
         TimeProvider timeProvider,
         ILogger<LedgerMerkleAnchorWorker> logger)
     {
         _queue = queue ?? throw new ArgumentNullException(nameof(queue));
         _repository = repository ?? throw new ArgumentNullException(nameof(repository));
+        _cryptoHash = cryptoHash ?? throw new ArgumentNullException(nameof(cryptoHash));
         _timeProvider = timeProvider ?? throw new ArgumentNullException(nameof(timeProvider));
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
         _options = options?.Value.Merkle ?? throw new ArgumentNullException(nameof(options));
@@ -89,7 +93,7 @@ public sealed class LedgerMerkleAnchorWorker : BackgroundService
                 .ThenBy(e => e.RecordedAt)
                 .ToList();
 
-            var rootHash = MerkleTreeBuilder.ComputeRoot(orderedEvents.Select(e => e.MerkleLeafHash).ToArray());
+            var rootHash = MerkleTreeBuilder.ComputeRoot(_cryptoHash, orderedEvents.Select(e => e.MerkleLeafHash).ToArray());
             var anchorId = Guid.NewGuid();
             var windowStart = orderedEvents.First().RecordedAt;
             var windowEnd = orderedEvents.Last().RecordedAt;

src/Findings/StellaOps.Findings.Ledger/Infrastructure/Merkle/MerkleTreeBuilder.cs

@@ -1,12 +1,14 @@
-using System.Security.Cryptography;
 using System.Text;
+using StellaOps.Cryptography;
 
 namespace StellaOps.Findings.Ledger.Infrastructure.Merkle;
 
 internal static class MerkleTreeBuilder
 {
-    public static string ComputeRoot(IReadOnlyList<string> leafHashes)
+    public static string ComputeRoot(ICryptoHash cryptoHash, IReadOnlyList<string> leafHashes)
     {
+        ArgumentNullException.ThrowIfNull(cryptoHash);
+
         if (leafHashes.Count == 0)
         {
             throw new ArgumentException("At least one leaf hash is required to compute a Merkle root.", nameof(leafHashes));
@@ -18,13 +20,13 @@ internal static class MerkleTreeBuilder
 
         while (currentLevel.Length > 1)
         {
-            currentLevel = ComputeNextLevel(currentLevel);
+            currentLevel = ComputeNextLevel(cryptoHash, currentLevel);
         }
 
         return currentLevel[0];
     }
 
-    private static string[] ComputeNextLevel(IReadOnlyList<string> level)
+    private static string[] ComputeNextLevel(ICryptoHash cryptoHash, IReadOnlyList<string> level)
     {
         var next = new string[(level.Count + 1) / 2];
         var index = 0;
@@ -33,16 +35,15 @@ internal static class MerkleTreeBuilder
         {
             var left = level[i];
             var right = i + 1 < level.Count ? level[i + 1] : level[i];
-            next[index++] = HashPair(left, right);
+            next[index++] = HashPair(cryptoHash, left, right);
         }
 
         return next;
     }
 
-    private static string HashPair(string left, string right)
+    private static string HashPair(ICryptoHash cryptoHash, string left, string right)
     {
         var bytes = Encoding.UTF8.GetBytes(left + right);
-        var hashBytes = SHA256.HashData(bytes);
-        return Convert.ToHexString(hashBytes).ToLowerInvariant();
+        return cryptoHash.ComputeHashHexForPurpose(bytes, HashPurpose.Merkle);
     }
 }

src/Findings/StellaOps.Findings.Ledger/StellaOps.Findings.Ledger.csproj

@@ -30,4 +30,8 @@
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\..\__Libraries\StellaOps.Cryptography\StellaOps.Cryptography.csproj" />
+  </ItemGroup>
+
 </Project>