Auth logging updates

SVSim.EmulatedEntrypoint/Middlewares/SessionidMappingMiddleware.cs

@@ -10,21 +10,55 @@ namespace SVSim.EmulatedEntrypoint.Middlewares;
 public class SessionidMappingMiddleware : IMiddleware
 {
     private readonly ShadowverseSessionService _shadowverseSessionService;
+    private readonly ILogger<SessionidMappingMiddleware> _logger;
 
-    public SessionidMappingMiddleware(ShadowverseSessionService shadowverseSessionService)
+    public SessionidMappingMiddleware(
+        ShadowverseSessionService shadowverseSessionService,
+        ILogger<SessionidMappingMiddleware> logger)
     {
         _shadowverseSessionService = shadowverseSessionService;
+        _logger = logger;
     }
 
     public async Task InvokeAsync(HttpContext context, RequestDelegate next)
     {
-        bool hasSessionId = context.Request.Headers.TryGetValue(NetworkConstants.UdidHeaderName, out var udid);
-        bool hasUdid = context.Request.Headers.TryGetValue(NetworkConstants.SessionIdHeaderName, out var sid);
-        if (hasSessionId && hasUdid)
+        // NOTE: the bool names below were historically inverted (hasSessionId held UDID and
+        // vice versa). Variable names corrected in-place; behavior unchanged.
+        bool hasUdid = context.Request.Headers.TryGetValue(NetworkConstants.UdidHeaderName, out var udid);
+        bool hasSid = context.Request.Headers.TryGetValue(NetworkConstants.SessionIdHeaderName, out var sid);
+
+        if (hasUdid && hasSid)
         {
-            _shadowverseSessionService.StoreUdidForSessionId(sid.FirstOrDefault(), Guid.Parse(Encryption.Decode(udid.FirstOrDefault())));
+            string? sidValue = sid.FirstOrDefault();
+            string? encodedUdid = udid.FirstOrDefault();
+            try
+            {
+                string? decoded = Encryption.Decode(encodedUdid);
+                Guid parsedUdid = Guid.Parse(decoded);
+                _shadowverseSessionService.StoreUdidForSessionId(sidValue, parsedUdid);
+                _logger.LogDebug(
+                    "Stored SID→UDID mapping for {Path} (sid={Sid}, udid={Udid}).",
+                    context.Request.Path, sidValue, parsedUdid);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex,
+                    "Failed to decode/parse UDID header for {Path} (sid={Sid}, encodedUdidLen={EncodedUdidLen}). " +
+                    "Downstream translation will fall back to Guid.Empty and almost certainly fail msgpack decrypt.",
+                    context.Request.Path, sidValue, encodedUdid?.Length ?? 0);
+            }
+        }
+        else if (hasUdid ^ hasSid)
+        {
+            // Only one of the two headers present — usually a client bug or a test that forgot
+            // to set both. The translation middleware will then fall back to Guid.Empty and
+            // surface as a generic msgpack/decrypt error, so warn here where the cause is clear.
+            _logger.LogWarning(
+                "Only one of UDID/SID headers present for {Path} (hasUdid={HasUdid}, hasSid={HasSid}). " +
+                "Translation will use Guid.Empty as the encryption key.",
+                context.Request.Path, hasUdid, hasSid);
         }
 
         await next.Invoke(context);
     }
-}
+}