Encryption Sent, Encrpytion Decoded, Offer Sent, Offer Recieved, JS -> C# / C# -> JS Broke (some disconnect here) SendRtcSignalToJsAsync

RelayServer/Services/Chat/ChatSocketBehavior.cs

@@ -122,6 +122,27 @@ public class ChatSocketBehavior : WebSocketBehavior
             return;
         }
 
+        string plainText;
+
+        try
+        {
+            plainText = E2EeHelper.DecryptForRecipient(
+                new EncryptedPayload
+                {
+                    CipherText = clientPayload.CipherText,
+                    Nonce = clientPayload.Nonce,
+                    Tag = clientPayload.Tag,
+                    EncryptedKey = clientPayload.EncryptedKey
+                },
+                ServerPrivateKey
+            );
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Failed to decrypt RTC signal: {ex.Message}");
+            return;
+        }
+
         var sessionIds = RtcChannelPresenceService.GetSessionsInChannel(clientPayload.ChannelId);
 
         foreach (var sessionId in sessionIds)
@@ -129,7 +150,28 @@ public class ChatSocketBehavior : WebSocketBehavior
             if (sessionId == ID)
                 continue;
 
-            Sessions.SendTo(JsonSerializer.Serialize(clientPayload), sessionId);
+            var username = RtcChannelPresenceService.GetUsernameForSession(sessionId);
+            if (string.IsNullOrWhiteSpace(username))
+                continue;
+
+            var clientKey = GetClientPublicKeyByUsernameSync(username);
+            if (clientKey is null)
+                continue;
+
+            var encrypted = E2EeHelper.EncryptForRecipient(plainText, clientKey.PublicKey);
+
+            var outbound = new SocketRtcSignalMessage
+            {
+                Type = SignalType.EncryptedSignal,
+                SenderUsername = clientPayload.SenderUsername,
+                ChannelId = clientPayload.ChannelId,
+                CipherText = encrypted.CipherText,
+                Nonce = encrypted.Nonce,
+                Tag = encrypted.Tag,
+                EncryptedKey = encrypted.EncryptedKey
+            };
+
+            Sessions.SendTo(JsonSerializer.Serialize(outbound), sessionId);
         }
 
         Console.WriteLine($"Forwarded encrypted RTC signal from {clientPayload.SenderUsername} to channel {clientPayload.ChannelId}");

RelayServer/Services/Rtc/RtcChannelPresenceService.cs

@@ -57,4 +57,11 @@ public static class RtcChannelPresenceService
         return SessionToChannel.TryGetValue(sessionId, out var currentChannel) &&
                string.Equals(currentChannel, channelId, StringComparison.Ordinal);
     }
+    
+    public static string? GetUsernameForSession(string sessionId)
+    {
+        return SessionToUsername.TryGetValue(sessionId, out var username)
+            ? username
+            : null;
+    }
 }