Use V2 message post with user auth, V3 with app auth.

Author: jforsell

src/SymphonyOSS.RestApiClient/Api/AgentApi/MessagesApi.cs

@@ -61,7 +61,15 @@ public MessagesApi(IAuthTokens authTokens, Configuration configuration, IApiExec
         public V2Message PostMessage(string sid, V2MessageSubmission message)
         {
             TraceSource.TraceEvent(TraceEventType.Verbose, 0, "Posting message to stream \"{0}\"", sid);
-            return _apiExecutor.Execute(_messagesApi.V3StreamSidMessageCreatePost, sid, _authTokens.SessionToken, message, _authTokens.KeyManagerToken);
+            if (_authTokens.KeyManagerToken == null)
+            {
+                // Use the endpoint that works with OBO authentication.
+                return _apiExecutor.Execute(_messagesApi.V3StreamSidMessageCreatePost, sid, _authTokens.SessionToken, message, _authTokens.KeyManagerToken);
+            }
+            else
+            {
+                return _apiExecutor.Execute(_messagesApi.V2StreamSidMessageCreatePost, sid, _authTokens.SessionToken, _authTokens.KeyManagerToken, message);
+            }
         }
 
         /// <summary>

test/SymphonyOSS.RestApiClient.Tests/MessagesApiTest.cs

@@ -48,7 +48,7 @@ public void EnsurePostMessage_uses_retry_strategy()
             const string sid = "sid";
             var message = new V2MessageSubmission();
             _messagesApi.PostMessage(sid, message);
-            _apiExecutorMock.Verify(obj => obj.Execute(It.IsAny<Func<string, string, V2MessageSubmission, string, V2Message>>(), sid, "sessionToken", message, "keyManagerToken"));
+            _apiExecutorMock.Verify(obj => obj.Execute(It.IsAny<Func<string, string, string, V2MessageSubmission, V2Message>>(), sid, "sessionToken", "keyManagerToken", message));
         }
 
         [Fact]