Handle unencrypted message while getting messages with crypto

src/Api/PubnubApi/EndPoint/Files/DownloadFileOperation.cs

@@ -173,7 +173,8 @@ private void ProcessFileDownloadRequest(Dictionary<string, object> externalQuery
                         }
                         catch (Exception ex)
                         {
-                            System.Diagnostics.Debug.WriteLine(ex.ToString());
+                            System.Diagnostics.Debug.WriteLine("{0}\nMessage might be not encrypted, returning as is...", ex.ToString());
+                            outputBytes = item1Bytes;
                         }
                     }
                     PNDownloadFileResult result = new PNDownloadFileResult();
@@ -241,7 +242,9 @@ private async Task<PNResult<PNDownloadFileResult>> ProcessFileDownloadRequest(Di
                     }
                     catch (Exception ex)
                     {
-                        System.Diagnostics.Debug.WriteLine(ex.ToString());
+                        System.Diagnostics.Debug.WriteLine("{0}\nMessage might be not encrypted, returning as is...", ex.ToString());
+                        outputBytes = item1Bytes;
+                        ret.Status = new PNStatus { Error = true, ErrorData = new PNErrorData("Decryption error", ex) };
                     }
                 }
 

src/Api/PubnubApi/PubnubCoreBase.cs

@@ -724,8 +724,19 @@ private void ResponseToUserCallback<T>(List<object> result, PNOperationType type
                                                 }
 
                                                 Announce(status);
+
+                                                LoggingMethod.WriteToLog(
+                                                        currentLog,
+                                                        string.Format(
+                                                            CultureInfo.InvariantCulture,
+                                                            "Failed to decrypt message on channel {0} in ResponseToUserCallback due to exception={1}.\nMessage might be not encrypted, returning as is...",
+                                                            currentMessageChannel,
+                                                            ex
+                                                        ),
+                                                        currentConfig.LogVerbosity
+                                                );
                                             }
-                                            object decodeMessage = (decryptMessage == "**DECRYPT ERROR**") ? decryptMessage : jsonLib.DeserializeToObject(decryptMessage);
+                                            object decodeMessage = jsonLib.DeserializeToObject((decryptMessage == "**DECRYPT ERROR**") ? payload.ToString() : decryptMessage);
 
                                             payloadContainer.Add(decodeMessage);
                                         }

src/Api/PubnubApi/Security/SecureMessage.cs

@@ -28,9 +28,9 @@
         {
             List<object> returnMessage = new List<object>();
 
             if (config.CryptoModule != null || config.CipherKey.Length > 0)
             {
                 config.CryptoModule ??= new CryptoModule(new LegacyCryptor(config.CipherKey, config.UseRandomInitializationVector, pubnubLog), null);
                 object[] myObjectArray = (from item in messageList
                                      select item as object).ToArray();
                 object[] enumerable = myObjectArray[0] as object[];
@@ -71,7 +71,8 @@
 
                             errorCallback.OnResponse(default(T), status);
                         }
-                        object decodeMessage = (decryptMessage == "**DECRYPT ERROR**") ? decryptMessage : jsonLib.DeserializeToObject(decryptMessage);
+                        pubnubLog.WriteToLog("Failed to decrypt message!\nMessage might be not encrypted, returning as is...");
+                        object decodeMessage = jsonLib.DeserializeToObject((decryptMessage == "**DECRYPT ERROR**") ? element.ToString() : decryptMessage);
                         receivedMsg.Add(decodeMessage);
                     }
                     returnMessage.Add(receivedMsg);
@@ -127,9 +128,9 @@
                                 Dictionary<string, object> dicDecrypt = new Dictionary<string, object>();
                                 foreach (KeyValuePair<string, object> kvpValue in dicValue)
                                 {
                                     if (kvpValue.Key == "message" && (config.CryptoModule != null || config.CipherKey.Length > 0))
                                     {
                                         config.CryptoModule ??= new CryptoModule(new LegacyCryptor(config.CipherKey, config.UseRandomInitializationVector, pubnubLog), null);
                                         string decryptMessage = "";
                                         try
                                         {
@@ -154,7 +155,8 @@
                                             errorCallback.OnResponse(default(T), status);
                                             #endregion
                                         }
-                                        object decodeMessage = (decryptMessage == "**DECRYPT ERROR**") ? decryptMessage : jsonLib.DeserializeToObject(decryptMessage);
+                                        pubnubLog.WriteToLog("Failed to decrypt message!\nMessage might be not encrypted, returning as is...");
+                                        object decodeMessage = jsonLib.DeserializeToObject((decryptMessage == "**DECRYPT ERROR**") ? decryptMessage : decryptMessage);
                                         dicDecrypt.Add(kvpValue.Key, decodeMessage);
                                     }
                                     else

src/UnitTests/PubnubApi.Tests/EncryptionTests.cs

@@ -793,6 +793,135 @@ public void TestPAMv3Signature()
             Assert.AreEqual("v2.k80LsDMD-sImA8rCBj-ntRKhZ8mSjHY8Ivngt9W3Yc4", signature);
         }
 
+        [Test]
+        async public void TestSubscribeDecryption()
+        {
+            bool done = false;
+            PNConfiguration config = CreateTestConfig();
+            config.CryptoModule = new CryptoModule(new AesCbcCryptor("enigma"), new List<ICryptor> { new LegacyCryptor("enigma") });
+
+            Pubnub sut = new Pubnub(config);
+
+            sut.AddListener(new SubscribeCallbackExt(
+                        (pb, message) =>
+                        {
+                            Assert.AreEqual("test", message.Message);
+                            done = true;
+                        },
+                        (pb, presence) => {},
+                        (pb, status) => {}
+                    )
+            );
+
+            sut.Subscribe<string>().Channels(new[] { "test" }).Execute();
+
+            Pubnub sender = new Pubnub(CreateTestConfig());
+
+            // Rust generated encrypted message
+            await sender.Publish()
+                .Channel("test")
+                .Message("UE5FRAFBQ1JIEALf+E65kseYJwTw2J6BUk9MePHiCcBCS+8ykXLkBIOA")
+                .ExecuteAsync();
+
+            // It will wait until the message is received or unit test timeout is reached
+            while (!done)
+            {
+                await System.Threading.Tasks.Task.Delay(100);
+            }
+        }
+
+        [Test]
+        async public void TestSubscribeDecryptionOnNonEncryptedMessage()
+        {
+            bool done = false;
+            PNConfiguration config = CreateTestConfig();
+            config.CryptoModule = new CryptoModule(new AesCbcCryptor("enigma"), new List<ICryptor> { new LegacyCryptor("enigma") });
+
+            Pubnub sut = new Pubnub(config);
+
+            sut.AddListener(new SubscribeCallbackExt(
+                        (pb, message) =>
+                        {
+                            Assert.AreEqual("test", message.Message);
+                            done = true;
+                        },
+                        (pb, presence) => {},
+                        (pb, status) => {}
+                    )
+            );
+
+            sut.Subscribe<string>().Channels(new[] { "test" }).Execute();
+
+            Pubnub sender = new Pubnub(CreateTestConfig());
+
+            // Rust generated encrypted message
+            await sender.Publish()
+                .Channel("test")
+                .Message("test")
+                .ExecuteAsync();
+
+            // It will wait until the message is received or unit test timeout is reached
+            while (!done)
+            {
+                await System.Threading.Tasks.Task.Delay(100);
+            }
+        }
+
+        [Test]
+        async public void TestHistoryDecryption()
+        {
+            PNConfiguration config = CreateTestConfig();
+            config.CryptoModule = new CryptoModule(new AesCbcCryptor("enigma"), new List<ICryptor> { new LegacyCryptor("enigma") });
+
+            Pubnub sut = new Pubnub(config);
+
+            Pubnub sender = new Pubnub(CreateTestConfig());
+
+            // Rust generated encrypted message
+            await sender.Publish()
+                .Channel("test")
+                .Message("UE5FRAFBQ1JIEALf+E65kseYJwTw2J6BUk9MePHiCcBCS+8ykXLkBIOA")
+                .ExecuteAsync();
+
+            PNResult<PNHistoryResult> result = await sut.History()
+                .Channel("test")
+                .Count(1)
+                .ExecuteAsync();
+
+            Assert.AreEqual("test", result.Result.Messages[0].Entry);
+        }
+
+        [Test]
+        async public void TestHistoryDecryptionOnNonEncryptedMessage()
+        {
+            PNConfiguration config = CreateTestConfig();
+            config.CryptoModule = new CryptoModule(new AesCbcCryptor("enigma"), new List<ICryptor> { new LegacyCryptor("enigma") });
+
+            Pubnub sut = new Pubnub(config);
+
+            Pubnub sender = new Pubnub(CreateTestConfig());
+
+            // Rust generated encrypted message
+            await sender.Publish()
+                .Channel("test")
+                .Message("test")
+                .ExecuteAsync();
+
+            PNResult<PNHistoryResult> result = await sut.History()
+                .Channel("test")
+                .Count(1)
+                .ExecuteAsync();
 
+            Assert.AreEqual("test", result.Result.Messages[0].Entry);
+        }
+
+        private PNConfiguration CreateTestConfig()
+        {
+            PNConfiguration config = new PNConfiguration(new UserId("test"));
+            config.SubscribeKey = "demo";
+            config.PublishKey = "demo";
+
+            return config;
+        }
     }
-}
+}