Workaround - React Native STOMP issue because NULL chopping

[omars94]

I was facing an issue where the stomp client doesn't get connected to server because of the null terminator and the connect message wasn't parsed at server side correctly because it was sent as string instead of binary array.

I did lots of debugging on it and the solution was to make isBinaryBody always true
like so

FrameImpl.prototype.serialize = function () {
       var cmdAndHeaders = this.serializeCmdAndHeaders();
       if (this.isBinaryBody || true) { // to always return as binary array
           return FrameImpl.toUnit8Array(cmdAndHeaders, this._binaryBody).buffer;
       }
       else {
           return cmdAndHeaders + this._body + byte_1.BYTE.NULL;
       }
   };

[kum-deepak]

Many thanks for this. I do not use React Native myself.

This was earlier reported as slightly different issue
(stomp-js/stomp-websocket#37). The underlying issue seems to be Reactive Native having issue with NULL characters in strings. NULLs in string are needed to support STOMP protocol. See: facebook/react-native#12731

Based on your analysis it seems, sending messages in binary bypasses the issue. I will wait for your results - based on that an option (say alwaysSendBinaryPackets) may be added to the config.

Making this change will control packets sent to the broker. However the communication may fail if the server sends a text packet. Some brokers (like RabbitMQ has an option to always send binary packets).

[kum-deepak]

A flag is added in configuration forceBinaryWSFrames, this will make outgoing frames to be binary.

[omars94]

was it added to the package yet?
I couldn't find this change in change-log

[omars94]

Tried it and its working perfectly.

[WhiteHatTux]

Using only binaryMessages was causing other problems for me, so I found this to handle the error on the spring server:

package com.beskgroup.dst.backend.config;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.WebSocketHandlerDecorator;

/**
* Register this in WebSocketConfig
*/
public class CustomWebSocketHandlerDecorator
  extends WebSocketHandlerDecorator {

  private static final Logger logger = LoggerFactory.getLogger(CustomWebSocketHandlerDecorator.class);

  public CustomWebSocketHandlerDecorator(WebSocketHandler delegate) {
    super(delegate);
  }

  @Override
  public void handleMessage(final WebSocketSession session, final WebSocketMessage<?> message)
    throws Exception {
    if (message instanceof TextMessage) {
      TextMessage msg = (TextMessage) message;
      String payload = msg.getPayload();

      // only add \00 if not present (iOS / Android)
      if (!payload.substring(payload.length() - 1).equals("\u0000") && !payload.equals("\n")) {
        final TextMessage message1 = new TextMessage(payload + "\u0000");
        super.handleMessage(session, message1);
        return;
      }
    }

    super.handleMessage(session, message);
  }
}

The register this decorator with your websocket:

public class WebSocketConfig
  extends AbstractWebSocketMessageBrokerConfigurer {

  @Override
  public void configureWebSocketTransport(WebSocketTransportRegistration registration) {
    registration.addDecoratorFactory(CustomWebSocketHandlerDecorator::new);
  }
  ....
} 

[slavikdenis]

@WhiteHatTux hi, we tried your implementation without any luck :/

[kum-deepak]

I think it may be worth trying to fix the underlying issue in React Native 😄

[slavikdenis]

@kum-deepak yeah that would be better 👍

[kum-deepak]

https://stomp-js.github.io/workaround/stompjs/rx-stomp/ng2-stompjs/2019/06/10/react-native-null-chopping-issue.html