Read websocket communication via userscript

Question

How can a greasemonkey script / Chrome's user-script intercept a running websocket communication?

My goal is to have additional statistics for a in-browser game

Are you also building the in-browser game? If so, I might recommend the pattern established by Redux Devtools, which is to provide a hook in the app that a Chrome plugin can hook into. Code at https://github.com/zalmoxisus/redux-devtools-extension, extension at https://chrome.google.com/webstore/detail/redux-devtools/lmhkpmbekcpmknklioeibfkpmmfibljd — carpeliam, Jan 21 '18 at 19:02
This comment shows a working tampermonkey script to intercept websocket communication: https://github.com/skepticfx/wshook/issues/5#issuecomment-531067029 — psmith, Apr 05 '21 at 08:08

A. STEFANI · Answer 1 · 2018-01-24T11:01:40.627

4

You may use Firefox, then add the Firebug module then add & use websocket-monitor module to monitor websocket.

If you want to hook websocket from javascript you may also use wshook.

edited Jan 24 '18 at 11:01

answered Jan 22 '18 at 03:14

A. STEFANI

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Why not using this websocket hook inside your module: https://github.com/skepticfx/wshook – A. STEFANI Jan 24 '18 at 07:34
1

You may take a look here : https://stackoverflow.com/questions/31181651/inspecting-websocket-frames-in-an-undetectable-way – A. STEFANI Jan 26 '18 at 17:21

score 1 · Answer 2 · edited Aug 28 '21 at 21:40

Credit to: https://github.com/Cryoscalpel

Not sure if this works in all ws games but you can create a proxy websocket message logger.

WebSocket.prototype.send = new Proxy(WebSocket.prototype.send, {
          apply: function(target, scope, args) {
             if(typeof(args[0]) === 'string') {
                let json = JSON.parse(args[0]);
                     console.log(json)
           }
                  let data = target.apply(scope, args);
                      return data;
        }
     })

Read websocket communication via userscript

2 Answers2