Python: imitate WebSocket connection as if comming from Browser-CodePudding

I am trying to automate an interaction with a game website by communicating with a WebSocket via Python. In particular, I am trying to communicate with the WebSocket at: "wss://socket.colonist.io".

If I simply execute the following JS-code from the browser, I receive the incoming messages as expected:

ws = new WebSocket('wss://socket.colonist.io');
ws.onmessage = e => {
console.log(e);
}

However, as soon as I am trying to connect to this WebSocket from outside the browser (with Node.JS or with Python), the connection gets immediately closed by the remote. An example using websocket-client in Python can be found below:

import websocket
def on_message(ws, data):
    print(f'received {data}')

websocket.enableTrace(True)
socket = websocket.WebSocketApp('wss://socket.colonist.io',
    header={'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36'},
    on_message=on_message)
socket.run_forever(origin='https://colonist.io')
socket.close()

The trace output is the following:

--- request header ---
GET / HTTP/1.1
Upgrade: websocket
Host: socket.colonist.io
Origin: https://colonist.io
Sec-WebSocket-Key: EE3U0EDp36JGZBHWUN5q4Q==
Sec-WebSocket-Version: 13
Connection: Upgrade
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36


-----------------------
--- response header ---
HTTP/1.1 101 Switching Protocols
Server: nginx/1.18.0 (Ubuntu)
Date: Sat, 24 Sep 2022 17:33:32 GMT
Connection: upgrade
Upgrade: websocket
Sec-WebSocket-Accept: EwMJ z82BuOBOSWONpuOhjNdVCQ=
-----------------------
websocket connected
Connection to remote host was lost. - goodbye

I also tried it using Python-Autobahn and Python-websockets, both with the same negative result.

I suspect the host somehow detects that the connection is not coming from a browser (although, I set a 'User-Agent' and the 'Origin') and therefore closes the connection immediately. Is there any possibility I can connect to this WebSocket from a Script NOT running in a browser? I am aware of the possibility of using Selenium to run and control a browser instance with Python, but I want to avoid this at all cost, due to performance reasons. (I want to control as many WebSocket connections concurrently as possible for my project).

CodePudding user response：

I found the problem. Because the connection worked from a new Incognito-Window from the Chrome-Console without ever visiting the host colonist.io and the "Application" tab from the Chrome developer panel did not show any stored cookies, I assumed no cookies were involved. After decrypting and analyzing the TLS communication with Wireshark I found out that a JWT gets sent as a cookie on the initial GET request. After adding this cookie to my Python implementation, it worked without any problems.

The remaining question now is: Where does this JWT come from if I don't see it in the "Application" tab and the only request being made is the WebSocket connection?