python MITM for holochaining

server.py

import asyncio
import websockets
from http.server import HTTPServer, SimpleHTTPRequestHandler
from socketserver import ThreadingMixIn

myip = b'127.0.0.1'

def replace_localhost(data):
    return data.replace(b'localhost', myip)

class MITMRequestHandler(SimpleHTTPRequestHandler):
    def end_headers(self):
        self.send_header('Access-Control-Allow-Origin', '*')
        SimpleHTTPRequestHandler.end_headers(self)

    def do_GET(self):
        if self.path.endswith('.js'):
            self.send_response(200)
            self.send_header('Content-type', 'application/javascript')
            self.end_headers()
            with open(self.path[1:], 'rb') as f:
                data = f.read()
                self.wfile.write(replace_localhost(data))
        else:
            SimpleHTTPRequestHandler.do_GET(self)

class ThreadedHTTPServer(ThreadingMixIn, HTTPServer):
    pass

async def websocket_tunnel_handler(websocket, path, local_port):
    async with websockets.connect(f'ws://localhost:{local_port}') as local_ws:
        async def forward_from_client():
            async for message in websocket:
                await local_ws.send(message)

        async def forward_from_server():
            async for message in local_ws:
                await websocket.send(message)

        await asyncio.gather(
            forward_from_client(),
            forward_from_server(),
        )

if __name__ == '__main__':
    # Start the HTTP server
    http_server = ThreadedHTTPServer(('', 8000), MITMRequestHandler)
    http_thread = threading.Thread(target=http_server.serve_forever, daemon=True)
    http_thread.start()

    # Define WebSocket tunnel handlers for each port
    tunnel_handler_1235 = lambda websocket, path: websocket_tunnel_handler(websocket, path, 1235)
    tunnel_handler_8889 = lambda websocket, path: websocket_tunnel_handler(websocket, path, 8889)

    # Start the WebSocket servers for each port
    websocket_server_1235 = websockets.serve(tunnel_handler_1235, myip, 1235)
    websocket_server_8889 = websockets.serve(tunnel_handler_8889, myip, 8889)

    # Run the WebSocket servers
    loop = asyncio.get_event_loop()
    loop.run_until_complete(websocket_server_1235)
    loop.run_until_complete(websocket_server_8889)
    loop.run_forever()