Python Proxy with Twisted

Question

Hello! I have this code:

from twisted.web import proxy, http
from twisted.internet import reactor

class akaProxy(proxy.Proxy):
    """
    Local proxy = bridge between browser and web application
    """

    def dataReceived(self, data):

        print "Received data..."

        headers = data.split("\n")
        request = headers[0].split(" ")

        method = request[0].lower()
        action = request[1]
        print action
        print "ended content manipulation"  
        return proxy.Proxy.dataReceived(self, data)

class ProxyFactory(http.HTTPFactory):
    protocol = akaProxy

def intercept(port):
    print "Intercept"
    try:                
        factory = ProxyFactory()
        reactor.listenTCP(port, factory)
        reactor.run()
    except Exception as excp:
        print str(excp)

intercept(1337)

I use above code to intercept everything between browser and web site. When using above, I configure my browser settings: to IP: 127.0.0.1 and Port: 1337. I put this script in remote server to act my remote server as proxy server. But when I change browser proxy IP settings to my server's it does not work. What I do wrong? What else I need to configure?

Answer 1

Presumably your dataReceived is raising an exception during its attempts to parse the data passed to it. Try enabling logging so you can see more of what's going on:

from twisted.python.log import startLogging
from sys import stdout
startLogging(stdout)

The reason your parser is likely to raise exceptions is that dataReceived is not called only with a complete request. It is called with whatever bytes are read from the TCP connection. This may be a complete request, a partial request, or even two requests (if pipelining is in use).