get_bridges.py

gistfile1.py

from tempfile import NamedTemporaryFile
from base64 import b64decode
from HTMLParser import HTMLParser
import urllib2
from urllib import urlencode


def read_captcha(value):
    dst_file = NamedTemporaryFile(suffix=".jpg")
    base64_data = value.split(",")[1]
    payload = b64decode(base64_data)
    dst_file.write(payload)
    return dst_file


class CaptchaPageParser(HTMLParser):
    captcha = None
    challenge = None

    def handle_starttag(self, tag, attrs):
        if tag == "img":
            attrs = dict(attrs)
            self.captcha = read_captcha(attrs["src"])
        elif tag == "input":
            attrs = dict(attrs)
            if attrs["id"] == "captcha_challenge_field":
                self.challenge = attrs["value"]


class BridgesPageParser(HTMLParser):
    bridges = []
    in_bridgelines = False

    def handle_starttag(self, tag, attrs):
        if tag == "div":
            attrs = dict(attrs)
            if attrs.get("id") == "bridgelines":
                self.in_bridgelines = True

    def handle_data(self, data):
        if self.in_bridgelines == True:
            self.bridges.append(data)

    def handle_endtag(self, tag):
        if tag == "div" and self.in_bridgelines == True:
            self.in_bridgelines = False

def solve_captcha(bridge_type="obfs4"):
    url = "https://bridges.torproject.org/bridges?transport=%s" % bridge_type
    response = urllib2.urlopen(url)
    captcha_parser = CaptchaPageParser()
    captcha_parser.feed(response.read())

    captcha_file_path = captcha_parser.captcha.name
    captcha_challenge = captcha_parser.challenge

    captcha_solution = raw_input("Open the file %s and solve the captcha: " % captcha_file_path)
    return captcha_solution, captcha_challenge

def get_bridges(bridge_type="obfs4"):
    captcha_solution, captcha_challenge = solve_captcha(bridge_type)

    url = "https://bridges.torproject.org/bridges"
    data = urlencode({
        "captcha_response_field": captcha_solution,
        "captcha_challenge_field": captcha_challenge,
        "submit": "submit"
    })
    response = urllib2.urlopen(url, data=data)
    bridges_parser = BridgesPageParser()
    bridges_parser.feed(response.read())

    if not bridges_parser.bridges:
        print "You probably got the captcha wrong. Try again."
        get_bridges(bridge_type)

    print bridges_parser.bridges

get_bridges()