Authenticating a Controller with a Tor subprocess using Stem

Question

I am trying to launch a new tor process (no tor processes currently running on the system) using a 'custom' config by using stems launch_tor_with_config.

I wrote a function that will successfully generate and capture a new hashed password. I then use that new password in the config, launch tor and try to authenticate using the same exact passhash and it fails.

Here is the code:

from stem.process import launch_tor_with_config
from stem.control import Controller

from subprocess import Popen, PIPE
import logging

def genTorPassHash(password):
    """ Launches a subprocess of tor to generate a hashed <password>"""
    logging.info("Generating a hashed password")
    torP = Popen(['tor', '--hush', '--hash-password', str(password)], stdout=PIPE, bufsize=1)
    try:
        with torP.stdout:
            for line in iter(torP.stdout.readline, b''):
                line = line.strip('\n')
                if not "16:" in line: 
                    logging.debug(line)
                else:
                    passhash = line
        torP.wait()
        logging.info("Got hashed password")
        logging.debug(passhash)
        return passhash
    except Exception as e:
        logging.exception(e)



def startTor(config):
    """ Starts a tor subprocess using a custom <config>
    returns Popen and controller
    """
    try:
        # start tor
        logging.info("Starting tor")
        torProcess = launch_tor_with_config( 
            config=config, # use our custom config
            tor_cmd='tor', # start tor normally
            completion_percent=100, # blocks until tor is 100%
            timeout=90, # wait 90 sec for tor to start
            take_ownership=True # subprocess will close with parent
            )
        # connect a controller
        logging.info("Connecting controller")
        torControl = Controller.from_port(address="127.0.0.1", port=int(config['ControlPort']))
        # auth controller
        torControl.authenticate(password=config['HashedControlPassword'])
        logging.info("Connected to tor process")
        return torProcess, torControl

    except Exception as e:
        logging.exception(e)


if __name__ == "__main__":
    logging.basicConfig(format='[%(asctime)s] %(message)s', datefmt="%H:%M:%S", level=logging.DEBUG)
    password =  genTorPassHash(raw_input("Type something: "))

    config = { 
        'ClientOnly': '1',
        'ControlPort': '9051',
        'DataDirectory': '~/.tor/temp',
        'Log': ['DEBUG stdout', 'ERR stderr' ],
        'HashedControlPassword' : password }

    torProcess, torControl = startTor(config)

This is what happens when I run the above code:

s4w3d0ff@FooManChoo ~ $ python stackOverflowTest.py
Type something: foo
[13:33:55] Generating a hashed password
[13:33:55] Got hashed password
[13:33:55] 16:84DE3F93CAFD3B0660BD6EC303A8A7C65B6BD0AC7E9454B3B130881A57
[13:33:55] Starting tor
[13:33:56] System call: tor --version (runtime: 0.01)
[13:33:56] Received from system (tor --version), stdout:
Tor version 0.2.4.27 (git-412e3f7dc9c6c01a).
[13:34:00] Connecting controller
[13:34:00] Sent to tor:
PROTOCOLINFO 1
[13:34:00] Received from tor:
250-PROTOCOLINFO 1
250-AUTH METHODS=HASHEDPASSWORD
250-VERSION Tor="0.2.4.27"
250 OK
[13:34:00] Sent to tor:
AUTHENTICATE "16:84DE3F93CAFD3B0660BD6EC303A8A7C65B6BD0AC7E9454B3B130881A57"
[13:34:00] Received from tor:
515 Authentication failed: Password did not match HashedControlPassword value from configuration
[13:34:00] Error while receiving a control message (SocketClosed): empty socket content
[13:34:00] Sent to tor:
SETEVENTS SIGNAL CONF_CHANGED
[13:34:00] Error while receiving a control message (SocketClosed): empty socket content
[13:34:00] Failed to send message: [Errno 32] Broken pipe
[13:34:00] Error while receiving a control message (SocketClosed): empty socket content
[13:34:00] Received empty socket content.
Traceback (most recent call last):
  File "stackOverflowTest.py", line 46, in startTor
    torControl.authenticate(password=config['HashedControlPassword'])
  File "/usr/local/lib/python2.7/dist-packages/stem/control.py", line 991, in authenticate
    stem.connection.authenticate(self, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/stem/connection.py", line 608, in authenticate
    raise auth_exc
AuthenticationFailure: Received empty socket content.
Traceback (most recent call last):
  File "stackOverflowTest.py", line 65, in <module>
    torProcess, torControl = startTor(config)
TypeError: 'NoneType' object is not iterable

Am I missing something?

Answer 1

The trouble is that you're authenticating with the password hash rather than the password itself. Try...

password = raw_input('password: ')
password_hash = genTorPassHash(password)

... then use the password_hash in the config and password for authentication