exclude_badExits/exclude_badExits.py

# -*- mode: python; indent-tabs-mode: nil; py-indent-offset: 4; coding: utf-8 -*-

# https://github.com/nusenu/noContactInfo_Exit_Excluder
# https://github.com/TheSmashy/TorExitRelayExclude
"""
This extends nusenu's basic idea of using the stem library to
dynamically exclude nodes that are likely to be bad by putting them
on the ExcludeNodes or ExcludeExitNodes setting of a running Tor.
* https://github.com/nusenu/noContactInfo_Exit_Excluder
* https://github.com/TheSmashy/TorExitRelayExclude

The basic cut is to exclude Exit nodes that do not have a contact.
That can be extended to nodes that do not have an email in the contact etc.

But there's a problem, and your Tor notice.log will tell you about it:
you could exclude the nodes needed to access hidden services or
directorues. So we need to add to the process the concept of a whitelist. 
In addition, we may have our own blacklist of nodes we want to exclude,
or use these lists for other applications like selektor.

So we make two files that are structured in YAML:
```
/etc/tor/torrc-goodnodes.yaml
Nodes:
  IntroductionPoints:
    - $NODEFINGERPRINT
  ...
By default all sections of the goodnodes.yaml are used as a whitelist.

/etc/tor/torrc-badnodes.yaml
Nodes:
  ExcludeExitNodes:
    BadExit:
      # $0000000000000000000000000000000000000007
```
That part requires [PyYAML](https://pyyaml.org/wiki/PyYAML)
https://github.com/yaml/pyyaml/

Right now only the ExcludeExitNodes section is used by we may add ExcludeNodes
later, and by default all sub-sections of the badnodes.yaml are used as a
ExcludeExitNodes but it can be customized with the lWanted commandline arg.

The original idea has also been extended to add different conditions for
exclusion: the ```--contact``` commandline arg is a comma sep list of conditions:
* Empty - no contact info
* NoEmail - no @ sign in the contact',
More may be added later.

Because you don't want to exclude the introduction points to any onion
you want to connect to, ```--white_onions``` should whitelist the 
introduction points to a  comma sep list of onions, but is 
currently broken in stem 1.8.0: see:
* https://github.com/torproject/stem/issues/96
* https://gitlab.torproject.org/legacy/trac/-/issues/25417

```--bad_output``` will write the torrc configuration to a file.

```--details_output``` will write the lookup URLs of the excluded nodes to a file

For usage, do ```python3 exclude_badExits.py --help`

"""

import sys
from stem.control import Controller
from stem.util.tor_tools import is_valid_fingerprint
import os
import getpass
import re
import time
import argparse

from stem.control import Controller
try:
    import yaml
except:
    yaml = None
    
try:
    import coloredlogs
    if 'COLOREDLOGS_LEVEL_STYLES' not in os.environ:
        os.environ['COLOREDLOGS_LEVEL_STYLES'] = 'spam=22;debug=28;verbose=34;notice=220;warning=202;success=118,bold;error=124;critical=background=red'
    # https://pypi.org/project/coloredlogs/
except ImportError as e:
    coloredlogs = False

global LOG
import logging
LOG = logging.getLogger()

sDETAILS_URL = "https://metrics.torproject.org/rs.html#details/"
# You can call this while bootstrapping

def oMakeController(sSock='/run/tor/control', port=9051):
    if os.path.exists(sSock):
        controller = Controller.from_socket_file(path=sSock)
    else:
        controller = Controller.from_port(port=port)
    sys.stdout.flush()
    p = getpass.unix_getpass(prompt='Controller Password: ', stream=sys.stderr)
    controller.authenticate(p)
    return controller

def lYamlBadNodes(sFile='/etc/tor/torrc-badnodes.yaml',
                  section='ExcludeExitNodes',
                  lWanted=['Hetzner','BadExit']):
    root = 'ExcludeNodes'
    l = []
    if not yaml: return l
    if os.path.exists(sFile):
        with open(sFile, 'rt') as oFd:
            o = yaml.safe_load(oFd)
        for elt in o[root][section].keys():
            if lWanted and elt not in lWanted: continue
            l += o[root][section][elt]
    # yq '.ExcludeNodes.Hetzner' < /etc/tor/torrc-badnodes.yaml |sed -e 's/^[[]/ExcludeNodesHetzner = [/'
    # yq '.ExcludeNodes.Hetzner|.[]' < /etc/tor/torrc-badnodes.yaml
    # yq '.ExcludeNodes.BadExit|.[]' < /etc/tor/torrc-badnodes.yaml
    return l

def lYamlGoodNodes(sFile='/etc/tor/torrc-goodnodes.yaml'):
    root='IncludeNodes'
    l = []
    if not yaml: return l
    if os.path.exists(sFile):
        with open(sFile, 'rt') as oFd:
            o = yaml.safe_load(oFd)
        for elt in o[root].keys():
            l += o[root][elt]
    # yq '.Nodes.IntroductionPoints|.[]' < /etc/tor/torrc-goodnodes.yaml
    return l

def lIntroductionPoints(lOnions):
    """not working in stem 1.8.3"""
    l = []
    for elt in lOnions:
        desc = controller.get_hidden_service_descriptor(elt, await_result=True, timeout=None)
        l = desc.introduction_points()
        if l:
            LOG.warn(f"{elt} NO introduction points\n")
            continue
        LOG.info(f"{elt} introduction points are...\n")

        for introduction_point in l:
            LOG.info('  %s:%s => %s' % (introduction_point.address,
                                        introduction_point.port,
                                        introduction_point.identifier))
            l += [introduction_point.address]
    return l

def oMainArgparser(_=None):
    # 'Mode: 0=chat 1=chat+audio 2=chat+audio+video default: 0'
    if not os.path.exists('/proc/sys/net/ipv6'):
        bIpV6 = 'False'
    else:
        bIpV6 = 'True'
    lIpV6Choices=[bIpV6, 'False']

    parser = argparse.ArgumentParser(add_help=True)
    parser.add_argument('--proxy_host', '--proxy-host', type=str,
                        default='127.0.0.1',
                        help='proxy host')
    parser.add_argument('--proxy_port', '--proxy-port', default=9051, type=int,
                        help='proxy control port')
    parser.add_argument('--proxy_ctl', '--proxy-ctl',
                        default='/run/tor/control', type=str,
                        help='control socket - takes precedence over proxy_port')
    parser.add_argument('--good_nodes', type=str,
                        default='/etc/tor/torrc-goodnodes.yaml',
                        help="Yaml file of good nodes that should not be excluded")
    parser.add_argument('--bad_nodes', type=str,
                        default='/etc/tor/torrc-badnodes.yaml',
                        help="Yaml file of bad nodes that should also be excluded")
    parser.add_argument('--contact', type=str, default='Empty,NoEmail',
                        help="comma sep list of conditions - Empty,NoEmail")
    parser.add_argument('--wait_boot', type=int, default=120,
                        help="Seconds to wait for Tor to booststrap")
    parser.add_argument('--log_level', type=int, default=20,
                        help="10=debug 20=info 30=warn 40=error")
    parser.add_argument('--bad_sections', type=str,
                        default='Hetzner,BadExit',
                        help="sections of the badnodes.yaml to use, comma separated, '' defaults to all")
    parser.add_argument('--white_onions', type=str,
                        default='',
                        help="comma sep. list of onions to whitelist their introduction points - BROKEN")
    parser.add_argument('--bad_output', type=str, default='',
                        help="Write the torrc configuration to a file")
    parser.add_argument('--details_output', type=str, default='',
                        help="Write the lookup URLs of the excluded nodes to a file")
    return parser

def iMain(lArgs):
    global     oTOX_OARGS
    parser = oMainArgparser()
    oArgs = parser.parse_args(lArgs)

    aKw = dict(level=oArgs.log_level,
            format='%(name)s %(levelname)-4s %(message)s',
            stream=sys.stdout,
            force=True)
    logging.basicConfig(**aKw)
    logging.getLogger('stem').setLevel(oArgs.log_level)
    
    controller = oMakeController(oArgs.proxy_ctl, oArgs.proxy_port)
    
    elt = controller.get_conf('UseMicrodescriptors')
    if elt != '0' :
        LOG.error('"UseMicrodescriptors 0" is required in your /etc/tor/torrc. Exiting.')
        return 2

    percent = i = 0
    # You can call this while boostrapping
    while percent < 100 and i < oArgs.wait_boot:
        bootstrap_status = controller.get_info("status/bootstrap-phase")
        progress_percent = re.match('.* PROGRESS=([0-9]+).*', bootstrap_status)
        percent = int(progress_percent.group(1))
        LOG.info(f"Bootstrapping {percent}%")
        time.sleep(5)
        i += 5
    elt = controller.get_conf('ExcludeExitNodes')
    if elt and elt != '{??}':
        LOG.warn(f'ExcludeExitNodes is in use already')

    lGood = lYamlGoodNodes(oArgs.good_nodes)
    LOG.info(f'lYamlGoodNodes {len(lGood)}')

    if oArgs.white_onions:
        l = lIntroductionPoints(oArgs.white_onions.split(,))
        lGood += l

    relays = controller.get_server_descriptors()

    if oArgs.bad_sections:
        sections = oArgs.bad_sections.split(',') 
        exit_excludelist = lYamlBadNodes(lWanted=sections)
    else:
        exit_excludelist = lYamlBadNodes()
        
    LOG.info(f'lYamlBadNodes {len(exit_excludelist)}')

    if oArgs.details_output:
        oFd = open(oArgs.details_output, 'wt')
    else:
        oFd = None

    lConds = oArgs.contact.split(',')
    for relay in relays:
        if not relay.exit_policy.is_exiting_allowed(): continue
        if ('Empty' in lConds and not relay.contact) or \
           ('NoEmail' in lConds and relay.contact and not b'@' in relay.contact):
            if is_valid_fingerprint(relay.fingerprint):
                exit_excludelist.append(relay.fingerprint)
                if oFd:
                    oFd.write(sDETAILS_URL +relay.fingerprint +"\n")
            else:
                LOG.warn('Invalid Fingerprint: %s' % relay.fingerprint)
    if oFd:
        LOG.info(f"Wrote details URLs to {oArgs.details_output}")
        oFd.close()
    
    exit_excludelist = list(set(exit_excludelist).difference(set(lGood)))
    LOG.info(f'ExcludeExitNodes {len(exit_excludelist)} net bad exit nodes')
    controller.set_conf('ExcludeExitNodes', exit_excludelist)
    elt = controller.get_conf('ExcludeExitNodes')
    if oArgs.bad_output:
        with open(oArgs.bad_output, 'wt') as oFd:
            oFd.write(f"ExcludeExitNodes {','.join(exit_excludelist)}\n")
        LOG.info(f"Wrote tor configuration to {oArgs.bad_output}")
        
    logging.getLogger('stem').setLevel(40)
    for elt in controller._event_listeners:
        controller.remove_event_listener(elt)
    controller.close()
    
    return(0)

if __name__ == '__main__':
    try:
        i = iMain(sys.argv[1:])
    except Exception as e:
        LOG.exception(e)
        i = 1
    sys.exit(i)