juniper-vpn.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import subprocess
import mechanize
import cookielib
import getpass
import sys
import os
import os.path
import errno
import ssl
import argparse
import atexit
import signal
import socket
import ConfigParser
import time
import zipfile
import urllib
import urlparse
import binascii
import hmac
import hashlib
import shlex
import tncc

ssl._create_default_https_context = ssl._create_unverified_context

"""
OATH code from https://github.com/bdauvergne/python-oath
Copyright 2010, Benjamin Dauvergne

* All rights reserved.
* Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:

     * Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
     * Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.'''
"""


def truncated_value(h):
    bytes = map(ord, h)
    offset = bytes[-1] & 0xf
    v = (bytes[offset] & 0x7f) << 24 | (bytes[offset + 1] & 0xff) << 16 | \
        (bytes[offset + 2] & 0xff) << 8 | (bytes[offset + 3] & 0xff)
    return v


def dec(h, p):
    v = truncated_value(h)
    v = v % (10**p)
    return '%0*d' % (p, v)


def int2beint64(i):
    hex_counter = hex(long(i))[2:-1]
    hex_counter = '0' * (16 - len(hex_counter)) + hex_counter
    bin_counter = binascii.unhexlify(hex_counter)
    return bin_counter


def hotp(key):
    key = binascii.unhexlify(key)
    counter = int2beint64(int(time.time()) / 30)
    return dec(hmac.new(key, counter, hashlib.sha256).digest(), 6)


def mkdir_p(path):
    try:
        os.mkdir(path)
    except OSError, exc:
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:
            raise


def read_narport(narport_file):
    with open(narport_file) as f_:
        return int(f_.read().strip())


class juniper_vpn(object):

    def __init__(self, args):
        self.args = args
        self.vpn_host = self.args.host
        self.fixed_password = args.password is not None
        self.last_connect = 0

        self.br = mechanize.Browser()

        self.cj = cookielib.LWPCookieJar()
        self.br.set_cookiejar(self.cj)

        # Browser options
        self.br.set_handle_equiv(True)
        self.br.set_handle_redirect(True)
        self.br.set_handle_referer(True)
        self.br.set_handle_robots(False)

        # Follows refresh 0 but not hangs on refresh > 0
        self.br.set_handle_refresh(mechanize._http.HTTPRefreshProcessor(),
                                   max_time=1)

        # Want debugging messages?
        # self.br.set_debug_http(True)
        # self.br.set_debug_redirects(True)
        # self.br.set_debug_responses(True)

        self.user_agent = ('Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.1) '
                           'Gecko/2008071615 Fedora/3.0.1-1.fc9 Firefox/3.0.1')
        self.br.addheaders = [('User-agent', self.user_agent)]

        self.last_action = None
        self.needs_2factor = False
        self.key = None

        self.plugin_jar = '/usr/share/icedtea-web/plugin.jar'
        self.host_checker = self.args.host_checker
        self.tncc_process = None
        self.tncc_jar = None

    def find_cookie(self, name):
        for cookie in self.cj:
            if cookie.name == name:
                return cookie
        return None

    def next_action(self):
        if self.find_cookie('DSID'):
            return 'connect'

        for form in self.br.forms():
            if form.name == 'frmLogin':
                return 'login'
            elif form.name == 'frmDefender':
                return 'key'
            elif form.name == 'frmConfirmation':
                return 'continue'
            elif form.name == 'frmSelectRoles':
                return 'select_roles'
            else:
                import ipdb
                ipdb.set_trace()
                pass
                raise Exception('Unknown form type:', form.name)
        return 'tncc'

    def run(self):
        # Open landing page
        self.r = self.br.open(
            'https://{}/dana-na/auth/{}/welcome.cgi'.format(self.vpn_host, self.args.url))
        while True:
            action = self.next_action()
            print 'next action [{}]: {}'.format(self.r.geturl(), action)
            if action == 'tncc':
                self.action_tncc()
            elif action == 'login':
                self.action_login()
            elif action == 'key':
                self.action_key()
            elif action == 'select_roles':
                self.action_select_roles()
            elif action == 'continue':
                self.action_continue()
            elif action == 'connect':
                self.action_connect()

            self.last_action = action

    def action_tncc(self):
        # Run tncc host checker
        # dspreauth_cookie = self.find_cookie('DSPREAUTH')
        # if dspreauth_cookie is None:
        #     raise Exception('Could not find DSPREAUTH key for host checker')

        # dssignin_cookie = self.find_cookie('DSSIGNIN')
        # t = tncc.tncc(self.args.host, self.cj)
        # self.cj.set_cookie(t.get_cookie(dspreauth_cookie, dssignin_cookie))

        # self.r = self.br.open(self.r.geturl())
        # Run tncc host checker
        dspreauth_cookie = self.find_cookie('DSPREAUTH')
        if dspreauth_cookie is None:
            raise Exception('Could not find DSPREAUTH key for host checker')

        dssignin_cookie = self.find_cookie('DSSIGNIN')
        if self.host_checker:
            t = tncc.tncc(self.vpn_host, self.cj)
            self.cj.set_cookie(t.get_cookie(dspreauth_cookie, dssignin_cookie))
        else:
            dssignin = (dssignin_cookie.value if dssignin_cookie else 'null')

            if not self.tncc_process:
                self.tncc_start()

            args = [('IC', self.vpn_host), ('Cookie', dspreauth_cookie.value), ('DSSIGNIN', dssignin)]

            print '[TNCC] starting with: {}'.format(args)
            try:
                self.tncc_send('start', args)
                results = self.tncc_recv()
            except:
                self.tncc_start()
                self.tncc_send('start', args)
                results = self.tncc_recv()
            self._close_socket()
            print '[TNCC] received: {}'.format(results)

            if len(results) < 4:
                raise Exception('tncc returned insufficent results', results)

            if results[0] == '200':
                dspreauth_cookie.value = results[2]
                self.cj.set_cookie(dspreauth_cookie)
            elif self.last_action == 'tncc':
                raise Exception('tncc returned non 200 code (' + results[0] + ')')
            else:
                self.cj.clear(self.vpn_host, '/dana-na/', 'DSPREAUTH')

        curl = urlparse.urlparse(self.r.geturl())
        state_id = urlparse.parse_qs(curl.query)['id'][0]
        postauth = "https://{}/dana-na/auth/{}/login.cgi?loginmode=mode_postAuth&postauth={}".format(self.vpn_host,
                                                                                                     self.args.url,
                                                                                                     state_id)
        print '[POSTAUTH] {}'.format(postauth)
        self.r = self.br.open(postauth)
        if not self.host_checker:
            self.tncc_set_cookie()

    def tncc_set_cookie(self):
        dspreauth_cookie = self.find_cookie('DSPREAUTH')
        if dspreauth_cookie is None:
            return
        try:
            self._open_socket()
            print '[TNCC]: setting cookie: {}'.format(dspreauth_cookie.value)
            self.tncc_send('setcookie', [('Cookie', dspreauth_cookie.value)])
            self._close_socket()
        except:
            # TNCC died, bummer
            print '[TNCC] dead!!'
            self.tncc_stop()

    def action_login(self):
        # The token used for two-factor is selected when this form is submitted.
        # If we aren't getting a password, then get the key now, otherwise
        # we could be sitting on the two factor key prompt later on waiting
        # on the user.

        self.br.select_form(nr=0)
        if self.args.password is None or self.last_action == 'login':
            # import ipdb; ipdb.set_trace()
            if 'password#2' in self.br.form:
                password2 = getpass.getpass('Password#2:')
                self.br.form['password#2'] = password2
                self.r = self.br.submit()
                return
            if self.fixed_password:
                print 'Login failed (Invalid username or password?)'
                sys.exit(1)
            else:
                self.args.password = getpass.getpass('Password:')
                self.needs_2factor = False

        if self.needs_2factor:
            if self.args.oath:
                self.key = hotp(self.args.oath)
            else:
                self.key = getpass.getpass('Two-factor key:')
        else:
            self.key = None

        # Enter username/password
        # self.br.select_form(nr=0)
        self.br.form['username'] = self.args.username
        self.br.form['password'] = self.args.password
        # Untested, a list of availables realms is provided when this
        # is necessary.
        # self.br.form['realm'] = 'Users'  # [realm]
        self.r = self.br.submit()

    def action_key(self):
        # Enter key
        self.needs_2factor = True
        if self.args.oath:
            if self.last_action == 'key':
                print 'Login failed (Invalid OATH key)'
                sys.exit(1)
            self.key = hotp(self.args.oath)
        elif self.key is None:
            self.key = getpass.getpass('Two-factor key:')
        self.br.select_form(nr=0)
        self.br.form['password'] = self.key
        self.key = None
        self.r = self.br.submit()

    def action_select_roles(self):
        links = list(self.br.links())
        if len(links) == 1:
            link = links[0]
        else:
            print 'Choose one of the following: '
            for i, link in enumerate(links):
                print '{} - {}'.format(i, link.text)
            choice = int(raw_input('Choice: '))
            link = links[choice]
        self.r = self.br.follow_link(text=link.text)

    def action_continue(self):
        # Yes, I want to terminate the existing connection
        self.br.select_form(nr=0)
        for c in self.br.form.controls:
            if c.type == 'checkbox':
                c.items[0].selected = True
        self.r = self.br.submit(name='btnContinue')

    def action_connect(self):
        if not self.host_checker:
            self.tncc_set_cookie()
        now = time.time()
        delay = 10.0 - (now - self.last_connect)
        if delay > 0:
            print 'Waiting %.0f...' % (delay)
            time.sleep(delay)
        self.last_connect = time.time()

        dsid = self.find_cookie('DSID').value
        dsfa = self.find_cookie('DSFirstAccess').value
        dsla = self.find_cookie('DSLastAccess').value
        action = []
        for arg in self.args.action:
            arg = arg.replace('%DSID%', dsid).replace('%HOST%', self.vpn_host).replace('%AGENT%', self.user_agent)
            arg = arg.replace('%DSFA%', dsfa).replace('%DSLA%', dsla)
            action.append(arg)

        pargs = {}
        if self.args.working_dir:
            pargs['cwd'] = self.args.working_dir

        p = subprocess.Popen(action, stdin=subprocess.PIPE, **pargs)
        self.vpn_process = p
        if args.stdin is not None:
            stdin = args.stdin.replace('%DSID%', dsid)
            stdin = stdin.replace('%DSFA%', dsfa).replace('%DSLA%', dsla)
            stdin = stdin.replace('%HOST%', self.args.host)
            stdin = stdin.replace('%NONE%', "")
            print '[STDIN] {}'.format(stdin)
            p.communicate(input=stdin)
            ret = p.wait()
        else:
            ret = p.wait()
        ret = p.returncode

        # Openconnect specific
        if ret == 2:
            self.cj.clear(self.vpn_host, '/', 'DSID')
            self.r = self.br.open(self.r.geturl())

    def tncc_send(self, cmd, params):
        v = cmd + '\n'
        for key, val in params:
            v = v + key + '=' + val + '\n'
        self.tncc_socket.send(v)
        # return self.tncc_process.communicate(v)

    def tncc_recv(self):
        # return out.splitlines()
        ret = self.tncc_socket.recv(1024)
        return ret.splitlines()

    def tncc_init(self):
        class_names = ('net.juniper.tnc.NARPlatform.linux.LinuxHttpNAR',
                       'net.juniper.tnc.HttpNAR.HttpNAR')
        self.class_name = None

        self.tncc_jar = os.path.expanduser('~/.juniper_networks/tncc.jar')
        try:
            if zipfile.ZipFile(self.tncc_jar, 'r').testzip() is not None:
                raise Exception()
        except:
            print 'Downloading tncc.jar...'
            mkdir_p(os.path.expanduser('~/.juniper_networks'))
            urllib.urlretrieve('https://{}/dana-cached/hc/tncc.jar', self.vpn_host, self.tncc_jar)

        with zipfile.ZipFile(self.tncc_jar, 'r') as jar:
            for name in class_names:
                try:
                    jar.getinfo(name.replace('.', '/') + '.class')
                    self.class_name = name
                    break
                except:
                    pass

        if self.class_name is None:
            raise Exception('Could not find class name for', self.tncc_jar)

    def tncc_stop(self):
        if self.tncc_socket is not None:
            try:
                self._close_socket()
            except:
                pass
            self.tncc_socket = None

        if self.tncc_process is not None:
            try:
                self.tncc_process.send_signal(signal.SIGINT)
            except:
                pass
            print 'waiting tncc to terminate...'
            self.tncc_process.wait()

    def tncc_start(self):
        # tncc is the host checker app. It can check different
        # security policies of the host and report back. We have
        # to send it a preauth key (from the DSPREAUTH cookie)
        # and it sends back a new cookie value we submit.
        # After logging in, we send back another cookie to tncc.
        # Subsequently, it contacts https://<vpn_host:443 every
        # 10 minutes.

        if not self.tncc_jar:
            self.tncc_init()

        narport = os.path.expanduser('~/.juniper_networks/narport.txt')
        if os.path.isfile(narport):
            self._narport = read_narport(narport)
            try:
                self._open_socket()
            except Exception as e:
                print 'WARNING: {} port {}: {}'.format(type(e).__name__, self._narport, e)
                os.remove(narport)
            else:
                return

        print 'Launching tncc process'
        self.tncc_process = subprocess.Popen(['java',
                                              '-classpath', self.tncc_jar + ':' + self.plugin_jar,
                                              self.class_name,
                                              'log_level', '2',
                                              'postRetries', '6',
                                              'ivehost', self.vpn_host,
                                              'home_dir', os.path.expanduser('~'),
                                              'Parameter0', '',
                                              'user_agent', self.user_agent,
                                              ], stdin=subprocess.PIPE,
                                             stdout=subprocess.PIPE)
        while not os.path.isfile(narport):
            time.sleep(0.5)
        self._narport = read_narport(narport)
        self._open_socket()

    def _open_socket(self):
        self.tncc_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.tncc_socket.connect(('127.0.0.1', self._narport))
        print 'tncc connection on port {}'.format(self._narport)

    def _close_socket(self):
        self.tncc_socket.close()

    def logout(self):
        print 'terminating...'
        self.tncc_stop()
        try:
            # self.cj.clear(self.vpn_host, '/', 'DSID')
            self.r = self.br.open("https://{}/dana-na/auth/logout.cgi".format(self.vpn_host))
            # self.r = self.br.open(self.r.geturl())
        except Exception as e:
            print 'WARNING: {} Logout call failed: {}'.format(type(e).__name__, e)

        if hasattr(self, 'vpn_process'):
            try:
                self.vpn_process.send_signal(signal.SIGINT)
                self.vpn_process.wait()
            except OSError as e:
                print 'Failed to terminate process: {}'.format(e)


def cleanup(jvpn):
    jvpn.logout()

if __name__ == "__main__":
    parser = argparse.ArgumentParser(conflict_handler='resolve')
    parser.add_argument('-h', '--host', type=str,
                        help='VPN host name')
    parser.add_argument('-l', '--url', type=str,
                        help='VPN url part')
    parser.add_argument('-u', '--username', type=str,
                        help='User name')
    parser.add_argument('-o', '--oath', type=str,
                        help='OATH key for two factor authentication (hex)')
    parser.add_argument('-c', '--config', type=str,
                        help='Config file')
    parser.add_argument('-s', '--stdin', type=str,
                        help="String to pass to action's stdin")
    parser.add_argument('-w', '--working-dir', type=str,
                        help='Working directory of action bin')
    parser.add_argument('-t', '--host-checker', type=str,
                        help='Use python host checker instead of tncc.jar')
    parser.add_argument('action', nargs=argparse.REMAINDER,
                        metavar='<action> [<args...>]',
                        help='External command')

    args = parser.parse_args()
    args.__dict__['password'] = None

    if len(args.action) and args.action[0] == '--':
        args.action = args.action[1:]

    if not len(args.action):
        args.action = None

    if args.config is not None:
        config = ConfigParser.RawConfigParser()
        config.read(args.config)
        for arg in ['username', 'host', 'url', 'password', 'oath', 'action', 'working_dir', 'stdin',
                    'host_checker']:
            if args.__dict__[arg] is None:
                try:
                    args.__dict__[arg] = config.get('vpn', arg)
                except:
                    pass
    if args.__dict__['url'] is None:
        args.__dict__['url'] = 'url_default'
    host_checker = args.__dict__['host_checker']
    host_checker = (host_checker is not None and host_checker.lower() in ('1', 'true', 'on', 'yes'))
    args.__dict__['host_checker'] = host_checker

    if not isinstance(args.action, list):
        args.action = shlex.split(args.action)

    if args.username is None or args.host is None or args.action == []:
        print "--user, --host, and <action> are required parameters"
        sys.exit(1)

    jvpn = juniper_vpn(args)
    atexit.register(cleanup, jvpn)
    jvpn.run()