openvpn.py

__author__ = 'Nick Apperley'

# -*- coding: utf-8 -*-
#
# Establishes an OpenVPN connection using an OVPN file. Based on a Hacking Lab Python script
# (http://media.hacking-lab.com/largefiles/livecd/z_openvpn_config/backtrack/vpn-with-python.py). Requires Python 3
# and the pexpect library (module).

import pexpect
from invalid_credentials_error import InvalidCredentialsError

# Set the timeout in seconds.
timeout = 15


def open_vpn_connection(username, password, conf_dir, ovpn_file):
    process = pexpect.spawn('openvpn %s' % ovpn_file, cwd=conf_dir, timeout=timeout)

    try:
        process.expect('Enter Auth Username:')
        process.sendline(username)
        process.expect('Enter Auth Password:')
        process.sendline(password)

        print('Connecting...')
        process.expect('Initialization Sequence Completed')
        print('Connected')
    except pexpect.EOF:
        print('Invalid username and/or password')
        raise InvalidCredentialsError('Invalid OpenVPN username and/or password')
    except pexpect.TIMEOUT:
        print('Connection failed!')
        raise TimeoutError('Cannot connect to OpenVPN server')
    return process


def close_vpn_connection(process):
    if process is not None:
        process.kill(0)
        print('Disconnected')