shadowsocksr/shadowsocks/crypto/m2.py

#!/usr/bin/env python

# Copyright (c) 2014 clowwindy
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

from __future__ import absolute_import, division, print_function, \
    with_statement

import sys
import logging

__all__ = ['ciphers']

has_m2 = True
try:
    __import__('M2Crypto')
except ImportError:
    has_m2 = False


def create_cipher(alg, key, iv, op, key_as_bytes=0, d=None, salt=None, i=1,
                  padding=1):

    import M2Crypto.EVP
    return M2Crypto.EVP.Cipher(alg.replace('-', '_'), key, iv, op,
                               key_as_bytes=0, d='md5', salt=None, i=1,
                               padding=1)


def err(alg, key, iv, op, key_as_bytes=0, d=None, salt=None, i=1, padding=1):
    logging.error(('M2Crypto is required to use %s, please run'
                   ' `apt-get install python-m2crypto`') % alg)
    sys.exit(1)


if has_m2:
    ciphers = {
        b'aes-128-cfb': (16, 16, create_cipher),
        b'aes-192-cfb': (24, 16, create_cipher),
        b'aes-256-cfb': (32, 16, create_cipher),
        b'bf-cfb': (16, 8, create_cipher),
        b'camellia-128-cfb': (16, 16, create_cipher),
        b'camellia-192-cfb': (24, 16, create_cipher),
        b'camellia-256-cfb': (32, 16, create_cipher),
        b'cast5-cfb': (16, 8, create_cipher),
        b'des-cfb': (8, 8, create_cipher),
        b'idea-cfb': (16, 8, create_cipher),
        b'rc2-cfb': (16, 8, create_cipher),
        b'rc4': (16, 0, create_cipher),
        b'seed-cfb': (16, 16, create_cipher),
    }
else:
    ciphers = {}