Source code for arcrest.packages.ntlm3.des

# This file is part of 'NTLM Authorization Proxy Server' http://sourceforge.net/projects/ntlmaps/
# Copyright 2001 Dmitry A. Rozmanov <dima@xenon.spb.ru>
#
# This library is free software: you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation, either
# version 3 of the License, or (at your option) any later version.

# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library.  If not, see <http://www.gnu.org/licenses/> or <http://www.gnu.org/licenses/lgpl.txt>.
from .. import six
import logging

from . import des_c


log = logging.getLogger(__name__)


[docs]class DES: des_c_obj = None def __init__(self, key_str): k = str_to_key56(key_str) k = key56_to_key64(k) key_str = b'' for i in k: key_str += six.int2byte(i & 0xFF) self.des_c_obj = des_c.DES(key_str)
[docs] def encrypt(self, plain_text): return self.des_c_obj.encrypt(plain_text)
[docs] def decrypt(self, crypted_text): return self.des_c_obj.decrypt(crypted_text)
DESException = 'DESException'
[docs]def str_to_key56(key_str): if not type(key_str) == six.binary_type: # TODO rsanders high - figure out how to make this not necessary key_str = key_str.encode('ascii') if len(key_str) < 7: key_str = key_str + b'\000\000\000\000\000\000\000'[:(7 - len(key_str))] key_56 = [] for i in six.iterbytes(key_str[:7]): key_56.append(i) return key_56
[docs]def key56_to_key64(key_56): key = [] for i in range(8): key.append(0) key[0] = key_56[0] key[1] = ((key_56[0] << 7) & 0xFF) | (key_56[1] >> 1) key[2] = ((key_56[1] << 6) & 0xFF) | (key_56[2] >> 2) key[3] = ((key_56[2] << 5) & 0xFF) | (key_56[3] >> 3) key[4] = ((key_56[3] << 4) & 0xFF) | (key_56[4] >> 4) key[5] = ((key_56[4] << 3) & 0xFF) | (key_56[5] >> 5) key[6] = ((key_56[5] << 2) & 0xFF) | (key_56[6] >> 6) key[7] = (key_56[6] << 1) & 0xFF key = set_key_odd_parity(key) return key
[docs]def set_key_odd_parity(key): for i in range(len(key)): for k in range(7): bit = 0 t = key[i] >> k bit = (t ^ bit) & 0x1 key[i] = (key[i] & 0xFE) | bit return key