2 # PyGOST -- Pure Python GOST cryptographic functions library
3 # Copyright (C) 2015-2019 Sergey Matveev <stargrave@stargrave.org>
5 # This program is free software: you can redistribute it and/or modify
6 # it under the terms of the GNU General Public License as published by
7 # the Free Software Foundation, either version 3 of the License, or
8 # (at your option) any later version.
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 # GNU General Public License for more details.
15 # You should have received a copy of the GNU General Public License
16 # along with this program. If not, see <http://www.gnu.org/licenses/>.
17 """ GOST R 34.11-94 hash function
19 This is implementation of :rfc:`5831`. Most function and variable names are
20 taken according to specification's terminology.
24 from functools import partial
25 from struct import pack
27 from pygost.gost28147 import addmod
28 from pygost.gost28147 import block2ns
29 from pygost.gost28147 import encrypt
30 from pygost.gost28147 import ns2block
31 from pygost.gost28147 import validate_sbox
32 from pygost.iface import PEP247
33 from pygost.pbkdf2 import pbkdf2 as pbkdf2_base
34 from pygost.utils import hexdec
35 from pygost.utils import hexenc
36 from pygost.utils import strxor
37 from pygost.utils import xrange # pylint: disable=redefined-builtin
40 DEFAULT_SBOX = "GostR3411_94_TestParamSet"
43 C3 = hexdec(b"ff00ffff000000ffff0000ff00ffff0000ff00ff00ff00ffff00ff00ff00ff00")
49 x4, x3, x2, x1 = x[0:8], x[8:16], x[16:24], x[24:32]
50 return b"".join((strxor(x1, x2), x4, x3, x2))
55 x[0], x[8], x[16], x[24], x[1], x[9], x[17], x[25], x[2],
56 x[10], x[18], x[26], x[3], x[11], x[19], x[27], x[4], x[12],
57 x[20], x[28], x[5], x[13], x[21], x[29], x[6], x[14], x[22],
58 x[30], x[7], x[15], x[23], x[31],
65 This is some kind of LFSR.
67 (y16, y15, y14, y13, y12, y11, y10, y9, y8, y7, y6, y5, y4, y3, y2, y1) = (
68 Y[0:2], Y[2:4], Y[4:6], Y[6:8], Y[8:10], Y[10:12], Y[12:14],
69 Y[14:16], Y[16:18], Y[18:20], Y[20:22], Y[22:24], Y[24:26],
70 Y[26:28], Y[28:30], Y[30:32],
72 by1, by2, by3, by4, by13, by16, byx = (
73 bytearray(y1), bytearray(y2), bytearray(y3), bytearray(y4),
74 bytearray(y13), bytearray(y16), bytearray(2),
76 byx[0] = by1[0] ^ by2[0] ^ by3[0] ^ by4[0] ^ by13[0] ^ by16[0]
77 byx[1] = by1[1] ^ by2[1] ^ by3[1] ^ by4[1] ^ by13[1] ^ by16[1]
79 bytes(byx), y16, y15, y14, y13, y12, y11, y10, y9, y8, y7, y6, y5, y4, y3, y2
83 def _step(hin, m, sbox):
110 h4, h3, h2, h1 = hin[0:8], hin[8:16], hin[16:24], hin[24:32]
111 s1 = ns2block(encrypt(sbox, k1[::-1], block2ns(h1[::-1])))[::-1]
112 s2 = ns2block(encrypt(sbox, k2[::-1], block2ns(h2[::-1])))[::-1]
113 s3 = ns2block(encrypt(sbox, k3[::-1], block2ns(h3[::-1])))[::-1]
114 s4 = ns2block(encrypt(sbox, k4[::-1], block2ns(h4[::-1])))[::-1]
115 s = b"".join((s4, s3, s2, s1))
118 # H_out = chi^61(H_in XOR chi(m XOR chi^12(S)))
130 class GOST341194(PEP247):
131 """ GOST 34.11-94 big-endian hash
137 '3bd8a3a35917871dfa0d49f9e73e7c57eea028dc061133eb560849ea20c133af'
138 >>> GOST341194("foobar").hexdigest()
139 '3bd8a3a35917871dfa0d49f9e73e7c57eea028dc061133eb560849ea20c133af'
141 block_size = BLOCKSIZE
142 digest_size = digest_size
144 def __init__(self, data=b"", sbox=DEFAULT_SBOX):
146 :param bytes data: provide initial data
147 :param bytes sbox: S-box to use
154 return GOST341194(copy(self.data), self.sbox)
156 def update(self, data):
157 """ Append data that has to be hashed
162 """ Get hash of the provided data
168 for i in xrange(0, len(m), BLOCKSIZE):
169 part = m[i:i + BLOCKSIZE][::-1]
170 _len += len(part) * 8
171 checksum = addmod(checksum, int(hexenc(part), 16), 2 ** 256)
172 if len(part) < BLOCKSIZE:
173 part = b"\x00" * (BLOCKSIZE - len(part)) + part
174 h = _step(h, part, self.sbox)
175 h = _step(h, 24 * b"\x00" + pack(">Q", _len), self.sbox)
177 checksum = hex(checksum)[2:].rstrip("L")
178 if len(checksum) % 2 != 0:
179 checksum = "0" + checksum
180 checksum = hexdec(checksum)
181 checksum = b"\x00" * (BLOCKSIZE - len(checksum)) + checksum
182 h = _step(h, checksum, self.sbox)
186 def new(data=b"", sbox=DEFAULT_SBOX):
187 return GOST341194(data, sbox)
190 PBKDF2_HASHER = partial(GOST341194, sbox="GostR3411_94_CryptoProParamSet")
193 def pbkdf2(password, salt, iterations, dklen):
194 return pbkdf2_base(PBKDF2_HASHER, password, salt, iterations, dklen)