# coding: utf-8
# PyGOST -- Pure Python GOST cryptographic functions library
-# Copyright (C) 2015-2019 Sergey Matveev <stargrave@stargrave.org>
+# Copyright (C) 2015-2020 Sergey Matveev <stargrave@stargrave.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
-""" GOST R 34.11-94 hash function
+"""GOST R 34.11-94 hash function
This is implementation of :rfc:`5831`. Most function and variable names are
taken according to specification's terminology.
from functools import partial
from struct import pack
-from pygost.gost28147 import addmod
from pygost.gost28147 import block2ns
from pygost.gost28147 import encrypt
from pygost.gost28147 import ns2block
from pygost.utils import hexdec
from pygost.utils import hexenc
from pygost.utils import strxor
-from pygost.utils import xrange # pylint: disable=redefined-builtin
+from pygost.utils import xrange
DEFAULT_SBOX = "id-GostR3411-94-CryptoProParamSet"
def _chi(Y):
- """ Chi function
+ """Chi function
This is some kind of LFSR.
"""
def _step(hin, m, sbox):
- """ Step function
+ """Step function
H_out = f(H_in, m)
"""
class GOST341194(PEP247):
- """ GOST 34.11-94 big-endian hash
+ """GOST 34.11-94 big-endian hash
>>> m = GOST341194()
>>> m.update("foo")
return GOST341194(copy(self.data), self.sbox)
def update(self, data):
- """ Append data that has to be hashed
+ """Append data that has to be hashed
"""
self.data += data
def digest(self):
- """ Get hash of the provided data
+ """Get hash of the provided data
"""
_len = 0
checksum = 0
for i in xrange(0, len(m), BLOCKSIZE):
part = m[i:i + BLOCKSIZE][::-1]
_len += len(part) * 8
- checksum = addmod(checksum, int(hexenc(part), 16), 2 ** 256)
+ checksum = (checksum + int(hexenc(part), 16)) % (2 ** 256)
if len(part) < BLOCKSIZE:
part = b"\x00" * (BLOCKSIZE - len(part)) + part
h = _step(h, part, self.sbox)