X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=pygost%2Fgost28147.py;h=a7bd2ee5f96f2a442a4c47068d94d14863c5fadb;hb=21a30721c31912c296e1faced73e2fd0db191be9;hp=6727fe394505864b8131dfb727a5f5bd43a274da;hpb=c5a63fc144c59342e32304e4e86b2bad479a8187;p=pygost.git diff --git a/pygost/gost28147.py b/pygost/gost28147.py index 6727fe3..a7bd2ee 100644 --- a/pygost/gost28147.py +++ b/pygost/gost28147.py @@ -1,6 +1,6 @@ # coding: utf-8 # PyGOST -- Pure Python GOST cryptographic functions library -# Copyright (C) 2015-2016 Sergey Matveev +# Copyright (C) 2015-2019 Sergey Matveev # # 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 @@ -24,11 +24,12 @@ data lengths. from functools import partial -from pygost.gost3413 import pad1 from pygost.gost3413 import pad2 +from pygost.gost3413 import pad_size +from pygost.gost3413 import unpad2 from pygost.utils import hexdec from pygost.utils import strxor -from pygost.utils import xrange +from pygost.utils import xrange # pylint: disable=redefined-builtin KEYSIZE = 32 @@ -123,16 +124,6 @@ SBOXES = { (13, 14, 4, 1, 7, 0, 5, 10, 3, 12, 8, 15, 6, 2, 9, 11), (1, 3, 10, 9, 5, 11, 4, 15, 8, 6, 7, 14, 13, 0, 2, 12), ), - "AppliedCryptography": ( - (4, 10, 9, 2, 13, 8, 0, 14, 6, 11, 1, 12, 7, 15, 5, 3), - (14, 11, 4, 12, 6, 13, 15, 10, 2, 3, 8, 1, 0, 7, 5, 9), - (5, 8, 1, 13, 10, 3, 4, 2, 14, 15, 12, 7, 6, 0, 9, 11), - (7, 13, 10, 1, 0, 8, 9, 15, 14, 4, 6, 12, 11, 2, 5, 3), - (6, 12, 7, 1, 5, 15, 13, 8, 4, 10, 9, 14, 0, 3, 11, 2), - (4, 11, 10, 0, 7, 2, 1, 13, 3, 6, 8, 5, 9, 12, 15, 14), - (13, 11, 4, 1, 3, 15, 5, 9, 0, 10, 14, 7, 6, 8, 2, 12), - (1, 15, 13, 0, 5, 7, 10, 4, 9, 2, 3, 14, 6, 11, 8, 12), - ), "Gost28147_tc26_ParamZ": ( (12, 4, 6, 2, 10, 5, 11, 9, 14, 8, 13, 7, 0, 3, 15, 1), (6, 8, 2, 3, 9, 10, 5, 12, 1, 14, 4, 7, 11, 13, 0, 15), @@ -154,6 +145,7 @@ SBOXES = { (7, 14, 12, 13, 9, 4, 8, 15, 10, 2, 6, 0, 3, 11, 5, 1), ), } +SBOXES["AppliedCryptography"] = SBOXES["GostR3411_94_TestParamSet"] def _K(s, _in): @@ -161,7 +153,7 @@ def _K(s, _in): :param s: S-box :param _in: 32-bit word - :return: substituted 32-bit word + :returns: substituted 32-bit word """ return ( (s[0][(_in >> 0) & 0x0F] << 0) + @@ -232,7 +224,7 @@ def xcrypt(seq, sbox, key, ns): :param bytes key: 256-bit encryption key :param ns: N1 and N2 integers :type ns: (int, int) - :return: resulting N1 and N2 + :returns: resulting N1 and N2 :rtype: (int, int) """ s = SBOXES[sbox] @@ -267,10 +259,10 @@ def ecb(key, data, action, sbox=DEFAULT_SBOX): :param bytes key: encryption key :param data: plaintext :type data: bytes, multiple of BLOCKSIZE - :param func action: encrypt/decrypt + :param func action: "encrypt"/"decrypt" :param sbox: S-box parameters to use :type sbox: str, SBOXES'es key - :return: ciphertext + :returns: ciphertext :rtype: bytes """ validate_key(key) @@ -289,7 +281,7 @@ ecb_encrypt = partial(ecb, action=encrypt) ecb_decrypt = partial(ecb, action=decrypt) -def cbc_encrypt(key, data, iv=8 * b"\x00", pad=True, sbox=DEFAULT_SBOX): +def cbc_encrypt(key, data, iv=8 * b"\x00", pad=True, sbox=DEFAULT_SBOX, mesh=False): """ CBC encryption mode of operation :param bytes key: encryption key @@ -299,7 +291,8 @@ def cbc_encrypt(key, data, iv=8 * b"\x00", pad=True, sbox=DEFAULT_SBOX): :type bool pad: perform ISO/IEC 7816-4 padding :param sbox: S-box parameters to use :type sbox: str, SBOXES'es key - :return: ciphertext + :param bool mesh: enable key meshing + :returns: ciphertext :rtype: bytes 34.13-2015 padding method 2 is used. @@ -315,23 +308,24 @@ def cbc_encrypt(key, data, iv=8 * b"\x00", pad=True, sbox=DEFAULT_SBOX): raise ValueError("Data is not blocksize aligned") ciphertext = [iv] for i in xrange(0, len(data), BLOCKSIZE): + if mesh and i >= MESH_MAX_DATA and i % MESH_MAX_DATA == 0: + key, _ = meshing(key, iv, sbox=sbox) ciphertext.append(ns2block(encrypt(sbox, key, block2ns( strxor(ciphertext[-1], data[i:i + BLOCKSIZE]) )))) return b"".join(ciphertext) -def cbc_decrypt(key, data, pad=True, sbox=DEFAULT_SBOX): +def cbc_decrypt(key, data, pad=True, sbox=DEFAULT_SBOX, mesh=False): """ CBC decryption mode of operation :param bytes key: encryption key :param bytes data: ciphertext - :param iv: initialization vector - :type iv: bytes, BLOCKSIZE length :type bool pad: perform ISO/IEC 7816-4 unpadding after decryption :param sbox: S-box parameters to use :type sbox: str, SBOXES'es key - :return: plaintext + :param bool mesh: enable key meshing + :returns: plaintext :rtype: bytes """ validate_key(key) @@ -340,21 +334,21 @@ def cbc_decrypt(key, data, pad=True, sbox=DEFAULT_SBOX): raise ValueError("Data is not blocksize aligned") if len(data) < 2 * BLOCKSIZE: raise ValueError("There is no either data, or IV in ciphertext") + iv = data[:BLOCKSIZE] plaintext = [] for i in xrange(BLOCKSIZE, len(data), BLOCKSIZE): + if ( + mesh and + (i - BLOCKSIZE) >= MESH_MAX_DATA and + (i - BLOCKSIZE) % MESH_MAX_DATA == 0 + ): + key, _ = meshing(key, iv, sbox=sbox) plaintext.append(strxor( ns2block(decrypt(sbox, key, block2ns(data[i:i + BLOCKSIZE]))), data[i - BLOCKSIZE:i], )) if pad: - last_block = bytearray(plaintext[-1]) - pad_index = last_block.rfind(b"\x80") - if pad_index == -1: - raise ValueError("Invalid padding") - for c in last_block[pad_index + 1:]: - if c != 0: - raise ValueError("Invalid padding") - plaintext[-1] = bytes(last_block[:pad_index]) + plaintext[-1] = unpad2(plaintext[-1], BLOCKSIZE) return b"".join(plaintext) @@ -367,7 +361,7 @@ def cnt(key, data, iv=8 * b"\x00", sbox=DEFAULT_SBOX): :type iv: bytes, BLOCKSIZE length :param sbox: S-box parameters to use :type sbox: str, SBOXES'es key - :return: ciphertext + :returns: ciphertext :rtype: bytes For decryption you use the same function again. @@ -378,14 +372,12 @@ def cnt(key, data, iv=8 * b"\x00", sbox=DEFAULT_SBOX): if not data: raise ValueError("No data supplied") n2, n1 = encrypt(sbox, key, block2ns(iv)) - size = len(data) - data = pad1(data, BLOCKSIZE) gamma = [] - for _ in xrange(0, len(data), BLOCKSIZE): + for _ in xrange(0, len(data) + pad_size(len(data), BLOCKSIZE), BLOCKSIZE): n1 = addmod(n1, C2, 2 ** 32) n2 = addmod(n2, C1, 2 ** 32 - 1) gamma.append(ns2block(encrypt(sbox, key, (n1, n2)))) - return strxor(b"".join(gamma), data[:size]) + return strxor(b"".join(gamma), data) MESH_CONST = hexdec("6900722264C904238D3ADB9646E92AC418FEAC9400ED0712C086DCC2EF4CA92B") @@ -410,7 +402,7 @@ def cfb_encrypt(key, data, iv=8 * b"\x00", sbox=DEFAULT_SBOX, mesh=False): :param sbox: S-box parameters to use :type sbox: str, SBOXES'es key :param bool mesh: enable key meshing - :return: ciphertext + :returns: ciphertext :rtype: bytes """ validate_key(key) @@ -418,10 +410,8 @@ def cfb_encrypt(key, data, iv=8 * b"\x00", sbox=DEFAULT_SBOX, mesh=False): validate_sbox(sbox) if not data: raise ValueError("No data supplied") - size = len(data) - data = pad1(data, BLOCKSIZE) ciphertext = [iv] - for i in xrange(0, len(data), BLOCKSIZE): + for i in xrange(0, len(data) + pad_size(len(data), BLOCKSIZE), BLOCKSIZE): if mesh and i >= MESH_MAX_DATA and i % MESH_MAX_DATA == 0: key, iv = meshing(key, ciphertext[-1], sbox=sbox) ciphertext.append(strxor( @@ -433,7 +423,7 @@ def cfb_encrypt(key, data, iv=8 * b"\x00", sbox=DEFAULT_SBOX, mesh=False): data[i:i + BLOCKSIZE], ns2block(encrypt(sbox, key, block2ns(ciphertext[-1]))), )) - return b"".join(ciphertext[1:])[:size] + return b"".join(ciphertext[1:]) def cfb_decrypt(key, data, iv=8 * b"\x00", sbox=DEFAULT_SBOX, mesh=False): @@ -446,7 +436,7 @@ def cfb_decrypt(key, data, iv=8 * b"\x00", sbox=DEFAULT_SBOX, mesh=False): :param sbox: S-box parameters to use :type sbox: str, SBOXES'es key :param bool mesh: enable key meshing - :return: ciphertext + :returns: ciphertext :rtype: bytes """ validate_key(key) @@ -454,11 +444,9 @@ def cfb_decrypt(key, data, iv=8 * b"\x00", sbox=DEFAULT_SBOX, mesh=False): validate_sbox(sbox) if not data: raise ValueError("No data supplied") - size = len(data) - data = pad1(data, BLOCKSIZE) plaintext = [] data = iv + data - for i in xrange(BLOCKSIZE, len(data), BLOCKSIZE): + for i in xrange(BLOCKSIZE, len(data) + pad_size(len(data), BLOCKSIZE), BLOCKSIZE): if ( mesh and (i - BLOCKSIZE) >= MESH_MAX_DATA and @@ -474,4 +462,4 @@ def cfb_decrypt(key, data, iv=8 * b"\x00", sbox=DEFAULT_SBOX, mesh=False): data[i:i + BLOCKSIZE], ns2block(encrypt(sbox, key, block2ns(data[i - BLOCKSIZE:i]))), )) - return b"".join(plaintext)[:size] + return b"".join(plaintext)