File size: 15,601 Bytes
55e2289 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 | ## twofish.py - pure Python implementation of the Twofish algorithm.
## Bjorn Edstrom <be@bjrn.se> 13 december 2007.
##
## Copyrights
## ==========
##
## This code is a derived from an implementation by Dr Brian Gladman
## (gladman@seven77.demon.co.uk) which is subject to the following license.
## This Python implementation is not subject to any other license.
##
##/* This is an independent implementation of the encryption algorithm: */
##/* */
##/* Twofish by Bruce Schneier and colleagues */
##/* */
##/* which is a candidate algorithm in the Advanced Encryption Standard */
##/* programme of the US National Institute of Standards and Technology. */
##/* */
##/* Copyright in this implementation is held by Dr B R Gladman but I */
##/* hereby give permission for its free direct or derivative use subject */
##/* to acknowledgment of its origin and compliance with any conditions */
##/* that the originators of t he algorithm place on its exploitation. */
##/* */
##/* My thanks to Doug Whiting and Niels Ferguson for comments that led */
##/* to improvements in this implementation. */
##/* */
##/* Dr Brian Gladman (gladman@seven77.demon.co.uk) 14th January 1999 */
##
## The above copyright notice must not be removed.
##
## Information
## ===========
##
## Anyone thinking of using this code should reconsider. It's slow.
## Try python-mcrypt instead. In case a faster library is not installed
## on the target system, this code can be used as a portable fallback.
# pylint: disable-all
block_size = 16
key_size = 32
class Twofish:
def __init__(self, key=None):
"""Twofish."""
if key:
self.set_key(key)
def set_key(self, key):
"""Init."""
key_len = len(key)
if key_len not in [16, 24, 32]:
# XXX: add padding?
raise KeyError("key must be 16, 24 or 32 bytes")
if key_len % 4:
# XXX: add padding?
raise KeyError("key not a multiple of 4")
if key_len > 32:
# XXX: prune?
raise KeyError("key_len > 32")
self.context = TWI()
key_word32 = [0] * 32
i = 0
while key:
key_word32[i] = struct.unpack("<L", key[0:4])[0]
key = key[4:]
i += 1
set_key(self.context, key_word32, key_len)
def decrypt(self, block):
"""Decrypt blocks."""
if len(block) % 16:
raise ValueError("block size must be a multiple of 16")
plaintext = b''
while block:
a, b, c, d = struct.unpack("<4L", block[:16])
temp = [a, b, c, d]
decrypt(self.context, temp)
plaintext += struct.pack("<4L", *temp)
block = block[16:]
return plaintext
def encrypt(self, block):
"""Encrypt blocks."""
if len(block) % 16:
raise ValueError("block size must be a multiple of 16")
ciphertext = b''
while block:
a, b, c, d = struct.unpack("<4L", block[0:16])
temp = [a, b, c, d]
encrypt(self.context, temp)
ciphertext += struct.pack("<4L", *temp)
block = block[16:]
return ciphertext
def get_name(self):
"""Return the name of the cipher."""
return "Twofish"
def get_block_size(self):
"""Get cipher block size in bytes."""
return 16
def get_key_size(self):
"""Get cipher key size in bytes."""
return 32
#
# Private.
#
import struct
import sys
WORD_BIGENDIAN = 0
if sys.byteorder == 'big':
WORD_BIGENDIAN = 1
def rotr32(x, n):
return (x >> n) | ((x << (32 - n)) & 0xFFFFFFFF)
def rotl32(x, n):
return ((x << n) & 0xFFFFFFFF) | (x >> (32 - n))
def byteswap32(x):
return ((x & 0xff) << 24) | (((x >> 8) & 0xff) << 16) | \
(((x >> 16) & 0xff) << 8) | ((x >> 24) & 0xff)
class TWI:
def __init__(self):
self.k_len = 0 # word32
self.l_key = [0]*40 # word32
self.s_key = [0]*4 # word32
self.qt_gen = 0 # word32
self.q_tab = [[0]*256, [0]*256] # byte
self.mt_gen = 0 # word32
self.m_tab = [[0]*256, [0]*256, [0]*256, [0]*256] # word32
self.mk_tab = [[0]*256, [0]*256, [0]*256, [0]*256] # word32
def byte(x, n):
return (x >> (8 * n)) & 0xff
tab_5b = [0, 90, 180, 238]
tab_ef = [0, 238, 180, 90]
ror4 = [0, 8, 1, 9, 2, 10, 3, 11, 4, 12, 5, 13, 6, 14, 7, 15]
ashx = [0, 9, 2, 11, 4, 13, 6, 15, 8, 1, 10, 3, 12, 5, 14, 7]
qt0 = [[8, 1, 7, 13, 6, 15, 3, 2, 0, 11, 5, 9, 14, 12, 10, 4],
[2, 8, 11, 13, 15, 7, 6, 14, 3, 1, 9, 4, 0, 10, 12, 5]]
qt1 = [[14, 12, 11, 8, 1, 2, 3, 5, 15, 4, 10, 6, 7, 0, 9, 13],
[1, 14, 2, 11, 4, 12, 3, 7, 6, 13, 10, 5, 15, 9, 0, 8]]
qt2 = [[11, 10, 5, 14, 6, 13, 9, 0, 12, 8, 15, 3, 2, 4, 7, 1],
[4, 12, 7, 5, 1, 6, 9, 10, 0, 14, 13, 8, 2, 11, 3, 15]]
qt3 = [[13, 7, 15, 4, 1, 2, 6, 14, 9, 11, 3, 0, 8, 5, 12, 10],
[11, 9, 5, 1, 12, 3, 13, 14, 6, 4, 7, 15, 2, 0, 8, 10]]
def qp(n, x): # word32, byte
n %= 0x100000000
x %= 0x100
a0 = x >> 4;
b0 = x & 15;
a1 = a0 ^ b0;
b1 = ror4[b0] ^ ashx[a0];
a2 = qt0[n][a1];
b2 = qt1[n][b1];
a3 = a2 ^ b2;
b3 = ror4[b2] ^ ashx[a2];
a4 = qt2[n][a3];
b4 = qt3[n][b3];
return (b4 << 4) | a4;
def gen_qtab(pkey):
for i in range(256):
pkey.q_tab[0][i] = qp(0, i)
pkey.q_tab[1][i] = qp(1, i)
def gen_mtab(pkey):
for i in range(256):
f01 = pkey.q_tab[1][i]
f01 = pkey.q_tab[1][i];
f5b = ((f01) ^ ((f01) >> 2) ^ tab_5b[(f01) & 3]);
fef = ((f01) ^ ((f01) >> 1) ^ ((f01) >> 2) ^ tab_ef[(f01) & 3]);
pkey.m_tab[0][i] = f01 + (f5b << 8) + (fef << 16) + (fef << 24);
pkey.m_tab[2][i] = f5b + (fef << 8) + (f01 << 16) + (fef << 24);
f01 = pkey.q_tab[0][i];
f5b = ((f01) ^ ((f01) >> 2) ^ tab_5b[(f01) & 3]);
fef = ((f01) ^ ((f01) >> 1) ^ ((f01) >> 2) ^ tab_ef[(f01) & 3]);
pkey.m_tab[1][i] = fef + (fef << 8) + (f5b << 16) + (f01 << 24);
pkey.m_tab[3][i] = f5b + (f01 << 8) + (fef << 16) + (f5b << 24);
def gen_mk_tab(pkey, key):
if pkey.k_len == 2:
for i in range(256):
by = i % 0x100
pkey.mk_tab[0][i] = pkey.m_tab[0][pkey.q_tab[0][pkey.q_tab[0][by] ^ byte(key[1],0)] ^ byte(key[0],0)];
pkey.mk_tab[1][i] = pkey.m_tab[1][pkey.q_tab[0][pkey.q_tab[1][by] ^ byte(key[1],1)] ^ byte(key[0],1)];
pkey.mk_tab[2][i] = pkey.m_tab[2][pkey.q_tab[1][pkey.q_tab[0][by] ^ byte(key[1],2)] ^ byte(key[0],2)];
pkey.mk_tab[3][i] = pkey.m_tab[3][pkey.q_tab[1][pkey.q_tab[1][by] ^ byte(key[1],3)] ^ byte(key[0],3)];
if pkey.k_len == 3:
for i in range(256):
by = i % 0x100
pkey.mk_tab[0][i] = pkey.m_tab[0][pkey.q_tab[0][pkey.q_tab[0][pkey.q_tab[1][by] ^ byte(key[2], 0)] ^ byte(key[1], 0)] ^ byte(key[0], 0)];
pkey.mk_tab[1][i] = pkey.m_tab[1][pkey.q_tab[0][pkey.q_tab[1][pkey.q_tab[1][by] ^ byte(key[2], 1)] ^ byte(key[1], 1)] ^ byte(key[0], 1)];
pkey.mk_tab[2][i] = pkey.m_tab[2][pkey.q_tab[1][pkey.q_tab[0][pkey.q_tab[0][by] ^ byte(key[2], 2)] ^ byte(key[1], 2)] ^ byte(key[0], 2)];
pkey.mk_tab[3][i] = pkey.m_tab[3][pkey.q_tab[1][pkey.q_tab[1][pkey.q_tab[0][by] ^ byte(key[2], 3)] ^ byte(key[1], 3)] ^ byte(key[0], 3)];
if pkey.k_len == 4:
for i in range(256):
by = i % 0x100
pkey.mk_tab[0][i] = pkey.m_tab[0][pkey.q_tab[0][pkey.q_tab[0][pkey.q_tab[1][pkey.q_tab[1][by] ^ byte(key[3], 0)] ^ byte(key[2], 0)] ^ byte(key[1], 0)] ^ byte(key[0], 0)];
pkey.mk_tab[1][i] = pkey.m_tab[1][pkey.q_tab[0][pkey.q_tab[1][pkey.q_tab[1][pkey.q_tab[0][by] ^ byte(key[3], 1)] ^ byte(key[2], 1)] ^ byte(key[1], 1)] ^ byte(key[0], 1)];
pkey.mk_tab[2][i] = pkey.m_tab[2][pkey.q_tab[1][pkey.q_tab[0][pkey.q_tab[0][pkey.q_tab[0][by] ^ byte(key[3], 2)] ^ byte(key[2], 2)] ^ byte(key[1], 2)] ^ byte(key[0], 2)];
pkey.mk_tab[3][i] = pkey.m_tab[3][pkey.q_tab[1][pkey.q_tab[1][pkey.q_tab[0][pkey.q_tab[1][by] ^ byte(key[3], 3)] ^ byte(key[2], 3)] ^ byte(key[1], 3)] ^ byte(key[0], 3)];
def h_fun(pkey, x, key):
b0 = byte(x, 0);
b1 = byte(x, 1);
b2 = byte(x, 2);
b3 = byte(x, 3);
if pkey.k_len >= 4:
b0 = pkey.q_tab[1][b0] ^ byte(key[3], 0);
b1 = pkey.q_tab[0][b1] ^ byte(key[3], 1);
b2 = pkey.q_tab[0][b2] ^ byte(key[3], 2);
b3 = pkey.q_tab[1][b3] ^ byte(key[3], 3);
if pkey.k_len >= 3:
b0 = pkey.q_tab[1][b0] ^ byte(key[2], 0);
b1 = pkey.q_tab[1][b1] ^ byte(key[2], 1);
b2 = pkey.q_tab[0][b2] ^ byte(key[2], 2);
b3 = pkey.q_tab[0][b3] ^ byte(key[2], 3);
if pkey.k_len >= 2:
b0 = pkey.q_tab[0][pkey.q_tab[0][b0] ^ byte(key[1], 0)] ^ byte(key[0], 0);
b1 = pkey.q_tab[0][pkey.q_tab[1][b1] ^ byte(key[1], 1)] ^ byte(key[0], 1);
b2 = pkey.q_tab[1][pkey.q_tab[0][b2] ^ byte(key[1], 2)] ^ byte(key[0], 2);
b3 = pkey.q_tab[1][pkey.q_tab[1][b3] ^ byte(key[1], 3)] ^ byte(key[0], 3);
return pkey.m_tab[0][b0] ^ pkey.m_tab[1][b1] ^ pkey.m_tab[2][b2] ^ pkey.m_tab[3][b3];
def mds_rem(p0, p1):
i, t, u = 0, 0, 0
for i in range(8):
t = p1 >> 24
p1 = ((p1 << 8) & 0xffffffff) | (p0 >> 24)
p0 = (p0 << 8) & 0xffffffff
u = (t << 1) & 0xffffffff
if t & 0x80:
u ^= 0x0000014d
p1 ^= t ^ ((u << 16) & 0xffffffff)
u ^= (t >> 1)
if t & 0x01:
u ^= 0x0000014d >> 1
p1 ^= ((u << 24) & 0xffffffff) | ((u << 8) & 0xffffffff)
return p1
def set_key(pkey, in_key, key_len):
pkey.qt_gen = 0
if not pkey.qt_gen:
gen_qtab(pkey)
pkey.qt_gen = 1
pkey.mt_gen = 0
if not pkey.mt_gen:
gen_mtab(pkey)
pkey.mt_gen = 1
pkey.k_len = (key_len * 8) // 64
a = 0
b = 0
me_key = [0,0,0,0]
mo_key = [0,0,0,0]
for i in range(pkey.k_len):
if WORD_BIGENDIAN:
a = byteswap32(in_key[i + 1])
me_key[i] = a
b = byteswap32(in_key[i + i + 1])
else:
a = in_key[i + i]
me_key[i] = a
b = in_key[i + i + 1]
mo_key[i] = b
pkey.s_key[pkey.k_len - i - 1] = mds_rem(a, b);
for i in range(0, 40, 2):
a = (0x01010101 * i) % 0x100000000;
b = (a + 0x01010101) % 0x100000000;
a = h_fun(pkey, a, me_key);
b = rotl32(h_fun(pkey, b, mo_key), 8);
pkey.l_key[i] = (a + b) % 0x100000000;
pkey.l_key[i + 1] = rotl32((a + 2 * b) % 0x100000000, 9);
gen_mk_tab(pkey, pkey.s_key)
def encrypt(pkey, in_blk):
blk = [0, 0, 0, 0]
if WORD_BIGENDIAN:
blk[0] = byteswap32(in_blk[0]) ^ pkey.l_key[0];
blk[1] = byteswap32(in_blk[1]) ^ pkey.l_key[1];
blk[2] = byteswap32(in_blk[2]) ^ pkey.l_key[2];
blk[3] = byteswap32(in_blk[3]) ^ pkey.l_key[3];
else:
blk[0] = in_blk[0] ^ pkey.l_key[0];
blk[1] = in_blk[1] ^ pkey.l_key[1];
blk[2] = in_blk[2] ^ pkey.l_key[2];
blk[3] = in_blk[3] ^ pkey.l_key[3];
for i in range(8):
t1 = ( pkey.mk_tab[0][byte(blk[1],3)] ^ pkey.mk_tab[1][byte(blk[1],0)] ^ pkey.mk_tab[2][byte(blk[1],1)] ^ pkey.mk_tab[3][byte(blk[1],2)] );
t0 = ( pkey.mk_tab[0][byte(blk[0],0)] ^ pkey.mk_tab[1][byte(blk[0],1)] ^ pkey.mk_tab[2][byte(blk[0],2)] ^ pkey.mk_tab[3][byte(blk[0],3)] );
blk[2] = rotr32(blk[2] ^ ((t0 + t1 + pkey.l_key[4 * (i) + 8]) % 0x100000000), 1);
blk[3] = rotl32(blk[3], 1) ^ ((t0 + 2 * t1 + pkey.l_key[4 * (i) + 9]) % 0x100000000);
t1 = ( pkey.mk_tab[0][byte(blk[3],3)] ^ pkey.mk_tab[1][byte(blk[3],0)] ^ pkey.mk_tab[2][byte(blk[3],1)] ^ pkey.mk_tab[3][byte(blk[3],2)] );
t0 = ( pkey.mk_tab[0][byte(blk[2],0)] ^ pkey.mk_tab[1][byte(blk[2],1)] ^ pkey.mk_tab[2][byte(blk[2],2)] ^ pkey.mk_tab[3][byte(blk[2],3)] );
blk[0] = rotr32(blk[0] ^ ((t0 + t1 + pkey.l_key[4 * (i) + 10]) % 0x100000000), 1);
blk[1] = rotl32(blk[1], 1) ^ ((t0 + 2 * t1 + pkey.l_key[4 * (i) + 11]) % 0x100000000);
if WORD_BIGENDIAN:
in_blk[0] = byteswap32(blk[2] ^ pkey.l_key[4]);
in_blk[1] = byteswap32(blk[3] ^ pkey.l_key[5]);
in_blk[2] = byteswap32(blk[0] ^ pkey.l_key[6]);
in_blk[3] = byteswap32(blk[1] ^ pkey.l_key[7]);
else:
in_blk[0] = blk[2] ^ pkey.l_key[4];
in_blk[1] = blk[3] ^ pkey.l_key[5];
in_blk[2] = blk[0] ^ pkey.l_key[6];
in_blk[3] = blk[1] ^ pkey.l_key[7];
return
def decrypt(pkey, in_blk):
blk = [0, 0, 0, 0]
if WORD_BIGENDIAN:
blk[0] = byteswap32(in_blk[0]) ^ pkey.l_key[4];
blk[1] = byteswap32(in_blk[1]) ^ pkey.l_key[5];
blk[2] = byteswap32(in_blk[2]) ^ pkey.l_key[6];
blk[3] = byteswap32(in_blk[3]) ^ pkey.l_key[7];
else:
blk[0] = in_blk[0] ^ pkey.l_key[4];
blk[1] = in_blk[1] ^ pkey.l_key[5];
blk[2] = in_blk[2] ^ pkey.l_key[6];
blk[3] = in_blk[3] ^ pkey.l_key[7];
for i in range(7, -1, -1):
t1 = ( pkey.mk_tab[0][byte(blk[1],3)] ^ pkey.mk_tab[1][byte(blk[1],0)] ^ pkey.mk_tab[2][byte(blk[1],1)] ^ pkey.mk_tab[3][byte(blk[1],2)] )
t0 = ( pkey.mk_tab[0][byte(blk[0],0)] ^ pkey.mk_tab[1][byte(blk[0],1)] ^ pkey.mk_tab[2][byte(blk[0],2)] ^ pkey.mk_tab[3][byte(blk[0],3)] )
blk[2] = rotl32(blk[2], 1) ^ ((t0 + t1 + pkey.l_key[4 * (i) + 10]) % 0x100000000)
blk[3] = rotr32(blk[3] ^ ((t0 + 2 * t1 + pkey.l_key[4 * (i) + 11]) % 0x100000000), 1)
t1 = ( pkey.mk_tab[0][byte(blk[3],3)] ^ pkey.mk_tab[1][byte(blk[3],0)] ^ pkey.mk_tab[2][byte(blk[3],1)] ^ pkey.mk_tab[3][byte(blk[3],2)] )
t0 = ( pkey.mk_tab[0][byte(blk[2],0)] ^ pkey.mk_tab[1][byte(blk[2],1)] ^ pkey.mk_tab[2][byte(blk[2],2)] ^ pkey.mk_tab[3][byte(blk[2],3)] )
blk[0] = rotl32(blk[0], 1) ^ ((t0 + t1 + pkey.l_key[4 * (i) + 8]) % 0x100000000)
blk[1] = rotr32(blk[1] ^ ((t0 + 2 * t1 + pkey.l_key[4 * (i) + 9]) % 0x100000000), 1)
if WORD_BIGENDIAN:
in_blk[0] = byteswap32(blk[2] ^ pkey.l_key[0]);
in_blk[1] = byteswap32(blk[3] ^ pkey.l_key[1]);
in_blk[2] = byteswap32(blk[0] ^ pkey.l_key[2]);
in_blk[3] = byteswap32(blk[1] ^ pkey.l_key[3]);
else:
in_blk[0] = blk[2] ^ pkey.l_key[0];
in_blk[1] = blk[3] ^ pkey.l_key[1];
in_blk[2] = blk[0] ^ pkey.l_key[2];
in_blk[3] = blk[1] ^ pkey.l_key[3];
return
__testkey = b'\xD4\x3B\xB7\x55\x6E\xA3\x2E\x46\xF2\xA2\x82\xB7\xD4\x5B\x4E\x0D\x57\xFF\x73\x9D\x4D\xC9\x2C\x1B\xD7\xFC\x01\x70\x0C\xC8\x21\x6F'
__testdat = b'\x90\xAF\xE9\x1B\xB2\x88\x54\x4F\x2C\x32\xDC\x23\x9B\x26\x35\xE6'
assert b'l\xb4V\x1c@\xbf\n\x97\x05\x93\x1c\xb6\xd4\x08\xe7\xfa' == Twofish(__testkey).encrypt(__testdat)
assert __testdat == Twofish(__testkey).decrypt(b'l\xb4V\x1c@\xbf\n\x97\x05\x93\x1c\xb6\xd4\x08\xe7\xfa')
|