| 1 |
|
| 2 |
/* This is an independent implementation of the encryption algorithm: */ |
| 3 |
/* */ |
| 4 |
/* Twofish by Bruce Schneier and colleagues */ |
| 5 |
/* */ |
| 6 |
/* which is a candidate algorithm in the Advanced Encryption Standard */ |
| 7 |
/* programme of the US National Institute of Standards and Technology. */ |
| 8 |
/* */ |
| 9 |
/* Copyright in this implementation is held by Dr B R Gladman but I */ |
| 10 |
/* hereby give permission for its free direct or derivative use subject */ |
| 11 |
/* to acknowledgment of its origin and compliance with any conditions */ |
| 12 |
/* that the originators of t he algorithm place on its exploitation. */ |
| 13 |
/* */ |
| 14 |
/* My thanks to Doug Whiting and Niels Ferguson for comments that led */ |
| 15 |
/* to improvements in this implementation. */ |
| 16 |
/* */ |
| 17 |
/* Dr Brian Gladman (gladman@seven77.demon.co.uk) 14th January 1999 */ |
| 18 |
|
| 19 |
/* $Id: twofish.c,v 1.1.1.1 1999/10/15 22:49:23 nmav Exp $ */ |
| 20 |
|
| 21 |
/* Timing data for Twofish (twofish.c) |
| 22 |
|
| 23 |
128 bit key: |
| 24 |
Key Setup: 8414 cycles |
| 25 |
Encrypt: 376 cycles = 68.1 mbits/sec |
| 26 |
Decrypt: 374 cycles = 68.4 mbits/sec |
| 27 |
Mean: 375 cycles = 68.3 mbits/sec |
| 28 |
|
| 29 |
192 bit key: |
| 30 |
Key Setup: 11628 cycles |
| 31 |
Encrypt: 376 cycles = 68.1 mbits/sec |
| 32 |
Decrypt: 374 cycles = 68.4 mbits/sec |
| 33 |
Mean: 375 cycles = 68.3 mbits/sec |
| 34 |
|
| 35 |
256 bit key: |
| 36 |
Key Setup: 15457 cycles |
| 37 |
Encrypt: 381 cycles = 67.2 mbits/sec |
| 38 |
Decrypt: 374 cycles = 68.4 mbits/sec |
| 39 |
Mean: 378 cycles = 67.8 mbits/sec |
| 40 |
|
| 41 |
*/ |
| 42 |
|
| 43 |
#include "libdefs.h" |
| 44 |
#include "swap.h" |
| 45 |
#include "twofish.h" |
| 46 |
|
| 47 |
/* word32 k_len; |
| 48 |
* word32 l_key[40]; |
| 49 |
* word32 s_key[4]; |
| 50 |
*/ |
| 51 |
|
| 52 |
/* Extract byte from a 32 bit quantity (little endian notation) */ |
| 53 |
#define byte(x,n) ((word8)((x) >> (8 * n))) |
| 54 |
|
| 55 |
/* finite field arithmetic for GF(2**8) with the modular */ |
| 56 |
/* polynomial x^8 + x^6 + x^5 + x^3 + 1 (0x169) */ |
| 57 |
|
| 58 |
#define G_M 0x0169 |
| 59 |
|
| 60 |
word8 tab_5b[4] = { 0, G_M >> 2, G_M >> 1, (G_M >> 1) ^ (G_M >> 2) }; |
| 61 |
word8 tab_ef[4] = { 0, (G_M >> 1) ^ (G_M >> 2), G_M >> 1, G_M >> 2 }; |
| 62 |
|
| 63 |
#define ffm_01(x) (x) |
| 64 |
#define ffm_5b(x) ((x) ^ ((x) >> 2) ^ tab_5b[(x) & 3]) |
| 65 |
#define ffm_ef(x) ((x) ^ ((x) >> 1) ^ ((x) >> 2) ^ tab_ef[(x) & 3]) |
| 66 |
|
| 67 |
word8 ror4[16] = { 0, 8, 1, 9, 2, 10, 3, 11, 4, 12, 5, 13, 6, 14, 7, 15 }; |
| 68 |
word8 ashx[16] = { 0, 9, 2, 11, 4, 13, 6, 15, 8, 1, 10, 3, 12, 5, 14, 7 }; |
| 69 |
|
| 70 |
word8 qt0[2][16] = { |
| 71 |
{8, 1, 7, 13, 6, 15, 3, 2, 0, 11, 5, 9, 14, 12, 10, 4}, |
| 72 |
{2, 8, 11, 13, 15, 7, 6, 14, 3, 1, 9, 4, 0, 10, 12, 5} |
| 73 |
}; |
| 74 |
|
| 75 |
word8 qt1[2][16] = { |
| 76 |
{14, 12, 11, 8, 1, 2, 3, 5, 15, 4, 10, 6, 7, 0, 9, 13}, |
| 77 |
{1, 14, 2, 11, 4, 12, 3, 7, 6, 13, 10, 5, 15, 9, 0, 8} |
| 78 |
}; |
| 79 |
|
| 80 |
word8 qt2[2][16] = { |
| 81 |
{11, 10, 5, 14, 6, 13, 9, 0, 12, 8, 15, 3, 2, 4, 7, 1}, |
| 82 |
{4, 12, 7, 5, 1, 6, 9, 10, 0, 14, 13, 8, 2, 11, 3, 15} |
| 83 |
}; |
| 84 |
|
| 85 |
word8 qt3[2][16] = { |
| 86 |
{13, 7, 15, 4, 1, 2, 6, 14, 9, 11, 3, 0, 8, 5, 12, 10}, |
| 87 |
{11, 9, 5, 1, 12, 3, 13, 14, 6, 4, 7, 15, 2, 0, 8, 10} |
| 88 |
}; |
| 89 |
|
| 90 |
word8 qp(const word32 n, const word8 x) |
| 91 |
{ |
| 92 |
word8 a0, a1, a2, a3, a4, b0, b1, b2, b3, b4; |
| 93 |
|
| 94 |
a0 = x >> 4; |
| 95 |
b0 = x & 15; |
| 96 |
a1 = a0 ^ b0; |
| 97 |
b1 = ror4[b0] ^ ashx[a0]; |
| 98 |
a2 = qt0[n][a1]; |
| 99 |
b2 = qt1[n][b1]; |
| 100 |
a3 = a2 ^ b2; |
| 101 |
b3 = ror4[b2] ^ ashx[a2]; |
| 102 |
a4 = qt2[n][a3]; |
| 103 |
b4 = qt3[n][b3]; |
| 104 |
return (b4 << 4) | a4; |
| 105 |
} |
| 106 |
|
| 107 |
#ifdef Q_TABLES |
| 108 |
|
| 109 |
#define q(n,x) pkey->q_tab[n][x] |
| 110 |
|
| 111 |
void gen_qtab(TWI * pkey) |
| 112 |
{ |
| 113 |
word32 i; |
| 114 |
|
| 115 |
for (i = 0; i < 256; ++i) { |
| 116 |
q(0, i) = qp(0, (word8) i); |
| 117 |
q(1, i) = qp(1, (word8) i); |
| 118 |
} |
| 119 |
} |
| 120 |
|
| 121 |
#else |
| 122 |
|
| 123 |
#define q(n,x) qp(n, x) |
| 124 |
|
| 125 |
#endif |
| 126 |
|
| 127 |
#ifdef M_TABLE |
| 128 |
|
| 129 |
void gen_mtab(TWI * pkey) |
| 130 |
{ |
| 131 |
word32 i, f01, f5b, fef; |
| 132 |
|
| 133 |
for (i = 0; i < 256; ++i) { |
| 134 |
f01 = q(1, i); |
| 135 |
f5b = ffm_5b(f01); |
| 136 |
fef = ffm_ef(f01); |
| 137 |
pkey->m_tab[0][i] = |
| 138 |
f01 + (f5b << 8) + (fef << 16) + (fef << 24); |
| 139 |
pkey->m_tab[2][i] = |
| 140 |
f5b + (fef << 8) + (f01 << 16) + (fef << 24); |
| 141 |
|
| 142 |
f01 = q(0, i); |
| 143 |
f5b = ffm_5b(f01); |
| 144 |
fef = ffm_ef(f01); |
| 145 |
pkey->m_tab[1][i] = |
| 146 |
fef + (fef << 8) + (f5b << 16) + (f01 << 24); |
| 147 |
pkey->m_tab[3][i] = |
| 148 |
f5b + (f01 << 8) + (fef << 16) + (f5b << 24); |
| 149 |
} |
| 150 |
} |
| 151 |
|
| 152 |
#define mds(n,x) pkey->m_tab[n][x] |
| 153 |
|
| 154 |
#else |
| 155 |
|
| 156 |
#define fm_00 ffm_01 |
| 157 |
#define fm_10 ffm_5b |
| 158 |
#define fm_20 ffm_ef |
| 159 |
#define fm_30 ffm_ef |
| 160 |
#define q_0(x) q(1,x) |
| 161 |
|
| 162 |
#define fm_01 ffm_ef |
| 163 |
#define fm_11 ffm_ef |
| 164 |
#define fm_21 ffm_5b |
| 165 |
#define fm_31 ffm_01 |
| 166 |
#define q_1(x) q(0,x) |
| 167 |
|
| 168 |
#define fm_02 ffm_5b |
| 169 |
#define fm_12 ffm_ef |
| 170 |
#define fm_22 ffm_01 |
| 171 |
#define fm_32 ffm_ef |
| 172 |
#define q_2(x) q(1,x) |
| 173 |
|
| 174 |
#define fm_03 ffm_5b |
| 175 |
#define fm_13 ffm_01 |
| 176 |
#define fm_23 ffm_ef |
| 177 |
#define fm_33 ffm_5b |
| 178 |
#define q_3(x) q(0,x) |
| 179 |
|
| 180 |
#define f_0(n,x) ((word32)fm_0##n(x)) |
| 181 |
#define f_1(n,x) ((word32)fm_1##n(x) << 8) |
| 182 |
#define f_2(n,x) ((word32)fm_2##n(x) << 16) |
| 183 |
#define f_3(n,x) ((word32)fm_3##n(x) << 24) |
| 184 |
|
| 185 |
#define mds(n,x) f_0(n,q_##n(x)) ^ f_1(n,q_##n(x)) ^ f_2(n,q_##n(x)) ^ f_3(n,q_##n(x)) |
| 186 |
|
| 187 |
#endif |
| 188 |
|
| 189 |
word32 h_fun(TWI * pkey, const word32 x, const word32 key[]) |
| 190 |
{ |
| 191 |
word32 b0, b1, b2, b3; |
| 192 |
|
| 193 |
#ifndef M_TABLE |
| 194 |
word32 m5b_b0, m5b_b1, m5b_b2, m5b_b3; |
| 195 |
word32 mef_b0, mef_b1, mef_b2, mef_b3; |
| 196 |
#endif |
| 197 |
|
| 198 |
b0 = byte(x, 0); |
| 199 |
b1 = byte(x, 1); |
| 200 |
b2 = byte(x, 2); |
| 201 |
b3 = byte(x, 3); |
| 202 |
|
| 203 |
switch (pkey->k_len) { |
| 204 |
case 4: |
| 205 |
b0 = q(1, b0) ^ byte(key[3], 0); |
| 206 |
b1 = q(0, b1) ^ byte(key[3], 1); |
| 207 |
b2 = q(0, b2) ^ byte(key[3], 2); |
| 208 |
b3 = q(1, b3) ^ byte(key[3], 3); |
| 209 |
case 3: |
| 210 |
b0 = q(1, b0) ^ byte(key[2], 0); |
| 211 |
b1 = q(1, b1) ^ byte(key[2], 1); |
| 212 |
b2 = q(0, b2) ^ byte(key[2], 2); |
| 213 |
b3 = q(0, b3) ^ byte(key[2], 3); |
| 214 |
case 2: |
| 215 |
b0 = q(0, q(0, b0) ^ byte(key[1], 0)) ^ byte(key[0], 0); |
| 216 |
b1 = q(0, q(1, b1) ^ byte(key[1], 1)) ^ byte(key[0], 1); |
| 217 |
b2 = q(1, q(0, b2) ^ byte(key[1], 2)) ^ byte(key[0], 2); |
| 218 |
b3 = q(1, q(1, b3) ^ byte(key[1], 3)) ^ byte(key[0], 3); |
| 219 |
} |
| 220 |
#ifdef M_TABLE |
| 221 |
|
| 222 |
return mds(0, b0) ^ mds(1, b1) ^ mds(2, b2) ^ mds(3, b3); |
| 223 |
|
| 224 |
#else |
| 225 |
|
| 226 |
b0 = q(1, b0); |
| 227 |
b1 = q(0, b1); |
| 228 |
b2 = q(1, b2); |
| 229 |
b3 = q(0, b3); |
| 230 |
m5b_b0 = ffm_5b(b0); |
| 231 |
m5b_b1 = ffm_5b(b1); |
| 232 |
m5b_b2 = ffm_5b(b2); |
| 233 |
m5b_b3 = ffm_5b(b3); |
| 234 |
mef_b0 = ffm_ef(b0); |
| 235 |
mef_b1 = ffm_ef(b1); |
| 236 |
mef_b2 = ffm_ef(b2); |
| 237 |
mef_b3 = ffm_ef(b3); |
| 238 |
b0 ^= mef_b1 ^ m5b_b2 ^ m5b_b3; |
| 239 |
b3 ^= m5b_b0 ^ mef_b1 ^ mef_b2; |
| 240 |
b2 ^= mef_b0 ^ m5b_b1 ^ mef_b3; |
| 241 |
b1 ^= mef_b0 ^ mef_b2 ^ m5b_b3; |
| 242 |
|
| 243 |
return b0 | (b3 << 8) | (b2 << 16) | (b1 << 24); |
| 244 |
|
| 245 |
#endif |
| 246 |
} |
| 247 |
|
| 248 |
#ifdef MK_TABLE |
| 249 |
|
| 250 |
#define q20(x) q(0,q(0,x) ^ byte(key[1],0)) ^ byte(key[0],0) |
| 251 |
#define q21(x) q(0,q(1,x) ^ byte(key[1],1)) ^ byte(key[0],1) |
| 252 |
#define q22(x) q(1,q(0,x) ^ byte(key[1],2)) ^ byte(key[0],2) |
| 253 |
#define q23(x) q(1,q(1,x) ^ byte(key[1],3)) ^ byte(key[0],3) |
| 254 |
|
| 255 |
#define q30(x) q(0,q(0,q(1, x) ^ byte(key[2],0)) ^ byte(key[1],0)) ^ byte(key[0],0) |
| 256 |
#define q31(x) q(0,q(1,q(1, x) ^ byte(key[2],1)) ^ byte(key[1],1)) ^ byte(key[0],1) |
| 257 |
#define q32(x) q(1,q(0,q(0, x) ^ byte(key[2],2)) ^ byte(key[1],2)) ^ byte(key[0],2) |
| 258 |
#define q33(x) q(1,q(1,q(0, x) ^ byte(key[2],3)) ^ byte(key[1],3)) ^ byte(key[0],3) |
| 259 |
|
| 260 |
#define q40(x) q(0,q(0,q(1, q(1, x) ^ byte(key[3],0)) ^ byte(key[2],0)) ^ byte(key[1],0)) ^ byte(key[0],0) |
| 261 |
#define q41(x) q(0,q(1,q(1, q(0, x) ^ byte(key[3],1)) ^ byte(key[2],1)) ^ byte(key[1],1)) ^ byte(key[0],1) |
| 262 |
#define q42(x) q(1,q(0,q(0, q(0, x) ^ byte(key[3],2)) ^ byte(key[2],2)) ^ byte(key[1],2)) ^ byte(key[0],2) |
| 263 |
#define q43(x) q(1,q(1,q(0, q(1, x) ^ byte(key[3],3)) ^ byte(key[2],3)) ^ byte(key[1],3)) ^ byte(key[0],3) |
| 264 |
|
| 265 |
void gen_mk_tab(TWI * pkey, word32 key[]) |
| 266 |
{ |
| 267 |
word32 i; |
| 268 |
word8 by; |
| 269 |
|
| 270 |
switch (pkey->k_len) { |
| 271 |
case 2: |
| 272 |
for (i = 0; i < 256; ++i) { |
| 273 |
by = (word8) i; |
| 274 |
#ifdef ONE_STEP |
| 275 |
pkey->mk_tab[0][i] = mds(0, q20(by)); |
| 276 |
pkey->mk_tab[1][i] = mds(1, q21(by)); |
| 277 |
pkey->mk_tab[2][i] = mds(2, q22(by)); |
| 278 |
pkey->mk_tab[3][i] = mds(3, q23(by)); |
| 279 |
#else |
| 280 |
pkey->sb[0][i] = q20(by); |
| 281 |
pkey->sb[1][i] = q21(by); |
| 282 |
pkey->sb[2][i] = q22(by); |
| 283 |
pkey->sb[3][i] = q23(by); |
| 284 |
#endif |
| 285 |
} |
| 286 |
break; |
| 287 |
|
| 288 |
case 3: |
| 289 |
for (i = 0; i < 256; ++i) { |
| 290 |
by = (word8) i; |
| 291 |
#ifdef ONE_STEP |
| 292 |
pkey->mk_tab[0][i] = mds(0, q30(by)); |
| 293 |
pkey->mk_tab[1][i] = mds(1, q31(by)); |
| 294 |
pkey->mk_tab[2][i] = mds(2, q32(by)); |
| 295 |
pkey->mk_tab[3][i] = mds(3, q33(by)); |
| 296 |
#else |
| 297 |
pkey->sb[0][i] = q30(by); |
| 298 |
pkey->sb[1][i] = q31(by); |
| 299 |
pkey->sb[2][i] = q32(by); |
| 300 |
pkey->sb[3][i] = q33(by); |
| 301 |
#endif |
| 302 |
} |
| 303 |
break; |
| 304 |
|
| 305 |
case 4: |
| 306 |
for (i = 0; i < 256; ++i) { |
| 307 |
by = (word8) i; |
| 308 |
#ifdef ONE_STEP |
| 309 |
pkey->mk_tab[0][i] = mds(0, q40(by)); |
| 310 |
pkey->mk_tab[1][i] = mds(1, q41(by)); |
| 311 |
pkey->mk_tab[2][i] = mds(2, q42(by)); |
| 312 |
pkey->mk_tab[3][i] = mds(3, q43(by)); |
| 313 |
#else |
| 314 |
pkey->sb[0][i] = q40(by); |
| 315 |
pkey->sb[1][i] = q41(by); |
| 316 |
pkey->sb[2][i] = q42(by); |
| 317 |
pkey->sb[3][i] = q43(by); |
| 318 |
#endif |
| 319 |
} |
| 320 |
} |
| 321 |
} |
| 322 |
|
| 323 |
#ifdef ONE_STEP |
| 324 |
#define g0_fun(x) ( pkey->mk_tab[0][byte(x,0)] ^ pkey->mk_tab[1][byte(x,1)] \ |
| 325 |
^ pkey->mk_tab[2][byte(x,2)] ^ pkey->mk_tab[3][byte(x,3)] ) |
| 326 |
#define g1_fun(x) ( pkey->mk_tab[0][byte(x,3)] ^ pkey->mk_tab[1][byte(x,0)] \ |
| 327 |
^ pkey->mk_tab[2][byte(x,1)] ^ pkey->mk_tab[3][byte(x,2)] ) |
| 328 |
#else |
| 329 |
#define g0_fun(x) ( mds(0, pkey->sb[0][byte(x,0)]) ^ mds(1, pkey->sb[1][byte(x,1)]) \ |
| 330 |
^ mds(2, pkey->sb[2][byte(x,2)]) ^ mds(3, pkey->sb[3][byte(x,3)]) ) |
| 331 |
#define g1_fun(x) ( mds(0, pkey->sb[0][byte(x,3)]) ^ mds(1, pkey->sb[1][byte(x,0)]) \ |
| 332 |
^ mds(2, pkey->sb[2][byte(x,1)]) ^ mds(3, pkey->sb[3][byte(x,2)]) ) |
| 333 |
#endif |
| 334 |
|
| 335 |
#else |
| 336 |
|
| 337 |
#define g0_fun(x) h_fun(pkey, x,pkey->s_key) |
| 338 |
#define g1_fun(x) h_fun(pkey, rotl(x,8),pkey->s_key) |
| 339 |
|
| 340 |
#endif |
| 341 |
|
| 342 |
/* The (12,8) Reed Soloman code has the generator polynomial |
| 343 |
|
| 344 |
g(x) = x^4 + (a + 1/a) * x^3 + a * x^2 + (a + 1/a) * x + 1 |
| 345 |
|
| 346 |
where the coefficients are in the finite field GF(2^8) with a |
| 347 |
modular polynomial a^8 + a^6 + a^3 + a^2 + 1. To generate the |
| 348 |
remainder we have to start with a 12th order polynomial with our |
| 349 |
eight input bytes as the coefficients of the 4th to 11th terms. |
| 350 |
That is: |
| 351 |
|
| 352 |
m[7] * x^11 + m[6] * x^10 ... + m[0] * x^4 + 0 * x^3 +... + 0 |
| 353 |
|
| 354 |
We then multiply the generator polynomial by m[7] * x^7 and subtract |
| 355 |
it - xor in GF(2^8) - from the above to eliminate the x^7 term (the |
| 356 |
artihmetic on the coefficients is done in GF(2^8). We then multiply |
| 357 |
the generator polynomial by x^6 * coeff(x^10) and use this to remove |
| 358 |
the x^10 term. We carry on in this way until the x^4 term is removed |
| 359 |
so that we are left with: |
| 360 |
|
| 361 |
r[3] * x^3 + r[2] * x^2 + r[1] 8 x^1 + r[0] |
| 362 |
|
| 363 |
which give the resulting 4 bytes of the remainder. This is equivalent |
| 364 |
to the matrix multiplication in the Twofish description but much faster |
| 365 |
to implement. |
| 366 |
|
| 367 |
*/ |
| 368 |
|
| 369 |
#define G_MOD 0x0000014d |
| 370 |
|
| 371 |
word32 mds_rem(word32 p0, word32 p1) |
| 372 |
{ |
| 373 |
word32 i, t, u; |
| 374 |
|
| 375 |
for (i = 0; i < 8; ++i) { |
| 376 |
t = p1 >> 24; /* get most significant coefficient */ |
| 377 |
|
| 378 |
p1 = (p1 << 8) | (p0 >> 24); |
| 379 |
p0 <<= 8; /* shift others up */ |
| 380 |
|
| 381 |
/* multiply t by a (the primitive element - i.e. left shift) */ |
| 382 |
|
| 383 |
u = (t << 1); |
| 384 |
|
| 385 |
if (t & 0x80) |
| 386 |
/* subtract modular polynomial on overflow */ |
| 387 |
u ^= G_MOD; |
| 388 |
|
| 389 |
p1 ^= t ^ (u << 16); /* remove t * (a * x^2 + 1) */ |
| 390 |
|
| 391 |
u ^= (t >> 1); /* form u = a * t + t / a = t * (a + 1 / a); */ |
| 392 |
|
| 393 |
if (t & 0x01) |
| 394 |
/* add the modular polynomial on underflow */ |
| 395 |
u ^= G_MOD >> 1; |
| 396 |
|
| 397 |
p1 ^= (u << 24) | (u << 8); /* remove t * (a + 1/a) * (x^3 + x) */ |
| 398 |
|
| 399 |
} |
| 400 |
|
| 401 |
return p1; |
| 402 |
} |
| 403 |
|
| 404 |
/* initialise the key schedule from the user supplied key */ |
| 405 |
|
| 406 |
void _mcrypt_twofish_set_key(TWI * pkey, const word32 in_key[], |
| 407 |
const word32 key_len) |
| 408 |
{ |
| 409 |
word32 i, a, b, me_key[4], mo_key[4]; |
| 410 |
|
| 411 |
#ifdef Q_TABLES |
| 412 |
pkey->qt_gen = 0; |
| 413 |
|
| 414 |
if (!pkey->qt_gen) { |
| 415 |
gen_qtab(pkey); |
| 416 |
pkey->qt_gen = 1; |
| 417 |
} |
| 418 |
#endif |
| 419 |
|
| 420 |
#ifdef M_TABLE |
| 421 |
pkey->mt_gen = 0; |
| 422 |
if (!pkey->mt_gen) { |
| 423 |
gen_mtab(pkey); |
| 424 |
pkey->mt_gen = 1; |
| 425 |
} |
| 426 |
#endif |
| 427 |
|
| 428 |
pkey->k_len = (key_len * 8) / 64; /* 2, 3 or 4 */ |
| 429 |
|
| 430 |
for (i = 0; i < pkey->k_len; ++i) { |
| 431 |
#ifdef WORDS_BIGENDIAN |
| 432 |
a = byteswap(in_key[i + i]); |
| 433 |
me_key[i] = a; |
| 434 |
b = byteswap(in_key[i + i + 1]); |
| 435 |
#else |
| 436 |
a = in_key[i + i]; |
| 437 |
me_key[i] = a; |
| 438 |
b = in_key[i + i + 1]; |
| 439 |
#endif |
| 440 |
mo_key[i] = b; |
| 441 |
pkey->s_key[pkey->k_len - i - 1] = mds_rem(a, b); |
| 442 |
} |
| 443 |
|
| 444 |
for (i = 0; i < 40; i += 2) { |
| 445 |
a = 0x01010101 * i; |
| 446 |
b = a + 0x01010101; |
| 447 |
a = h_fun(pkey, a, me_key); |
| 448 |
b = rotl(h_fun(pkey, b, mo_key), 8); |
| 449 |
pkey->l_key[i] = a + b; |
| 450 |
pkey->l_key[i + 1] = rotl(a + 2 * b, 9); |
| 451 |
} |
| 452 |
|
| 453 |
#ifdef MK_TABLE |
| 454 |
gen_mk_tab(pkey, pkey->s_key); |
| 455 |
#endif |
| 456 |
|
| 457 |
} |
| 458 |
|
| 459 |
/* encrypt a block of text */ |
| 460 |
|
| 461 |
#define f_rnd(i) \ |
| 462 |
t1 = g1_fun(blk[1]); t0 = g0_fun(blk[0]); \ |
| 463 |
blk[2] = rotr(blk[2] ^ (t0 + t1 + pkey->l_key[4 * (i) + 8]), 1); \ |
| 464 |
blk[3] = rotl(blk[3], 1) ^ (t0 + 2 * t1 + pkey->l_key[4 * (i) + 9]); \ |
| 465 |
t1 = g1_fun(blk[3]); t0 = g0_fun(blk[2]); \ |
| 466 |
blk[0] = rotr(blk[0] ^ (t0 + t1 + pkey->l_key[4 * (i) + 10]), 1); \ |
| 467 |
blk[1] = rotl(blk[1], 1) ^ (t0 + 2 * t1 + pkey->l_key[4 * (i) + 11]) |
| 468 |
|
| 469 |
void _mcrypt_twofish_encrypt(TWI * pkey, word32 * in_blk) |
| 470 |
{ |
| 471 |
word32 t0, t1, blk[4]; |
| 472 |
|
| 473 |
#ifndef WORDS_BIGENDIAN |
| 474 |
blk[0] = in_blk[0] ^ pkey->l_key[0]; |
| 475 |
blk[1] = in_blk[1] ^ pkey->l_key[1]; |
| 476 |
blk[2] = in_blk[2] ^ pkey->l_key[2]; |
| 477 |
blk[3] = in_blk[3] ^ pkey->l_key[3]; |
| 478 |
#else |
| 479 |
blk[0] = byteswap(in_blk[0]) ^ pkey->l_key[0]; |
| 480 |
blk[1] = byteswap(in_blk[1]) ^ pkey->l_key[1]; |
| 481 |
blk[2] = byteswap(in_blk[2]) ^ pkey->l_key[2]; |
| 482 |
blk[3] = byteswap(in_blk[3]) ^ pkey->l_key[3]; |
| 483 |
#endif |
| 484 |
|
| 485 |
f_rnd(0); |
| 486 |
f_rnd(1); |
| 487 |
f_rnd(2); |
| 488 |
f_rnd(3); |
| 489 |
f_rnd(4); |
| 490 |
f_rnd(5); |
| 491 |
f_rnd(6); |
| 492 |
f_rnd(7); |
| 493 |
|
| 494 |
#ifndef WORDS_BIGENDIAN |
| 495 |
in_blk[0] = blk[2] ^ pkey->l_key[4]; |
| 496 |
in_blk[1] = blk[3] ^ pkey->l_key[5]; |
| 497 |
in_blk[2] = blk[0] ^ pkey->l_key[6]; |
| 498 |
in_blk[3] = blk[1] ^ pkey->l_key[7]; |
| 499 |
#else |
| 500 |
in_blk[0] = byteswap(blk[2] ^ pkey->l_key[4]); |
| 501 |
in_blk[1] = byteswap(blk[3] ^ pkey->l_key[5]); |
| 502 |
in_blk[2] = byteswap(blk[0] ^ pkey->l_key[6]); |
| 503 |
in_blk[3] = byteswap(blk[1] ^ pkey->l_key[7]); |
| 504 |
#endif |
| 505 |
} |
| 506 |
|
| 507 |
/* decrypt a block of text */ |
| 508 |
|
| 509 |
#define i_rnd(i) \ |
| 510 |
t1 = g1_fun(blk[1]); t0 = g0_fun(blk[0]); \ |
| 511 |
blk[2] = rotl(blk[2], 1) ^ (t0 + t1 + pkey->l_key[4 * (i) + 10]); \ |
| 512 |
blk[3] = rotr(blk[3] ^ (t0 + 2 * t1 + pkey->l_key[4 * (i) + 11]), 1); \ |
| 513 |
t1 = g1_fun(blk[3]); t0 = g0_fun(blk[2]); \ |
| 514 |
blk[0] = rotl(blk[0], 1) ^ (t0 + t1 + pkey->l_key[4 * (i) + 8]); \ |
| 515 |
blk[1] = rotr(blk[1] ^ (t0 + 2 * t1 + pkey->l_key[4 * (i) + 9]), 1) |
| 516 |
|
| 517 |
void _mcrypt_twofish_decrypt(TWI * pkey, word32 * in_blk) |
| 518 |
{ |
| 519 |
word32 t0, t1, blk[4]; |
| 520 |
|
| 521 |
#ifdef WORDS_BIGENDIAN |
| 522 |
blk[0] = byteswap(in_blk[0]) ^ pkey->l_key[4]; |
| 523 |
blk[1] = byteswap(in_blk[1]) ^ pkey->l_key[5]; |
| 524 |
blk[2] = byteswap(in_blk[2]) ^ pkey->l_key[6]; |
| 525 |
blk[3] = byteswap(in_blk[3]) ^ pkey->l_key[7]; |
| 526 |
#else |
| 527 |
blk[0] = in_blk[0] ^ pkey->l_key[4]; |
| 528 |
blk[1] = in_blk[1] ^ pkey->l_key[5]; |
| 529 |
blk[2] = in_blk[2] ^ pkey->l_key[6]; |
| 530 |
blk[3] = in_blk[3] ^ pkey->l_key[7]; |
| 531 |
#endif |
| 532 |
|
| 533 |
i_rnd(7); |
| 534 |
i_rnd(6); |
| 535 |
i_rnd(5); |
| 536 |
i_rnd(4); |
| 537 |
i_rnd(3); |
| 538 |
i_rnd(2); |
| 539 |
i_rnd(1); |
| 540 |
i_rnd(0); |
| 541 |
|
| 542 |
#ifdef WORDS_BIGENDIAN |
| 543 |
in_blk[0] = byteswap(blk[2] ^ pkey->l_key[0]); |
| 544 |
in_blk[1] = byteswap(blk[3] ^ pkey->l_key[1]); |
| 545 |
in_blk[2] = byteswap(blk[0] ^ pkey->l_key[2]); |
| 546 |
in_blk[3] = byteswap(blk[1] ^ pkey->l_key[3]); |
| 547 |
#else |
| 548 |
in_blk[0] = blk[2] ^ pkey->l_key[0]; |
| 549 |
in_blk[1] = blk[3] ^ pkey->l_key[1]; |
| 550 |
in_blk[2] = blk[0] ^ pkey->l_key[2]; |
| 551 |
in_blk[3] = blk[1] ^ pkey->l_key[3]; |
| 552 |
#endif |
| 553 |
|
| 554 |
} |
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