| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: twofish-mktab.c,v 1.4 2000/10/08 12:08:10 mdw Exp $ |
| 4 | * |
| 5 | * Build constant tables for Twofish |
| 6 | * |
| 7 | * (c) 2000 Straylight/Edgeware |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of Catacomb. |
| 13 | * |
| 14 | * Catacomb is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU Library General Public License as |
| 16 | * published by the Free Software Foundation; either version 2 of the |
| 17 | * License, or (at your option) any later version. |
| 18 | * |
| 19 | * Catacomb is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU Library General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU Library General Public |
| 25 | * License along with Catacomb; if not, write to the Free |
| 26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 27 | * MA 02111-1307, USA. |
| 28 | */ |
| 29 | |
| 30 | /*----- Revision history --------------------------------------------------* |
| 31 | * |
| 32 | * $Log: twofish-mktab.c,v $ |
| 33 | * Revision 1.4 2000/10/08 12:08:10 mdw |
| 34 | * Escape literal newlines in output string. |
| 35 | * |
| 36 | * Revision 1.3 2000/06/26 17:14:42 mdw |
| 37 | * (rslog): Ensure that log(1) = 0 (not 255, as previously). While the two |
| 38 | * are strictly equivalent, it means that the exp table is larger than it |
| 39 | * otherwise needs to be. |
| 40 | * |
| 41 | * Revision 1.2 2000/06/18 23:12:15 mdw |
| 42 | * Change typesetting of Galois Field names. |
| 43 | * |
| 44 | * Revision 1.1 2000/06/17 12:10:17 mdw |
| 45 | * New cipher. |
| 46 | * |
| 47 | */ |
| 48 | |
| 49 | /*----- Header files ------------------------------------------------------*/ |
| 50 | |
| 51 | #include <stdio.h> |
| 52 | #include <stdlib.h> |
| 53 | |
| 54 | #include <mLib/bits.h> |
| 55 | |
| 56 | /*----- Data structures ---------------------------------------------------*/ |
| 57 | |
| 58 | typedef struct { octet t[4][16]; } t_tab; |
| 59 | typedef struct { octet q[256]; } q_tab; |
| 60 | |
| 61 | /*----- Various Twofish tables --------------------------------------------*/ |
| 62 | |
| 63 | /* --- The t-tables --- */ |
| 64 | |
| 65 | static const t_tab qt0 = {{ |
| 66 | { 0x8, 0x1, 0x7, 0xd, 0x6, 0xf, 0x3, 0x2, |
| 67 | 0x0, 0xb, 0x5, 0x9, 0xe, 0xc, 0xa, 0x4 }, |
| 68 | { 0xe, 0xc, 0xb, 0x8, 0x1, 0x2, 0x3, 0x5, |
| 69 | 0xf, 0x4, 0xa, 0x6, 0x7, 0x0, 0x9, 0xd }, |
| 70 | { 0xb, 0xa, 0x5, 0xe, 0x6, 0xd, 0x9, 0x0, |
| 71 | 0xc, 0x8, 0xf, 0x3, 0x2, 0x4, 0x7, 0x1 }, |
| 72 | { 0xd, 0x7, 0xf, 0x4, 0x1, 0x2, 0x6, 0xe, |
| 73 | 0x9, 0xb, 0x3, 0x0, 0x8, 0x5, 0xc, 0xa } |
| 74 | }}; |
| 75 | |
| 76 | static const t_tab qt1 = {{ |
| 77 | { 0x2, 0x8, 0xb, 0xd, 0xf, 0x7, 0x6, 0xe, |
| 78 | 0x3, 0x1, 0x9, 0x4, 0x0, 0xa, 0xc, 0x5 }, |
| 79 | { 0x1, 0xe, 0x2, 0xb, 0x4, 0xc, 0x3, 0x7, |
| 80 | 0x6, 0xd, 0xa, 0x5, 0xf, 0x9, 0x0, 0x8 }, |
| 81 | { 0x4, 0xc, 0x7, 0x5, 0x1, 0x6, 0x9, 0xa, |
| 82 | 0x0, 0xe, 0xd, 0x8, 0x2, 0xb, 0x3, 0xf }, |
| 83 | { 0xb, 0x9, 0x5, 0x1, 0xc, 0x3, 0xd, 0xe, |
| 84 | 0x6, 0x4, 0x7, 0xf, 0x2, 0x0, 0x8, 0xa } |
| 85 | }}; |
| 86 | |
| 87 | static q_tab q0, q1; |
| 88 | |
| 89 | /* --- The MDS and Reed-Solomon matrices --- */ |
| 90 | |
| 91 | static const octet mds[16] = { |
| 92 | 0x01, 0xef, 0x5b, 0x5b, |
| 93 | 0x5b, 0xef, 0xef, 0x01, |
| 94 | 0xef, 0x5b, 0x01, 0xef, |
| 95 | 0xef, 0x01, 0xef, 0x5b |
| 96 | }; |
| 97 | |
| 98 | static const octet rs[32] = { |
| 99 | 0x01, 0xa4, 0x55, 0x87, 0x5a, 0x58, 0xdb, 0x9e, |
| 100 | 0xa4, 0x56, 0x82, 0xf3, 0x1e, 0xc6, 0x68, 0xe5, |
| 101 | 0x02, 0xa1, 0xfc, 0xc1, 0x47, 0xae, 0x3d, 0x19, |
| 102 | 0xa4, 0x55, 0x87, 0x5a, 0x58, 0xdb, 0x9e, 0x03 |
| 103 | }; |
| 104 | |
| 105 | /*----- Magic macros ------------------------------------------------------*/ |
| 106 | |
| 107 | #define ROR4(x) ((((x) >> 1) | ((x) << 3)) & 15) |
| 108 | |
| 109 | /*----- Building and printing @q@ tables ----------------------------------*/ |
| 110 | |
| 111 | /* --- @mkq@ --- * |
| 112 | * |
| 113 | * Arguments: @q_tab *q@ = pointer to output @q@ table |
| 114 | * @const t_tab *t@ = pointer to input @t@ table |
| 115 | * @const char *name@ = name of @q@ table |
| 116 | * |
| 117 | * Returns: --- |
| 118 | * |
| 119 | * Use: Constructs a 256-entry @q@-table. |
| 120 | */ |
| 121 | |
| 122 | static void mkq(q_tab *q, const t_tab *t, const char *name) |
| 123 | { |
| 124 | int i; |
| 125 | int ok = 1; |
| 126 | |
| 127 | /* --- Ensure the t-table is well-formed --- */ |
| 128 | |
| 129 | for (i = 0; i < 4; i++) { |
| 130 | octet f[16] = { 0 }; |
| 131 | int j; |
| 132 | |
| 133 | for (j = 0; j < 16; j++) { |
| 134 | if (f[t->t[i][j]]) { |
| 135 | fprintf(stderr, "duplicate %i in %s[%i] (col %i and %i)\n", |
| 136 | t->t[i][j], name, i, j, f[t->t[i][j]]); |
| 137 | ok = 0; |
| 138 | } |
| 139 | f[t->t[i][j]] = j; |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | if (!ok) |
| 144 | exit(EXIT_FAILURE); |
| 145 | |
| 146 | /* --- Construct the @q@ table --- */ |
| 147 | |
| 148 | for (i = 0; i < 256; i++) { |
| 149 | int a = i >> 4, b = i & 15; |
| 150 | int aa = t->t[0][a ^ b], bb = t->t[1][a ^ ((a << 3) & 15) ^ ROR4(b)]; |
| 151 | a = t->t[2][aa ^ bb], b = t->t[3][aa ^ ((aa << 3) & 15) ^ ROR4(bb)]; |
| 152 | q->q[i] = a | (b << 4); |
| 153 | } |
| 154 | |
| 155 | /* Consider testing @q@ for linear and differential properties here */ |
| 156 | } |
| 157 | |
| 158 | /* --- @printq@ --- * |
| 159 | * |
| 160 | * Arguments: @const q_tab *t@ = pointer to table |
| 161 | * @const char *name@ = pointer to table name |
| 162 | * |
| 163 | * Returns: --- |
| 164 | * |
| 165 | * Use: Prints a q table. |
| 166 | */ |
| 167 | |
| 168 | static void printq(const q_tab *q, const char *name) |
| 169 | { |
| 170 | int i; |
| 171 | int j; |
| 172 | |
| 173 | printf("\ |
| 174 | #define TWOFISH_%s { \\\n\ |
| 175 | ", name); |
| 176 | j = 0; |
| 177 | for (i = 0; i < 256; i++) { |
| 178 | printf("0x%02x", q->q[i]); |
| 179 | j = (j + 1) & 7; |
| 180 | if (i == 255) |
| 181 | fputs(" \\\n}\n\n", stdout); |
| 182 | else if (j == 0) |
| 183 | fputs(", \\\n ", stdout); |
| 184 | else |
| 185 | fputs(", ", stdout); |
| 186 | } |
| 187 | } |
| 188 | |
| 189 | /*----- %$\gf{2^8}$% arithmetic -------------------------------------------*/ |
| 190 | |
| 191 | #define MDS_MOD 0x169 |
| 192 | #define RS_MOD 0x14d |
| 193 | |
| 194 | /* --- @mul@ --- * |
| 195 | * |
| 196 | * Arguments: @unsigned x, y@ = polynomials over %$\gf{2^8}$% |
| 197 | * @unsigned m@ = modulus |
| 198 | * |
| 199 | * Returns: The product of two polynomials. |
| 200 | * |
| 201 | * Use: Computes a product of polynomials, quite slowly. |
| 202 | */ |
| 203 | |
| 204 | static unsigned mul(unsigned x, unsigned y, unsigned m) |
| 205 | { |
| 206 | unsigned a = 0; |
| 207 | unsigned i; |
| 208 | |
| 209 | for (i = 0; i < 8; i++) { |
| 210 | if (y & 1) |
| 211 | a ^= x; |
| 212 | y >>= 1; |
| 213 | x <<= 1; |
| 214 | if (x & 0x100) |
| 215 | x ^= m; |
| 216 | } |
| 217 | |
| 218 | return (a); |
| 219 | } |
| 220 | |
| 221 | /* --- @mmul@ --- * |
| 222 | * |
| 223 | * Arguments: @octet *d@ = destination vector |
| 224 | * @const octet *p@ = matrix of bytes |
| 225 | * @const octet *q@ = vector from somewhere else |
| 226 | * @size_t r@ = size of destination or number of rows in matrix |
| 227 | * @size_t n@ = length of row and vector |
| 228 | * @unsigned m@ = modulus polynomial |
| 229 | * |
| 230 | * Returns: --- |
| 231 | * |
| 232 | * Use: Computes an inner product of matrices over the finite field |
| 233 | * %$\gf{2^8}[x]/(m(x))$%. This isn't particularly rapid. |
| 234 | */ |
| 235 | |
| 236 | static void mmul(octet *d, const octet *p, const octet *q, |
| 237 | size_t r, size_t n, unsigned m) |
| 238 | { |
| 239 | while (r) { |
| 240 | const octet *qq = q; |
| 241 | unsigned a = 0; |
| 242 | unsigned i; |
| 243 | |
| 244 | for (i = 0; i < n; i++) |
| 245 | a ^= mul(*p++, *qq++, m); |
| 246 | *d++ = a; |
| 247 | r--; |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | /* --- @qrds@ --- * |
| 252 | * |
| 253 | * Arguments: --- |
| 254 | * |
| 255 | * Returns: --- |
| 256 | * |
| 257 | * Use: Prints the MDS/q table. |
| 258 | */ |
| 259 | |
| 260 | static void qmds(void) |
| 261 | { |
| 262 | uint32 t[4][256]; |
| 263 | int i, j; |
| 264 | static const q_tab *q[4] = { &q1, &q0, &q1, &q0 }; |
| 265 | |
| 266 | for (i = 0; i < 4; i++) { |
| 267 | octet in[4] = { 0, 0, 0, 0 }; |
| 268 | octet out[4]; |
| 269 | |
| 270 | for (j = 0; j < 256; j++) { |
| 271 | in[i] = q[i]->q[j]; |
| 272 | mmul(out, mds, in, 4, 4, MDS_MOD); |
| 273 | t[i][j] = LOAD32_L(out); |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | puts("\ |
| 278 | /* --- Expanded MDS tables --- *\n\ |
| 279 | *\n\ |
| 280 | * The table contains output vectors for computing the result of pushing\n\ |
| 281 | * bytes through appropriate @q@ tables and the MDS matrix.\n\ |
| 282 | */\n\ |
| 283 | \n\ |
| 284 | #define TWOFISH_QMDS { \\"); |
| 285 | for (i = 0; i < 4; i++) { |
| 286 | fputs(" { ", stdout); |
| 287 | for (j = 0; j < 256; j++) { |
| 288 | printf("0x%08lx", (unsigned long)t[i][j]); |
| 289 | if (j == 255) { |
| 290 | if (i == 3) |
| 291 | puts(" } \\\n}"); |
| 292 | else |
| 293 | puts(" }, \\\n\ |
| 294 | \\"); |
| 295 | } else if (j % 4 == 3) |
| 296 | fputs(", \\\n ", stdout); |
| 297 | else |
| 298 | fputs(", ", stdout); |
| 299 | } |
| 300 | } |
| 301 | |
| 302 | putchar('\n'); |
| 303 | } |
| 304 | |
| 305 | /* --- @rslog@ --- * |
| 306 | * |
| 307 | * Arguments: --- |
| 308 | * |
| 309 | * Returns: --- |
| 310 | * |
| 311 | * Use: Produces the log and antilog tables for doing the RS |
| 312 | * arithmetic efficiently. |
| 313 | */ |
| 314 | |
| 315 | static void rslog(void) |
| 316 | { |
| 317 | octet rslog[256]; |
| 318 | octet rsexp[256]; |
| 319 | |
| 320 | unsigned x = 1; |
| 321 | unsigned i; |
| 322 | |
| 323 | rslog[0] = 0; |
| 324 | for (i = 0; i < 255; i++) { |
| 325 | rslog[x] = i; |
| 326 | rsexp[i] = x; |
| 327 | x <<= 1; |
| 328 | if (x & 0x100) |
| 329 | x ^= RS_MOD; |
| 330 | } |
| 331 | |
| 332 | x = 0; |
| 333 | for (i = 0; i < 32; i++) { |
| 334 | if (rslog[rs[i]] > x) |
| 335 | x = rslog[rs[i]]; |
| 336 | } |
| 337 | |
| 338 | fputs("\ |
| 339 | /* --- Reed-Solomon log tables --- *\n\ |
| 340 | *\n\ |
| 341 | * The Reed-Solomon multiplies are accelerated by using log tables.\n\ |
| 342 | */\n\ |
| 343 | \n\ |
| 344 | #define TWOFISH_RSLOG { \\\n\ |
| 345 | ", stdout); |
| 346 | |
| 347 | for (i = 0; i < 256; i++) { |
| 348 | printf("0x%02x", rslog[i]); |
| 349 | if (i == 255) |
| 350 | puts(" \\\n}\n"); |
| 351 | else if (i % 8 == 7) |
| 352 | fputs(", \\\n ", stdout); |
| 353 | else |
| 354 | fputs(", ", stdout); |
| 355 | } |
| 356 | |
| 357 | fputs("\ |
| 358 | #define TWOFISH_RSEXP { \\\n\ |
| 359 | ", stdout); |
| 360 | |
| 361 | for (i = 0; i < 255 + x + 1; i++) { |
| 362 | printf("0x%02x", rsexp[i % 255]); |
| 363 | if (i == 255 + x) |
| 364 | puts(" \\\n}\n"); |
| 365 | else if (i % 8 == 7) |
| 366 | fputs(", \\\n ", stdout); |
| 367 | else |
| 368 | fputs(", ", stdout); |
| 369 | } |
| 370 | |
| 371 | fputs("\ |
| 372 | /* --- Reed-Solomon matrix with log entries --- */\n\ |
| 373 | \n\ |
| 374 | #define TWOFISH_RS { \\\n\ |
| 375 | ", stdout); |
| 376 | |
| 377 | for (i = 0; i < 32; i++) { |
| 378 | printf("0x%02x", rslog[rs[i]]); |
| 379 | if (i == 31) |
| 380 | puts(" \\\n}\n"); |
| 381 | else if (i % 8 == 7) |
| 382 | fputs(", \\\n ", stdout); |
| 383 | else |
| 384 | fputs(", ", stdout); |
| 385 | } |
| 386 | } |
| 387 | |
| 388 | /*----- Main program ------------------------------------------------------*/ |
| 389 | |
| 390 | /* --- @main@ --- */ |
| 391 | |
| 392 | int main(void) |
| 393 | { |
| 394 | fputs("\ |
| 395 | /* -*-c-*-\n\ |
| 396 | *\n\ |
| 397 | * Twofish q tables [generated]\n\ |
| 398 | */\n\ |
| 399 | \n\ |
| 400 | #ifndef CATACOMB_TWOFISH_TAB_H\n\ |
| 401 | #define CATACOMB_TWOFISH_TAB_H\n\ |
| 402 | \n\ |
| 403 | ", stdout); |
| 404 | |
| 405 | /* --- The q tables --- */ |
| 406 | |
| 407 | puts("\ |
| 408 | /* --- Precomputed @q@ tables --- */\n\ |
| 409 | "); |
| 410 | mkq(&q0, &qt0, "qt0"); |
| 411 | mkq(&q1, &qt1, "qt1"); |
| 412 | printq(&q0, "Q0"); |
| 413 | printq(&q1, "Q1"); |
| 414 | |
| 415 | /* --- The MDS/q tables --- */ |
| 416 | |
| 417 | qmds(); |
| 418 | rslog(); |
| 419 | |
| 420 | /* --- Done --- */ |
| 421 | |
| 422 | puts("#endif"); |
| 423 | |
| 424 | if (fclose(stdout)) { |
| 425 | fprintf(stderr, "error writing data\n"); |
| 426 | exit(EXIT_FAILURE); |
| 427 | } |
| 428 | |
| 429 | return (0); |
| 430 | } |
| 431 | |
| 432 | /*----- That's all, folks -------------------------------------------------*/ |