| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: ecb-def.h,v 1.4 2004/04/17 09:58:37 mdw Exp $ |
| 4 | * |
| 5 | * Definitions electronic code book mode |
| 6 | * |
| 7 | * (c) 1999 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 | #ifndef CATACOMB_ECB_DEF_H |
| 31 | #define CATACOMB_ECB_DEF_H |
| 32 | |
| 33 | #ifdef __cplusplus |
| 34 | extern "C" { |
| 35 | #endif |
| 36 | |
| 37 | /*----- Header files ------------------------------------------------------*/ |
| 38 | |
| 39 | #include <assert.h> |
| 40 | #include <string.h> |
| 41 | |
| 42 | #include <mLib/bits.h> |
| 43 | #include <mLib/sub.h> |
| 44 | |
| 45 | #ifndef CATACOMB_ARENA_H |
| 46 | # include "arena.h" |
| 47 | #endif |
| 48 | |
| 49 | #ifndef CATACOMB_BLKC_H |
| 50 | # include "blkc.h" |
| 51 | #endif |
| 52 | |
| 53 | #ifndef CATACOMB_GCIPHER_H |
| 54 | # include "gcipher.h" |
| 55 | #endif |
| 56 | |
| 57 | #ifndef CATACOMB_PARANOIA_H |
| 58 | # include "paranoia.h" |
| 59 | #endif |
| 60 | |
| 61 | /*----- Macros ------------------------------------------------------------*/ |
| 62 | |
| 63 | /* --- @ECB_DEF@ --- * |
| 64 | * |
| 65 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher |
| 66 | * |
| 67 | * Use: Creates an implementation for ECB stealing mode. |
| 68 | */ |
| 69 | |
| 70 | #define ECB_DEF(PRE, pre) \ |
| 71 | \ |
| 72 | /* --- @pre_ecbsetkey@ --- * \ |
| 73 | * \ |
| 74 | * Arguments: @pre_ecbctx *ctx@ = pointer to ECB context block \ |
| 75 | * @const pre_ctx *k@ = pointer to cipher context \ |
| 76 | * \ |
| 77 | * Returns: --- \ |
| 78 | * \ |
| 79 | * Use: Sets the ECB context to use a different cipher key. \ |
| 80 | */ \ |
| 81 | \ |
| 82 | void pre##_ecbsetkey(pre##_ecbctx *ctx, const pre##_ctx *k) \ |
| 83 | { \ |
| 84 | ctx->ctx = *k; \ |
| 85 | } \ |
| 86 | \ |
| 87 | /* --- @pre_ecbinit@ --- * \ |
| 88 | * \ |
| 89 | * Arguments: @pre_ecbctx *ctx@ = pointer to cipher context \ |
| 90 | * @const void *key@ = pointer to the key buffer \ |
| 91 | * @size_t sz@ = size of the key \ |
| 92 | * @const void *iv@ = pointer to initialization vector \ |
| 93 | * \ |
| 94 | * Returns: --- \ |
| 95 | * \ |
| 96 | * Use: Initializes an ECB context ready for use. This is \ |
| 97 | * equivalent to calls to @pre_init@ and @pre_setkey@. \ |
| 98 | */ \ |
| 99 | \ |
| 100 | void pre##_ecbinit(pre##_ecbctx *ctx, \ |
| 101 | const void *key, size_t sz, \ |
| 102 | const void *iv) \ |
| 103 | { \ |
| 104 | pre##_init(&ctx->ctx, key, sz); \ |
| 105 | } \ |
| 106 | \ |
| 107 | /* --- @pre_ecbencrypt@ --- * \ |
| 108 | * \ |
| 109 | * Arguments: @pre_ecbctx *ctx@ = pointer to ECB context block \ |
| 110 | * @const void *src@ = pointer to source data \ |
| 111 | * @void *dest@ = pointer to destination data \ |
| 112 | * @size_t sz@ = size of block to be encrypted \ |
| 113 | * \ |
| 114 | * Returns: --- \ |
| 115 | * \ |
| 116 | * Use: Encrypts a block with a block cipher in ECB mode, with \ |
| 117 | * ciphertext stealing and other clever tricks. \ |
| 118 | * Essentially, data can be encrypted in arbitrary sized \ |
| 119 | * chunks, although decryption must use the same chunks. \ |
| 120 | */ \ |
| 121 | \ |
| 122 | void pre##_ecbencrypt(pre##_ecbctx *ctx, \ |
| 123 | const void *src, void *dest, \ |
| 124 | size_t sz) \ |
| 125 | { \ |
| 126 | const octet *s = src; \ |
| 127 | octet *d = dest; \ |
| 128 | \ |
| 129 | /* --- Empty blocks are trivial --- */ \ |
| 130 | \ |
| 131 | if (!sz) \ |
| 132 | return; \ |
| 133 | \ |
| 134 | /* --- Short blocks aren't allowed in ECB --- * \ |
| 135 | * \ |
| 136 | * There's absolutely nothing secure I can do with them. \ |
| 137 | */ \ |
| 138 | \ |
| 139 | assert(((void)"ECB must have at least one whole block to work with", \ |
| 140 | sz >= PRE##_BLKSZ)); \ |
| 141 | \ |
| 142 | /* --- Do the main chunk of encryption --- * \ |
| 143 | * \ |
| 144 | * This will do the whole lot if it's a whole number of blocks. Just \ |
| 145 | * give each block to the cipher in turn. This is trivial. \ |
| 146 | * Hopefully... \ |
| 147 | */ \ |
| 148 | \ |
| 149 | while (sz >= 2 * PRE##_BLKSZ || sz == PRE##_BLKSZ) { \ |
| 150 | uint32 x[PRE##_BLKSZ / 4]; \ |
| 151 | if (!s) \ |
| 152 | BLKC_ZERO(PRE, x); \ |
| 153 | else { \ |
| 154 | BLKC_LOAD(PRE, x, s); \ |
| 155 | s += PRE##_BLKSZ; \ |
| 156 | } \ |
| 157 | pre##_eblk(&ctx->ctx, x, x); \ |
| 158 | if (d) { \ |
| 159 | BLKC_STORE(PRE, d, x); \ |
| 160 | d += PRE##_BLKSZ; \ |
| 161 | } \ |
| 162 | sz -= PRE##_BLKSZ; \ |
| 163 | } \ |
| 164 | \ |
| 165 | /* --- Do the tail-end block and bit-left-over --- * \ |
| 166 | * \ |
| 167 | * This isn't very efficient. That shouldn't matter much. \ |
| 168 | */ \ |
| 169 | \ |
| 170 | if (sz) { \ |
| 171 | uint32 x[PRE##_BLKSZ / 4]; \ |
| 172 | octet b[PRE##_BLKSZ]; \ |
| 173 | unsigned i; \ |
| 174 | \ |
| 175 | /* --- Let @sz@ be the size of the partial block --- */ \ |
| 176 | \ |
| 177 | sz -= PRE##_BLKSZ; \ |
| 178 | \ |
| 179 | /* --- First stage --- * \ |
| 180 | * \ |
| 181 | * Read in the current block, and encrypt it. The first part of \ |
| 182 | * the result is the partial ciphertext block. Don't write that \ |
| 183 | * out yet, because I've not read the partial plaintext block. \ |
| 184 | */ \ |
| 185 | \ |
| 186 | if (!s) \ |
| 187 | BLKC_ZERO(PRE, x); \ |
| 188 | else { \ |
| 189 | BLKC_LOAD(PRE, x, s); \ |
| 190 | s += PRE##_BLKSZ; \ |
| 191 | } \ |
| 192 | pre##_eblk(&ctx->ctx, x, x); \ |
| 193 | BLKC_STORE(PRE, b, x); \ |
| 194 | \ |
| 195 | /* --- Second stage --- * \ |
| 196 | * \ |
| 197 | * Now move in the partial plaintext block, writing out the \ |
| 198 | * ciphertext as I go. Then encrypt, and write the complete \ |
| 199 | * ciphertext block. \ |
| 200 | */ \ |
| 201 | \ |
| 202 | if (d) d += PRE##_BLKSZ; \ |
| 203 | for (i = 0; i < sz; i++) { \ |
| 204 | register octet y = b[i]; \ |
| 205 | b[i] = s[i]; \ |
| 206 | if (d) d[i] = y; \ |
| 207 | } \ |
| 208 | BLKC_LOAD(PRE, x, b); \ |
| 209 | pre##_eblk(&ctx->ctx, x, x); \ |
| 210 | if (d) BLKC_STORE(PRE, d - PRE##_BLKSZ, x); \ |
| 211 | } \ |
| 212 | \ |
| 213 | /* --- Done --- */ \ |
| 214 | \ |
| 215 | return; \ |
| 216 | } \ |
| 217 | \ |
| 218 | /* --- @pre_ecbdecrypt@ --- * \ |
| 219 | * \ |
| 220 | * Arguments: @pre_ecbctx *ctx@ = pointer to ECB context block \ |
| 221 | * @const void *src@ = pointer to source data \ |
| 222 | * @void *dest@ = pointer to destination data \ |
| 223 | * @size_t sz@ = size of block to be encrypted \ |
| 224 | * \ |
| 225 | * Returns: --- \ |
| 226 | * \ |
| 227 | * Use: Decrypts a block with a block cipher in ECB mode, with \ |
| 228 | * ciphertext stealing and other clever tricks. \ |
| 229 | * Essentially, data can be encrypted in arbitrary sized \ |
| 230 | * chunks, although decryption must use the same chunks. \ |
| 231 | */ \ |
| 232 | \ |
| 233 | void pre##_ecbdecrypt(pre##_ecbctx *ctx, \ |
| 234 | const void *src, void *dest, \ |
| 235 | size_t sz) \ |
| 236 | { \ |
| 237 | const octet *s = src; \ |
| 238 | octet *d = dest; \ |
| 239 | \ |
| 240 | /* --- Empty blocks are trivial --- */ \ |
| 241 | \ |
| 242 | if (!sz) \ |
| 243 | return; \ |
| 244 | \ |
| 245 | /* --- Short blocks aren't allowed in ECB --- * \ |
| 246 | * \ |
| 247 | * There's absolutely nothing secure I can do with them. \ |
| 248 | */ \ |
| 249 | \ |
| 250 | assert(((void)"ECB must have at least one whole block to work with", \ |
| 251 | sz >= PRE##_BLKSZ)); \ |
| 252 | \ |
| 253 | /* --- Do the main chunk of decryption --- * \ |
| 254 | * \ |
| 255 | * This will do the whole lot if it's a whole number of blocks. \ |
| 256 | * Each block is just handed to the block cipher in turn. \ |
| 257 | */ \ |
| 258 | \ |
| 259 | while (sz >= 2 * PRE##_BLKSZ || sz == PRE##_BLKSZ) { \ |
| 260 | uint32 x[PRE##_BLKSZ / 4]; \ |
| 261 | BLKC_LOAD(PRE, x, s); \ |
| 262 | pre##_dblk(&ctx->ctx, x, x); \ |
| 263 | BLKC_STORE(PRE, d, x); \ |
| 264 | s += PRE##_BLKSZ; \ |
| 265 | d += PRE##_BLKSZ; \ |
| 266 | sz -= PRE##_BLKSZ; \ |
| 267 | } \ |
| 268 | \ |
| 269 | /* --- Do the tail-end block and bit-left-over --- * \ |
| 270 | * \ |
| 271 | * This isn't very efficient. That shouldn't matter much. \ |
| 272 | */ \ |
| 273 | \ |
| 274 | if (sz) { \ |
| 275 | uint32 x[PRE##_BLKSZ / 4]; \ |
| 276 | octet b[PRE##_BLKSZ]; \ |
| 277 | unsigned i; \ |
| 278 | \ |
| 279 | /* --- Let @sz@ be the size of the partial block --- */ \ |
| 280 | \ |
| 281 | sz -= PRE##_BLKSZ; \ |
| 282 | \ |
| 283 | /* --- First stage --- * \ |
| 284 | * \ |
| 285 | * Take the complete ciphertext block, and decrypt it. This block \ |
| 286 | * is carried over for the next encryption operation. \ |
| 287 | */ \ |
| 288 | \ |
| 289 | BLKC_LOAD(PRE, x, s); \ |
| 290 | pre##_dblk(&ctx->ctx, x, x); \ |
| 291 | BLKC_STORE(PRE, b, x); \ |
| 292 | \ |
| 293 | /* --- Second stage --- * \ |
| 294 | * \ |
| 295 | * The first few bytes are the partial plaintext block. Write that \ |
| 296 | * and replace with the partial ciphertext block. Then decrypt \ |
| 297 | * what's left as the complete plaintext. \ |
| 298 | */ \ |
| 299 | \ |
| 300 | s += PRE##_BLKSZ; \ |
| 301 | d += PRE##_BLKSZ; \ |
| 302 | for (i = 0; i < sz; i++) { \ |
| 303 | register octet y = s[i]; \ |
| 304 | d[i] = b[i]; \ |
| 305 | b[i] = y; \ |
| 306 | } \ |
| 307 | BLKC_LOAD(PRE, x, b); \ |
| 308 | pre##_dblk(&ctx->ctx, x, x); \ |
| 309 | BLKC_STORE(PRE, d - PRE##_BLKSZ, x); \ |
| 310 | } \ |
| 311 | \ |
| 312 | /* --- Done --- */ \ |
| 313 | \ |
| 314 | return; \ |
| 315 | } \ |
| 316 | \ |
| 317 | /* --- Generic cipher interface --- */ \ |
| 318 | \ |
| 319 | static const gcipher_ops gops; \ |
| 320 | \ |
| 321 | typedef struct gctx { \ |
| 322 | gcipher c; \ |
| 323 | pre##_ecbctx k; \ |
| 324 | } gctx; \ |
| 325 | \ |
| 326 | static gcipher *ginit(const void *k, size_t sz) \ |
| 327 | { \ |
| 328 | gctx *g = S_CREATE(gctx); \ |
| 329 | g->c.ops = &gops; \ |
| 330 | pre##_ecbinit(&g->k, k, sz, 0); \ |
| 331 | return (&g->c); \ |
| 332 | } \ |
| 333 | \ |
| 334 | static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \ |
| 335 | { \ |
| 336 | gctx *g = (gctx *)c; \ |
| 337 | pre##_ecbencrypt(&g->k, s, t, sz); \ |
| 338 | } \ |
| 339 | \ |
| 340 | static void gdecrypt(gcipher *c, const void *s, void *t, size_t sz) \ |
| 341 | { \ |
| 342 | gctx *g = (gctx *)c; \ |
| 343 | pre##_ecbdecrypt(&g->k, s, t, sz); \ |
| 344 | } \ |
| 345 | \ |
| 346 | static void gdestroy(gcipher *c) \ |
| 347 | { \ |
| 348 | gctx *g = (gctx *)c; \ |
| 349 | BURN(*g); \ |
| 350 | S_DESTROY(g); \ |
| 351 | } \ |
| 352 | \ |
| 353 | static const gcipher_ops gops = { \ |
| 354 | &pre##_ecb, \ |
| 355 | gencrypt, gdecrypt, gdestroy, 0, 0 \ |
| 356 | }; \ |
| 357 | \ |
| 358 | const gccipher pre##_ecb = { \ |
| 359 | #pre "-ecb", pre##_keysz, PRE##_BLKSZ, \ |
| 360 | ginit \ |
| 361 | }; \ |
| 362 | \ |
| 363 | ECB_TEST(PRE, pre) |
| 364 | |
| 365 | /*----- Test rig ----------------------------------------------------------*/ |
| 366 | |
| 367 | #ifdef TEST_RIG |
| 368 | |
| 369 | #include <stdio.h> |
| 370 | |
| 371 | #include "daftstory.h" |
| 372 | |
| 373 | /* --- @ECB_TEST@ --- * |
| 374 | * |
| 375 | * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions |
| 376 | * |
| 377 | * Use: Standard test rig for ECB functions. |
| 378 | */ |
| 379 | |
| 380 | #define ECB_TEST(PRE, pre) \ |
| 381 | \ |
| 382 | /* --- Initial plaintext for the test --- */ \ |
| 383 | \ |
| 384 | static const octet text[] = TEXT; \ |
| 385 | \ |
| 386 | /* --- Key and IV to use --- */ \ |
| 387 | \ |
| 388 | static const octet key[] = KEY; \ |
| 389 | static const octet iv[] = IV; \ |
| 390 | \ |
| 391 | /* --- Buffers for encryption and decryption output --- */ \ |
| 392 | \ |
| 393 | static octet ct[sizeof(text)]; \ |
| 394 | static octet pt[sizeof(text)]; \ |
| 395 | \ |
| 396 | static void hexdump(const octet *p, size_t sz) \ |
| 397 | { \ |
| 398 | const octet *q = p + sz; \ |
| 399 | for (sz = 0; p < q; p++, sz++) { \ |
| 400 | printf("%02x", *p); \ |
| 401 | if ((sz + 1) % PRE##_BLKSZ == 0) \ |
| 402 | putchar(':'); \ |
| 403 | } \ |
| 404 | } \ |
| 405 | \ |
| 406 | int main(void) \ |
| 407 | { \ |
| 408 | size_t sz = 0, rest; \ |
| 409 | pre##_ecbctx ctx; \ |
| 410 | int status = 0; \ |
| 411 | int done = 0; \ |
| 412 | \ |
| 413 | size_t keysz = PRE##_KEYSZ ? \ |
| 414 | PRE##_KEYSZ : strlen((const char *)key); \ |
| 415 | \ |
| 416 | fputs(#pre "-ecb: ", stdout); \ |
| 417 | \ |
| 418 | pre##_ecbinit(&ctx, key, keysz, iv); \ |
| 419 | \ |
| 420 | while (sz <= sizeof(text)) { \ |
| 421 | rest = sizeof(text) - sz; \ |
| 422 | if ((sz != 0 && sz < PRE##_BLKSZ) || \ |
| 423 | (rest != 0 && rest < PRE##_BLKSZ)) \ |
| 424 | goto next; \ |
| 425 | memcpy(ct, text, sizeof(text)); \ |
| 426 | pre##_ecbencrypt(&ctx, ct, ct, sz); \ |
| 427 | pre##_ecbencrypt(&ctx, ct + sz, ct + sz, rest); \ |
| 428 | memcpy(pt, ct, sizeof(text)); \ |
| 429 | pre##_ecbdecrypt(&ctx, pt, pt, sz); \ |
| 430 | pre##_ecbdecrypt(&ctx, pt + sz, pt + sz, rest); \ |
| 431 | if (memcmp(pt, text, sizeof(text)) == 0) { \ |
| 432 | done++; \ |
| 433 | if (sizeof(text) < 40 || done % 8 == 0) \ |
| 434 | fputc('.', stdout); \ |
| 435 | if (done % 480 == 0) \ |
| 436 | fputs("\n\t", stdout); \ |
| 437 | fflush(stdout); \ |
| 438 | } else { \ |
| 439 | printf("\nError (sz = %lu)\n", (unsigned long)sz); \ |
| 440 | status = 1; \ |
| 441 | printf("\tplaintext = "); hexdump(text, sz); \ |
| 442 | printf(", "); hexdump(text + sz, rest); \ |
| 443 | fputc('\n', stdout); \ |
| 444 | printf("\tciphertext = "); hexdump(ct, sz); \ |
| 445 | printf(", "); hexdump(ct + sz, rest); \ |
| 446 | fputc('\n', stdout); \ |
| 447 | printf("\trecovered text = "); hexdump(pt, sz); \ |
| 448 | printf(", "); hexdump(pt + sz, rest); \ |
| 449 | fputc('\n', stdout); \ |
| 450 | fputc('\n', stdout); \ |
| 451 | } \ |
| 452 | next: \ |
| 453 | if (sz < 63) \ |
| 454 | sz++; \ |
| 455 | else \ |
| 456 | sz += 9; \ |
| 457 | } \ |
| 458 | \ |
| 459 | fputs(status ? " failed\n" : " ok\n", stdout); \ |
| 460 | return (status); \ |
| 461 | } |
| 462 | |
| 463 | #else |
| 464 | # define ECB_TEST(PRE, pre) |
| 465 | #endif |
| 466 | |
| 467 | /*----- That's all, folks -------------------------------------------------*/ |
| 468 | |
| 469 | #ifdef __cplusplus |
| 470 | } |
| 471 | #endif |
| 472 | |
| 473 | #endif |