| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Definitions for the MGF-1 mask generator |
| 4 | * |
| 5 | * (c) 2000 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of Catacomb. |
| 11 | * |
| 12 | * Catacomb is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU Library General Public License as |
| 14 | * published by the Free Software Foundation; either version 2 of the |
| 15 | * License, or (at your option) any later version. |
| 16 | * |
| 17 | * Catacomb is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU Library General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU Library General Public |
| 23 | * License along with Catacomb; if not, write to the Free |
| 24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 25 | * MA 02111-1307, USA. |
| 26 | */ |
| 27 | |
| 28 | #ifndef CATACOMB_MGF_DEF_H |
| 29 | #define CATACOMB_MGF_DEF_H |
| 30 | |
| 31 | #ifdef __cplusplus |
| 32 | extern "C" { |
| 33 | #endif |
| 34 | |
| 35 | /*----- Header files ------------------------------------------------------*/ |
| 36 | |
| 37 | #include <stdarg.h> |
| 38 | #include <stdlib.h> |
| 39 | #include <string.h> |
| 40 | |
| 41 | #include <mLib/bits.h> |
| 42 | #include <mLib/sub.h> |
| 43 | |
| 44 | #ifndef CATACOMB_ARENA_H |
| 45 | # include "arena.h" |
| 46 | #endif |
| 47 | |
| 48 | #ifndef CATACOMB_GCIPHER_H |
| 49 | # include "gcipher.h" |
| 50 | #endif |
| 51 | |
| 52 | #ifndef CATACOMB_GRAND_H |
| 53 | # include "grand.h" |
| 54 | #endif |
| 55 | |
| 56 | #ifndef CATACOMB_PARANOIA_H |
| 57 | # include "paranoia.h" |
| 58 | #endif |
| 59 | |
| 60 | /*----- Macros ------------------------------------------------------------*/ |
| 61 | |
| 62 | #define MGF_DEF(PRE, pre) \ |
| 63 | \ |
| 64 | /* --- Useful constants --- */ \ |
| 65 | \ |
| 66 | const octet pre##_mgfkeysz[] = { KSZ_ANY, PRE##_HASHSZ }; \ |
| 67 | \ |
| 68 | /* --- @pre_mgfkeybegin@, @pre_mgfkeyadd@ --- * \ |
| 69 | * \ |
| 70 | * Arguments: @pre_mgfctx *k@ = pointer to context to initialize \ |
| 71 | * @const void *p@ = pointer to data to contribute \ |
| 72 | * \ |
| 73 | * Returns: --- \ |
| 74 | * \ |
| 75 | * Use: A multi-step keying procedure for initializing an MGF \ |
| 76 | * context. The data is contributed to a hashing context \ |
| 77 | * which is then used for mask generation. If you only \ |
| 78 | * have a fixed buffer, you can save a lot of effort by \ |
| 79 | * simply calling @pre_mgfinit@. \ |
| 80 | */ \ |
| 81 | \ |
| 82 | void pre##_mgfkeybegin(pre##_mgfctx *k) \ |
| 83 | { \ |
| 84 | k->c = 0; \ |
| 85 | k->bsz = 0; \ |
| 86 | pre##_init(&k->k); \ |
| 87 | } \ |
| 88 | \ |
| 89 | void pre##_mgfkeyadd(pre##_mgfctx *k, const void *p, size_t sz) \ |
| 90 | { \ |
| 91 | pre##_hash(&k->k, p, sz); \ |
| 92 | } \ |
| 93 | \ |
| 94 | /* ---- @pre_mgfinit@ --- * \ |
| 95 | * \ |
| 96 | * Arguments: @pre_mgfctx *k@ = pointer to context to initialize \ |
| 97 | * @const void *p@ = pointer to data to contribute \ |
| 98 | * @size_t sz@ = size of data to contribute \ |
| 99 | * \ |
| 100 | * Returns: --- \ |
| 101 | * \ |
| 102 | * Use: A simpler interface to initialization if all of your \ |
| 103 | * keying material is in one place. \ |
| 104 | */ \ |
| 105 | \ |
| 106 | void pre##_mgfinit(pre##_mgfctx *k, const void *p, size_t sz) \ |
| 107 | { \ |
| 108 | k->c = 0; \ |
| 109 | k->bsz = 0; \ |
| 110 | pre##_init(&k->k); \ |
| 111 | pre##_hash(&k->k, p, sz); \ |
| 112 | } \ |
| 113 | \ |
| 114 | /* --- @pre_mgfencrypt@ --- * \ |
| 115 | * \ |
| 116 | * Arguments: @pre_mgfctx *k@ = pointer to masking context \ |
| 117 | * @const void *s@ = pointer to source buffer \ |
| 118 | * @void *d@ = pointer to destination buffer \ |
| 119 | * @size_t sz@ = size of buffers \ |
| 120 | * \ |
| 121 | * Returns: --- \ |
| 122 | * \ |
| 123 | * Use: Outputs pseudorandom data, or masks an input buffer. \ |
| 124 | * \ |
| 125 | * If @s@ is nonzero, the source material is exclusive- \ |
| 126 | * orred with the generated mask. If @d@ is zero, the \ |
| 127 | * generator is simply spun around for a while, which \ |
| 128 | * isn't very useful. \ |
| 129 | */ \ |
| 130 | \ |
| 131 | void pre##_mgfencrypt(pre##_mgfctx *k, const void *s, \ |
| 132 | void *d, size_t sz) \ |
| 133 | { \ |
| 134 | const octet *ss = s; \ |
| 135 | octet *dd = d; \ |
| 136 | \ |
| 137 | /* --- Empty the buffer if there's anything there --- */ \ |
| 138 | \ |
| 139 | if (k->bsz) { \ |
| 140 | const octet *p = k->buf + PRE##_HASHSZ - k->bsz; \ |
| 141 | size_t n = sz > k->bsz ? k->bsz : sz; \ |
| 142 | sz -= n; \ |
| 143 | k->bsz -= n; \ |
| 144 | if (dd) { \ |
| 145 | if (!ss) { \ |
| 146 | memcpy(dd, p, n); \ |
| 147 | dd += n; \ |
| 148 | } else { \ |
| 149 | while (n) { \ |
| 150 | *dd++ = *ss++ ^ *p++; \ |
| 151 | n--; \ |
| 152 | } \ |
| 153 | } \ |
| 154 | } \ |
| 155 | } \ |
| 156 | \ |
| 157 | /* --- While necessary, generate some more mask --- */ \ |
| 158 | \ |
| 159 | while (sz) { \ |
| 160 | pre##_ctx c = k->k; /* Not quick! */ \ |
| 161 | size_t n; \ |
| 162 | \ |
| 163 | STORE32(k->buf, k->c); \ |
| 164 | k->c++; \ |
| 165 | pre##_hash(&c, k->buf, 4); \ |
| 166 | pre##_done(&c, k->buf); \ |
| 167 | n = sz > PRE##_HASHSZ ? PRE##_HASHSZ : sz; \ |
| 168 | k->bsz = PRE##_HASHSZ - n; \ |
| 169 | sz -= n; \ |
| 170 | if (dd) { \ |
| 171 | const octet *p = k->buf; \ |
| 172 | if (!ss) { \ |
| 173 | memcpy(dd, p, n); \ |
| 174 | dd += n; \ |
| 175 | } else { \ |
| 176 | while (n) { \ |
| 177 | *dd++ = *ss++ ^ *p++; \ |
| 178 | n--; \ |
| 179 | } \ |
| 180 | } \ |
| 181 | } \ |
| 182 | } \ |
| 183 | } \ |
| 184 | \ |
| 185 | /* --- @pre_mgfsetindex@ --- * \ |
| 186 | * \ |
| 187 | * Arguments: @pre_mgfctx *k@ = pointer to masking context \ |
| 188 | * @uint32 *c@ = new index to set \ |
| 189 | * \ |
| 190 | * Returns: --- \ |
| 191 | * \ |
| 192 | * Use: Sets a new index. This may be used to step around the \ |
| 193 | * output stream in a rather crude way. \ |
| 194 | */ \ |
| 195 | \ |
| 196 | void pre##_mgfsetindex(pre##_mgfctx *k, uint32 c) \ |
| 197 | { \ |
| 198 | k->c = c; \ |
| 199 | k->bsz = 0; \ |
| 200 | } \ |
| 201 | \ |
| 202 | /* --- Generic cipher interface --- */ \ |
| 203 | \ |
| 204 | static const gcipher_ops gops; \ |
| 205 | \ |
| 206 | typedef struct gctx { \ |
| 207 | gcipher c; \ |
| 208 | pre##_mgfctx k; \ |
| 209 | } gctx; \ |
| 210 | \ |
| 211 | static gcipher *ginit(const void *k, size_t sz) \ |
| 212 | { \ |
| 213 | gctx *g = S_CREATE(gctx); \ |
| 214 | g->c.ops = &gops; \ |
| 215 | pre##_mgfinit(&g->k, k, sz); \ |
| 216 | return (&g->c); \ |
| 217 | } \ |
| 218 | \ |
| 219 | static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \ |
| 220 | { \ |
| 221 | gctx *g = (gctx *)c; \ |
| 222 | pre##_mgfencrypt(&g->k, s, t, sz); \ |
| 223 | } \ |
| 224 | \ |
| 225 | static void gdestroy(gcipher *c) \ |
| 226 | { \ |
| 227 | gctx *g = (gctx *)c; \ |
| 228 | BURN(*g); \ |
| 229 | S_DESTROY(g); \ |
| 230 | } \ |
| 231 | \ |
| 232 | static const gcipher_ops gops = { \ |
| 233 | &pre##_mgf, \ |
| 234 | gencrypt, gencrypt, gdestroy, 0, 0 \ |
| 235 | }; \ |
| 236 | \ |
| 237 | const gccipher pre##_mgf = { \ |
| 238 | #pre "-mgf", pre##_mgfkeysz, 0, \ |
| 239 | ginit \ |
| 240 | }; \ |
| 241 | \ |
| 242 | /* --- Generic random number generator interface --- */ \ |
| 243 | \ |
| 244 | typedef struct grctx { \ |
| 245 | grand r; \ |
| 246 | pre##_mgfctx k; \ |
| 247 | } grctx; \ |
| 248 | \ |
| 249 | static void grdestroy(grand *r) \ |
| 250 | { \ |
| 251 | grctx *g = (grctx *)r; \ |
| 252 | BURN(*g); \ |
| 253 | S_DESTROY(g); \ |
| 254 | } \ |
| 255 | \ |
| 256 | static int grmisc(grand *r, unsigned op, ...) \ |
| 257 | { \ |
| 258 | grctx *g = (grctx *)r; \ |
| 259 | va_list ap; \ |
| 260 | int rc = 0; \ |
| 261 | va_start(ap, op); \ |
| 262 | \ |
| 263 | switch (op) { \ |
| 264 | case GRAND_CHECK: \ |
| 265 | switch (va_arg(ap, unsigned)) { \ |
| 266 | case GRAND_CHECK: \ |
| 267 | case GRAND_SEEDINT: \ |
| 268 | case GRAND_SEEDUINT32: \ |
| 269 | case GRAND_SEEDBLOCK: \ |
| 270 | case GRAND_SEEDRAND: \ |
| 271 | rc = 1; \ |
| 272 | break; \ |
| 273 | default: \ |
| 274 | rc = 0; \ |
| 275 | break; \ |
| 276 | } \ |
| 277 | break; \ |
| 278 | case GRAND_SEEDINT: \ |
| 279 | pre##_mgfsetindex(&g->k, va_arg(ap, unsigned)); \ |
| 280 | break; \ |
| 281 | case GRAND_SEEDUINT32: \ |
| 282 | pre##_mgfsetindex(&g->k, va_arg(ap, uint32)); \ |
| 283 | break; \ |
| 284 | case GRAND_SEEDBLOCK: { \ |
| 285 | const void *p = va_arg(ap, const void *); \ |
| 286 | size_t sz = va_arg(ap, size_t); \ |
| 287 | pre##_hash(&g->k.k, p, sz); \ |
| 288 | } break; \ |
| 289 | case GRAND_SEEDRAND: { \ |
| 290 | octet buf[PRE##_BUFSZ]; \ |
| 291 | grand *rr = va_arg(ap, grand *); \ |
| 292 | rr->ops->fill(rr, buf, sizeof(buf)); \ |
| 293 | pre##_hash(&g->k.k, buf, sizeof(buf)); \ |
| 294 | } break; \ |
| 295 | default: \ |
| 296 | GRAND_BADOP; \ |
| 297 | break; \ |
| 298 | } \ |
| 299 | \ |
| 300 | va_end(ap); \ |
| 301 | return (rc); \ |
| 302 | } \ |
| 303 | \ |
| 304 | static octet grbyte(grand *r) \ |
| 305 | { \ |
| 306 | grctx *g = (grctx *)r; \ |
| 307 | octet o; \ |
| 308 | pre##_mgfencrypt(&g->k, 0, &o, 1); \ |
| 309 | return (o); \ |
| 310 | } \ |
| 311 | \ |
| 312 | static uint32 grword(grand *r) \ |
| 313 | { \ |
| 314 | grctx *g = (grctx *)r; \ |
| 315 | octet b[4]; \ |
| 316 | pre##_mgfencrypt(&g->k, 0, b, sizeof(b)); \ |
| 317 | return (LOAD32(b)); \ |
| 318 | } \ |
| 319 | \ |
| 320 | static void grfill(grand *r, void *p, size_t sz) \ |
| 321 | { \ |
| 322 | grctx *g = (grctx *)r; \ |
| 323 | pre##_mgfencrypt(&g->k, 0, p, sz); \ |
| 324 | } \ |
| 325 | \ |
| 326 | static const grand_ops grops = { \ |
| 327 | #pre "-mgf", \ |
| 328 | GRAND_CRYPTO, 0, \ |
| 329 | grmisc, grdestroy, \ |
| 330 | grword, grbyte, grword, grand_range, grfill \ |
| 331 | }; \ |
| 332 | \ |
| 333 | /* --- @pre_mgfrand@ --- * \ |
| 334 | * \ |
| 335 | * Arguments: @const void *k@ = pointer to key material \ |
| 336 | * @size_t sz@ = size of key material \ |
| 337 | * \ |
| 338 | * Returns: Pointer to a generic random number generator instance. \ |
| 339 | * \ |
| 340 | * Use: Creates a random number interface wrapper around an \ |
| 341 | * MGF-1-mode hash function. \ |
| 342 | */ \ |
| 343 | \ |
| 344 | extern grand *pre##_mgfrand(const void *k, size_t sz) \ |
| 345 | { \ |
| 346 | grctx *g = S_CREATE(grctx); \ |
| 347 | g->r.ops = &grops; \ |
| 348 | pre##_mgfinit(&g->k, k, sz); \ |
| 349 | return (&g->r); \ |
| 350 | } \ |
| 351 | \ |
| 352 | MGF_TEST(PRE, pre) |
| 353 | |
| 354 | /*----- Test rig ----------------------------------------------------------*/ |
| 355 | |
| 356 | #ifdef TEST_RIG |
| 357 | |
| 358 | #include <stdio.h> |
| 359 | |
| 360 | #include "daftstory.h" |
| 361 | |
| 362 | /* --- @MGF_TEST@ --- * |
| 363 | * |
| 364 | * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions |
| 365 | * |
| 366 | * Use: Standard test rig for MGF functions. |
| 367 | */ |
| 368 | |
| 369 | #define MGF_TEST(PRE, pre) \ |
| 370 | \ |
| 371 | /* --- Initial plaintext for the test --- */ \ |
| 372 | \ |
| 373 | static const octet text[] = TEXT; \ |
| 374 | \ |
| 375 | /* --- Key and IV to use --- */ \ |
| 376 | \ |
| 377 | static const octet key[] = KEY; \ |
| 378 | \ |
| 379 | /* --- Buffers for encryption and decryption output --- */ \ |
| 380 | \ |
| 381 | static octet ct[sizeof(text)]; \ |
| 382 | static octet pt[sizeof(text)]; \ |
| 383 | \ |
| 384 | static void hexdump(const octet *p, size_t sz) \ |
| 385 | { \ |
| 386 | const octet *q = p + sz; \ |
| 387 | for (sz = 0; p < q; p++, sz++) { \ |
| 388 | printf("%02x", *p); \ |
| 389 | if ((sz + 1) % PRE##_HASHSZ == 0) \ |
| 390 | putchar(':'); \ |
| 391 | } \ |
| 392 | } \ |
| 393 | \ |
| 394 | int main(void) \ |
| 395 | { \ |
| 396 | size_t sz = 0, rest; \ |
| 397 | pre##_mgfctx ctx; \ |
| 398 | int status = 0; \ |
| 399 | int done = 0; \ |
| 400 | \ |
| 401 | size_t keysz = strlen((const char *)key); \ |
| 402 | \ |
| 403 | fputs(#pre "-mgf: ", stdout); \ |
| 404 | \ |
| 405 | pre##_mgfinit(&ctx, key, keysz); \ |
| 406 | \ |
| 407 | while (sz <= sizeof(text)) { \ |
| 408 | rest = sizeof(text) - sz; \ |
| 409 | memcpy(ct, text, sizeof(text)); \ |
| 410 | pre##_mgfsetindex(&ctx, 0); \ |
| 411 | pre##_mgfencrypt(&ctx, ct, ct, sz); \ |
| 412 | pre##_mgfencrypt(&ctx, ct + sz, ct + sz, rest); \ |
| 413 | memcpy(pt, ct, sizeof(text)); \ |
| 414 | pre##_mgfsetindex(&ctx, 0); \ |
| 415 | pre##_mgfencrypt(&ctx, pt, pt, rest); \ |
| 416 | pre##_mgfencrypt(&ctx, pt + rest, pt + rest, sz); \ |
| 417 | if (memcmp(pt, text, sizeof(text)) == 0) { \ |
| 418 | done++; \ |
| 419 | if (sizeof(text) < 40 || done % 8 == 0) \ |
| 420 | fputc('.', stdout); \ |
| 421 | if (done % 480 == 0) \ |
| 422 | fputs("\n\t", stdout); \ |
| 423 | fflush(stdout); \ |
| 424 | } else { \ |
| 425 | printf("\nError (sz = %lu)\n", (unsigned long)sz); \ |
| 426 | status = 1; \ |
| 427 | printf("\tplaintext = "); hexdump(text, sz); \ |
| 428 | printf(", "); hexdump(text + sz, rest); \ |
| 429 | fputc('\n', stdout); \ |
| 430 | printf("\tciphertext = "); hexdump(ct, sz); \ |
| 431 | printf(", "); hexdump(ct + sz, rest); \ |
| 432 | fputc('\n', stdout); \ |
| 433 | printf("\trecovered text = "); hexdump(pt, sz); \ |
| 434 | printf(", "); hexdump(pt + sz, rest); \ |
| 435 | fputc('\n', stdout); \ |
| 436 | fputc('\n', stdout); \ |
| 437 | } \ |
| 438 | if (sz < 63) \ |
| 439 | sz++; \ |
| 440 | else \ |
| 441 | sz += 9; \ |
| 442 | } \ |
| 443 | \ |
| 444 | fputs(status ? " failed\n" : " ok\n", stdout); \ |
| 445 | return (status); \ |
| 446 | } |
| 447 | |
| 448 | #else |
| 449 | # define MGF_TEST(PRE, pre) |
| 450 | #endif |
| 451 | |
| 452 | /*----- That's all, folks -------------------------------------------------*/ |
| 453 | |
| 454 | #ifdef __cplusplus |
| 455 | } |
| 456 | #endif |
| 457 | |
| 458 | #endif |