| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: tlsprf.c,v 1.3 2004/04/08 01:36:15 mdw Exp $ |
| 4 | * |
| 5 | * The TLS pseudo-random function |
| 6 | * |
| 7 | * (c) 2001 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 | /*----- Header files ------------------------------------------------------*/ |
| 31 | |
| 32 | #include <mLib/alloc.h> |
| 33 | #include <mLib/dstr.h> |
| 34 | #include <mLib/sub.h> |
| 35 | |
| 36 | #include "arena.h" |
| 37 | #include "gmac.h" |
| 38 | #include "grand.h" |
| 39 | #include "paranoia.h" |
| 40 | #include "tlsprf.h" |
| 41 | |
| 42 | /*----- The data expansion function ---------------------------------------*/ |
| 43 | |
| 44 | /* --- @tlsdx_init@ --- * |
| 45 | * |
| 46 | * Arguments: @tlsdx_ctx *c@ = pointer to a context |
| 47 | * @gmac *m@ = pointer to a generic MAC instance |
| 48 | * @const void *sd@ = pointer to the seed block |
| 49 | * @size_t sdsz@ = size of the seed block |
| 50 | * |
| 51 | * Returns: --- |
| 52 | * |
| 53 | * Use: Initializes a context for the TLS data expansion function. |
| 54 | * This doesn't take ownership of the MAC instance or the seed |
| 55 | * memory, nor does it allocate copies. |
| 56 | */ |
| 57 | |
| 58 | void tlsdx_init(tlsdx_ctx *c, gmac *m, const void *sd, size_t sdsz) |
| 59 | { |
| 60 | c->k = m; |
| 61 | c->hashsz = GM_CLASS(c->k)->hashsz; |
| 62 | c->sd = sd; c->sdsz = sdsz; |
| 63 | |
| 64 | c->i = GM_INIT(c->k); |
| 65 | GH_HASH(c->i, sd, sdsz); |
| 66 | c->ai = GH_DONE(c->i, 0); |
| 67 | c->o = GM_INIT(c->k); |
| 68 | GH_HASH(c->o, c->ai, c->hashsz); |
| 69 | GH_HASH(c->o, sd, sdsz); |
| 70 | c->p = GH_DONE(c->o, 0); |
| 71 | c->sz = c->hashsz; |
| 72 | } |
| 73 | |
| 74 | /* --- @tlsdx_encrypt@ --- * |
| 75 | * |
| 76 | * Arguments: @tlsdx_ctx *c@ = pointer to a context |
| 77 | * @const void *src@ = pointer to source data |
| 78 | * @void *dest@ = pointer to destination buffer |
| 79 | * @size_t sz@ = size of buffer |
| 80 | * |
| 81 | * Returns: --- |
| 82 | * |
| 83 | * Use: Encrypts data using the TLS data expansion function. If the |
| 84 | * destination pointer is null, the generator is spun and no |
| 85 | * output is produced; if the source pointer is null, raw output |
| 86 | * from the generator is written; otherwise, the source data is |
| 87 | * XORed with the generator output. |
| 88 | */ |
| 89 | |
| 90 | void tlsdx_encrypt(tlsdx_ctx *c, const void *src, void *dest, size_t sz) |
| 91 | { |
| 92 | const octet *s = src; |
| 93 | octet *d = dest; |
| 94 | ghash *h; |
| 95 | size_t i; |
| 96 | size_t n; |
| 97 | |
| 98 | while (sz) { |
| 99 | if (c->sz) |
| 100 | n = c->sz; |
| 101 | else { |
| 102 | h = GM_INIT(c->k); |
| 103 | GH_HASH(h, c->ai, c->hashsz); |
| 104 | c->ai = GH_DONE(h, 0); |
| 105 | GH_DESTROY(c->i); |
| 106 | c->i = h; |
| 107 | GH_DESTROY(c->o); |
| 108 | h = c->o = GM_INIT(c->k); |
| 109 | GH_HASH(h, c->ai, c->hashsz); |
| 110 | GH_HASH(h, c->sd, c->sdsz); |
| 111 | c->p = GH_DONE(h, 0); |
| 112 | c->sz = n = c->hashsz; |
| 113 | } |
| 114 | if (n > sz) |
| 115 | n = sz; |
| 116 | if (d) { |
| 117 | if (!s) |
| 118 | memcpy(d, c->p, n); |
| 119 | else { |
| 120 | for (i = 0; i < n; i++) d[i] = s[i] ^ c->p[i]; |
| 121 | s += n; |
| 122 | } |
| 123 | d += n; |
| 124 | } |
| 125 | c->p += n; |
| 126 | c->sz -= n; |
| 127 | sz -= n; |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | /* --- @tlsdx_free@ --- * |
| 132 | * |
| 133 | * Arguments: @tlsdx_ctx *c@ = pointer to the context block |
| 134 | * |
| 135 | * Returns: --- |
| 136 | * |
| 137 | * Use: Frees a context for the TLS data expansion function |
| 138 | */ |
| 139 | |
| 140 | void tlsdx_free(tlsdx_ctx *c) |
| 141 | { |
| 142 | GH_DESTROY(c->i); |
| 143 | GH_DESTROY(c->o); |
| 144 | } |
| 145 | |
| 146 | /* --- Generic random number generator --- */ |
| 147 | |
| 148 | typedef struct dx_grctx { |
| 149 | grand r; |
| 150 | grand_ops ops; |
| 151 | tlsdx_ctx dx; |
| 152 | } dx_grctx; |
| 153 | |
| 154 | static void dx_grdestroy(grand *r) |
| 155 | { |
| 156 | dx_grctx *g = (dx_grctx *)r; |
| 157 | xfree((char *)g->ops.name); |
| 158 | xfree((octet *)g->dx.sd); |
| 159 | g->dx.k->ops->destroy(g->dx.k); |
| 160 | tlsdx_free(&g->dx); |
| 161 | BURN(*g); |
| 162 | S_DESTROY(g); |
| 163 | } |
| 164 | |
| 165 | static void dx_seed(dx_grctx *g, const void *p, size_t sz) |
| 166 | { |
| 167 | octet *q; |
| 168 | xfree((octet *)g->dx.sd); |
| 169 | g->dx.sd = q = xmalloc(sz); |
| 170 | memcpy(q, p, sz); |
| 171 | g->dx.sdsz = sz; |
| 172 | } |
| 173 | |
| 174 | static int dx_grmisc(grand *r, unsigned op, ...) |
| 175 | { |
| 176 | dx_grctx *g = (dx_grctx *)r; |
| 177 | va_list ap; |
| 178 | int rc = 0; |
| 179 | uint32 i; |
| 180 | octet buf[4]; |
| 181 | va_start(ap, op); |
| 182 | |
| 183 | switch (op) { |
| 184 | case GRAND_CHECK: |
| 185 | switch (va_arg(ap, unsigned)) { |
| 186 | case GRAND_CHECK: |
| 187 | case GRAND_SEEDINT: |
| 188 | case GRAND_SEEDUINT32: |
| 189 | case GRAND_SEEDBLOCK: |
| 190 | case GRAND_SEEDRAND: |
| 191 | rc = 1; |
| 192 | break; |
| 193 | default: |
| 194 | rc = 0; |
| 195 | break; |
| 196 | } |
| 197 | break; |
| 198 | case GRAND_SEEDINT: |
| 199 | i = va_arg(ap, unsigned); |
| 200 | STORE32(buf, i); |
| 201 | dx_seed(g, buf, sizeof(buf)); |
| 202 | break; |
| 203 | case GRAND_SEEDUINT32: |
| 204 | i = va_arg(ap, uint32); |
| 205 | STORE32(buf, i); |
| 206 | dx_seed(g, buf, sizeof(buf)); |
| 207 | break; |
| 208 | case GRAND_SEEDBLOCK: { |
| 209 | const void *p = va_arg(ap, const void *); |
| 210 | size_t sz = va_arg(ap, size_t); |
| 211 | dx_seed(g, p, sz); |
| 212 | } break; |
| 213 | case GRAND_SEEDRAND: { |
| 214 | grand *rr = va_arg(ap, grand *); |
| 215 | octet buf[16]; |
| 216 | rr->ops->fill(rr, buf, sizeof(buf)); |
| 217 | dx_seed(g, buf, sizeof(buf)); |
| 218 | } break; |
| 219 | default: |
| 220 | GRAND_BADOP; |
| 221 | break; |
| 222 | } |
| 223 | |
| 224 | va_end(ap); |
| 225 | return (rc); |
| 226 | } |
| 227 | |
| 228 | static octet dx_grbyte(grand *r) |
| 229 | { |
| 230 | dx_grctx *g = (dx_grctx *)r; |
| 231 | octet o; |
| 232 | tlsdx_encrypt(&g->dx, 0, &o, 1); |
| 233 | return (o); |
| 234 | } |
| 235 | |
| 236 | static uint32 dx_grword(grand *r) |
| 237 | { |
| 238 | dx_grctx *g = (dx_grctx *)r; |
| 239 | octet b[4]; |
| 240 | tlsdx_encrypt(&g->dx, 0, &b, sizeof(b)); |
| 241 | return (LOAD32(b)); |
| 242 | } |
| 243 | |
| 244 | static void dx_grfill(grand *r, void *p, size_t sz) |
| 245 | { |
| 246 | dx_grctx *g = (dx_grctx *)r; |
| 247 | tlsdx_encrypt(&g->dx, 0, p, sz); |
| 248 | } |
| 249 | |
| 250 | static const grand_ops dx_grops = { |
| 251 | "<tlsdx-dummy>", |
| 252 | GRAND_CRYPTO, 0, |
| 253 | dx_grmisc, dx_grdestroy, |
| 254 | dx_grword, dx_grbyte, dx_grword, grand_range, dx_grfill |
| 255 | }; |
| 256 | |
| 257 | /* ---@tlsdx_rand@ --- * |
| 258 | * |
| 259 | * Arguments: @const gcmac *mc@ = MAC function to use |
| 260 | * @const void *k@ = pointer to the key material |
| 261 | * @size_t ksz@ = size of the key material |
| 262 | * @const void *sd@ = pointer to the seed material |
| 263 | * @size_t sdsz@ = size of the seed material |
| 264 | * |
| 265 | * Returns: Pointer to generic random number generator interface. |
| 266 | * |
| 267 | * Use: Creates a generic generator which does TLS data expansion. |
| 268 | */ |
| 269 | |
| 270 | grand *tlsdx_rand(const gcmac *mc, const void *k, size_t ksz, |
| 271 | const void *sd, size_t sdsz) |
| 272 | { |
| 273 | dx_grctx *g = S_CREATE(dx_grctx); |
| 274 | dstr d = DSTR_INIT; |
| 275 | gmac *m = GM_KEY(mc, k, ksz); |
| 276 | octet *q = xmalloc(sdsz); |
| 277 | memcpy(q, sd, sdsz); |
| 278 | dstr_putf(&d, "tlsdx(%s)", mc->name); |
| 279 | g->ops = dx_grops; |
| 280 | g->ops.name = xstrdup(d.buf); |
| 281 | g->r.ops = &g->ops; |
| 282 | dstr_destroy(&d); |
| 283 | tlsdx_init(&g->dx, m, q, sdsz); |
| 284 | return (&g->r); |
| 285 | } |
| 286 | |
| 287 | /* --- The actual very paranoid PRF ---------------------------------------*/ |
| 288 | |
| 289 | /* --- @tlsprf_init@ --- * |
| 290 | * |
| 291 | * Arguments: @tlsprf_ctx *c@ = pointer to context block |
| 292 | * @const gcmac *mcx, *mcy@ = left and right MAC functions |
| 293 | * @const void *k@ = pointer to the key material |
| 294 | * @size_t ksz@ = size of the key material |
| 295 | * @const void *sd@ = pointer to the seed material |
| 296 | * @size_t sdsz@ = size of the seed material |
| 297 | * |
| 298 | * Returns: --- |
| 299 | * |
| 300 | * Use: Initializes a TLS PRF context. |
| 301 | */ |
| 302 | |
| 303 | void tlsprf_init(tlsprf_ctx *c, const gcmac *mcx, const gcmac *mcy, |
| 304 | const void *k, size_t ksz, const void *sd, size_t sdsz) |
| 305 | { |
| 306 | size_t n = (ksz + 1)/2; |
| 307 | const octet *kk = k; |
| 308 | tlsdx_init(&c->px, mcx->key(kk, n), sd, sdsz); |
| 309 | tlsdx_init(&c->py, mcy->key(kk + ksz - n, n), sd, sdsz); |
| 310 | } |
| 311 | |
| 312 | /* --- @tlsprf_encrypt@ --- * |
| 313 | * |
| 314 | * Arguments: @tlsprf_ctx *c@ = pointer to a context |
| 315 | * @const void *src@ = pointer to source data |
| 316 | * @void *dest@ = pointer to destination buffer |
| 317 | * @size_t sz@ = size of buffer |
| 318 | * |
| 319 | * Returns: --- |
| 320 | * |
| 321 | * Use: Encrypts data using the TLS pseudo-random function. If the |
| 322 | * destination pointer is null, the generator is spun and no |
| 323 | * output is produced; if the source pointer is null, raw output |
| 324 | * from the generator is written; otherwise, the source data is |
| 325 | * XORed with the generator output. |
| 326 | */ |
| 327 | |
| 328 | void tlsprf_encrypt(tlsprf_ctx *c, const void *src, void *dest, size_t sz) |
| 329 | { |
| 330 | tlsdx_encrypt(&c->px, src, dest, sz); |
| 331 | tlsdx_encrypt(&c->py, dest, dest, sz); |
| 332 | } |
| 333 | |
| 334 | /* --- @tlsprf_free@ --- * |
| 335 | * |
| 336 | * Arguments: @tlsprf_ctx *c@ = pointer to a context |
| 337 | * |
| 338 | * Returns: --- |
| 339 | * |
| 340 | * Use: Frees a TLS PRF context. |
| 341 | */ |
| 342 | |
| 343 | void tlsprf_free(tlsprf_ctx *c) |
| 344 | { |
| 345 | c->px.k->ops->destroy(c->px.k); |
| 346 | c->py.k->ops->destroy(c->py.k); |
| 347 | tlsdx_free(&c->px); |
| 348 | tlsdx_free(&c->py); |
| 349 | } |
| 350 | |
| 351 | /* --- Generic random number generator --- */ |
| 352 | |
| 353 | typedef struct prf_grctx { |
| 354 | grand r; |
| 355 | grand_ops ops; |
| 356 | tlsprf_ctx prf; |
| 357 | } prf_grctx; |
| 358 | |
| 359 | static void prf_grdestroy(grand *r) |
| 360 | { |
| 361 | prf_grctx *g = (prf_grctx *)r; |
| 362 | xfree((char *)g->ops.name); |
| 363 | xfree((octet *)g->prf.px.sd); |
| 364 | tlsprf_free(&g->prf); |
| 365 | BURN(*g); |
| 366 | S_DESTROY(g); |
| 367 | } |
| 368 | |
| 369 | static void prf_seed(prf_grctx *g, const void *p, size_t sz) |
| 370 | { |
| 371 | octet *q; |
| 372 | |
| 373 | xfree((octet *)g->prf.px.sz); |
| 374 | g->prf.px.sd = g->prf.py.sd = q = xmalloc(sz); |
| 375 | memcpy(q, p, sz); |
| 376 | g->prf.px.sdsz = g->prf.py.sdsz = sz; |
| 377 | } |
| 378 | |
| 379 | static int prf_grmisc(grand *r, unsigned op, ...) |
| 380 | { |
| 381 | prf_grctx *g = (prf_grctx *)r; |
| 382 | va_list ap; |
| 383 | int rc = 0; |
| 384 | uint32 i; |
| 385 | octet buf[4]; |
| 386 | va_start(ap, op); |
| 387 | |
| 388 | switch (op) { |
| 389 | case GRAND_CHECK: |
| 390 | switch (va_arg(ap, unsigned)) { |
| 391 | case GRAND_CHECK: |
| 392 | case GRAND_SEEDINT: |
| 393 | case GRAND_SEEDUINT32: |
| 394 | case GRAND_SEEDBLOCK: |
| 395 | case GRAND_SEEDRAND: |
| 396 | rc = 1; |
| 397 | break; |
| 398 | default: |
| 399 | rc = 0; |
| 400 | break; |
| 401 | } |
| 402 | break; |
| 403 | case GRAND_SEEDINT: |
| 404 | i = va_arg(ap, unsigned); |
| 405 | STORE32(buf, i); |
| 406 | prf_seed(g, buf, sizeof(buf)); |
| 407 | break; |
| 408 | case GRAND_SEEDUINT32: |
| 409 | i = va_arg(ap, uint32); |
| 410 | STORE32(buf, i); |
| 411 | prf_seed(g, buf, sizeof(buf)); |
| 412 | break; |
| 413 | case GRAND_SEEDBLOCK: { |
| 414 | const void *p = va_arg(ap, const void *); |
| 415 | size_t sz = va_arg(ap, size_t); |
| 416 | prf_seed(g, p, sz); |
| 417 | } break; |
| 418 | case GRAND_SEEDRAND: { |
| 419 | grand *rr = va_arg(ap, grand *); |
| 420 | octet buf[16]; |
| 421 | rr->ops->fill(rr, buf, sizeof(buf)); |
| 422 | prf_seed(g, buf, sizeof(buf)); |
| 423 | } break; |
| 424 | default: |
| 425 | GRAND_BADOP; |
| 426 | break; |
| 427 | } |
| 428 | |
| 429 | va_end(ap); |
| 430 | return (rc); |
| 431 | } |
| 432 | |
| 433 | static octet prf_grbyte(grand *r) |
| 434 | { |
| 435 | prf_grctx *g = (prf_grctx *)r; |
| 436 | octet o; |
| 437 | tlsprf_encrypt(&g->prf, 0, &o, 1); |
| 438 | return (o); |
| 439 | } |
| 440 | |
| 441 | static uint32 prf_grword(grand *r) |
| 442 | { |
| 443 | prf_grctx *g = (prf_grctx *)r; |
| 444 | octet b[4]; |
| 445 | tlsprf_encrypt(&g->prf, 0, &b, sizeof(b)); |
| 446 | return (LOAD32(b)); |
| 447 | } |
| 448 | |
| 449 | static void prf_grfill(grand *r, void *p, size_t sz) |
| 450 | { |
| 451 | prf_grctx *g = (prf_grctx *)r; |
| 452 | tlsprf_encrypt(&g->prf, 0, p, sz); |
| 453 | } |
| 454 | |
| 455 | static const grand_ops prf_grops = { |
| 456 | "<tlsprf-dummy>", |
| 457 | GRAND_CRYPTO, 0, |
| 458 | prf_grmisc, prf_grdestroy, |
| 459 | prf_grword, prf_grbyte, prf_grword, grand_range, prf_grfill |
| 460 | }; |
| 461 | |
| 462 | /* ---@tlsprf_rand@ --- * |
| 463 | * |
| 464 | * Arguments: @const gcmac *mcx, *mcy@ = MAC function to use |
| 465 | * @const void *k@ = pointer to the key material |
| 466 | * @size_t ksz@ = size of the key material |
| 467 | * @const void *sd@ = pointer to the seed material |
| 468 | * @size_t sdsz@ = size of the seed material |
| 469 | * |
| 470 | * Returns: Pointer to generic random number generator interface. |
| 471 | * |
| 472 | * Use: Creates a generic generator which does TLS data expansion. |
| 473 | */ |
| 474 | |
| 475 | grand *tlsprf_rand(const gcmac *mcx, const gcmac *mcy, |
| 476 | const void *k, size_t ksz, const void *sd, size_t sdsz) |
| 477 | { |
| 478 | prf_grctx *g = S_CREATE(prf_grctx); |
| 479 | dstr d = DSTR_INIT; |
| 480 | octet *q = xmalloc(sdsz); |
| 481 | memcpy(q, sd, sdsz); |
| 482 | dstr_putf(&d, "tlsprf(%s,%s)", mcx->name, mcy->name); |
| 483 | g->ops = prf_grops; |
| 484 | g->ops.name = xstrdup(d.buf); |
| 485 | g->r.ops = &g->ops; |
| 486 | dstr_destroy(&d); |
| 487 | tlsprf_init(&g->prf, mcx, mcy, k, ksz, q, sdsz); |
| 488 | return (&g->r); |
| 489 | } |
| 490 | |
| 491 | /*----- Test rig ----------------------------------------------------------*/ |
| 492 | |
| 493 | #ifdef TEST_RIG |
| 494 | |
| 495 | #include <stdio.h> |
| 496 | #include <string.h> |
| 497 | |
| 498 | #include <mLib/quis.h> |
| 499 | #include <mLib/testrig.h> |
| 500 | |
| 501 | #include "sha-hmac.h" |
| 502 | #include "md5-hmac.h" |
| 503 | |
| 504 | static int v_generate(dstr *v) |
| 505 | { |
| 506 | grand *g; |
| 507 | dstr d = DSTR_INIT; |
| 508 | int ok = 1; |
| 509 | |
| 510 | g = tlsprf_rand(&md5_hmac, &sha_hmac, |
| 511 | v[0].buf, v[0].len, v[1].buf, v[1].len); |
| 512 | dstr_ensure(&d, v[2].len); |
| 513 | d.len = v[2].len; |
| 514 | g->ops->fill(g, d.buf, d.len); |
| 515 | g->ops->destroy(g); |
| 516 | if (memcmp(v[2].buf, d.buf, d.len) != 0) { |
| 517 | ok = 0; |
| 518 | printf("\nfail tlsprf:" |
| 519 | "\n\tkey = "); |
| 520 | type_hex.dump(&v[0], stdout); |
| 521 | printf("\n\tseed = "); type_hex.dump(&v[1], stdout); |
| 522 | printf("\n\texpected = "); type_hex.dump(&v[2], stdout); |
| 523 | printf("\n\tcalculated = "); type_hex.dump(&d, stdout); |
| 524 | putchar('\n'); |
| 525 | } |
| 526 | return (ok); |
| 527 | } |
| 528 | |
| 529 | static test_chunk defs[] = { |
| 530 | { "tlsprf", v_generate, { &type_hex, &type_hex, &type_hex, 0 } }, |
| 531 | { 0, 0, { 0 } } |
| 532 | }; |
| 533 | |
| 534 | int main(int argc, char *argv[]) |
| 535 | { |
| 536 | test_run(argc, argv, defs, SRCDIR"/tests/tlsprf"); |
| 537 | return (0); |
| 538 | } |
| 539 | |
| 540 | #endif |
| 541 | |
| 542 | /*----- That's all, folks -------------------------------------------------*/ |