| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * The CMAC message-authentication code |
| 4 | * |
| 5 | * (c) 2017 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_CMAC_DEF_H |
| 29 | #define CATACOMB_CMAC_DEF_H |
| 30 | |
| 31 | #ifdef __cplusplus |
| 32 | extern "C" { |
| 33 | #endif |
| 34 | |
| 35 | /*----- Header files ------------------------------------------------------*/ |
| 36 | |
| 37 | #include <string.h> |
| 38 | |
| 39 | #include <mLib/bits.h> |
| 40 | #include <mLib/sub.h> |
| 41 | |
| 42 | #ifndef CATACOMB_ARENA_H |
| 43 | # include "arena.h" |
| 44 | #endif |
| 45 | |
| 46 | #ifndef CATACOMB_BLKC_H |
| 47 | # include "blkc.h" |
| 48 | #endif |
| 49 | |
| 50 | #ifndef CATACOMB_GMAC_H |
| 51 | # include "gmac.h" |
| 52 | #endif |
| 53 | |
| 54 | #ifndef CATACOMB_PARANOIA_H |
| 55 | # include "paranoia.h" |
| 56 | #endif |
| 57 | |
| 58 | #ifndef CATACOMB_RSVR_H |
| 59 | # include "rsvr.h" |
| 60 | #endif |
| 61 | |
| 62 | /*----- Low-level OMAC definitions ----------------------------------------*/ |
| 63 | |
| 64 | /* --- @OMAC_BLOCK@ --- * |
| 65 | * |
| 66 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher |
| 67 | * @pre_ctx *k@ = pointer to expanded blockcipher key |
| 68 | * @uint32 *a@ = accumulator state to update |
| 69 | * @octet *p@ = pointer to input block to accumulate |
| 70 | * |
| 71 | * Use: Update the state @a@ from the input block @p@. |
| 72 | */ |
| 73 | |
| 74 | #define OMAC_BLOCK(PRE, pre, k, a, p) do { \ |
| 75 | pre##_ctx *_k = (k); uint32 *_a = (a); const octet *_pp = (p); \ |
| 76 | BLKC_XLOAD(PRE, _a, _pp); pre##_eblk(_k, _a, _a); \ |
| 77 | } while (0) |
| 78 | |
| 79 | /* --- @OMAC_DEF@ --- * |
| 80 | * |
| 81 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher |
| 82 | * |
| 83 | * Use: Creates low-level implementation for the OMAC message- |
| 84 | * authentication mode. |
| 85 | */ |
| 86 | |
| 87 | #define OMAC_DEF(PRE, pre) \ |
| 88 | \ |
| 89 | /* Buffering policy for OMAC. */ \ |
| 90 | const rsvr_policy pre##_omacpolicy = \ |
| 91 | { RSVRF_FULL, PRE##_BLKSZ, PRE##_BLKSZ }; \ |
| 92 | \ |
| 93 | /* --- @pre_omacmasks@ --- * \ |
| 94 | * \ |
| 95 | * Arguments: @pre_ctx *k@ = pointer to expanded blockcipher key \ |
| 96 | * @uint32 *m0, *m1@ = buffers to store the masks \ |
| 97 | * \ |
| 98 | * Returns: --- \ |
| 99 | * \ |
| 100 | * Use: Initialize the OMAC masks. The mask buffers are \ |
| 101 | * @PRE_BLKSZ/4@ words long. The mmask @m0@ is applied to \ |
| 102 | * messages which are a whole number of blocks long; @m1@ \ |
| 103 | * is applied to messages with an incomplete final block, \ |
| 104 | * following the 10* padding. \ |
| 105 | */ \ |
| 106 | \ |
| 107 | void pre##_omacmasks(pre##_ctx *k, uint32 *m0, uint32 *m1) \ |
| 108 | { \ |
| 109 | uint32 t[PRE##_BLKSZ/4]; \ |
| 110 | \ |
| 111 | BLKC_ZERO(PRE, t); pre##_eblk(k, t, t); \ |
| 112 | BLKC_BLSHIFT(PRE, IRRED, m0, t); \ |
| 113 | BLKC_BLSHIFT(PRE, IRRED, m1, m0); \ |
| 114 | } \ |
| 115 | \ |
| 116 | /* --- @pre_omacdone@ --- * \ |
| 117 | * \ |
| 118 | * Arguments: @pre_ctx *k@ = pointer to expanded blockcipher key \ |
| 119 | * @const uint32 *m0, *m1@ = masks \ |
| 120 | * @uint32 *a@ = accumulator state to update \ |
| 121 | * @octet *p@ = pointer to input buffer (clobbered) \ |
| 122 | * @unsigned n@ = size of input buffer (no more than \ |
| 123 | * @PRE_BLKSZ@) \ |
| 124 | * \ |
| 125 | * Returns: --- \ |
| 126 | * \ |
| 127 | * Use: Update and finalize the OMAC hash state with the last \ |
| 128 | * few bytes of input. The final tag is left in @a@. \ |
| 129 | */ \ |
| 130 | \ |
| 131 | void pre##_omacdone(pre##_ctx *k, const uint32 *m0, const uint32 *m1, \ |
| 132 | uint32 *a, octet *p, unsigned n) \ |
| 133 | { \ |
| 134 | /* Do any necessary padding and apply the appropriate mask to the \ |
| 135 | * accumulator. \ |
| 136 | */ \ |
| 137 | if (n == PRE##_BLKSZ) \ |
| 138 | BLKC_XMOVE(PRE, a, m0); \ |
| 139 | else { \ |
| 140 | p[n] = 0x80; memset(p + n + 1, 0, PRE##_BLKSZ - n - 1); \ |
| 141 | BLKC_XMOVE(PRE, a, m1); \ |
| 142 | } \ |
| 143 | \ |
| 144 | /* Fetch the buffer contents and cycle the block cipher one last \ |
| 145 | * time. \ |
| 146 | */ \ |
| 147 | BLKC_XLOAD(PRE, a, p); \ |
| 148 | pre##_eblk(k, a, a); \ |
| 149 | } |
| 150 | |
| 151 | /*----- Properly cooked CMAC ----------------------------------------------*/ |
| 152 | |
| 153 | /* --- @CMAC_DEF@ --- * |
| 154 | * |
| 155 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher |
| 156 | * |
| 157 | * Use: Creates an implementation for the CMAC message-authentication |
| 158 | * mode. |
| 159 | */ |
| 160 | |
| 161 | #define CMAC_DEF(PRE, pre) CMAC_DEFX(PRE, pre, #pre, #pre) |
| 162 | |
| 163 | #define CMAC_DEFX(PRE, pre, name, fname) \ |
| 164 | \ |
| 165 | OMAC_DEF(PRE, pre) \ |
| 166 | \ |
| 167 | /* --- @pre_cmacsetkey@ --- * \ |
| 168 | * \ |
| 169 | * Arguments: @pre_cmackey *key@ = pointer to CMAC key block \ |
| 170 | * @ocnst void *k@ = pointer to key material \ |
| 171 | * @size_t ksz@ = size of key material \ |
| 172 | * \ |
| 173 | * Returns: --- \ |
| 174 | * \ |
| 175 | * Use: Initializes a CMAC key. This can be used for several \ |
| 176 | * MAC operations. \ |
| 177 | */ \ |
| 178 | \ |
| 179 | void pre##_cmacsetkey(pre##_cmackey *key, const void *k, size_t ksz) \ |
| 180 | { \ |
| 181 | pre##_init(&key->ctx, k, ksz); \ |
| 182 | pre##_omacmasks(&key->ctx, key->m0, key->m1); \ |
| 183 | } \ |
| 184 | \ |
| 185 | /* --- @pre##_cmacinit@ --- * \ |
| 186 | * \ |
| 187 | * Arguments: @pre_cmacctx *ctx@ = pointer to context block \ |
| 188 | * @pre_cmackey *k@ = key block \ |
| 189 | * \ |
| 190 | * Returns: --- \ |
| 191 | * \ |
| 192 | * Use: Initializes a CMAC context ready to process a message. \ |
| 193 | * It's not necessary to keep the key around. \ |
| 194 | */ \ |
| 195 | \ |
| 196 | void pre##_cmacinit(pre##_cmacctx *ctx, const pre##_cmackey *k) \ |
| 197 | { ctx->k = *k; ctx->off = 0; BLKC_ZERO(PRE, ctx->a); } \ |
| 198 | \ |
| 199 | /* --- @pre_cmachash@ --- * \ |
| 200 | * \ |
| 201 | * Arguments: @pre_cmacctx *ctx@ = pointer to CMAC context block \ |
| 202 | * @ocnst void *p@ = pointer to message buffer \ |
| 203 | * @size_t sz@ = size of message buffer \ |
| 204 | * \ |
| 205 | * Returns: --- \ |
| 206 | * \ |
| 207 | * Use: Hashes some input data. \ |
| 208 | */ \ |
| 209 | \ |
| 210 | void pre##_cmachash(pre##_cmacctx *ctx, const void *p, size_t sz) \ |
| 211 | { \ |
| 212 | rsvr_state st; \ |
| 213 | const octet *q; \ |
| 214 | \ |
| 215 | rsvr_setup(&st, &pre##_omacpolicy, ctx->b, &ctx->off, p, sz); \ |
| 216 | RSVR_DO(&st) while ((q = RSVR_NEXT(&st, PRE##_BLKSZ)) != 0) \ |
| 217 | OMAC_BLOCK(PRE, pre, &ctx->k.ctx, ctx->a, q); \ |
| 218 | } \ |
| 219 | \ |
| 220 | /* --- @pre_cmacdone@ --- * \ |
| 221 | * \ |
| 222 | * Arguments: @pre_cmacctx *ctx@ = pointer to CMAC context block \ |
| 223 | * @void *t@ = where to write the tag \ |
| 224 | * \ |
| 225 | * Returns: --- \ |
| 226 | * \ |
| 227 | * Use: Finishes a MAC operation and produces the tag. The \ |
| 228 | * context is clobbered and can't be used for anything \ |
| 229 | * useful any more. \ |
| 230 | */ \ |
| 231 | \ |
| 232 | void pre##_cmacdone(pre##_cmacctx *ctx, void *t) \ |
| 233 | { \ |
| 234 | pre##_omacdone(&ctx->k.ctx, ctx->k.m0, ctx->k.m1, \ |
| 235 | ctx->a, ctx->b, ctx->off); \ |
| 236 | BLKC_STORE(PRE, t, ctx->a); \ |
| 237 | } \ |
| 238 | \ |
| 239 | /* --- Generic MAC interface --- */ \ |
| 240 | \ |
| 241 | static const gmac_ops gkops; \ |
| 242 | static const ghash_ops gops; \ |
| 243 | \ |
| 244 | typedef struct gkctx { \ |
| 245 | gmac m; \ |
| 246 | pre##_cmackey k; \ |
| 247 | } gkctx; \ |
| 248 | \ |
| 249 | typedef struct gctx { \ |
| 250 | ghash h; \ |
| 251 | pre##_cmacctx c; \ |
| 252 | octet buf[PRE##_BLKSZ]; \ |
| 253 | } gctx; \ |
| 254 | \ |
| 255 | static ghash *gkinit(gmac *m) \ |
| 256 | { \ |
| 257 | gkctx *gk = (gkctx *)m; \ |
| 258 | gctx *g = S_CREATE(gctx); \ |
| 259 | g->h.ops = &gops; \ |
| 260 | pre##_cmacinit(&g->c, &gk->k); \ |
| 261 | return (&g->h); \ |
| 262 | } \ |
| 263 | \ |
| 264 | static gmac *gkey(const void *k, size_t sz) \ |
| 265 | { \ |
| 266 | gkctx *gk = S_CREATE(gkctx); \ |
| 267 | gk->m.ops = &gkops; \ |
| 268 | pre##_cmacsetkey(&gk->k, k, sz); \ |
| 269 | return (&gk->m); \ |
| 270 | } \ |
| 271 | \ |
| 272 | static void ghhash(ghash *h, const void *p, size_t sz) \ |
| 273 | { gctx *g = (gctx *)h; pre##_cmachash(&g->c, p, sz); } \ |
| 274 | \ |
| 275 | static octet *ghdone(ghash *h, void *buf) \ |
| 276 | { \ |
| 277 | gctx *g = (gctx *)h; \ |
| 278 | if (!buf) buf = g->buf; \ |
| 279 | pre##_cmacdone(&g->c, buf); \ |
| 280 | return (buf); \ |
| 281 | } \ |
| 282 | \ |
| 283 | static ghash *ghcopy(ghash *h) \ |
| 284 | { \ |
| 285 | gctx *g = (gctx *)h; \ |
| 286 | gctx *gg = S_CREATE(gctx); \ |
| 287 | memcpy(gg, g, sizeof(gctx)); \ |
| 288 | return (&gg->h); \ |
| 289 | } \ |
| 290 | \ |
| 291 | static void ghdestroy(ghash *h) \ |
| 292 | { gctx *g = (gctx *)h; BURN(*g); S_DESTROY(g); } \ |
| 293 | \ |
| 294 | static void gkdestroy(gmac *m) \ |
| 295 | { gkctx *gk = (gkctx *)m; BURN(*gk); S_DESTROY(gk); } \ |
| 296 | \ |
| 297 | static ghash *ghinit(void) \ |
| 298 | { \ |
| 299 | assert(((void)"Attempt to instantiate an unkeyed MAC", 0)); \ |
| 300 | return (0); \ |
| 301 | } \ |
| 302 | \ |
| 303 | const gcmac pre##_cmac = \ |
| 304 | { name "-cmac", PRE##_BLKSZ, pre##_keysz, gkey }; \ |
| 305 | static const gmac_ops gkops = { &pre##_cmac, gkinit, gkdestroy }; \ |
| 306 | static const gchash gch = { name "-cmac", PRE##_BLKSZ, ghinit }; \ |
| 307 | static const ghash_ops gops = \ |
| 308 | { &gch, ghhash, ghdone, ghdestroy, ghcopy }; \ |
| 309 | \ |
| 310 | CMAC_TESTX(PRE, pre, name, fname) |
| 311 | |
| 312 | #define CMAC_TEST(PRE, pre) HMAC_TESTX(PRE, pre, #pre, #pre) |
| 313 | |
| 314 | /* --- @CMAC_TEST@ --- * |
| 315 | * |
| 316 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher |
| 317 | * |
| 318 | * Use: Standard test rig for CMAC functions. |
| 319 | */ |
| 320 | |
| 321 | #ifdef TEST_RIG |
| 322 | |
| 323 | #include <stdio.h> |
| 324 | |
| 325 | #include <mLib/dstr.h> |
| 326 | #include <mLib/macros.h> |
| 327 | #include <mLib/quis.h> |
| 328 | #include <mLib/testrig.h> |
| 329 | |
| 330 | #define CMAC_TESTX(PRE, pre, name, fname) \ |
| 331 | \ |
| 332 | static int macverify(dstr *v) \ |
| 333 | { \ |
| 334 | pre##_cmacctx cctx; \ |
| 335 | pre##_cmackey ckey; \ |
| 336 | int ok = 1; \ |
| 337 | int i; \ |
| 338 | octet *p; \ |
| 339 | int szs[] = { 1, 7, 192, -1, 0 }, *ip; \ |
| 340 | size_t csz; \ |
| 341 | dstr d; \ |
| 342 | \ |
| 343 | dstr_create(&d); \ |
| 344 | dstr_ensure(&d, PRE##_BLKSZ); \ |
| 345 | d.len = PRE##_BLKSZ; \ |
| 346 | \ |
| 347 | pre##_cmacsetkey(&ckey, v[0].buf, v[0].len); \ |
| 348 | \ |
| 349 | for (ip = szs; *ip; ip++) { \ |
| 350 | i = *ip; \ |
| 351 | csz = v[1].len; \ |
| 352 | if (i == -1) \ |
| 353 | i = csz; \ |
| 354 | if (i > csz) \ |
| 355 | continue; \ |
| 356 | p = (octet *)v[1].buf; \ |
| 357 | pre##_cmacinit(&cctx, &ckey); \ |
| 358 | while (csz) { \ |
| 359 | if (i > csz) \ |
| 360 | i = csz; \ |
| 361 | pre##_cmachash(&cctx, p, i); \ |
| 362 | p += i; \ |
| 363 | csz -= i; \ |
| 364 | } \ |
| 365 | pre##_cmacdone(&cctx, d.buf); \ |
| 366 | if (MEMCMP(d.buf, !=, v[2].buf, PRE##_BLKSZ)) { \ |
| 367 | printf("\nfail:\n\tstep = %i\n\tkey = ", *ip); \ |
| 368 | type_hex.dump(&v[0], stdout); \ |
| 369 | fputs("\n\tinput = ", stdout); \ |
| 370 | type_hex.dump(&v[1], stdout); \ |
| 371 | fputs("\n\texpected = ", stdout); \ |
| 372 | type_hex.dump(&v[2], stdout); \ |
| 373 | fputs("\n\tcomputed = ", stdout); \ |
| 374 | type_hex.dump(&d, stdout); \ |
| 375 | putchar('\n'); \ |
| 376 | ok = 0; \ |
| 377 | } \ |
| 378 | } \ |
| 379 | \ |
| 380 | dstr_destroy(&d); \ |
| 381 | return (ok); \ |
| 382 | } \ |
| 383 | \ |
| 384 | static test_chunk macdefs[] = { \ |
| 385 | { name "-cmac", macverify, \ |
| 386 | { &type_hex, &type_hex, &type_hex, 0 } }, \ |
| 387 | { 0, 0, { 0 } } \ |
| 388 | }; \ |
| 389 | \ |
| 390 | int main(int argc, char *argv[]) \ |
| 391 | { \ |
| 392 | ego(argv[0]); \ |
| 393 | test_run(argc, argv, macdefs, SRCDIR"/t/" fname); \ |
| 394 | return (0); \ |
| 395 | } |
| 396 | |
| 397 | #else |
| 398 | # define CMAC_TESTX(PRE, pre, name, fname) |
| 399 | #endif |
| 400 | |
| 401 | /*----- That's all, folks -------------------------------------------------*/ |
| 402 | |
| 403 | #ifdef __cplusplus |
| 404 | } |
| 405 | #endif |
| 406 | |
| 407 | #endif |