| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * The CCM authenticated-encryption mode |
| 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_CCM_DEF_H |
| 29 | #define CATACOMB_CCM_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_CT_H |
| 51 | # include "ct.h" |
| 52 | #endif |
| 53 | |
| 54 | #ifndef CATACOMB_KEYSZ_H |
| 55 | # include "keysz.h" |
| 56 | #endif |
| 57 | |
| 58 | #ifndef CATACOMB_PARANOIA_H |
| 59 | # include "paranoia.h" |
| 60 | #endif |
| 61 | |
| 62 | #ifndef CATACOMB_RSVR_H |
| 63 | # include "rsvr.h" |
| 64 | #endif |
| 65 | |
| 66 | /*----- Common machinery --------------------------------------------------*/ |
| 67 | |
| 68 | /* --- @ccm_check@ --- * |
| 69 | * |
| 70 | * Arguments: @const ccm_params *p@ = pointer to parameters |
| 71 | * |
| 72 | * Returns: True (nonzero) if the parameters are OK; false (zero) if |
| 73 | * there's a problem. |
| 74 | * |
| 75 | * Use: Verify that the CCM parameters are acceptable. |
| 76 | */ |
| 77 | |
| 78 | extern int ccm_check(const ccm_params */*p*/); |
| 79 | |
| 80 | /* --- @ccm_fmthdr@ --- * |
| 81 | * |
| 82 | * Arguments: @const ccm_params *p@ = pointer to parameters |
| 83 | * @octet *b@ = block-size buffer to write header |
| 84 | * @const void *n@ = pointer to nonce |
| 85 | * |
| 86 | * Returns: --- |
| 87 | * |
| 88 | * Use: Format a MAC header block. |
| 89 | */ |
| 90 | |
| 91 | extern void ccm_fmthdr(const ccm_params */*p*/, |
| 92 | octet */*b*/, const void */*n*/); |
| 93 | |
| 94 | /* --- @ccm_fmtctr@ --- * |
| 95 | * |
| 96 | * Arguments: @const ccm_params *p@ = pointer to parameters |
| 97 | * @octet *b@ = block-size buffer to write header |
| 98 | * @const void *n@ = pointer to nonce |
| 99 | * |
| 100 | * Returns: --- |
| 101 | * |
| 102 | * Use: Format an initial counter block. |
| 103 | */ |
| 104 | |
| 105 | extern void ccm_fmtctr(const ccm_params */*p*/, |
| 106 | octet */*b*/, const void */*n*/); |
| 107 | |
| 108 | /*----- Macros ------------------------------------------------------------*/ |
| 109 | |
| 110 | /* --- @CCM_DEF@ --- * |
| 111 | * |
| 112 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher |
| 113 | * |
| 114 | * Use: Creates an implementation for the CCM authenticated- |
| 115 | * encryption mode. |
| 116 | */ |
| 117 | |
| 118 | #define CCM_DEF(PRE, pre) CCM_DEFX(PRE, pre, #pre, #pre) |
| 119 | |
| 120 | #define CCM_DEFX(PRE, pre, name, fname) \ |
| 121 | \ |
| 122 | const octet pre##_ccmnoncesz[] = \ |
| 123 | { KSZ_RANGE, PRE##_BLKSZ/2 - (PRE##_BLKSZ <= 16 ? 1 : 2), \ |
| 124 | CCM_NSZMIN(PRE), CCM_NSZMAX(PRE), 1 }; \ |
| 125 | const octet pre##_ccmtagsz[] = \ |
| 126 | { KSZ_RANGE, CCM_TSZMAX(PRE), \ |
| 127 | CCM_TSZMIN(PRE), CCM_TSZMAX(PRE), PRE##_BLKSZ == 16 ? 2 : 1 }; \ |
| 128 | \ |
| 129 | static const rsvr_policy pre##_ccmpolicy = \ |
| 130 | { RSVRF_FULL, PRE##_BLKSZ, PRE##_BLKSZ }; \ |
| 131 | \ |
| 132 | /* --- @pre_ccminthash@ --- * \ |
| 133 | * \ |
| 134 | * Arguments: @pre_ccmctx *ctx@ = pointer to context block \ |
| 135 | * @const void *p@ = pointer to material to hash \ |
| 136 | * @size_t sz@ = size of the input buffer \ |
| 137 | * \ |
| 138 | * Returns: --- \ |
| 139 | * \ |
| 140 | * Use: Internal operation for feeding stuff into the CBC-MAC \ |
| 141 | * context. \ |
| 142 | */ \ |
| 143 | \ |
| 144 | static void pre##_ccminthash(pre##_ccmctx *ctx, \ |
| 145 | const void *p, size_t sz) \ |
| 146 | { \ |
| 147 | rsvr_state st; \ |
| 148 | const octet *q; \ |
| 149 | \ |
| 150 | rsvr_setup(&st, &pre##_ccmpolicy, ctx->b, &ctx->off, p, sz); \ |
| 151 | RSVR_DO(&st) while ((q = RSVR_NEXT(&st, PRE##_BLKSZ)) != 0) { \ |
| 152 | BLKC_XLOAD(PRE, ctx->a, q); \ |
| 153 | pre##_eblk(&ctx->k, ctx->a, ctx->a); \ |
| 154 | } \ |
| 155 | } \ |
| 156 | \ |
| 157 | /* --- @pre_ccminit@ --- * \ |
| 158 | * \ |
| 159 | * Arguments: @pre_ccmctx *aad@ = pointer to CCM context \ |
| 160 | * @const pre_ctx *k@ = pointer to key material \ |
| 161 | * @const void *n@ = pointer to nonce \ |
| 162 | * @size_t nsz@ = size of the nonce \ |
| 163 | * @size_t hsz@ = size of the AAD \ |
| 164 | * @size_t msz@ = size of the message/ciphertext \ |
| 165 | * @size_t tsz@ = size of the tag to produce \ |
| 166 | * \ |
| 167 | * Returns: Zero on success; nonzero if the parameters are invalid. \ |
| 168 | * \ |
| 169 | * Use: Initialize an CCM operation context with a given key. \ |
| 170 | * \ |
| 171 | * The original key needn't be kept around any more. \ |
| 172 | */ \ |
| 173 | \ |
| 174 | int pre##_ccminit(pre##_ccmctx *ctx, const pre##_ctx *k, \ |
| 175 | const void *n, size_t nsz, \ |
| 176 | size_t hsz, size_t msz, size_t tsz) \ |
| 177 | { ctx->k = *k; return (pre##_ccmreinit(ctx, n, nsz, hsz, msz, tsz)); } \ |
| 178 | \ |
| 179 | /* --- @pre_ccmreinit@ --- * \ |
| 180 | * \ |
| 181 | * Arguments: @pre_ccmctx *ctx@ = pointer to CCM context \ |
| 182 | * @const void *n@ = pointer to nonce \ |
| 183 | * @size_t nsz@ = size of nonce \ |
| 184 | * @size_t hsz@ = size of the AAD \ |
| 185 | * @size_t msz@ = size of the message/ciphertext \ |
| 186 | * @size_t tsz@ = size of the tag to produce \ |
| 187 | * \ |
| 188 | * Returns: Zero on success; nonzero if the parameters are invalid. \ |
| 189 | * \ |
| 190 | * Use: Reinitialize an CCM operation context, changing the \ |
| 191 | * nonce. \ |
| 192 | */ \ |
| 193 | \ |
| 194 | int pre##_ccmreinit(pre##_ccmctx *ctx, const void *n, size_t nsz, \ |
| 195 | size_t hsz, size_t msz, size_t tsz) \ |
| 196 | { \ |
| 197 | kludge64 t; \ |
| 198 | octet b[12]; \ |
| 199 | size_t sz; \ |
| 200 | \ |
| 201 | /* Set up the parameters and check that they make sense. */ \ |
| 202 | ctx->p.hsz = hsz; ctx->p.msz = msz; \ |
| 203 | ctx->p.bsz = PRE##_BLKSZ; ctx->p.nsz = nsz; ctx->p.tsz = tsz; \ |
| 204 | if (!ccm_check(&ctx->p)) return (-1); \ |
| 205 | \ |
| 206 | /* Prepare the counter and the final MAC mask. The initial counter \ |
| 207 | * is used to make the MAC mask, so generate that, keeping it for \ |
| 208 | * later. \ |
| 209 | */ \ |
| 210 | ccm_fmtctr(&ctx->p, ctx->b, n); \ |
| 211 | BLKC_LOAD(PRE, ctx->c, ctx->b); \ |
| 212 | pre##_eblk(&ctx->k, ctx->c, ctx->s0); \ |
| 213 | \ |
| 214 | /* Prepare the MAC header and leave it in the buffer. */ \ |
| 215 | ccm_fmthdr(&ctx->p, ctx->b, n); \ |
| 216 | BLKC_ZERO(PRE, ctx->a); \ |
| 217 | \ |
| 218 | /* Initialize our state. The buffer is currently full (with the \ |
| 219 | * MAC header), and we're always awaiting AAD, though we've not yet \ |
| 220 | * seen any. (Even if we're not expecting AAD, this will trigger \ |
| 221 | * appropriate initialization when encryption or decryption begins.) \ |
| 222 | */ \ |
| 223 | ctx->off = PRE##_BLKSZ; ctx->i = 0; \ |
| 224 | ctx->st = CCMST_AAD; \ |
| 225 | \ |
| 226 | /* If there's AAD to come, then do the AAD framing. This aligns \ |
| 227 | * badly with the blocking, so feed the framing in the hard way. \ |
| 228 | */ \ |
| 229 | if (hsz) { \ |
| 230 | if (hsz < 0xfffe) \ |
| 231 | { STORE16(b, hsz); sz = 2; } \ |
| 232 | else if (hsz <= MASK32) \ |
| 233 | { b[0] = 0xff; b[1] = 0xfe; STORE32(b + 2, hsz); sz = 6; } \ |
| 234 | else { \ |
| 235 | b[0] = b[1] = 0xff; \ |
| 236 | ASSIGN64(t, hsz); STORE64_(b + 2, t); \ |
| 237 | sz = 10; \ |
| 238 | } \ |
| 239 | pre##_ccminthash(ctx, b, sz); \ |
| 240 | } \ |
| 241 | \ |
| 242 | /* All done. */ \ |
| 243 | return (0); \ |
| 244 | } \ |
| 245 | \ |
| 246 | /* --- @pre_ccmaadhash@ --- * \ |
| 247 | * \ |
| 248 | * Arguments: @pre_ccmctx *ctx@ = pointer to AAD context \ |
| 249 | * @const void *p@ = pointer to AAD material \ |
| 250 | * @size_t sz@ = length of AAD material \ |
| 251 | * \ |
| 252 | * Returns: --- \ |
| 253 | * \ |
| 254 | * Use: Feeds AAD into the context. This must be done before \ |
| 255 | * any of the message/ciphertext is processed because CCM \ |
| 256 | * is really annoying like that. \ |
| 257 | */ \ |
| 258 | \ |
| 259 | void pre##_ccmaadhash(pre##_ccmctx *ctx, const void *p, size_t sz) \ |
| 260 | { \ |
| 261 | assert(ctx->st == CCMST_AAD); \ |
| 262 | assert(sz <= ctx->p.hsz - ctx->i); \ |
| 263 | ctx->i += sz; \ |
| 264 | pre##_ccminthash(ctx, p, sz); \ |
| 265 | } \ |
| 266 | \ |
| 267 | /* --- @pre_ccmencdecsetup@ --- * \ |
| 268 | * \ |
| 269 | * Arguments: @pre_ccmctx *ctx@ = pointer to context block \ |
| 270 | * @size_t sz@ = size of message block \ |
| 271 | * \ |
| 272 | * Returns: --- \ |
| 273 | * \ |
| 274 | * Use: Prepares for an encrypt or decryption operation, \ |
| 275 | * transitioning from the AAD state and updating the \ |
| 276 | * message size. \ |
| 277 | */ \ |
| 278 | \ |
| 279 | static void pre##_ccmencdecsetup(pre##_ccmctx *ctx, size_t sz) \ |
| 280 | { \ |
| 281 | if (ctx->st != CCMST_MSG) { \ |
| 282 | /* Make sure we're currently in the AAD state and we've seen all of \ |
| 283 | * the AAD we expected. \ |
| 284 | */ \ |
| 285 | assert(ctx->st == CCMST_AAD); \ |
| 286 | assert(ctx->i == ctx->p.hsz); \ |
| 287 | \ |
| 288 | /* Pad the final AAD block out until we hit a block boundary. Note \ |
| 289 | * that we don't cycle the block cipher here: instead, leave the \ |
| 290 | * buffer full so that we do that next time. \ |
| 291 | */ \ |
| 292 | memset(ctx->b + ctx->off, 0, PRE##_BLKSZ - ctx->off); \ |
| 293 | ctx->off = PRE##_BLKSZ; \ |
| 294 | \ |
| 295 | /* Now we're ready to process the message text. */ \ |
| 296 | ctx->st = CCMST_MSG; ctx->i = 0; \ |
| 297 | } \ |
| 298 | \ |
| 299 | /* Update the size. */ \ |
| 300 | assert(sz <= ctx->p.msz - ctx->i); \ |
| 301 | ctx->i += sz; \ |
| 302 | } \ |
| 303 | \ |
| 304 | /* --- @pre_ccmencrypt@ --- * \ |
| 305 | * \ |
| 306 | * Arguments: @pre_ccmctx *ctx@ = pointer to CCM operation context \ |
| 307 | * @const void *src@ = pointer to plaintext message chunk \ |
| 308 | * @size_t sz@ = size of the plaintext \ |
| 309 | * @buf *dst@ = a buffer to write the ciphertext to \ |
| 310 | * \ |
| 311 | * Returns: Zero on success; @-1@ on failure. \ |
| 312 | * \ |
| 313 | * Use: Encrypts a chunk of a plaintext message, writing a \ |
| 314 | * chunk of ciphertext to the output buffer and updating \ |
| 315 | * the operation state. \ |
| 316 | * \ |
| 317 | * For CCM, we always write a ciphertext chunk the same \ |
| 318 | * size as the plaintext. The messing about with @buf@ \ |
| 319 | * objects makes the interface consistent with other AEAD \ |
| 320 | * schemes which can't do this. \ |
| 321 | */ \ |
| 322 | \ |
| 323 | int pre##_ccmencrypt(pre##_ccmctx *ctx, \ |
| 324 | const void *src, size_t sz, buf *dst) \ |
| 325 | { \ |
| 326 | rsvr_plan plan; \ |
| 327 | uint32 t[PRE##_BLKSZ/4], u[PRE##_BLKSZ]; \ |
| 328 | const octet *p = src; \ |
| 329 | octet *q, *r, y; \ |
| 330 | \ |
| 331 | /* Allocate space for the ciphertext. */ \ |
| 332 | if (sz) { q = buf_get(dst, sz); if (!q) return (-1); } \ |
| 333 | else q = 0; \ |
| 334 | \ |
| 335 | /* Set stuff up. */ \ |
| 336 | pre##_ccmencdecsetup(ctx, sz); \ |
| 337 | \ |
| 338 | /* Determine the buffering plan. Our buffer is going to do double- \ |
| 339 | * duty here. The end portion is going to contain mask from the \ |
| 340 | * encrypted counter which we mix into the plaintext to encrypt it; \ |
| 341 | * the start portion, which originally mask bytes we've already used, \ |
| 342 | * will hold the input plaintext, which will eventually be \ |
| 343 | * collected into the CBC-MAC state. \ |
| 344 | */ \ |
| 345 | rsvr_mkplan(&plan, &pre##_ccmpolicy, ctx->off, sz); \ |
| 346 | \ |
| 347 | /* Initial portion, fulfilled from the buffer. If the buffer is \ |
| 348 | * empty, then that means that we haven't yet encrypted the current \ |
| 349 | * counter, so we should do that and advance it. \ |
| 350 | */ \ |
| 351 | if (plan.head) { \ |
| 352 | if (!ctx->off) { \ |
| 353 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ |
| 354 | BLKC_STORE(PRE, ctx->b, t); \ |
| 355 | } \ |
| 356 | r = ctx->b + ctx->off; ctx->off += plan.head; \ |
| 357 | while (plan.head--) { y = *p++; *q++ = y ^ *r; *r++ = y; } \ |
| 358 | } \ |
| 359 | \ |
| 360 | /* If we've filled up the buffer then we need to cycle the MAC and \ |
| 361 | * reset the offset. \ |
| 362 | */ \ |
| 363 | if (plan.from_rsvr) { \ |
| 364 | BLKC_XLOAD(PRE, ctx->a, ctx->b); \ |
| 365 | pre##_eblk(&ctx->k, ctx->a, ctx->a); \ |
| 366 | ctx->off = 0; \ |
| 367 | } \ |
| 368 | \ |
| 369 | /* Now to process the main body of the input. */ \ |
| 370 | while (plan.from_input) { \ |
| 371 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ |
| 372 | BLKC_LOAD(PRE, u, p); p += PRE##_BLKSZ; \ |
| 373 | BLKC_XSTORE(PRE, q, t, u); q += PRE##_BLKSZ; \ |
| 374 | BLKC_XMOVE(PRE, ctx->a, u); pre##_eblk(&ctx->k, ctx->a, ctx->a); \ |
| 375 | plan.from_input -= PRE##_BLKSZ; \ |
| 376 | } \ |
| 377 | \ |
| 378 | /* Finally, deal with any final portion. If there is one, we know \ |
| 379 | * that the buffer is empty: we must have filled it above, or this \ |
| 380 | * would all count as `initial' data. \ |
| 381 | */ \ |
| 382 | if (plan.tail) { \ |
| 383 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ |
| 384 | BLKC_STORE(PRE, ctx->b, t); \ |
| 385 | r = ctx->b; ctx->off = plan.tail; \ |
| 386 | while (plan.tail--) { y = *p++; *q++ = y ^ *r; *r++ = y; } \ |
| 387 | } \ |
| 388 | \ |
| 389 | /* Done. */ \ |
| 390 | return (0); \ |
| 391 | } \ |
| 392 | \ |
| 393 | /* --- @pre_ccmdecrypt@ --- * \ |
| 394 | * \ |
| 395 | * Arguments: @pre_ccmctx *ctx@ = pointer to CCM operation context \ |
| 396 | * @const void *src@ = pointer to ciphertext message chunk \ |
| 397 | * @size_t sz@ = size of the ciphertext \ |
| 398 | * @buf *dst@ = a buffer to write the plaintext to \ |
| 399 | * \ |
| 400 | * Returns: Zero on success; @-1@ on failure. \ |
| 401 | * \ |
| 402 | * Use: Decrypts a chunk of a ciphertext message, writing a \ |
| 403 | * chunk of plaintext to the output buffer and updating \ |
| 404 | * the operation state. \ |
| 405 | * \ |
| 406 | * For CCM, we always write a plaintext chunk the same \ |
| 407 | * size as the ciphertext. The messing about with @buf@ \ |
| 408 | * objects makes the interface consistent with other AEAD \ |
| 409 | * schemes which can't do this. \ |
| 410 | */ \ |
| 411 | \ |
| 412 | int pre##_ccmdecrypt(pre##_ccmctx *ctx, \ |
| 413 | const void *src, size_t sz, buf *dst) \ |
| 414 | { \ |
| 415 | rsvr_plan plan; \ |
| 416 | uint32 t[PRE##_BLKSZ/4]; \ |
| 417 | const octet *p = src; \ |
| 418 | octet *q, *r, y; \ |
| 419 | \ |
| 420 | /* Allocate space for the plaintext. */ \ |
| 421 | if (sz) { q = buf_get(dst, sz); if (!q) return (-1); } \ |
| 422 | else q = 0; \ |
| 423 | \ |
| 424 | /* Set stuff up. */ \ |
| 425 | pre##_ccmencdecsetup(ctx, sz); \ |
| 426 | \ |
| 427 | /* Determine the buffering plan. Our buffer is going to do double- \ |
| 428 | * duty here. The end portion is going to contain mask from the \ |
| 429 | * encrypted counter which we mix into the plaintext to encrypt it; \ |
| 430 | * the start portion, which originally mask bytes we've already used, \ |
| 431 | * will hold the recovered plaintext, which will eventually be \ |
| 432 | * collected into the CBC-MAC state. \ |
| 433 | */ \ |
| 434 | rsvr_mkplan(&plan, &pre##_ccmpolicy, ctx->off, sz); \ |
| 435 | \ |
| 436 | /* Initial portion, fulfilled from the buffer. If the buffer is \ |
| 437 | * empty, then that means that we haven't yet encrypted the current \ |
| 438 | * counter, so we should do that and advance it. \ |
| 439 | */ \ |
| 440 | if (plan.head) { \ |
| 441 | if (!ctx->off) { \ |
| 442 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ |
| 443 | BLKC_STORE(PRE, ctx->b, t); \ |
| 444 | } \ |
| 445 | r = ctx->b + ctx->off; ctx->off += plan.head; \ |
| 446 | while (plan.head--) { y = *p++ ^ *r; *q++ = *r++ = y; } \ |
| 447 | } \ |
| 448 | \ |
| 449 | /* If we've filled up the buffer then we need to cycle the MAC and \ |
| 450 | * reset the offset. \ |
| 451 | */ \ |
| 452 | if (plan.from_rsvr) { \ |
| 453 | BLKC_XLOAD(PRE, ctx->a, ctx->b); \ |
| 454 | pre##_eblk(&ctx->k, ctx->a, ctx->a); \ |
| 455 | ctx->off = 0; \ |
| 456 | } \ |
| 457 | \ |
| 458 | /* Now to process the main body of the input. */ \ |
| 459 | while (plan.from_input) { \ |
| 460 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ |
| 461 | BLKC_XLOAD(PRE, t, p); p += PRE##_BLKSZ; \ |
| 462 | BLKC_STORE(PRE, q, t); q += PRE##_BLKSZ; \ |
| 463 | BLKC_XMOVE(PRE, ctx->a, t); pre##_eblk(&ctx->k, ctx->a, ctx->a); \ |
| 464 | plan.from_input -= PRE##_BLKSZ; \ |
| 465 | } \ |
| 466 | \ |
| 467 | /* Finally, deal with any final portion. If there is one, we know \ |
| 468 | * that the buffer is empty: we must have filled it above, or this \ |
| 469 | * would all count as `initial' data. \ |
| 470 | */ \ |
| 471 | if (plan.tail) { \ |
| 472 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ |
| 473 | BLKC_STORE(PRE, ctx->b, t); \ |
| 474 | r = ctx->b; ctx->off = plan.tail; \ |
| 475 | while (plan.tail--) { y = *p++ ^ *r; *q++ = *r++ = y; } \ |
| 476 | } \ |
| 477 | \ |
| 478 | /* Done. */ \ |
| 479 | return (0); \ |
| 480 | } \ |
| 481 | \ |
| 482 | /* --- @pre_ccmtag@ --- * \ |
| 483 | * \ |
| 484 | * Arguments: @pre_ccmctx *ctx@ = pointer to an CCM context \ |
| 485 | * @octet *t@ = where to write a (full-length) tag \ |
| 486 | * @size_t tsz@ = size of the tag (to check) \ |
| 487 | * \ |
| 488 | * Returns: --- \ |
| 489 | * \ |
| 490 | * Use: Finishes an CCM operation, by calculating the tag. \ |
| 491 | */ \ |
| 492 | \ |
| 493 | static void pre##_ccmtag(pre##_ccmctx *ctx, octet *t, size_t tsz) \ |
| 494 | { \ |
| 495 | /* Make sure we're in good shape. It's just about possible that \ |
| 496 | * we're still in the AAD state, but there was no actual message, so \ |
| 497 | * handle this situation. \ |
| 498 | */ \ |
| 499 | switch (ctx->st) { \ |
| 500 | case CCMST_AAD: \ |
| 501 | assert(ctx->i == ctx->p.hsz); \ |
| 502 | assert(!ctx->p.msz); \ |
| 503 | break; \ |
| 504 | case CCMST_MSG: \ |
| 505 | /* hsz already checked in `pre_ccmencdecsetup'. */ \ |
| 506 | assert(ctx->i == ctx->p.msz); \ |
| 507 | break; \ |
| 508 | default: abort(); \ |
| 509 | } \ |
| 510 | assert(tsz == ctx->p.tsz); \ |
| 511 | \ |
| 512 | /* Pad the final plaintext block out and cycle the block cipher one \ |
| 513 | * last time. \ |
| 514 | */ \ |
| 515 | memset(ctx->b + ctx->off, 0, PRE##_BLKSZ - ctx->off); \ |
| 516 | BLKC_XLOAD(PRE, ctx->a, ctx->b); \ |
| 517 | pre##_eblk(&ctx->k, ctx->a, ctx->a); \ |
| 518 | \ |
| 519 | /* Mask the CBC-MAC tag (which prevents the standard extension \ |
| 520 | * attack) and store the result. \ |
| 521 | */ \ |
| 522 | BLKC_XSTORE(PRE, t, ctx->a, ctx->s0); \ |
| 523 | } \ |
| 524 | \ |
| 525 | /* --- @pre_ccmencryptdone@ --- * \ |
| 526 | * \ |
| 527 | * Arguments: @pre_ccmctx *ctx@ = pointer to an CCM context \ |
| 528 | * @buf *dst@ = buffer for remaining ciphertext \ |
| 529 | * @void *tag@ = where to write the tag \ |
| 530 | * @size_t tsz@ = length of tag to store \ |
| 531 | * \ |
| 532 | * Returns: Zero on success; @-1@ on failure. \ |
| 533 | * \ |
| 534 | * Use: Completes an CCM encryption operation. The @aad@ \ |
| 535 | * pointer may be null if there is no additional \ |
| 536 | * authenticated data. CCM doesn't buffer ciphertext, but \ |
| 537 | * the output buffer is provided anyway for consistency \ |
| 538 | * with other AEAD schemes which don't have this property; \ |
| 539 | * the function will fail if the output buffer is broken. \ |
| 540 | */ \ |
| 541 | \ |
| 542 | int pre##_ccmencryptdone(pre##_ccmctx *ctx, buf *dst, \ |
| 543 | void *tag, size_t tsz) \ |
| 544 | { \ |
| 545 | octet t[PRE##_BLKSZ]; \ |
| 546 | \ |
| 547 | /* Some initial checks. */ \ |
| 548 | if (!BOK(dst)) return (-1); \ |
| 549 | \ |
| 550 | /* Calculate and return the tag. */ \ |
| 551 | pre##_ccmtag(ctx, t, tsz); \ |
| 552 | memcpy(tag, t, tsz); \ |
| 553 | \ |
| 554 | /* Done. */ \ |
| 555 | return (0); \ |
| 556 | } \ |
| 557 | \ |
| 558 | /* --- @pre_ccmdecryptdone@ --- * \ |
| 559 | * \ |
| 560 | * Arguments: @pre_ccmctx *ctx@ = pointer to an CCM context \ |
| 561 | * @buf *dst@ = buffer for remaining plaintext \ |
| 562 | * @const void *tag@ = tag to verify \ |
| 563 | * @size_t tsz@ = length of tag \ |
| 564 | * \ |
| 565 | * Returns: @+1@ for complete success; @0@ if tag verification \ |
| 566 | * failed; @-1@ for other kinds of errors. \ |
| 567 | * \ |
| 568 | * Use: Completes an CCM decryption operation. The @aad@ \ |
| 569 | * pointer may be null if there is no additional \ |
| 570 | * authenticated data. CCM doesn't buffer plaintext, but \ |
| 571 | * the output buffer is provided anyway for consistency \ |
| 572 | * with other AEAD schemes which don't have this property; \ |
| 573 | * the function will fail if the output buffer is broken. \ |
| 574 | */ \ |
| 575 | \ |
| 576 | int pre##_ccmdecryptdone(pre##_ccmctx *ctx, buf *dst, \ |
| 577 | const void *tag, size_t tsz) \ |
| 578 | { \ |
| 579 | octet t[PRE##_BLKSZ]; \ |
| 580 | \ |
| 581 | /* Some initial checks. */ \ |
| 582 | if (!BOK(dst)) return (-1); \ |
| 583 | \ |
| 584 | /* Calculate and check the tag. */ \ |
| 585 | pre##_ccmtag(ctx, t, tsz); \ |
| 586 | if (!ct_memeq(tag, t, tsz)) return (0); \ |
| 587 | else return (+1); \ |
| 588 | } \ |
| 589 | \ |
| 590 | /* --- Generic AEAD interface --- */ \ |
| 591 | \ |
| 592 | typedef struct gctx { \ |
| 593 | gaead_aad a; \ |
| 594 | pre##_ccmctx ctx; \ |
| 595 | } gctx; \ |
| 596 | \ |
| 597 | static void gahash(gaead_aad *a, const void *h, size_t hsz) \ |
| 598 | { gctx *ctx = (gctx *)a; pre##_ccmaadhash(&ctx->ctx, h, hsz); } \ |
| 599 | \ |
| 600 | static void gadestroy(gaead_aad *a) { ; } \ |
| 601 | \ |
| 602 | static const gaead_aadops gaops = \ |
| 603 | { &pre##_ccm, 0, gahash, gadestroy }; \ |
| 604 | \ |
| 605 | typedef struct gectx { \ |
| 606 | gaead_enc e; \ |
| 607 | gctx g; \ |
| 608 | } gectx; \ |
| 609 | \ |
| 610 | static gaead_aad *geaad(gaead_enc *e) \ |
| 611 | { gectx *enc = (gectx *)e; return (&enc->g.a); } \ |
| 612 | \ |
| 613 | static int gereinit(gaead_enc *e, const void *n, size_t nsz, \ |
| 614 | size_t hsz, size_t msz, size_t tsz) \ |
| 615 | { \ |
| 616 | gectx *enc = (gectx *)e; \ |
| 617 | return (pre##_ccmreinit(&enc->g.ctx, n, nsz, hsz, msz, tsz)); \ |
| 618 | } \ |
| 619 | \ |
| 620 | static int geenc(gaead_enc *e, const void *m, size_t msz, buf *b) \ |
| 621 | { \ |
| 622 | gectx *enc = (gectx *)e; \ |
| 623 | return (pre##_ccmencrypt(&enc->g.ctx, m, msz, b)); \ |
| 624 | } \ |
| 625 | \ |
| 626 | static int gedone(gaead_enc *e, const gaead_aad *a, \ |
| 627 | buf *b, void *t, size_t tsz) \ |
| 628 | { \ |
| 629 | gectx *enc = (gectx *)e; \ |
| 630 | assert((!a && !enc->g.ctx.p.hsz) || a == &enc->g.a); \ |
| 631 | return (pre##_ccmencryptdone(&enc->g.ctx, b, t, tsz)); \ |
| 632 | } \ |
| 633 | \ |
| 634 | static void gedestroy(gaead_enc *e) \ |
| 635 | { gectx *enc = (gectx *)e; BURN(*enc); S_DESTROY(enc); } \ |
| 636 | \ |
| 637 | static const gaead_encops geops = \ |
| 638 | { &pre##_ccm, geaad, gereinit, geenc, gedone, gedestroy }; \ |
| 639 | \ |
| 640 | typedef struct gdctx { \ |
| 641 | gaead_dec d; \ |
| 642 | gctx g; \ |
| 643 | } gdctx; \ |
| 644 | \ |
| 645 | static gaead_aad *gdaad(gaead_dec *d) \ |
| 646 | { gdctx *dec = (gdctx *)d; return (&dec->g.a); } \ |
| 647 | \ |
| 648 | static int gdreinit(gaead_dec *d, const void *n, size_t nsz, \ |
| 649 | size_t hsz, size_t csz, size_t tsz) \ |
| 650 | { \ |
| 651 | gdctx *dec = (gdctx *)d; \ |
| 652 | return (pre##_ccmreinit(&dec->g.ctx, n, nsz, hsz, csz, tsz)); \ |
| 653 | } \ |
| 654 | \ |
| 655 | static int gddec(gaead_dec *d, const void *c, size_t csz, buf *b) \ |
| 656 | { \ |
| 657 | gdctx *dec = (gdctx *)d; \ |
| 658 | return (pre##_ccmdecrypt(&dec->g.ctx, c, csz, b)); \ |
| 659 | } \ |
| 660 | \ |
| 661 | static int gddone(gaead_dec *d, const gaead_aad *a, \ |
| 662 | buf *b, const void *t, size_t tsz) \ |
| 663 | { \ |
| 664 | gdctx *dec = (gdctx *)d; \ |
| 665 | assert((!a && !dec->g.ctx.p.hsz) || a == &dec->g.a); \ |
| 666 | return (pre##_ccmdecryptdone(&dec->g.ctx, b, t, tsz)); \ |
| 667 | } \ |
| 668 | \ |
| 669 | static void gddestroy(gaead_dec *d) \ |
| 670 | { gdctx *dec = (gdctx *)d; BURN(*dec); S_DESTROY(dec); } \ |
| 671 | \ |
| 672 | static const gaead_decops gdops = \ |
| 673 | { &pre##_ccm, gdaad, gdreinit, gddec, gddone, gddestroy }; \ |
| 674 | \ |
| 675 | typedef struct gkctx { \ |
| 676 | gaead_key k; \ |
| 677 | pre##_ctx key; \ |
| 678 | } gkctx; \ |
| 679 | \ |
| 680 | static gaead_enc *gkenc(const gaead_key *k, const void *n, size_t nsz, \ |
| 681 | size_t hsz, size_t msz, size_t tsz) \ |
| 682 | { \ |
| 683 | gkctx *key = (gkctx *)k; \ |
| 684 | gectx *enc = S_CREATE(gectx); \ |
| 685 | \ |
| 686 | enc->e.ops = &geops; enc->g.a.ops = &gaops; \ |
| 687 | if (pre##_ccminit(&enc->g.ctx, &key->key, n, nsz, hsz, msz, tsz)) \ |
| 688 | { gedestroy(&enc->e); return (0); } \ |
| 689 | return (&enc->e); \ |
| 690 | } \ |
| 691 | \ |
| 692 | static gaead_dec *gkdec(const gaead_key *k, const void *n, size_t nsz, \ |
| 693 | size_t hsz, size_t csz, size_t tsz) \ |
| 694 | { \ |
| 695 | gkctx *key = (gkctx *)k; \ |
| 696 | gdctx *dec = S_CREATE(gdctx); \ |
| 697 | \ |
| 698 | dec->d.ops = &gdops; dec->g.a.ops = &gaops; \ |
| 699 | if (pre##_ccminit(&dec->g.ctx, &key->key, n, nsz, hsz, csz, tsz)) \ |
| 700 | { gddestroy(&dec->d); return (0); } \ |
| 701 | return (&dec->d); \ |
| 702 | } \ |
| 703 | \ |
| 704 | static void gkdestroy(gaead_key *k) \ |
| 705 | { gkctx *key = (gkctx *)k; BURN(*key); S_DESTROY(key); } \ |
| 706 | \ |
| 707 | static const gaead_keyops gkops = \ |
| 708 | { &pre##_ccm, 0, gkenc, gkdec, gkdestroy }; \ |
| 709 | \ |
| 710 | static gaead_key *gckey(const void *k, size_t ksz) \ |
| 711 | { \ |
| 712 | gkctx *key = S_CREATE(gkctx); \ |
| 713 | key->k.ops = &gkops; \ |
| 714 | pre##_init(&key->key, k, ksz); \ |
| 715 | return (&key->k); \ |
| 716 | } \ |
| 717 | \ |
| 718 | const gcaead pre##_ccm = { \ |
| 719 | name "-ccm", \ |
| 720 | pre##_keysz, pre##_ccmnoncesz, pre##_ccmtagsz, \ |
| 721 | PRE##_BLKSZ, 0, 0, \ |
| 722 | AEADF_PCHSZ | AEADF_PCMSZ | AEADF_PCTSZ | \ |
| 723 | AEADF_AADNDEP | AEADF_AADFIRST, \ |
| 724 | gckey \ |
| 725 | }; \ |
| 726 | \ |
| 727 | CCM_TESTX(PRE, pre, name, fname) |
| 728 | |
| 729 | /*----- Test rig ----------------------------------------------------------*/ |
| 730 | |
| 731 | #define CCM_TEST(PRE, pre) CCM_TESTX(PRE, pre, #pre, #pre) |
| 732 | |
| 733 | /* --- @CCM_TEST@ --- * |
| 734 | * |
| 735 | * Arguments: @PRE, pre@ = prefixes for the underlying block cipher |
| 736 | * |
| 737 | * Use: Standard test rig for CCM functions. |
| 738 | */ |
| 739 | |
| 740 | #ifdef TEST_RIG |
| 741 | |
| 742 | #include <stdio.h> |
| 743 | |
| 744 | #include <mLib/dstr.h> |
| 745 | #include <mLib/macros.h> |
| 746 | #include <mLib/quis.h> |
| 747 | #include <mLib/testrig.h> |
| 748 | |
| 749 | #define CCM_TESTX(PRE, pre, name, fname) \ |
| 750 | \ |
| 751 | static int ccmverify(dstr *v) \ |
| 752 | { \ |
| 753 | pre##_ctx key; \ |
| 754 | pre##_ccmctx ctx; \ |
| 755 | int ok = 1, win; \ |
| 756 | int i; \ |
| 757 | octet *p; \ |
| 758 | int szs[] = { 1, 7, 192, -1, 0 }, *ip; \ |
| 759 | size_t hsz, msz; \ |
| 760 | dstr d = DSTR_INIT, t = DSTR_INIT; \ |
| 761 | buf b; \ |
| 762 | \ |
| 763 | dstr_ensure(&d, v[4].len > v[3].len ? v[4].len : v[3].len); \ |
| 764 | dstr_ensure(&t, v[5].len); t.len = v[5].len; \ |
| 765 | \ |
| 766 | pre##_init(&key, v[0].buf, v[0].len); \ |
| 767 | \ |
| 768 | for (ip = szs; *ip; ip++) { \ |
| 769 | \ |
| 770 | pre##_ccminit(&ctx, &key, (octet *)v[1].buf, v[1].len, \ |
| 771 | v[2].len, v[3].len, v[5].len); \ |
| 772 | \ |
| 773 | i = *ip; \ |
| 774 | hsz = v[2].len; \ |
| 775 | if (i == -1) i = hsz; \ |
| 776 | if (i > hsz) continue; \ |
| 777 | p = (octet *)v[2].buf; \ |
| 778 | while (hsz) { \ |
| 779 | if (i > hsz) i = hsz; \ |
| 780 | pre##_ccmaadhash(&ctx, p, i); \ |
| 781 | p += i; hsz -= i; \ |
| 782 | } \ |
| 783 | \ |
| 784 | buf_init(&b, d.buf, d.sz); \ |
| 785 | i = *ip; \ |
| 786 | msz = v[3].len; \ |
| 787 | if (i == -1) i = msz; \ |
| 788 | if (i > msz) continue; \ |
| 789 | p = (octet *)v[3].buf; \ |
| 790 | while (msz) { \ |
| 791 | if (i > msz) i = msz; \ |
| 792 | if (pre##_ccmencrypt(&ctx, p, i, &b)) { \ |
| 793 | puts("!! ccmencrypt reports failure"); \ |
| 794 | goto fail_enc; \ |
| 795 | } \ |
| 796 | p += i; msz -= i; \ |
| 797 | } \ |
| 798 | \ |
| 799 | if (pre##_ccmencryptdone(&ctx, &b, (octet *)t.buf, t.len)) { \ |
| 800 | puts("!! ccmencryptdone reports failure"); \ |
| 801 | goto fail_enc; \ |
| 802 | } \ |
| 803 | d.len = BLEN(&b); \ |
| 804 | \ |
| 805 | if (d.len != v[4].len || \ |
| 806 | MEMCMP(d.buf, !=, v[4].buf, v[4].len) || \ |
| 807 | MEMCMP(t.buf, !=, v[5].buf, v[5].len)) { \ |
| 808 | fail_enc: \ |
| 809 | printf("\nfail encrypt:\n\tstep = %i", *ip); \ |
| 810 | fputs("\n\tkey = ", stdout); type_hex.dump(&v[0], stdout); \ |
| 811 | fputs("\n\tnonce = ", stdout); type_hex.dump(&v[1], stdout); \ |
| 812 | fputs("\n\theader = ", stdout); type_hex.dump(&v[2], stdout); \ |
| 813 | fputs("\n\tmessage = ", stdout); type_hex.dump(&v[3], stdout); \ |
| 814 | fputs("\n\texp ct = ", stdout); type_hex.dump(&v[4], stdout); \ |
| 815 | fputs("\n\tcalc ct = ", stdout); type_hex.dump(&d, stdout); \ |
| 816 | fputs("\n\texp tag = ", stdout); type_hex.dump(&v[5], stdout); \ |
| 817 | fputs("\n\tcalc tag = ", stdout); type_hex.dump(&t, stdout); \ |
| 818 | putchar('\n'); \ |
| 819 | ok = 0; \ |
| 820 | } \ |
| 821 | \ |
| 822 | pre##_ccminit(&ctx, &key, (octet *)v[1].buf, v[1].len, \ |
| 823 | v[2].len, v[4].len, v[5].len); \ |
| 824 | \ |
| 825 | i = *ip; \ |
| 826 | hsz = v[2].len; \ |
| 827 | if (i == -1) i = hsz; \ |
| 828 | if (i > hsz) continue; \ |
| 829 | p = (octet *)v[2].buf; \ |
| 830 | while (hsz) { \ |
| 831 | if (i > hsz) i = hsz; \ |
| 832 | pre##_ccmaadhash(&ctx, p, i); \ |
| 833 | p += i; hsz -= i; \ |
| 834 | } \ |
| 835 | \ |
| 836 | buf_init(&b, d.buf, d.sz); \ |
| 837 | i = *ip; \ |
| 838 | msz = v[4].len; \ |
| 839 | if (i == -1) i = msz; \ |
| 840 | if (i > msz) continue; \ |
| 841 | p = (octet *)v[4].buf; \ |
| 842 | while (msz) { \ |
| 843 | if (i > msz) i = msz; \ |
| 844 | if (pre##_ccmdecrypt(&ctx, p, i, &b)) { \ |
| 845 | puts("!! ccmdecrypt reports failure"); \ |
| 846 | win = 0; goto fail_dec; \ |
| 847 | } \ |
| 848 | p += i; msz -= i; \ |
| 849 | } \ |
| 850 | \ |
| 851 | win = pre##_ccmdecryptdone(&ctx, &b, (octet *)v[5].buf, v[5].len); \ |
| 852 | if (win < 0) { \ |
| 853 | puts("!! ccmdecryptdone reports failure"); \ |
| 854 | goto fail_dec; \ |
| 855 | } \ |
| 856 | d.len = BLEN(&b); \ |
| 857 | \ |
| 858 | if (d.len != v[3].len || !win || \ |
| 859 | MEMCMP(d.buf, !=, v[3].buf, v[3].len)) { \ |
| 860 | fail_dec: \ |
| 861 | printf("\nfail decrypt:\n\tstep = %i", *ip); \ |
| 862 | fputs("\n\tkey = ", stdout); type_hex.dump(&v[0], stdout); \ |
| 863 | fputs("\n\tnonce = ", stdout); type_hex.dump(&v[1], stdout); \ |
| 864 | fputs("\n\theader = ", stdout); type_hex.dump(&v[2], stdout); \ |
| 865 | fputs("\n\tciphertext = ", stdout); type_hex.dump(&v[4], stdout); \ |
| 866 | fputs("\n\texp pt = ", stdout); type_hex.dump(&v[3], stdout); \ |
| 867 | fputs("\n\tcalc pt = ", stdout); type_hex.dump(&d, stdout); \ |
| 868 | fputs("\n\ttag = ", stdout); type_hex.dump(&v[5], stdout); \ |
| 869 | printf("\n\tverify %s", win ? "ok" : "FAILED"); \ |
| 870 | putchar('\n'); \ |
| 871 | ok = 0; \ |
| 872 | } \ |
| 873 | } \ |
| 874 | \ |
| 875 | dstr_destroy(&d); dstr_destroy(&t); \ |
| 876 | return (ok); \ |
| 877 | } \ |
| 878 | \ |
| 879 | static test_chunk aeaddefs[] = { \ |
| 880 | { name "-ccm", ccmverify, \ |
| 881 | { &type_hex, &type_hex, &type_hex, &type_hex, \ |
| 882 | &type_hex, &type_hex, 0 } }, \ |
| 883 | { 0, 0, { 0 } } \ |
| 884 | }; \ |
| 885 | \ |
| 886 | int main(int argc, char *argv[]) \ |
| 887 | { \ |
| 888 | ego(argv[0]); \ |
| 889 | test_run(argc, argv, aeaddefs, SRCDIR"/t/" fname); \ |
| 890 | return (0); \ |
| 891 | } |
| 892 | |
| 893 | #else |
| 894 | # define CCM_TESTX(PRE, pre, name, fname) |
| 895 | #endif |
| 896 | |
| 897 | /*----- That's all, folks -------------------------------------------------*/ |
| 898 | |
| 899 | #ifdef __cplusplus |
| 900 | } |
| 901 | #endif |
| 902 | |
| 903 | #endif |