1 /* 2 * CCM: Counter with CBC-MAC 3 * 4 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the Free 8 * Software Foundation; either version 2 of the License, or (at your option) 9 * any later version. 10 * 11 */ 12 13 #include <crypto/internal/aead.h> 14 #include <crypto/internal/hash.h> 15 #include <crypto/internal/skcipher.h> 16 #include <crypto/scatterwalk.h> 17 #include <linux/err.h> 18 #include <linux/init.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/slab.h> 22 23 #include "internal.h" 24 25 struct ccm_instance_ctx { 26 struct crypto_skcipher_spawn ctr; 27 struct crypto_ahash_spawn mac; 28 }; 29 30 struct crypto_ccm_ctx { 31 struct crypto_ahash *mac; 32 struct crypto_skcipher *ctr; 33 }; 34 35 struct crypto_rfc4309_ctx { 36 struct crypto_aead *child; 37 u8 nonce[3]; 38 }; 39 40 struct crypto_rfc4309_req_ctx { 41 struct scatterlist src[3]; 42 struct scatterlist dst[3]; 43 struct aead_request subreq; 44 }; 45 46 struct crypto_ccm_req_priv_ctx { 47 u8 odata[16]; 48 u8 idata[16]; 49 u8 auth_tag[16]; 50 u32 flags; 51 struct scatterlist src[3]; 52 struct scatterlist dst[3]; 53 union { 54 struct ahash_request ahreq; 55 struct skcipher_request skreq; 56 }; 57 }; 58 59 struct cbcmac_tfm_ctx { 60 struct crypto_cipher *child; 61 }; 62 63 struct cbcmac_desc_ctx { 64 unsigned int len; 65 }; 66 67 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx( 68 struct aead_request *req) 69 { 70 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); 71 72 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); 73 } 74 75 static int set_msg_len(u8 *block, unsigned int msglen, int csize) 76 { 77 __be32 data; 78 79 memset(block, 0, csize); 80 block += csize; 81 82 if (csize >= 4) 83 csize = 4; 84 else if (msglen > (1 << (8 * csize))) 85 return -EOVERFLOW; 86 87 data = cpu_to_be32(msglen); 88 memcpy(block - csize, (u8 *)&data + 4 - csize, csize); 89 90 return 0; 91 } 92 93 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key, 94 unsigned int keylen) 95 { 96 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 97 struct crypto_skcipher *ctr = ctx->ctr; 98 struct crypto_ahash *mac = ctx->mac; 99 int err = 0; 100 101 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); 102 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) & 103 CRYPTO_TFM_REQ_MASK); 104 err = crypto_skcipher_setkey(ctr, key, keylen); 105 crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) & 106 CRYPTO_TFM_RES_MASK); 107 if (err) 108 goto out; 109 110 crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK); 111 crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) & 112 CRYPTO_TFM_REQ_MASK); 113 err = crypto_ahash_setkey(mac, key, keylen); 114 crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) & 115 CRYPTO_TFM_RES_MASK); 116 117 out: 118 return err; 119 } 120 121 static int crypto_ccm_setauthsize(struct crypto_aead *tfm, 122 unsigned int authsize) 123 { 124 switch (authsize) { 125 case 4: 126 case 6: 127 case 8: 128 case 10: 129 case 12: 130 case 14: 131 case 16: 132 break; 133 default: 134 return -EINVAL; 135 } 136 137 return 0; 138 } 139 140 static int format_input(u8 *info, struct aead_request *req, 141 unsigned int cryptlen) 142 { 143 struct crypto_aead *aead = crypto_aead_reqtfm(req); 144 unsigned int lp = req->iv[0]; 145 unsigned int l = lp + 1; 146 unsigned int m; 147 148 m = crypto_aead_authsize(aead); 149 150 memcpy(info, req->iv, 16); 151 152 /* format control info per RFC 3610 and 153 * NIST Special Publication 800-38C 154 */ 155 *info |= (8 * ((m - 2) / 2)); 156 if (req->assoclen) 157 *info |= 64; 158 159 return set_msg_len(info + 16 - l, cryptlen, l); 160 } 161 162 static int format_adata(u8 *adata, unsigned int a) 163 { 164 int len = 0; 165 166 /* add control info for associated data 167 * RFC 3610 and NIST Special Publication 800-38C 168 */ 169 if (a < 65280) { 170 *(__be16 *)adata = cpu_to_be16(a); 171 len = 2; 172 } else { 173 *(__be16 *)adata = cpu_to_be16(0xfffe); 174 *(__be32 *)&adata[2] = cpu_to_be32(a); 175 len = 6; 176 } 177 178 return len; 179 } 180 181 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain, 182 unsigned int cryptlen) 183 { 184 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 185 struct crypto_aead *aead = crypto_aead_reqtfm(req); 186 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 187 struct ahash_request *ahreq = &pctx->ahreq; 188 unsigned int assoclen = req->assoclen; 189 struct scatterlist sg[3]; 190 u8 *odata = pctx->odata; 191 u8 *idata = pctx->idata; 192 int ilen, err; 193 194 /* format control data for input */ 195 err = format_input(odata, req, cryptlen); 196 if (err) 197 goto out; 198 199 sg_init_table(sg, 3); 200 sg_set_buf(&sg[0], odata, 16); 201 202 /* format associated data and compute into mac */ 203 if (assoclen) { 204 ilen = format_adata(idata, assoclen); 205 sg_set_buf(&sg[1], idata, ilen); 206 sg_chain(sg, 3, req->src); 207 } else { 208 ilen = 0; 209 sg_chain(sg, 2, req->src); 210 } 211 212 ahash_request_set_tfm(ahreq, ctx->mac); 213 ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL); 214 ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16); 215 err = crypto_ahash_init(ahreq); 216 if (err) 217 goto out; 218 err = crypto_ahash_update(ahreq); 219 if (err) 220 goto out; 221 222 /* we need to pad the MAC input to a round multiple of the block size */ 223 ilen = 16 - (assoclen + ilen) % 16; 224 if (ilen < 16) { 225 memset(idata, 0, ilen); 226 sg_init_table(sg, 2); 227 sg_set_buf(&sg[0], idata, ilen); 228 if (plain) 229 sg_chain(sg, 2, plain); 230 plain = sg; 231 cryptlen += ilen; 232 } 233 234 ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen); 235 err = crypto_ahash_finup(ahreq); 236 out: 237 return err; 238 } 239 240 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err) 241 { 242 struct aead_request *req = areq->data; 243 struct crypto_aead *aead = crypto_aead_reqtfm(req); 244 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 245 u8 *odata = pctx->odata; 246 247 if (!err) 248 scatterwalk_map_and_copy(odata, req->dst, 249 req->assoclen + req->cryptlen, 250 crypto_aead_authsize(aead), 1); 251 aead_request_complete(req, err); 252 } 253 254 static inline int crypto_ccm_check_iv(const u8 *iv) 255 { 256 /* 2 <= L <= 8, so 1 <= L' <= 7. */ 257 if (1 > iv[0] || iv[0] > 7) 258 return -EINVAL; 259 260 return 0; 261 } 262 263 static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag) 264 { 265 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 266 struct scatterlist *sg; 267 u8 *iv = req->iv; 268 int err; 269 270 err = crypto_ccm_check_iv(iv); 271 if (err) 272 return err; 273 274 pctx->flags = aead_request_flags(req); 275 276 /* Note: rfc 3610 and NIST 800-38C require counter of 277 * zero to encrypt auth tag. 278 */ 279 memset(iv + 15 - iv[0], 0, iv[0] + 1); 280 281 sg_init_table(pctx->src, 3); 282 sg_set_buf(pctx->src, tag, 16); 283 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen); 284 if (sg != pctx->src + 1) 285 sg_chain(pctx->src, 2, sg); 286 287 if (req->src != req->dst) { 288 sg_init_table(pctx->dst, 3); 289 sg_set_buf(pctx->dst, tag, 16); 290 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen); 291 if (sg != pctx->dst + 1) 292 sg_chain(pctx->dst, 2, sg); 293 } 294 295 return 0; 296 } 297 298 static int crypto_ccm_encrypt(struct aead_request *req) 299 { 300 struct crypto_aead *aead = crypto_aead_reqtfm(req); 301 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 302 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 303 struct skcipher_request *skreq = &pctx->skreq; 304 struct scatterlist *dst; 305 unsigned int cryptlen = req->cryptlen; 306 u8 *odata = pctx->odata; 307 u8 *iv = req->iv; 308 int err; 309 310 err = crypto_ccm_init_crypt(req, odata); 311 if (err) 312 return err; 313 314 err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen); 315 if (err) 316 return err; 317 318 dst = pctx->src; 319 if (req->src != req->dst) 320 dst = pctx->dst; 321 322 skcipher_request_set_tfm(skreq, ctx->ctr); 323 skcipher_request_set_callback(skreq, pctx->flags, 324 crypto_ccm_encrypt_done, req); 325 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv); 326 err = crypto_skcipher_encrypt(skreq); 327 if (err) 328 return err; 329 330 /* copy authtag to end of dst */ 331 scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen, 332 crypto_aead_authsize(aead), 1); 333 return err; 334 } 335 336 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq, 337 int err) 338 { 339 struct aead_request *req = areq->data; 340 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 341 struct crypto_aead *aead = crypto_aead_reqtfm(req); 342 unsigned int authsize = crypto_aead_authsize(aead); 343 unsigned int cryptlen = req->cryptlen - authsize; 344 struct scatterlist *dst; 345 346 pctx->flags = 0; 347 348 dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst); 349 350 if (!err) { 351 err = crypto_ccm_auth(req, dst, cryptlen); 352 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize)) 353 err = -EBADMSG; 354 } 355 aead_request_complete(req, err); 356 } 357 358 static int crypto_ccm_decrypt(struct aead_request *req) 359 { 360 struct crypto_aead *aead = crypto_aead_reqtfm(req); 361 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 362 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 363 struct skcipher_request *skreq = &pctx->skreq; 364 struct scatterlist *dst; 365 unsigned int authsize = crypto_aead_authsize(aead); 366 unsigned int cryptlen = req->cryptlen; 367 u8 *authtag = pctx->auth_tag; 368 u8 *odata = pctx->odata; 369 u8 *iv = pctx->idata; 370 int err; 371 372 cryptlen -= authsize; 373 374 err = crypto_ccm_init_crypt(req, authtag); 375 if (err) 376 return err; 377 378 scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen, 379 authsize, 0); 380 381 dst = pctx->src; 382 if (req->src != req->dst) 383 dst = pctx->dst; 384 385 memcpy(iv, req->iv, 16); 386 387 skcipher_request_set_tfm(skreq, ctx->ctr); 388 skcipher_request_set_callback(skreq, pctx->flags, 389 crypto_ccm_decrypt_done, req); 390 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv); 391 err = crypto_skcipher_decrypt(skreq); 392 if (err) 393 return err; 394 395 err = crypto_ccm_auth(req, sg_next(dst), cryptlen); 396 if (err) 397 return err; 398 399 /* verify */ 400 if (crypto_memneq(authtag, odata, authsize)) 401 return -EBADMSG; 402 403 return err; 404 } 405 406 static int crypto_ccm_init_tfm(struct crypto_aead *tfm) 407 { 408 struct aead_instance *inst = aead_alg_instance(tfm); 409 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst); 410 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm); 411 struct crypto_ahash *mac; 412 struct crypto_skcipher *ctr; 413 unsigned long align; 414 int err; 415 416 mac = crypto_spawn_ahash(&ictx->mac); 417 if (IS_ERR(mac)) 418 return PTR_ERR(mac); 419 420 ctr = crypto_spawn_skcipher(&ictx->ctr); 421 err = PTR_ERR(ctr); 422 if (IS_ERR(ctr)) 423 goto err_free_mac; 424 425 ctx->mac = mac; 426 ctx->ctr = ctr; 427 428 align = crypto_aead_alignmask(tfm); 429 align &= ~(crypto_tfm_ctx_alignment() - 1); 430 crypto_aead_set_reqsize( 431 tfm, 432 align + sizeof(struct crypto_ccm_req_priv_ctx) + 433 max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr))); 434 435 return 0; 436 437 err_free_mac: 438 crypto_free_ahash(mac); 439 return err; 440 } 441 442 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm) 443 { 444 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm); 445 446 crypto_free_ahash(ctx->mac); 447 crypto_free_skcipher(ctx->ctr); 448 } 449 450 static void crypto_ccm_free(struct aead_instance *inst) 451 { 452 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst); 453 454 crypto_drop_ahash(&ctx->mac); 455 crypto_drop_skcipher(&ctx->ctr); 456 kfree(inst); 457 } 458 459 static int crypto_ccm_create_common(struct crypto_template *tmpl, 460 struct rtattr **tb, 461 const char *ctr_name, 462 const char *mac_name) 463 { 464 struct crypto_attr_type *algt; 465 struct aead_instance *inst; 466 struct skcipher_alg *ctr; 467 struct crypto_alg *mac_alg; 468 struct hash_alg_common *mac; 469 struct ccm_instance_ctx *ictx; 470 int err; 471 472 algt = crypto_get_attr_type(tb); 473 if (IS_ERR(algt)) 474 return PTR_ERR(algt); 475 476 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 477 return -EINVAL; 478 479 mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type, 480 CRYPTO_ALG_TYPE_HASH, 481 CRYPTO_ALG_TYPE_AHASH_MASK | 482 CRYPTO_ALG_ASYNC); 483 if (IS_ERR(mac_alg)) 484 return PTR_ERR(mac_alg); 485 486 mac = __crypto_hash_alg_common(mac_alg); 487 err = -EINVAL; 488 if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 || 489 mac->digestsize != 16) 490 goto out_put_mac; 491 492 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL); 493 err = -ENOMEM; 494 if (!inst) 495 goto out_put_mac; 496 497 ictx = aead_instance_ctx(inst); 498 err = crypto_init_ahash_spawn(&ictx->mac, mac, 499 aead_crypto_instance(inst)); 500 if (err) 501 goto err_free_inst; 502 503 crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst)); 504 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0, 505 crypto_requires_sync(algt->type, 506 algt->mask)); 507 if (err) 508 goto err_drop_mac; 509 510 ctr = crypto_spawn_skcipher_alg(&ictx->ctr); 511 512 /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */ 513 err = -EINVAL; 514 if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 || 515 crypto_skcipher_alg_ivsize(ctr) != 16 || 516 ctr->base.cra_blocksize != 1) 517 goto err_drop_ctr; 518 519 /* ctr and cbcmac must use the same underlying block cipher. */ 520 if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0) 521 goto err_drop_ctr; 522 523 err = -ENAMETOOLONG; 524 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 525 "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME) 526 goto err_drop_ctr; 527 528 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 529 "ccm_base(%s,%s)", ctr->base.cra_driver_name, 530 mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME) 531 goto err_drop_ctr; 532 533 inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC; 534 inst->alg.base.cra_priority = (mac->base.cra_priority + 535 ctr->base.cra_priority) / 2; 536 inst->alg.base.cra_blocksize = 1; 537 inst->alg.base.cra_alignmask = mac->base.cra_alignmask | 538 ctr->base.cra_alignmask; 539 inst->alg.ivsize = 16; 540 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr); 541 inst->alg.maxauthsize = 16; 542 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx); 543 inst->alg.init = crypto_ccm_init_tfm; 544 inst->alg.exit = crypto_ccm_exit_tfm; 545 inst->alg.setkey = crypto_ccm_setkey; 546 inst->alg.setauthsize = crypto_ccm_setauthsize; 547 inst->alg.encrypt = crypto_ccm_encrypt; 548 inst->alg.decrypt = crypto_ccm_decrypt; 549 550 inst->free = crypto_ccm_free; 551 552 err = aead_register_instance(tmpl, inst); 553 if (err) 554 goto err_drop_ctr; 555 556 out_put_mac: 557 crypto_mod_put(mac_alg); 558 return err; 559 560 err_drop_ctr: 561 crypto_drop_skcipher(&ictx->ctr); 562 err_drop_mac: 563 crypto_drop_ahash(&ictx->mac); 564 err_free_inst: 565 kfree(inst); 566 goto out_put_mac; 567 } 568 569 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb) 570 { 571 const char *cipher_name; 572 char ctr_name[CRYPTO_MAX_ALG_NAME]; 573 char mac_name[CRYPTO_MAX_ALG_NAME]; 574 575 cipher_name = crypto_attr_alg_name(tb[1]); 576 if (IS_ERR(cipher_name)) 577 return PTR_ERR(cipher_name); 578 579 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", 580 cipher_name) >= CRYPTO_MAX_ALG_NAME) 581 return -ENAMETOOLONG; 582 583 if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)", 584 cipher_name) >= CRYPTO_MAX_ALG_NAME) 585 return -ENAMETOOLONG; 586 587 return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name); 588 } 589 590 static int crypto_ccm_base_create(struct crypto_template *tmpl, 591 struct rtattr **tb) 592 { 593 const char *ctr_name; 594 const char *mac_name; 595 596 ctr_name = crypto_attr_alg_name(tb[1]); 597 if (IS_ERR(ctr_name)) 598 return PTR_ERR(ctr_name); 599 600 mac_name = crypto_attr_alg_name(tb[2]); 601 if (IS_ERR(mac_name)) 602 return PTR_ERR(mac_name); 603 604 return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name); 605 } 606 607 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key, 608 unsigned int keylen) 609 { 610 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent); 611 struct crypto_aead *child = ctx->child; 612 int err; 613 614 if (keylen < 3) 615 return -EINVAL; 616 617 keylen -= 3; 618 memcpy(ctx->nonce, key + keylen, 3); 619 620 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 621 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 622 CRYPTO_TFM_REQ_MASK); 623 err = crypto_aead_setkey(child, key, keylen); 624 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) & 625 CRYPTO_TFM_RES_MASK); 626 627 return err; 628 } 629 630 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent, 631 unsigned int authsize) 632 { 633 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent); 634 635 switch (authsize) { 636 case 8: 637 case 12: 638 case 16: 639 break; 640 default: 641 return -EINVAL; 642 } 643 644 return crypto_aead_setauthsize(ctx->child, authsize); 645 } 646 647 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req) 648 { 649 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req); 650 struct aead_request *subreq = &rctx->subreq; 651 struct crypto_aead *aead = crypto_aead_reqtfm(req); 652 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead); 653 struct crypto_aead *child = ctx->child; 654 struct scatterlist *sg; 655 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child), 656 crypto_aead_alignmask(child) + 1); 657 658 /* L' */ 659 iv[0] = 3; 660 661 memcpy(iv + 1, ctx->nonce, 3); 662 memcpy(iv + 4, req->iv, 8); 663 664 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0); 665 666 sg_init_table(rctx->src, 3); 667 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8); 668 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen); 669 if (sg != rctx->src + 1) 670 sg_chain(rctx->src, 2, sg); 671 672 if (req->src != req->dst) { 673 sg_init_table(rctx->dst, 3); 674 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8); 675 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen); 676 if (sg != rctx->dst + 1) 677 sg_chain(rctx->dst, 2, sg); 678 } 679 680 aead_request_set_tfm(subreq, child); 681 aead_request_set_callback(subreq, req->base.flags, req->base.complete, 682 req->base.data); 683 aead_request_set_crypt(subreq, rctx->src, 684 req->src == req->dst ? rctx->src : rctx->dst, 685 req->cryptlen, iv); 686 aead_request_set_ad(subreq, req->assoclen - 8); 687 688 return subreq; 689 } 690 691 static int crypto_rfc4309_encrypt(struct aead_request *req) 692 { 693 if (req->assoclen != 16 && req->assoclen != 20) 694 return -EINVAL; 695 696 req = crypto_rfc4309_crypt(req); 697 698 return crypto_aead_encrypt(req); 699 } 700 701 static int crypto_rfc4309_decrypt(struct aead_request *req) 702 { 703 if (req->assoclen != 16 && req->assoclen != 20) 704 return -EINVAL; 705 706 req = crypto_rfc4309_crypt(req); 707 708 return crypto_aead_decrypt(req); 709 } 710 711 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm) 712 { 713 struct aead_instance *inst = aead_alg_instance(tfm); 714 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst); 715 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm); 716 struct crypto_aead *aead; 717 unsigned long align; 718 719 aead = crypto_spawn_aead(spawn); 720 if (IS_ERR(aead)) 721 return PTR_ERR(aead); 722 723 ctx->child = aead; 724 725 align = crypto_aead_alignmask(aead); 726 align &= ~(crypto_tfm_ctx_alignment() - 1); 727 crypto_aead_set_reqsize( 728 tfm, 729 sizeof(struct crypto_rfc4309_req_ctx) + 730 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + 731 align + 32); 732 733 return 0; 734 } 735 736 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm) 737 { 738 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm); 739 740 crypto_free_aead(ctx->child); 741 } 742 743 static void crypto_rfc4309_free(struct aead_instance *inst) 744 { 745 crypto_drop_aead(aead_instance_ctx(inst)); 746 kfree(inst); 747 } 748 749 static int crypto_rfc4309_create(struct crypto_template *tmpl, 750 struct rtattr **tb) 751 { 752 struct crypto_attr_type *algt; 753 struct aead_instance *inst; 754 struct crypto_aead_spawn *spawn; 755 struct aead_alg *alg; 756 const char *ccm_name; 757 int err; 758 759 algt = crypto_get_attr_type(tb); 760 if (IS_ERR(algt)) 761 return PTR_ERR(algt); 762 763 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 764 return -EINVAL; 765 766 ccm_name = crypto_attr_alg_name(tb[1]); 767 if (IS_ERR(ccm_name)) 768 return PTR_ERR(ccm_name); 769 770 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 771 if (!inst) 772 return -ENOMEM; 773 774 spawn = aead_instance_ctx(inst); 775 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst)); 776 err = crypto_grab_aead(spawn, ccm_name, 0, 777 crypto_requires_sync(algt->type, algt->mask)); 778 if (err) 779 goto out_free_inst; 780 781 alg = crypto_spawn_aead_alg(spawn); 782 783 err = -EINVAL; 784 785 /* We only support 16-byte blocks. */ 786 if (crypto_aead_alg_ivsize(alg) != 16) 787 goto out_drop_alg; 788 789 /* Not a stream cipher? */ 790 if (alg->base.cra_blocksize != 1) 791 goto out_drop_alg; 792 793 err = -ENAMETOOLONG; 794 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 795 "rfc4309(%s)", alg->base.cra_name) >= 796 CRYPTO_MAX_ALG_NAME || 797 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 798 "rfc4309(%s)", alg->base.cra_driver_name) >= 799 CRYPTO_MAX_ALG_NAME) 800 goto out_drop_alg; 801 802 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC; 803 inst->alg.base.cra_priority = alg->base.cra_priority; 804 inst->alg.base.cra_blocksize = 1; 805 inst->alg.base.cra_alignmask = alg->base.cra_alignmask; 806 807 inst->alg.ivsize = 8; 808 inst->alg.chunksize = crypto_aead_alg_chunksize(alg); 809 inst->alg.maxauthsize = 16; 810 811 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx); 812 813 inst->alg.init = crypto_rfc4309_init_tfm; 814 inst->alg.exit = crypto_rfc4309_exit_tfm; 815 816 inst->alg.setkey = crypto_rfc4309_setkey; 817 inst->alg.setauthsize = crypto_rfc4309_setauthsize; 818 inst->alg.encrypt = crypto_rfc4309_encrypt; 819 inst->alg.decrypt = crypto_rfc4309_decrypt; 820 821 inst->free = crypto_rfc4309_free; 822 823 err = aead_register_instance(tmpl, inst); 824 if (err) 825 goto out_drop_alg; 826 827 out: 828 return err; 829 830 out_drop_alg: 831 crypto_drop_aead(spawn); 832 out_free_inst: 833 kfree(inst); 834 goto out; 835 } 836 837 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent, 838 const u8 *inkey, unsigned int keylen) 839 { 840 struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent); 841 842 return crypto_cipher_setkey(ctx->child, inkey, keylen); 843 } 844 845 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc) 846 { 847 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc); 848 int bs = crypto_shash_digestsize(pdesc->tfm); 849 u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs; 850 851 ctx->len = 0; 852 memset(dg, 0, bs); 853 854 return 0; 855 } 856 857 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p, 858 unsigned int len) 859 { 860 struct crypto_shash *parent = pdesc->tfm; 861 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent); 862 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc); 863 struct crypto_cipher *tfm = tctx->child; 864 int bs = crypto_shash_digestsize(parent); 865 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs; 866 867 while (len > 0) { 868 unsigned int l = min(len, bs - ctx->len); 869 870 crypto_xor(dg + ctx->len, p, l); 871 ctx->len +=l; 872 len -= l; 873 p += l; 874 875 if (ctx->len == bs) { 876 crypto_cipher_encrypt_one(tfm, dg, dg); 877 ctx->len = 0; 878 } 879 } 880 881 return 0; 882 } 883 884 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out) 885 { 886 struct crypto_shash *parent = pdesc->tfm; 887 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent); 888 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc); 889 struct crypto_cipher *tfm = tctx->child; 890 int bs = crypto_shash_digestsize(parent); 891 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs; 892 893 if (ctx->len) 894 crypto_cipher_encrypt_one(tfm, dg, dg); 895 896 memcpy(out, dg, bs); 897 return 0; 898 } 899 900 static int cbcmac_init_tfm(struct crypto_tfm *tfm) 901 { 902 struct crypto_cipher *cipher; 903 struct crypto_instance *inst = (void *)tfm->__crt_alg; 904 struct crypto_spawn *spawn = crypto_instance_ctx(inst); 905 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm); 906 907 cipher = crypto_spawn_cipher(spawn); 908 if (IS_ERR(cipher)) 909 return PTR_ERR(cipher); 910 911 ctx->child = cipher; 912 913 return 0; 914 }; 915 916 static void cbcmac_exit_tfm(struct crypto_tfm *tfm) 917 { 918 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm); 919 crypto_free_cipher(ctx->child); 920 } 921 922 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb) 923 { 924 struct shash_instance *inst; 925 struct crypto_alg *alg; 926 int err; 927 928 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH); 929 if (err) 930 return err; 931 932 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, 933 CRYPTO_ALG_TYPE_MASK); 934 if (IS_ERR(alg)) 935 return PTR_ERR(alg); 936 937 inst = shash_alloc_instance("cbcmac", alg); 938 err = PTR_ERR(inst); 939 if (IS_ERR(inst)) 940 goto out_put_alg; 941 942 err = crypto_init_spawn(shash_instance_ctx(inst), alg, 943 shash_crypto_instance(inst), 944 CRYPTO_ALG_TYPE_MASK); 945 if (err) 946 goto out_free_inst; 947 948 inst->alg.base.cra_priority = alg->cra_priority; 949 inst->alg.base.cra_blocksize = 1; 950 951 inst->alg.digestsize = alg->cra_blocksize; 952 inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx), 953 alg->cra_alignmask + 1) + 954 alg->cra_blocksize; 955 956 inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx); 957 inst->alg.base.cra_init = cbcmac_init_tfm; 958 inst->alg.base.cra_exit = cbcmac_exit_tfm; 959 960 inst->alg.init = crypto_cbcmac_digest_init; 961 inst->alg.update = crypto_cbcmac_digest_update; 962 inst->alg.final = crypto_cbcmac_digest_final; 963 inst->alg.setkey = crypto_cbcmac_digest_setkey; 964 965 err = shash_register_instance(tmpl, inst); 966 967 out_free_inst: 968 if (err) 969 shash_free_instance(shash_crypto_instance(inst)); 970 971 out_put_alg: 972 crypto_mod_put(alg); 973 return err; 974 } 975 976 static struct crypto_template crypto_ccm_tmpls[] = { 977 { 978 .name = "cbcmac", 979 .create = cbcmac_create, 980 .free = shash_free_instance, 981 .module = THIS_MODULE, 982 }, { 983 .name = "ccm_base", 984 .create = crypto_ccm_base_create, 985 .module = THIS_MODULE, 986 }, { 987 .name = "ccm", 988 .create = crypto_ccm_create, 989 .module = THIS_MODULE, 990 }, { 991 .name = "rfc4309", 992 .create = crypto_rfc4309_create, 993 .module = THIS_MODULE, 994 }, 995 }; 996 997 static int __init crypto_ccm_module_init(void) 998 { 999 return crypto_register_templates(crypto_ccm_tmpls, 1000 ARRAY_SIZE(crypto_ccm_tmpls)); 1001 } 1002 1003 static void __exit crypto_ccm_module_exit(void) 1004 { 1005 crypto_unregister_templates(crypto_ccm_tmpls, 1006 ARRAY_SIZE(crypto_ccm_tmpls)); 1007 } 1008 1009 subsys_initcall(crypto_ccm_module_init); 1010 module_exit(crypto_ccm_module_exit); 1011 1012 MODULE_LICENSE("GPL"); 1013 MODULE_DESCRIPTION("Counter with CBC MAC"); 1014 MODULE_ALIAS_CRYPTO("ccm_base"); 1015 MODULE_ALIAS_CRYPTO("rfc4309"); 1016 MODULE_ALIAS_CRYPTO("ccm"); 1017