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 auth_tag[16]; 49 u32 flags; 50 struct scatterlist src[3]; 51 struct scatterlist dst[3]; 52 struct skcipher_request skreq; 53 }; 54 55 struct cbcmac_tfm_ctx { 56 struct crypto_cipher *child; 57 }; 58 59 struct cbcmac_desc_ctx { 60 unsigned int len; 61 }; 62 63 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx( 64 struct aead_request *req) 65 { 66 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); 67 68 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); 69 } 70 71 static int set_msg_len(u8 *block, unsigned int msglen, int csize) 72 { 73 __be32 data; 74 75 memset(block, 0, csize); 76 block += csize; 77 78 if (csize >= 4) 79 csize = 4; 80 else if (msglen > (1 << (8 * csize))) 81 return -EOVERFLOW; 82 83 data = cpu_to_be32(msglen); 84 memcpy(block - csize, (u8 *)&data + 4 - csize, csize); 85 86 return 0; 87 } 88 89 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key, 90 unsigned int keylen) 91 { 92 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 93 struct crypto_skcipher *ctr = ctx->ctr; 94 struct crypto_ahash *mac = ctx->mac; 95 int err = 0; 96 97 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); 98 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) & 99 CRYPTO_TFM_REQ_MASK); 100 err = crypto_skcipher_setkey(ctr, key, keylen); 101 crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) & 102 CRYPTO_TFM_RES_MASK); 103 if (err) 104 goto out; 105 106 crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK); 107 crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) & 108 CRYPTO_TFM_REQ_MASK); 109 err = crypto_ahash_setkey(mac, key, keylen); 110 crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) & 111 CRYPTO_TFM_RES_MASK); 112 113 out: 114 return err; 115 } 116 117 static int crypto_ccm_setauthsize(struct crypto_aead *tfm, 118 unsigned int authsize) 119 { 120 switch (authsize) { 121 case 4: 122 case 6: 123 case 8: 124 case 10: 125 case 12: 126 case 14: 127 case 16: 128 break; 129 default: 130 return -EINVAL; 131 } 132 133 return 0; 134 } 135 136 static int format_input(u8 *info, struct aead_request *req, 137 unsigned int cryptlen) 138 { 139 struct crypto_aead *aead = crypto_aead_reqtfm(req); 140 unsigned int lp = req->iv[0]; 141 unsigned int l = lp + 1; 142 unsigned int m; 143 144 m = crypto_aead_authsize(aead); 145 146 memcpy(info, req->iv, 16); 147 148 /* format control info per RFC 3610 and 149 * NIST Special Publication 800-38C 150 */ 151 *info |= (8 * ((m - 2) / 2)); 152 if (req->assoclen) 153 *info |= 64; 154 155 return set_msg_len(info + 16 - l, cryptlen, l); 156 } 157 158 static int format_adata(u8 *adata, unsigned int a) 159 { 160 int len = 0; 161 162 /* add control info for associated data 163 * RFC 3610 and NIST Special Publication 800-38C 164 */ 165 if (a < 65280) { 166 *(__be16 *)adata = cpu_to_be16(a); 167 len = 2; 168 } else { 169 *(__be16 *)adata = cpu_to_be16(0xfffe); 170 *(__be32 *)&adata[2] = cpu_to_be32(a); 171 len = 6; 172 } 173 174 return len; 175 } 176 177 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain, 178 unsigned int cryptlen) 179 { 180 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 181 struct crypto_aead *aead = crypto_aead_reqtfm(req); 182 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 183 AHASH_REQUEST_ON_STACK(ahreq, ctx->mac); 184 unsigned int assoclen = req->assoclen; 185 struct scatterlist sg[3]; 186 u8 odata[16]; 187 u8 idata[16]; 188 int ilen, err; 189 190 /* format control data for input */ 191 err = format_input(odata, req, cryptlen); 192 if (err) 193 goto out; 194 195 sg_init_table(sg, 3); 196 sg_set_buf(&sg[0], odata, 16); 197 198 /* format associated data and compute into mac */ 199 if (assoclen) { 200 ilen = format_adata(idata, assoclen); 201 sg_set_buf(&sg[1], idata, ilen); 202 sg_chain(sg, 3, req->src); 203 } else { 204 ilen = 0; 205 sg_chain(sg, 2, req->src); 206 } 207 208 ahash_request_set_tfm(ahreq, ctx->mac); 209 ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL); 210 ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16); 211 err = crypto_ahash_init(ahreq); 212 if (err) 213 goto out; 214 err = crypto_ahash_update(ahreq); 215 if (err) 216 goto out; 217 218 /* we need to pad the MAC input to a round multiple of the block size */ 219 ilen = 16 - (assoclen + ilen) % 16; 220 if (ilen < 16) { 221 memset(idata, 0, ilen); 222 sg_init_table(sg, 2); 223 sg_set_buf(&sg[0], idata, ilen); 224 if (plain) 225 sg_chain(sg, 2, plain); 226 plain = sg; 227 cryptlen += ilen; 228 } 229 230 ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen); 231 err = crypto_ahash_finup(ahreq); 232 out: 233 return err; 234 } 235 236 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err) 237 { 238 struct aead_request *req = areq->data; 239 struct crypto_aead *aead = crypto_aead_reqtfm(req); 240 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 241 u8 *odata = pctx->odata; 242 243 if (!err) 244 scatterwalk_map_and_copy(odata, req->dst, 245 req->assoclen + req->cryptlen, 246 crypto_aead_authsize(aead), 1); 247 aead_request_complete(req, err); 248 } 249 250 static inline int crypto_ccm_check_iv(const u8 *iv) 251 { 252 /* 2 <= L <= 8, so 1 <= L' <= 7. */ 253 if (1 > iv[0] || iv[0] > 7) 254 return -EINVAL; 255 256 return 0; 257 } 258 259 static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag) 260 { 261 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 262 struct scatterlist *sg; 263 u8 *iv = req->iv; 264 int err; 265 266 err = crypto_ccm_check_iv(iv); 267 if (err) 268 return err; 269 270 pctx->flags = aead_request_flags(req); 271 272 /* Note: rfc 3610 and NIST 800-38C require counter of 273 * zero to encrypt auth tag. 274 */ 275 memset(iv + 15 - iv[0], 0, iv[0] + 1); 276 277 sg_init_table(pctx->src, 3); 278 sg_set_buf(pctx->src, tag, 16); 279 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen); 280 if (sg != pctx->src + 1) 281 sg_chain(pctx->src, 2, sg); 282 283 if (req->src != req->dst) { 284 sg_init_table(pctx->dst, 3); 285 sg_set_buf(pctx->dst, tag, 16); 286 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen); 287 if (sg != pctx->dst + 1) 288 sg_chain(pctx->dst, 2, sg); 289 } 290 291 return 0; 292 } 293 294 static int crypto_ccm_encrypt(struct aead_request *req) 295 { 296 struct crypto_aead *aead = crypto_aead_reqtfm(req); 297 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 298 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 299 struct skcipher_request *skreq = &pctx->skreq; 300 struct scatterlist *dst; 301 unsigned int cryptlen = req->cryptlen; 302 u8 *odata = pctx->odata; 303 u8 *iv = req->iv; 304 int err; 305 306 err = crypto_ccm_init_crypt(req, odata); 307 if (err) 308 return err; 309 310 err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen); 311 if (err) 312 return err; 313 314 dst = pctx->src; 315 if (req->src != req->dst) 316 dst = pctx->dst; 317 318 skcipher_request_set_tfm(skreq, ctx->ctr); 319 skcipher_request_set_callback(skreq, pctx->flags, 320 crypto_ccm_encrypt_done, req); 321 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv); 322 err = crypto_skcipher_encrypt(skreq); 323 if (err) 324 return err; 325 326 /* copy authtag to end of dst */ 327 scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen, 328 crypto_aead_authsize(aead), 1); 329 return err; 330 } 331 332 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq, 333 int err) 334 { 335 struct aead_request *req = areq->data; 336 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 337 struct crypto_aead *aead = crypto_aead_reqtfm(req); 338 unsigned int authsize = crypto_aead_authsize(aead); 339 unsigned int cryptlen = req->cryptlen - authsize; 340 struct scatterlist *dst; 341 342 pctx->flags = 0; 343 344 dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst); 345 346 if (!err) { 347 err = crypto_ccm_auth(req, dst, cryptlen); 348 if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize)) 349 err = -EBADMSG; 350 } 351 aead_request_complete(req, err); 352 } 353 354 static int crypto_ccm_decrypt(struct aead_request *req) 355 { 356 struct crypto_aead *aead = crypto_aead_reqtfm(req); 357 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 358 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 359 struct skcipher_request *skreq = &pctx->skreq; 360 struct scatterlist *dst; 361 unsigned int authsize = crypto_aead_authsize(aead); 362 unsigned int cryptlen = req->cryptlen; 363 u8 *authtag = pctx->auth_tag; 364 u8 *odata = pctx->odata; 365 u8 *iv = req->iv; 366 int err; 367 368 cryptlen -= authsize; 369 370 err = crypto_ccm_init_crypt(req, authtag); 371 if (err) 372 return err; 373 374 scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen, 375 authsize, 0); 376 377 dst = pctx->src; 378 if (req->src != req->dst) 379 dst = pctx->dst; 380 381 skcipher_request_set_tfm(skreq, ctx->ctr); 382 skcipher_request_set_callback(skreq, pctx->flags, 383 crypto_ccm_decrypt_done, req); 384 skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv); 385 err = crypto_skcipher_decrypt(skreq); 386 if (err) 387 return err; 388 389 err = crypto_ccm_auth(req, sg_next(dst), cryptlen); 390 if (err) 391 return err; 392 393 /* verify */ 394 if (crypto_memneq(authtag, odata, authsize)) 395 return -EBADMSG; 396 397 return err; 398 } 399 400 static int crypto_ccm_init_tfm(struct crypto_aead *tfm) 401 { 402 struct aead_instance *inst = aead_alg_instance(tfm); 403 struct ccm_instance_ctx *ictx = aead_instance_ctx(inst); 404 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm); 405 struct crypto_ahash *mac; 406 struct crypto_skcipher *ctr; 407 unsigned long align; 408 int err; 409 410 mac = crypto_spawn_ahash(&ictx->mac); 411 if (IS_ERR(mac)) 412 return PTR_ERR(mac); 413 414 ctr = crypto_spawn_skcipher(&ictx->ctr); 415 err = PTR_ERR(ctr); 416 if (IS_ERR(ctr)) 417 goto err_free_mac; 418 419 ctx->mac = mac; 420 ctx->ctr = ctr; 421 422 align = crypto_aead_alignmask(tfm); 423 align &= ~(crypto_tfm_ctx_alignment() - 1); 424 crypto_aead_set_reqsize( 425 tfm, 426 align + sizeof(struct crypto_ccm_req_priv_ctx) + 427 crypto_skcipher_reqsize(ctr)); 428 429 return 0; 430 431 err_free_mac: 432 crypto_free_ahash(mac); 433 return err; 434 } 435 436 static void crypto_ccm_exit_tfm(struct crypto_aead *tfm) 437 { 438 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm); 439 440 crypto_free_ahash(ctx->mac); 441 crypto_free_skcipher(ctx->ctr); 442 } 443 444 static void crypto_ccm_free(struct aead_instance *inst) 445 { 446 struct ccm_instance_ctx *ctx = aead_instance_ctx(inst); 447 448 crypto_drop_ahash(&ctx->mac); 449 crypto_drop_skcipher(&ctx->ctr); 450 kfree(inst); 451 } 452 453 static int crypto_ccm_create_common(struct crypto_template *tmpl, 454 struct rtattr **tb, 455 const char *full_name, 456 const char *ctr_name, 457 const char *mac_name) 458 { 459 struct crypto_attr_type *algt; 460 struct aead_instance *inst; 461 struct skcipher_alg *ctr; 462 struct crypto_alg *mac_alg; 463 struct hash_alg_common *mac; 464 struct ccm_instance_ctx *ictx; 465 int err; 466 467 algt = crypto_get_attr_type(tb); 468 if (IS_ERR(algt)) 469 return PTR_ERR(algt); 470 471 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 472 return -EINVAL; 473 474 mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type, 475 CRYPTO_ALG_TYPE_HASH, 476 CRYPTO_ALG_TYPE_AHASH_MASK | 477 CRYPTO_ALG_ASYNC); 478 if (IS_ERR(mac_alg)) 479 return PTR_ERR(mac_alg); 480 481 mac = __crypto_hash_alg_common(mac_alg); 482 err = -EINVAL; 483 if (mac->digestsize != 16) 484 goto out_put_mac; 485 486 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL); 487 err = -ENOMEM; 488 if (!inst) 489 goto out_put_mac; 490 491 ictx = aead_instance_ctx(inst); 492 err = crypto_init_ahash_spawn(&ictx->mac, mac, 493 aead_crypto_instance(inst)); 494 if (err) 495 goto err_free_inst; 496 497 crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst)); 498 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0, 499 crypto_requires_sync(algt->type, 500 algt->mask)); 501 if (err) 502 goto err_drop_mac; 503 504 ctr = crypto_spawn_skcipher_alg(&ictx->ctr); 505 506 /* Not a stream cipher? */ 507 err = -EINVAL; 508 if (ctr->base.cra_blocksize != 1) 509 goto err_drop_ctr; 510 511 /* We want the real thing! */ 512 if (crypto_skcipher_alg_ivsize(ctr) != 16) 513 goto err_drop_ctr; 514 515 err = -ENAMETOOLONG; 516 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 517 "ccm_base(%s,%s)", ctr->base.cra_driver_name, 518 mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME) 519 goto err_drop_ctr; 520 521 memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME); 522 523 inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC; 524 inst->alg.base.cra_priority = (mac->base.cra_priority + 525 ctr->base.cra_priority) / 2; 526 inst->alg.base.cra_blocksize = 1; 527 inst->alg.base.cra_alignmask = mac->base.cra_alignmask | 528 ctr->base.cra_alignmask; 529 inst->alg.ivsize = 16; 530 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr); 531 inst->alg.maxauthsize = 16; 532 inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx); 533 inst->alg.init = crypto_ccm_init_tfm; 534 inst->alg.exit = crypto_ccm_exit_tfm; 535 inst->alg.setkey = crypto_ccm_setkey; 536 inst->alg.setauthsize = crypto_ccm_setauthsize; 537 inst->alg.encrypt = crypto_ccm_encrypt; 538 inst->alg.decrypt = crypto_ccm_decrypt; 539 540 inst->free = crypto_ccm_free; 541 542 err = aead_register_instance(tmpl, inst); 543 if (err) 544 goto err_drop_ctr; 545 546 out_put_mac: 547 crypto_mod_put(mac_alg); 548 return err; 549 550 err_drop_ctr: 551 crypto_drop_skcipher(&ictx->ctr); 552 err_drop_mac: 553 crypto_drop_ahash(&ictx->mac); 554 err_free_inst: 555 kfree(inst); 556 goto out_put_mac; 557 } 558 559 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb) 560 { 561 const char *cipher_name; 562 char ctr_name[CRYPTO_MAX_ALG_NAME]; 563 char mac_name[CRYPTO_MAX_ALG_NAME]; 564 char full_name[CRYPTO_MAX_ALG_NAME]; 565 566 cipher_name = crypto_attr_alg_name(tb[1]); 567 if (IS_ERR(cipher_name)) 568 return PTR_ERR(cipher_name); 569 570 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", 571 cipher_name) >= CRYPTO_MAX_ALG_NAME) 572 return -ENAMETOOLONG; 573 574 if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)", 575 cipher_name) >= CRYPTO_MAX_ALG_NAME) 576 return -ENAMETOOLONG; 577 578 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >= 579 CRYPTO_MAX_ALG_NAME) 580 return -ENAMETOOLONG; 581 582 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name, 583 mac_name); 584 } 585 586 static struct crypto_template crypto_ccm_tmpl = { 587 .name = "ccm", 588 .create = crypto_ccm_create, 589 .module = THIS_MODULE, 590 }; 591 592 static int crypto_ccm_base_create(struct crypto_template *tmpl, 593 struct rtattr **tb) 594 { 595 const char *ctr_name; 596 const char *cipher_name; 597 char full_name[CRYPTO_MAX_ALG_NAME]; 598 599 ctr_name = crypto_attr_alg_name(tb[1]); 600 if (IS_ERR(ctr_name)) 601 return PTR_ERR(ctr_name); 602 603 cipher_name = crypto_attr_alg_name(tb[2]); 604 if (IS_ERR(cipher_name)) 605 return PTR_ERR(cipher_name); 606 607 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)", 608 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME) 609 return -ENAMETOOLONG; 610 611 return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name, 612 cipher_name); 613 } 614 615 static struct crypto_template crypto_ccm_base_tmpl = { 616 .name = "ccm_base", 617 .create = crypto_ccm_base_create, 618 .module = THIS_MODULE, 619 }; 620 621 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key, 622 unsigned int keylen) 623 { 624 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent); 625 struct crypto_aead *child = ctx->child; 626 int err; 627 628 if (keylen < 3) 629 return -EINVAL; 630 631 keylen -= 3; 632 memcpy(ctx->nonce, key + keylen, 3); 633 634 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 635 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 636 CRYPTO_TFM_REQ_MASK); 637 err = crypto_aead_setkey(child, key, keylen); 638 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) & 639 CRYPTO_TFM_RES_MASK); 640 641 return err; 642 } 643 644 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent, 645 unsigned int authsize) 646 { 647 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent); 648 649 switch (authsize) { 650 case 8: 651 case 12: 652 case 16: 653 break; 654 default: 655 return -EINVAL; 656 } 657 658 return crypto_aead_setauthsize(ctx->child, authsize); 659 } 660 661 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req) 662 { 663 struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req); 664 struct aead_request *subreq = &rctx->subreq; 665 struct crypto_aead *aead = crypto_aead_reqtfm(req); 666 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead); 667 struct crypto_aead *child = ctx->child; 668 struct scatterlist *sg; 669 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child), 670 crypto_aead_alignmask(child) + 1); 671 672 /* L' */ 673 iv[0] = 3; 674 675 memcpy(iv + 1, ctx->nonce, 3); 676 memcpy(iv + 4, req->iv, 8); 677 678 scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0); 679 680 sg_init_table(rctx->src, 3); 681 sg_set_buf(rctx->src, iv + 16, req->assoclen - 8); 682 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen); 683 if (sg != rctx->src + 1) 684 sg_chain(rctx->src, 2, sg); 685 686 if (req->src != req->dst) { 687 sg_init_table(rctx->dst, 3); 688 sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8); 689 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen); 690 if (sg != rctx->dst + 1) 691 sg_chain(rctx->dst, 2, sg); 692 } 693 694 aead_request_set_tfm(subreq, child); 695 aead_request_set_callback(subreq, req->base.flags, req->base.complete, 696 req->base.data); 697 aead_request_set_crypt(subreq, rctx->src, 698 req->src == req->dst ? rctx->src : rctx->dst, 699 req->cryptlen, iv); 700 aead_request_set_ad(subreq, req->assoclen - 8); 701 702 return subreq; 703 } 704 705 static int crypto_rfc4309_encrypt(struct aead_request *req) 706 { 707 if (req->assoclen != 16 && req->assoclen != 20) 708 return -EINVAL; 709 710 req = crypto_rfc4309_crypt(req); 711 712 return crypto_aead_encrypt(req); 713 } 714 715 static int crypto_rfc4309_decrypt(struct aead_request *req) 716 { 717 if (req->assoclen != 16 && req->assoclen != 20) 718 return -EINVAL; 719 720 req = crypto_rfc4309_crypt(req); 721 722 return crypto_aead_decrypt(req); 723 } 724 725 static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm) 726 { 727 struct aead_instance *inst = aead_alg_instance(tfm); 728 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst); 729 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm); 730 struct crypto_aead *aead; 731 unsigned long align; 732 733 aead = crypto_spawn_aead(spawn); 734 if (IS_ERR(aead)) 735 return PTR_ERR(aead); 736 737 ctx->child = aead; 738 739 align = crypto_aead_alignmask(aead); 740 align &= ~(crypto_tfm_ctx_alignment() - 1); 741 crypto_aead_set_reqsize( 742 tfm, 743 sizeof(struct crypto_rfc4309_req_ctx) + 744 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + 745 align + 32); 746 747 return 0; 748 } 749 750 static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm) 751 { 752 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm); 753 754 crypto_free_aead(ctx->child); 755 } 756 757 static void crypto_rfc4309_free(struct aead_instance *inst) 758 { 759 crypto_drop_aead(aead_instance_ctx(inst)); 760 kfree(inst); 761 } 762 763 static int crypto_rfc4309_create(struct crypto_template *tmpl, 764 struct rtattr **tb) 765 { 766 struct crypto_attr_type *algt; 767 struct aead_instance *inst; 768 struct crypto_aead_spawn *spawn; 769 struct aead_alg *alg; 770 const char *ccm_name; 771 int err; 772 773 algt = crypto_get_attr_type(tb); 774 if (IS_ERR(algt)) 775 return PTR_ERR(algt); 776 777 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 778 return -EINVAL; 779 780 ccm_name = crypto_attr_alg_name(tb[1]); 781 if (IS_ERR(ccm_name)) 782 return PTR_ERR(ccm_name); 783 784 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 785 if (!inst) 786 return -ENOMEM; 787 788 spawn = aead_instance_ctx(inst); 789 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst)); 790 err = crypto_grab_aead(spawn, ccm_name, 0, 791 crypto_requires_sync(algt->type, algt->mask)); 792 if (err) 793 goto out_free_inst; 794 795 alg = crypto_spawn_aead_alg(spawn); 796 797 err = -EINVAL; 798 799 /* We only support 16-byte blocks. */ 800 if (crypto_aead_alg_ivsize(alg) != 16) 801 goto out_drop_alg; 802 803 /* Not a stream cipher? */ 804 if (alg->base.cra_blocksize != 1) 805 goto out_drop_alg; 806 807 err = -ENAMETOOLONG; 808 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 809 "rfc4309(%s)", alg->base.cra_name) >= 810 CRYPTO_MAX_ALG_NAME || 811 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 812 "rfc4309(%s)", alg->base.cra_driver_name) >= 813 CRYPTO_MAX_ALG_NAME) 814 goto out_drop_alg; 815 816 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC; 817 inst->alg.base.cra_priority = alg->base.cra_priority; 818 inst->alg.base.cra_blocksize = 1; 819 inst->alg.base.cra_alignmask = alg->base.cra_alignmask; 820 821 inst->alg.ivsize = 8; 822 inst->alg.chunksize = crypto_aead_alg_chunksize(alg); 823 inst->alg.maxauthsize = 16; 824 825 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx); 826 827 inst->alg.init = crypto_rfc4309_init_tfm; 828 inst->alg.exit = crypto_rfc4309_exit_tfm; 829 830 inst->alg.setkey = crypto_rfc4309_setkey; 831 inst->alg.setauthsize = crypto_rfc4309_setauthsize; 832 inst->alg.encrypt = crypto_rfc4309_encrypt; 833 inst->alg.decrypt = crypto_rfc4309_decrypt; 834 835 inst->free = crypto_rfc4309_free; 836 837 err = aead_register_instance(tmpl, inst); 838 if (err) 839 goto out_drop_alg; 840 841 out: 842 return err; 843 844 out_drop_alg: 845 crypto_drop_aead(spawn); 846 out_free_inst: 847 kfree(inst); 848 goto out; 849 } 850 851 static struct crypto_template crypto_rfc4309_tmpl = { 852 .name = "rfc4309", 853 .create = crypto_rfc4309_create, 854 .module = THIS_MODULE, 855 }; 856 857 static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent, 858 const u8 *inkey, unsigned int keylen) 859 { 860 struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent); 861 862 return crypto_cipher_setkey(ctx->child, inkey, keylen); 863 } 864 865 static int crypto_cbcmac_digest_init(struct shash_desc *pdesc) 866 { 867 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc); 868 int bs = crypto_shash_digestsize(pdesc->tfm); 869 u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs; 870 871 ctx->len = 0; 872 memset(dg, 0, bs); 873 874 return 0; 875 } 876 877 static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p, 878 unsigned int len) 879 { 880 struct crypto_shash *parent = pdesc->tfm; 881 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent); 882 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc); 883 struct crypto_cipher *tfm = tctx->child; 884 int bs = crypto_shash_digestsize(parent); 885 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs; 886 887 while (len > 0) { 888 unsigned int l = min(len, bs - ctx->len); 889 890 crypto_xor(dg + ctx->len, p, l); 891 ctx->len +=l; 892 len -= l; 893 p += l; 894 895 if (ctx->len == bs) { 896 crypto_cipher_encrypt_one(tfm, dg, dg); 897 ctx->len = 0; 898 } 899 } 900 901 return 0; 902 } 903 904 static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out) 905 { 906 struct crypto_shash *parent = pdesc->tfm; 907 struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent); 908 struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc); 909 struct crypto_cipher *tfm = tctx->child; 910 int bs = crypto_shash_digestsize(parent); 911 u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs; 912 913 if (ctx->len) 914 crypto_cipher_encrypt_one(tfm, dg, dg); 915 916 memcpy(out, dg, bs); 917 return 0; 918 } 919 920 static int cbcmac_init_tfm(struct crypto_tfm *tfm) 921 { 922 struct crypto_cipher *cipher; 923 struct crypto_instance *inst = (void *)tfm->__crt_alg; 924 struct crypto_spawn *spawn = crypto_instance_ctx(inst); 925 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm); 926 927 cipher = crypto_spawn_cipher(spawn); 928 if (IS_ERR(cipher)) 929 return PTR_ERR(cipher); 930 931 ctx->child = cipher; 932 933 return 0; 934 }; 935 936 static void cbcmac_exit_tfm(struct crypto_tfm *tfm) 937 { 938 struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm); 939 crypto_free_cipher(ctx->child); 940 } 941 942 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb) 943 { 944 struct shash_instance *inst; 945 struct crypto_alg *alg; 946 int err; 947 948 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH); 949 if (err) 950 return err; 951 952 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, 953 CRYPTO_ALG_TYPE_MASK); 954 if (IS_ERR(alg)) 955 return PTR_ERR(alg); 956 957 inst = shash_alloc_instance("cbcmac", alg); 958 err = PTR_ERR(inst); 959 if (IS_ERR(inst)) 960 goto out_put_alg; 961 962 err = crypto_init_spawn(shash_instance_ctx(inst), alg, 963 shash_crypto_instance(inst), 964 CRYPTO_ALG_TYPE_MASK); 965 if (err) 966 goto out_free_inst; 967 968 inst->alg.base.cra_priority = alg->cra_priority; 969 inst->alg.base.cra_blocksize = 1; 970 971 inst->alg.digestsize = alg->cra_blocksize; 972 inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx), 973 alg->cra_alignmask + 1) + 974 alg->cra_blocksize; 975 976 inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx); 977 inst->alg.base.cra_init = cbcmac_init_tfm; 978 inst->alg.base.cra_exit = cbcmac_exit_tfm; 979 980 inst->alg.init = crypto_cbcmac_digest_init; 981 inst->alg.update = crypto_cbcmac_digest_update; 982 inst->alg.final = crypto_cbcmac_digest_final; 983 inst->alg.setkey = crypto_cbcmac_digest_setkey; 984 985 err = shash_register_instance(tmpl, inst); 986 987 out_free_inst: 988 if (err) 989 shash_free_instance(shash_crypto_instance(inst)); 990 991 out_put_alg: 992 crypto_mod_put(alg); 993 return err; 994 } 995 996 static struct crypto_template crypto_cbcmac_tmpl = { 997 .name = "cbcmac", 998 .create = cbcmac_create, 999 .free = shash_free_instance, 1000 .module = THIS_MODULE, 1001 }; 1002 1003 static int __init crypto_ccm_module_init(void) 1004 { 1005 int err; 1006 1007 err = crypto_register_template(&crypto_cbcmac_tmpl); 1008 if (err) 1009 goto out; 1010 1011 err = crypto_register_template(&crypto_ccm_base_tmpl); 1012 if (err) 1013 goto out_undo_cbcmac; 1014 1015 err = crypto_register_template(&crypto_ccm_tmpl); 1016 if (err) 1017 goto out_undo_base; 1018 1019 err = crypto_register_template(&crypto_rfc4309_tmpl); 1020 if (err) 1021 goto out_undo_ccm; 1022 1023 out: 1024 return err; 1025 1026 out_undo_ccm: 1027 crypto_unregister_template(&crypto_ccm_tmpl); 1028 out_undo_base: 1029 crypto_unregister_template(&crypto_ccm_base_tmpl); 1030 out_undo_cbcmac: 1031 crypto_register_template(&crypto_cbcmac_tmpl); 1032 goto out; 1033 } 1034 1035 static void __exit crypto_ccm_module_exit(void) 1036 { 1037 crypto_unregister_template(&crypto_rfc4309_tmpl); 1038 crypto_unregister_template(&crypto_ccm_tmpl); 1039 crypto_unregister_template(&crypto_ccm_base_tmpl); 1040 crypto_unregister_template(&crypto_cbcmac_tmpl); 1041 } 1042 1043 module_init(crypto_ccm_module_init); 1044 module_exit(crypto_ccm_module_exit); 1045 1046 MODULE_LICENSE("GPL"); 1047 MODULE_DESCRIPTION("Counter with CBC MAC"); 1048 MODULE_ALIAS_CRYPTO("ccm_base"); 1049 MODULE_ALIAS_CRYPTO("rfc4309"); 1050 MODULE_ALIAS_CRYPTO("ccm"); 1051