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/skcipher.h> 15 #include <crypto/scatterwalk.h> 16 #include <linux/err.h> 17 #include <linux/init.h> 18 #include <linux/kernel.h> 19 #include <linux/module.h> 20 #include <linux/slab.h> 21 22 #include "internal.h" 23 24 struct ccm_instance_ctx { 25 struct crypto_skcipher_spawn ctr; 26 struct crypto_spawn cipher; 27 }; 28 29 struct crypto_ccm_ctx { 30 struct crypto_cipher *cipher; 31 struct crypto_ablkcipher *ctr; 32 }; 33 34 struct crypto_rfc4309_ctx { 35 struct crypto_aead *child; 36 u8 nonce[3]; 37 }; 38 39 struct crypto_ccm_req_priv_ctx { 40 u8 odata[16]; 41 u8 idata[16]; 42 u8 auth_tag[16]; 43 u32 ilen; 44 u32 flags; 45 struct scatterlist src[2]; 46 struct scatterlist dst[2]; 47 struct ablkcipher_request abreq; 48 }; 49 50 static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx( 51 struct aead_request *req) 52 { 53 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); 54 55 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); 56 } 57 58 static int set_msg_len(u8 *block, unsigned int msglen, int csize) 59 { 60 __be32 data; 61 62 memset(block, 0, csize); 63 block += csize; 64 65 if (csize >= 4) 66 csize = 4; 67 else if (msglen > (1 << (8 * csize))) 68 return -EOVERFLOW; 69 70 data = cpu_to_be32(msglen); 71 memcpy(block - csize, (u8 *)&data + 4 - csize, csize); 72 73 return 0; 74 } 75 76 static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key, 77 unsigned int keylen) 78 { 79 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 80 struct crypto_ablkcipher *ctr = ctx->ctr; 81 struct crypto_cipher *tfm = ctx->cipher; 82 int err = 0; 83 84 crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); 85 crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) & 86 CRYPTO_TFM_REQ_MASK); 87 err = crypto_ablkcipher_setkey(ctr, key, keylen); 88 crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) & 89 CRYPTO_TFM_RES_MASK); 90 if (err) 91 goto out; 92 93 crypto_cipher_clear_flags(tfm, CRYPTO_TFM_REQ_MASK); 94 crypto_cipher_set_flags(tfm, crypto_aead_get_flags(aead) & 95 CRYPTO_TFM_REQ_MASK); 96 err = crypto_cipher_setkey(tfm, key, keylen); 97 crypto_aead_set_flags(aead, crypto_cipher_get_flags(tfm) & 98 CRYPTO_TFM_RES_MASK); 99 100 out: 101 return err; 102 } 103 104 static int crypto_ccm_setauthsize(struct crypto_aead *tfm, 105 unsigned int authsize) 106 { 107 switch (authsize) { 108 case 4: 109 case 6: 110 case 8: 111 case 10: 112 case 12: 113 case 14: 114 case 16: 115 break; 116 default: 117 return -EINVAL; 118 } 119 120 return 0; 121 } 122 123 static int format_input(u8 *info, struct aead_request *req, 124 unsigned int cryptlen) 125 { 126 struct crypto_aead *aead = crypto_aead_reqtfm(req); 127 unsigned int lp = req->iv[0]; 128 unsigned int l = lp + 1; 129 unsigned int m; 130 131 m = crypto_aead_authsize(aead); 132 133 memcpy(info, req->iv, 16); 134 135 /* format control info per RFC 3610 and 136 * NIST Special Publication 800-38C 137 */ 138 *info |= (8 * ((m - 2) / 2)); 139 if (req->assoclen) 140 *info |= 64; 141 142 return set_msg_len(info + 16 - l, cryptlen, l); 143 } 144 145 static int format_adata(u8 *adata, unsigned int a) 146 { 147 int len = 0; 148 149 /* add control info for associated data 150 * RFC 3610 and NIST Special Publication 800-38C 151 */ 152 if (a < 65280) { 153 *(__be16 *)adata = cpu_to_be16(a); 154 len = 2; 155 } else { 156 *(__be16 *)adata = cpu_to_be16(0xfffe); 157 *(__be32 *)&adata[2] = cpu_to_be32(a); 158 len = 6; 159 } 160 161 return len; 162 } 163 164 static void compute_mac(struct crypto_cipher *tfm, u8 *data, int n, 165 struct crypto_ccm_req_priv_ctx *pctx) 166 { 167 unsigned int bs = 16; 168 u8 *odata = pctx->odata; 169 u8 *idata = pctx->idata; 170 int datalen, getlen; 171 172 datalen = n; 173 174 /* first time in here, block may be partially filled. */ 175 getlen = bs - pctx->ilen; 176 if (datalen >= getlen) { 177 memcpy(idata + pctx->ilen, data, getlen); 178 crypto_xor(odata, idata, bs); 179 crypto_cipher_encrypt_one(tfm, odata, odata); 180 datalen -= getlen; 181 data += getlen; 182 pctx->ilen = 0; 183 } 184 185 /* now encrypt rest of data */ 186 while (datalen >= bs) { 187 crypto_xor(odata, data, bs); 188 crypto_cipher_encrypt_one(tfm, odata, odata); 189 190 datalen -= bs; 191 data += bs; 192 } 193 194 /* check and see if there's leftover data that wasn't 195 * enough to fill a block. 196 */ 197 if (datalen) { 198 memcpy(idata + pctx->ilen, data, datalen); 199 pctx->ilen += datalen; 200 } 201 } 202 203 static void get_data_to_compute(struct crypto_cipher *tfm, 204 struct crypto_ccm_req_priv_ctx *pctx, 205 struct scatterlist *sg, unsigned int len) 206 { 207 struct scatter_walk walk; 208 u8 *data_src; 209 int n; 210 211 scatterwalk_start(&walk, sg); 212 213 while (len) { 214 n = scatterwalk_clamp(&walk, len); 215 if (!n) { 216 scatterwalk_start(&walk, sg_next(walk.sg)); 217 n = scatterwalk_clamp(&walk, len); 218 } 219 data_src = scatterwalk_map(&walk, 0); 220 221 compute_mac(tfm, data_src, n, pctx); 222 len -= n; 223 224 scatterwalk_unmap(data_src, 0); 225 scatterwalk_advance(&walk, n); 226 scatterwalk_done(&walk, 0, len); 227 if (len) 228 crypto_yield(pctx->flags); 229 } 230 231 /* any leftover needs padding and then encrypted */ 232 if (pctx->ilen) { 233 int padlen; 234 u8 *odata = pctx->odata; 235 u8 *idata = pctx->idata; 236 237 padlen = 16 - pctx->ilen; 238 memset(idata + pctx->ilen, 0, padlen); 239 crypto_xor(odata, idata, 16); 240 crypto_cipher_encrypt_one(tfm, odata, odata); 241 pctx->ilen = 0; 242 } 243 } 244 245 static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain, 246 unsigned int cryptlen) 247 { 248 struct crypto_aead *aead = crypto_aead_reqtfm(req); 249 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 250 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 251 struct crypto_cipher *cipher = ctx->cipher; 252 unsigned int assoclen = req->assoclen; 253 u8 *odata = pctx->odata; 254 u8 *idata = pctx->idata; 255 int err; 256 257 /* format control data for input */ 258 err = format_input(odata, req, cryptlen); 259 if (err) 260 goto out; 261 262 /* encrypt first block to use as start in computing mac */ 263 crypto_cipher_encrypt_one(cipher, odata, odata); 264 265 /* format associated data and compute into mac */ 266 if (assoclen) { 267 pctx->ilen = format_adata(idata, assoclen); 268 get_data_to_compute(cipher, pctx, req->assoc, req->assoclen); 269 } 270 271 /* compute plaintext into mac */ 272 get_data_to_compute(cipher, pctx, plain, cryptlen); 273 274 out: 275 return err; 276 } 277 278 static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err) 279 { 280 struct aead_request *req = areq->data; 281 struct crypto_aead *aead = crypto_aead_reqtfm(req); 282 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 283 u8 *odata = pctx->odata; 284 285 if (!err) 286 scatterwalk_map_and_copy(odata, req->dst, req->cryptlen, 287 crypto_aead_authsize(aead), 1); 288 aead_request_complete(req, err); 289 } 290 291 static inline int crypto_ccm_check_iv(const u8 *iv) 292 { 293 /* 2 <= L <= 8, so 1 <= L' <= 7. */ 294 if (1 > iv[0] || iv[0] > 7) 295 return -EINVAL; 296 297 return 0; 298 } 299 300 static int crypto_ccm_encrypt(struct aead_request *req) 301 { 302 struct crypto_aead *aead = crypto_aead_reqtfm(req); 303 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 304 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 305 struct ablkcipher_request *abreq = &pctx->abreq; 306 struct scatterlist *dst; 307 unsigned int cryptlen = req->cryptlen; 308 u8 *odata = pctx->odata; 309 u8 *iv = req->iv; 310 int err; 311 312 err = crypto_ccm_check_iv(iv); 313 if (err) 314 return err; 315 316 pctx->flags = aead_request_flags(req); 317 318 err = crypto_ccm_auth(req, req->src, cryptlen); 319 if (err) 320 return err; 321 322 /* Note: rfc 3610 and NIST 800-38C require counter of 323 * zero to encrypt auth tag. 324 */ 325 memset(iv + 15 - iv[0], 0, iv[0] + 1); 326 327 sg_init_table(pctx->src, 2); 328 sg_set_buf(pctx->src, odata, 16); 329 scatterwalk_sg_chain(pctx->src, 2, req->src); 330 331 dst = pctx->src; 332 if (req->src != req->dst) { 333 sg_init_table(pctx->dst, 2); 334 sg_set_buf(pctx->dst, odata, 16); 335 scatterwalk_sg_chain(pctx->dst, 2, req->dst); 336 dst = pctx->dst; 337 } 338 339 ablkcipher_request_set_tfm(abreq, ctx->ctr); 340 ablkcipher_request_set_callback(abreq, pctx->flags, 341 crypto_ccm_encrypt_done, req); 342 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv); 343 err = crypto_ablkcipher_encrypt(abreq); 344 if (err) 345 return err; 346 347 /* copy authtag to end of dst */ 348 scatterwalk_map_and_copy(odata, req->dst, cryptlen, 349 crypto_aead_authsize(aead), 1); 350 return err; 351 } 352 353 static void crypto_ccm_decrypt_done(struct crypto_async_request *areq, 354 int err) 355 { 356 struct aead_request *req = areq->data; 357 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 358 struct crypto_aead *aead = crypto_aead_reqtfm(req); 359 unsigned int authsize = crypto_aead_authsize(aead); 360 unsigned int cryptlen = req->cryptlen - authsize; 361 362 if (!err) { 363 err = crypto_ccm_auth(req, req->dst, cryptlen); 364 if (!err && memcmp(pctx->auth_tag, pctx->odata, authsize)) 365 err = -EBADMSG; 366 } 367 aead_request_complete(req, err); 368 } 369 370 static int crypto_ccm_decrypt(struct aead_request *req) 371 { 372 struct crypto_aead *aead = crypto_aead_reqtfm(req); 373 struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead); 374 struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req); 375 struct ablkcipher_request *abreq = &pctx->abreq; 376 struct scatterlist *dst; 377 unsigned int authsize = crypto_aead_authsize(aead); 378 unsigned int cryptlen = req->cryptlen; 379 u8 *authtag = pctx->auth_tag; 380 u8 *odata = pctx->odata; 381 u8 *iv = req->iv; 382 int err; 383 384 if (cryptlen < authsize) 385 return -EINVAL; 386 cryptlen -= authsize; 387 388 err = crypto_ccm_check_iv(iv); 389 if (err) 390 return err; 391 392 pctx->flags = aead_request_flags(req); 393 394 scatterwalk_map_and_copy(authtag, req->src, cryptlen, authsize, 0); 395 396 memset(iv + 15 - iv[0], 0, iv[0] + 1); 397 398 sg_init_table(pctx->src, 2); 399 sg_set_buf(pctx->src, authtag, 16); 400 scatterwalk_sg_chain(pctx->src, 2, req->src); 401 402 dst = pctx->src; 403 if (req->src != req->dst) { 404 sg_init_table(pctx->dst, 2); 405 sg_set_buf(pctx->dst, authtag, 16); 406 scatterwalk_sg_chain(pctx->dst, 2, req->dst); 407 dst = pctx->dst; 408 } 409 410 ablkcipher_request_set_tfm(abreq, ctx->ctr); 411 ablkcipher_request_set_callback(abreq, pctx->flags, 412 crypto_ccm_decrypt_done, req); 413 ablkcipher_request_set_crypt(abreq, pctx->src, dst, cryptlen + 16, iv); 414 err = crypto_ablkcipher_decrypt(abreq); 415 if (err) 416 return err; 417 418 err = crypto_ccm_auth(req, req->dst, cryptlen); 419 if (err) 420 return err; 421 422 /* verify */ 423 if (memcmp(authtag, odata, authsize)) 424 return -EBADMSG; 425 426 return err; 427 } 428 429 static int crypto_ccm_init_tfm(struct crypto_tfm *tfm) 430 { 431 struct crypto_instance *inst = (void *)tfm->__crt_alg; 432 struct ccm_instance_ctx *ictx = crypto_instance_ctx(inst); 433 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm); 434 struct crypto_cipher *cipher; 435 struct crypto_ablkcipher *ctr; 436 unsigned long align; 437 int err; 438 439 cipher = crypto_spawn_cipher(&ictx->cipher); 440 if (IS_ERR(cipher)) 441 return PTR_ERR(cipher); 442 443 ctr = crypto_spawn_skcipher(&ictx->ctr); 444 err = PTR_ERR(ctr); 445 if (IS_ERR(ctr)) 446 goto err_free_cipher; 447 448 ctx->cipher = cipher; 449 ctx->ctr = ctr; 450 451 align = crypto_tfm_alg_alignmask(tfm); 452 align &= ~(crypto_tfm_ctx_alignment() - 1); 453 tfm->crt_aead.reqsize = align + 454 sizeof(struct crypto_ccm_req_priv_ctx) + 455 crypto_ablkcipher_reqsize(ctr); 456 457 return 0; 458 459 err_free_cipher: 460 crypto_free_cipher(cipher); 461 return err; 462 } 463 464 static void crypto_ccm_exit_tfm(struct crypto_tfm *tfm) 465 { 466 struct crypto_ccm_ctx *ctx = crypto_tfm_ctx(tfm); 467 468 crypto_free_cipher(ctx->cipher); 469 crypto_free_ablkcipher(ctx->ctr); 470 } 471 472 static struct crypto_instance *crypto_ccm_alloc_common(struct rtattr **tb, 473 const char *full_name, 474 const char *ctr_name, 475 const char *cipher_name) 476 { 477 struct crypto_attr_type *algt; 478 struct crypto_instance *inst; 479 struct crypto_alg *ctr; 480 struct crypto_alg *cipher; 481 struct ccm_instance_ctx *ictx; 482 int err; 483 484 algt = crypto_get_attr_type(tb); 485 err = PTR_ERR(algt); 486 if (IS_ERR(algt)) 487 return ERR_PTR(err); 488 489 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 490 return ERR_PTR(-EINVAL); 491 492 cipher = crypto_alg_mod_lookup(cipher_name, CRYPTO_ALG_TYPE_CIPHER, 493 CRYPTO_ALG_TYPE_MASK); 494 err = PTR_ERR(cipher); 495 if (IS_ERR(cipher)) 496 return ERR_PTR(err); 497 498 err = -EINVAL; 499 if (cipher->cra_blocksize != 16) 500 goto out_put_cipher; 501 502 inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL); 503 err = -ENOMEM; 504 if (!inst) 505 goto out_put_cipher; 506 507 ictx = crypto_instance_ctx(inst); 508 509 err = crypto_init_spawn(&ictx->cipher, cipher, inst, 510 CRYPTO_ALG_TYPE_MASK); 511 if (err) 512 goto err_free_inst; 513 514 crypto_set_skcipher_spawn(&ictx->ctr, inst); 515 err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0, 516 crypto_requires_sync(algt->type, 517 algt->mask)); 518 if (err) 519 goto err_drop_cipher; 520 521 ctr = crypto_skcipher_spawn_alg(&ictx->ctr); 522 523 /* Not a stream cipher? */ 524 err = -EINVAL; 525 if (ctr->cra_blocksize != 1) 526 goto err_drop_ctr; 527 528 /* We want the real thing! */ 529 if (ctr->cra_ablkcipher.ivsize != 16) 530 goto err_drop_ctr; 531 532 err = -ENAMETOOLONG; 533 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, 534 "ccm_base(%s,%s)", ctr->cra_driver_name, 535 cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) 536 goto err_drop_ctr; 537 538 memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME); 539 540 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD; 541 inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC; 542 inst->alg.cra_priority = cipher->cra_priority + ctr->cra_priority; 543 inst->alg.cra_blocksize = 1; 544 inst->alg.cra_alignmask = cipher->cra_alignmask | ctr->cra_alignmask | 545 (__alignof__(u32) - 1); 546 inst->alg.cra_type = &crypto_aead_type; 547 inst->alg.cra_aead.ivsize = 16; 548 inst->alg.cra_aead.maxauthsize = 16; 549 inst->alg.cra_ctxsize = sizeof(struct crypto_ccm_ctx); 550 inst->alg.cra_init = crypto_ccm_init_tfm; 551 inst->alg.cra_exit = crypto_ccm_exit_tfm; 552 inst->alg.cra_aead.setkey = crypto_ccm_setkey; 553 inst->alg.cra_aead.setauthsize = crypto_ccm_setauthsize; 554 inst->alg.cra_aead.encrypt = crypto_ccm_encrypt; 555 inst->alg.cra_aead.decrypt = crypto_ccm_decrypt; 556 557 out: 558 crypto_mod_put(cipher); 559 return inst; 560 561 err_drop_ctr: 562 crypto_drop_skcipher(&ictx->ctr); 563 err_drop_cipher: 564 crypto_drop_spawn(&ictx->cipher); 565 err_free_inst: 566 kfree(inst); 567 out_put_cipher: 568 inst = ERR_PTR(err); 569 goto out; 570 } 571 572 static struct crypto_instance *crypto_ccm_alloc(struct rtattr **tb) 573 { 574 int err; 575 const char *cipher_name; 576 char ctr_name[CRYPTO_MAX_ALG_NAME]; 577 char full_name[CRYPTO_MAX_ALG_NAME]; 578 579 cipher_name = crypto_attr_alg_name(tb[1]); 580 err = PTR_ERR(cipher_name); 581 if (IS_ERR(cipher_name)) 582 return ERR_PTR(err); 583 584 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", 585 cipher_name) >= CRYPTO_MAX_ALG_NAME) 586 return ERR_PTR(-ENAMETOOLONG); 587 588 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >= 589 CRYPTO_MAX_ALG_NAME) 590 return ERR_PTR(-ENAMETOOLONG); 591 592 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name); 593 } 594 595 static void crypto_ccm_free(struct crypto_instance *inst) 596 { 597 struct ccm_instance_ctx *ctx = crypto_instance_ctx(inst); 598 599 crypto_drop_spawn(&ctx->cipher); 600 crypto_drop_skcipher(&ctx->ctr); 601 kfree(inst); 602 } 603 604 static struct crypto_template crypto_ccm_tmpl = { 605 .name = "ccm", 606 .alloc = crypto_ccm_alloc, 607 .free = crypto_ccm_free, 608 .module = THIS_MODULE, 609 }; 610 611 static struct crypto_instance *crypto_ccm_base_alloc(struct rtattr **tb) 612 { 613 int err; 614 const char *ctr_name; 615 const char *cipher_name; 616 char full_name[CRYPTO_MAX_ALG_NAME]; 617 618 ctr_name = crypto_attr_alg_name(tb[1]); 619 err = PTR_ERR(ctr_name); 620 if (IS_ERR(ctr_name)) 621 return ERR_PTR(err); 622 623 cipher_name = crypto_attr_alg_name(tb[2]); 624 err = PTR_ERR(cipher_name); 625 if (IS_ERR(cipher_name)) 626 return ERR_PTR(err); 627 628 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)", 629 ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME) 630 return ERR_PTR(-ENAMETOOLONG); 631 632 return crypto_ccm_alloc_common(tb, full_name, ctr_name, cipher_name); 633 } 634 635 static struct crypto_template crypto_ccm_base_tmpl = { 636 .name = "ccm_base", 637 .alloc = crypto_ccm_base_alloc, 638 .free = crypto_ccm_free, 639 .module = THIS_MODULE, 640 }; 641 642 static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key, 643 unsigned int keylen) 644 { 645 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent); 646 struct crypto_aead *child = ctx->child; 647 int err; 648 649 if (keylen < 3) 650 return -EINVAL; 651 652 keylen -= 3; 653 memcpy(ctx->nonce, key + keylen, 3); 654 655 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 656 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 657 CRYPTO_TFM_REQ_MASK); 658 err = crypto_aead_setkey(child, key, keylen); 659 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) & 660 CRYPTO_TFM_RES_MASK); 661 662 return err; 663 } 664 665 static int crypto_rfc4309_setauthsize(struct crypto_aead *parent, 666 unsigned int authsize) 667 { 668 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent); 669 670 switch (authsize) { 671 case 8: 672 case 12: 673 case 16: 674 break; 675 default: 676 return -EINVAL; 677 } 678 679 return crypto_aead_setauthsize(ctx->child, authsize); 680 } 681 682 static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req) 683 { 684 struct aead_request *subreq = aead_request_ctx(req); 685 struct crypto_aead *aead = crypto_aead_reqtfm(req); 686 struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead); 687 struct crypto_aead *child = ctx->child; 688 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child), 689 crypto_aead_alignmask(child) + 1); 690 691 /* L' */ 692 iv[0] = 3; 693 694 memcpy(iv + 1, ctx->nonce, 3); 695 memcpy(iv + 4, req->iv, 8); 696 697 aead_request_set_tfm(subreq, child); 698 aead_request_set_callback(subreq, req->base.flags, req->base.complete, 699 req->base.data); 700 aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv); 701 aead_request_set_assoc(subreq, req->assoc, req->assoclen); 702 703 return subreq; 704 } 705 706 static int crypto_rfc4309_encrypt(struct aead_request *req) 707 { 708 req = crypto_rfc4309_crypt(req); 709 710 return crypto_aead_encrypt(req); 711 } 712 713 static int crypto_rfc4309_decrypt(struct aead_request *req) 714 { 715 req = crypto_rfc4309_crypt(req); 716 717 return crypto_aead_decrypt(req); 718 } 719 720 static int crypto_rfc4309_init_tfm(struct crypto_tfm *tfm) 721 { 722 struct crypto_instance *inst = (void *)tfm->__crt_alg; 723 struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst); 724 struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm); 725 struct crypto_aead *aead; 726 unsigned long align; 727 728 aead = crypto_spawn_aead(spawn); 729 if (IS_ERR(aead)) 730 return PTR_ERR(aead); 731 732 ctx->child = aead; 733 734 align = crypto_aead_alignmask(aead); 735 align &= ~(crypto_tfm_ctx_alignment() - 1); 736 tfm->crt_aead.reqsize = sizeof(struct aead_request) + 737 ALIGN(crypto_aead_reqsize(aead), 738 crypto_tfm_ctx_alignment()) + 739 align + 16; 740 741 return 0; 742 } 743 744 static void crypto_rfc4309_exit_tfm(struct crypto_tfm *tfm) 745 { 746 struct crypto_rfc4309_ctx *ctx = crypto_tfm_ctx(tfm); 747 748 crypto_free_aead(ctx->child); 749 } 750 751 static struct crypto_instance *crypto_rfc4309_alloc(struct rtattr **tb) 752 { 753 struct crypto_attr_type *algt; 754 struct crypto_instance *inst; 755 struct crypto_aead_spawn *spawn; 756 struct crypto_alg *alg; 757 const char *ccm_name; 758 int err; 759 760 algt = crypto_get_attr_type(tb); 761 err = PTR_ERR(algt); 762 if (IS_ERR(algt)) 763 return ERR_PTR(err); 764 765 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 766 return ERR_PTR(-EINVAL); 767 768 ccm_name = crypto_attr_alg_name(tb[1]); 769 err = PTR_ERR(ccm_name); 770 if (IS_ERR(ccm_name)) 771 return ERR_PTR(err); 772 773 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 774 if (!inst) 775 return ERR_PTR(-ENOMEM); 776 777 spawn = crypto_instance_ctx(inst); 778 crypto_set_aead_spawn(spawn, inst); 779 err = crypto_grab_aead(spawn, ccm_name, 0, 780 crypto_requires_sync(algt->type, algt->mask)); 781 if (err) 782 goto out_free_inst; 783 784 alg = crypto_aead_spawn_alg(spawn); 785 786 err = -EINVAL; 787 788 /* We only support 16-byte blocks. */ 789 if (alg->cra_aead.ivsize != 16) 790 goto out_drop_alg; 791 792 /* Not a stream cipher? */ 793 if (alg->cra_blocksize != 1) 794 goto out_drop_alg; 795 796 err = -ENAMETOOLONG; 797 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, 798 "rfc4309(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME || 799 snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, 800 "rfc4309(%s)", alg->cra_driver_name) >= 801 CRYPTO_MAX_ALG_NAME) 802 goto out_drop_alg; 803 804 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD; 805 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC; 806 inst->alg.cra_priority = alg->cra_priority; 807 inst->alg.cra_blocksize = 1; 808 inst->alg.cra_alignmask = alg->cra_alignmask; 809 inst->alg.cra_type = &crypto_nivaead_type; 810 811 inst->alg.cra_aead.ivsize = 8; 812 inst->alg.cra_aead.maxauthsize = 16; 813 814 inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx); 815 816 inst->alg.cra_init = crypto_rfc4309_init_tfm; 817 inst->alg.cra_exit = crypto_rfc4309_exit_tfm; 818 819 inst->alg.cra_aead.setkey = crypto_rfc4309_setkey; 820 inst->alg.cra_aead.setauthsize = crypto_rfc4309_setauthsize; 821 inst->alg.cra_aead.encrypt = crypto_rfc4309_encrypt; 822 inst->alg.cra_aead.decrypt = crypto_rfc4309_decrypt; 823 824 inst->alg.cra_aead.geniv = "seqiv"; 825 826 out: 827 return inst; 828 829 out_drop_alg: 830 crypto_drop_aead(spawn); 831 out_free_inst: 832 kfree(inst); 833 inst = ERR_PTR(err); 834 goto out; 835 } 836 837 static void crypto_rfc4309_free(struct crypto_instance *inst) 838 { 839 crypto_drop_spawn(crypto_instance_ctx(inst)); 840 kfree(inst); 841 } 842 843 static struct crypto_template crypto_rfc4309_tmpl = { 844 .name = "rfc4309", 845 .alloc = crypto_rfc4309_alloc, 846 .free = crypto_rfc4309_free, 847 .module = THIS_MODULE, 848 }; 849 850 static int __init crypto_ccm_module_init(void) 851 { 852 int err; 853 854 err = crypto_register_template(&crypto_ccm_base_tmpl); 855 if (err) 856 goto out; 857 858 err = crypto_register_template(&crypto_ccm_tmpl); 859 if (err) 860 goto out_undo_base; 861 862 err = crypto_register_template(&crypto_rfc4309_tmpl); 863 if (err) 864 goto out_undo_ccm; 865 866 out: 867 return err; 868 869 out_undo_ccm: 870 crypto_unregister_template(&crypto_ccm_tmpl); 871 out_undo_base: 872 crypto_unregister_template(&crypto_ccm_base_tmpl); 873 goto out; 874 } 875 876 static void __exit crypto_ccm_module_exit(void) 877 { 878 crypto_unregister_template(&crypto_rfc4309_tmpl); 879 crypto_unregister_template(&crypto_ccm_tmpl); 880 crypto_unregister_template(&crypto_ccm_base_tmpl); 881 } 882 883 module_init(crypto_ccm_module_init); 884 module_exit(crypto_ccm_module_exit); 885 886 MODULE_LICENSE("GPL"); 887 MODULE_DESCRIPTION("Counter with CBC MAC"); 888 MODULE_ALIAS("ccm_base"); 889 MODULE_ALIAS("rfc4309"); 890