1 /* 2 * GCM: Galois/Counter Mode. 3 * 4 * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi> 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 version 2 as published 8 * by the Free Software Foundation. 9 */ 10 11 #include <crypto/gf128mul.h> 12 #include <crypto/internal/aead.h> 13 #include <crypto/internal/skcipher.h> 14 #include <crypto/internal/hash.h> 15 #include <crypto/null.h> 16 #include <crypto/scatterwalk.h> 17 #include <crypto/gcm.h> 18 #include <crypto/hash.h> 19 #include "internal.h" 20 #include <linux/err.h> 21 #include <linux/init.h> 22 #include <linux/kernel.h> 23 #include <linux/module.h> 24 #include <linux/slab.h> 25 26 struct gcm_instance_ctx { 27 struct crypto_skcipher_spawn ctr; 28 struct crypto_ahash_spawn ghash; 29 }; 30 31 struct crypto_gcm_ctx { 32 struct crypto_skcipher *ctr; 33 struct crypto_ahash *ghash; 34 }; 35 36 struct crypto_rfc4106_ctx { 37 struct crypto_aead *child; 38 u8 nonce[4]; 39 }; 40 41 struct crypto_rfc4106_req_ctx { 42 struct scatterlist src[3]; 43 struct scatterlist dst[3]; 44 struct aead_request subreq; 45 }; 46 47 struct crypto_rfc4543_instance_ctx { 48 struct crypto_aead_spawn aead; 49 }; 50 51 struct crypto_rfc4543_ctx { 52 struct crypto_aead *child; 53 struct crypto_sync_skcipher *null; 54 u8 nonce[4]; 55 }; 56 57 struct crypto_rfc4543_req_ctx { 58 struct aead_request subreq; 59 }; 60 61 struct crypto_gcm_ghash_ctx { 62 unsigned int cryptlen; 63 struct scatterlist *src; 64 int (*complete)(struct aead_request *req, u32 flags); 65 }; 66 67 struct crypto_gcm_req_priv_ctx { 68 u8 iv[16]; 69 u8 auth_tag[16]; 70 u8 iauth_tag[16]; 71 struct scatterlist src[3]; 72 struct scatterlist dst[3]; 73 struct scatterlist sg; 74 struct crypto_gcm_ghash_ctx ghash_ctx; 75 union { 76 struct ahash_request ahreq; 77 struct skcipher_request skreq; 78 } u; 79 }; 80 81 static struct { 82 u8 buf[16]; 83 struct scatterlist sg; 84 } *gcm_zeroes; 85 86 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc); 87 88 static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx( 89 struct aead_request *req) 90 { 91 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); 92 93 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); 94 } 95 96 static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key, 97 unsigned int keylen) 98 { 99 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); 100 struct crypto_ahash *ghash = ctx->ghash; 101 struct crypto_skcipher *ctr = ctx->ctr; 102 struct { 103 be128 hash; 104 u8 iv[16]; 105 106 struct crypto_wait wait; 107 108 struct scatterlist sg[1]; 109 struct skcipher_request req; 110 } *data; 111 int err; 112 113 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); 114 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) & 115 CRYPTO_TFM_REQ_MASK); 116 err = crypto_skcipher_setkey(ctr, key, keylen); 117 crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) & 118 CRYPTO_TFM_RES_MASK); 119 if (err) 120 return err; 121 122 data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr), 123 GFP_KERNEL); 124 if (!data) 125 return -ENOMEM; 126 127 crypto_init_wait(&data->wait); 128 sg_init_one(data->sg, &data->hash, sizeof(data->hash)); 129 skcipher_request_set_tfm(&data->req, ctr); 130 skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP | 131 CRYPTO_TFM_REQ_MAY_BACKLOG, 132 crypto_req_done, 133 &data->wait); 134 skcipher_request_set_crypt(&data->req, data->sg, data->sg, 135 sizeof(data->hash), data->iv); 136 137 err = crypto_wait_req(crypto_skcipher_encrypt(&data->req), 138 &data->wait); 139 140 if (err) 141 goto out; 142 143 crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK); 144 crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) & 145 CRYPTO_TFM_REQ_MASK); 146 err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128)); 147 crypto_aead_set_flags(aead, crypto_ahash_get_flags(ghash) & 148 CRYPTO_TFM_RES_MASK); 149 150 out: 151 kzfree(data); 152 return err; 153 } 154 155 static int crypto_gcm_setauthsize(struct crypto_aead *tfm, 156 unsigned int authsize) 157 { 158 switch (authsize) { 159 case 4: 160 case 8: 161 case 12: 162 case 13: 163 case 14: 164 case 15: 165 case 16: 166 break; 167 default: 168 return -EINVAL; 169 } 170 171 return 0; 172 } 173 174 static void crypto_gcm_init_common(struct aead_request *req) 175 { 176 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 177 __be32 counter = cpu_to_be32(1); 178 struct scatterlist *sg; 179 180 memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag)); 181 memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE); 182 memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4); 183 184 sg_init_table(pctx->src, 3); 185 sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag)); 186 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen); 187 if (sg != pctx->src + 1) 188 sg_chain(pctx->src, 2, sg); 189 190 if (req->src != req->dst) { 191 sg_init_table(pctx->dst, 3); 192 sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag)); 193 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen); 194 if (sg != pctx->dst + 1) 195 sg_chain(pctx->dst, 2, sg); 196 } 197 } 198 199 static void crypto_gcm_init_crypt(struct aead_request *req, 200 unsigned int cryptlen) 201 { 202 struct crypto_aead *aead = crypto_aead_reqtfm(req); 203 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); 204 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 205 struct skcipher_request *skreq = &pctx->u.skreq; 206 struct scatterlist *dst; 207 208 dst = req->src == req->dst ? pctx->src : pctx->dst; 209 210 skcipher_request_set_tfm(skreq, ctx->ctr); 211 skcipher_request_set_crypt(skreq, pctx->src, dst, 212 cryptlen + sizeof(pctx->auth_tag), 213 pctx->iv); 214 } 215 216 static inline unsigned int gcm_remain(unsigned int len) 217 { 218 len &= 0xfU; 219 return len ? 16 - len : 0; 220 } 221 222 static void gcm_hash_len_done(struct crypto_async_request *areq, int err); 223 224 static int gcm_hash_update(struct aead_request *req, 225 crypto_completion_t compl, 226 struct scatterlist *src, 227 unsigned int len, u32 flags) 228 { 229 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 230 struct ahash_request *ahreq = &pctx->u.ahreq; 231 232 ahash_request_set_callback(ahreq, flags, compl, req); 233 ahash_request_set_crypt(ahreq, src, NULL, len); 234 235 return crypto_ahash_update(ahreq); 236 } 237 238 static int gcm_hash_remain(struct aead_request *req, 239 unsigned int remain, 240 crypto_completion_t compl, u32 flags) 241 { 242 return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags); 243 } 244 245 static int gcm_hash_len(struct aead_request *req, u32 flags) 246 { 247 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 248 struct ahash_request *ahreq = &pctx->u.ahreq; 249 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 250 be128 lengths; 251 252 lengths.a = cpu_to_be64(req->assoclen * 8); 253 lengths.b = cpu_to_be64(gctx->cryptlen * 8); 254 memcpy(pctx->iauth_tag, &lengths, 16); 255 sg_init_one(&pctx->sg, pctx->iauth_tag, 16); 256 ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req); 257 ahash_request_set_crypt(ahreq, &pctx->sg, 258 pctx->iauth_tag, sizeof(lengths)); 259 260 return crypto_ahash_finup(ahreq); 261 } 262 263 static int gcm_hash_len_continue(struct aead_request *req, u32 flags) 264 { 265 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 266 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 267 268 return gctx->complete(req, flags); 269 } 270 271 static void gcm_hash_len_done(struct crypto_async_request *areq, int err) 272 { 273 struct aead_request *req = areq->data; 274 275 if (err) 276 goto out; 277 278 err = gcm_hash_len_continue(req, 0); 279 if (err == -EINPROGRESS) 280 return; 281 282 out: 283 aead_request_complete(req, err); 284 } 285 286 static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags) 287 { 288 return gcm_hash_len(req, flags) ?: 289 gcm_hash_len_continue(req, flags); 290 } 291 292 static void gcm_hash_crypt_remain_done(struct crypto_async_request *areq, 293 int err) 294 { 295 struct aead_request *req = areq->data; 296 297 if (err) 298 goto out; 299 300 err = gcm_hash_crypt_remain_continue(req, 0); 301 if (err == -EINPROGRESS) 302 return; 303 304 out: 305 aead_request_complete(req, err); 306 } 307 308 static int gcm_hash_crypt_continue(struct aead_request *req, u32 flags) 309 { 310 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 311 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 312 unsigned int remain; 313 314 remain = gcm_remain(gctx->cryptlen); 315 if (remain) 316 return gcm_hash_remain(req, remain, 317 gcm_hash_crypt_remain_done, flags) ?: 318 gcm_hash_crypt_remain_continue(req, flags); 319 320 return gcm_hash_crypt_remain_continue(req, flags); 321 } 322 323 static void gcm_hash_crypt_done(struct crypto_async_request *areq, int err) 324 { 325 struct aead_request *req = areq->data; 326 327 if (err) 328 goto out; 329 330 err = gcm_hash_crypt_continue(req, 0); 331 if (err == -EINPROGRESS) 332 return; 333 334 out: 335 aead_request_complete(req, err); 336 } 337 338 static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags) 339 { 340 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 341 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 342 343 if (gctx->cryptlen) 344 return gcm_hash_update(req, gcm_hash_crypt_done, 345 gctx->src, gctx->cryptlen, flags) ?: 346 gcm_hash_crypt_continue(req, flags); 347 348 return gcm_hash_crypt_remain_continue(req, flags); 349 } 350 351 static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq, 352 int err) 353 { 354 struct aead_request *req = areq->data; 355 356 if (err) 357 goto out; 358 359 err = gcm_hash_assoc_remain_continue(req, 0); 360 if (err == -EINPROGRESS) 361 return; 362 363 out: 364 aead_request_complete(req, err); 365 } 366 367 static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags) 368 { 369 unsigned int remain; 370 371 remain = gcm_remain(req->assoclen); 372 if (remain) 373 return gcm_hash_remain(req, remain, 374 gcm_hash_assoc_remain_done, flags) ?: 375 gcm_hash_assoc_remain_continue(req, flags); 376 377 return gcm_hash_assoc_remain_continue(req, flags); 378 } 379 380 static void gcm_hash_assoc_done(struct crypto_async_request *areq, int err) 381 { 382 struct aead_request *req = areq->data; 383 384 if (err) 385 goto out; 386 387 err = gcm_hash_assoc_continue(req, 0); 388 if (err == -EINPROGRESS) 389 return; 390 391 out: 392 aead_request_complete(req, err); 393 } 394 395 static int gcm_hash_init_continue(struct aead_request *req, u32 flags) 396 { 397 if (req->assoclen) 398 return gcm_hash_update(req, gcm_hash_assoc_done, 399 req->src, req->assoclen, flags) ?: 400 gcm_hash_assoc_continue(req, flags); 401 402 return gcm_hash_assoc_remain_continue(req, flags); 403 } 404 405 static void gcm_hash_init_done(struct crypto_async_request *areq, int err) 406 { 407 struct aead_request *req = areq->data; 408 409 if (err) 410 goto out; 411 412 err = gcm_hash_init_continue(req, 0); 413 if (err == -EINPROGRESS) 414 return; 415 416 out: 417 aead_request_complete(req, err); 418 } 419 420 static int gcm_hash(struct aead_request *req, u32 flags) 421 { 422 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 423 struct ahash_request *ahreq = &pctx->u.ahreq; 424 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); 425 426 ahash_request_set_tfm(ahreq, ctx->ghash); 427 428 ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req); 429 return crypto_ahash_init(ahreq) ?: 430 gcm_hash_init_continue(req, flags); 431 } 432 433 static int gcm_enc_copy_hash(struct aead_request *req, u32 flags) 434 { 435 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 436 struct crypto_aead *aead = crypto_aead_reqtfm(req); 437 u8 *auth_tag = pctx->auth_tag; 438 439 crypto_xor(auth_tag, pctx->iauth_tag, 16); 440 scatterwalk_map_and_copy(auth_tag, req->dst, 441 req->assoclen + req->cryptlen, 442 crypto_aead_authsize(aead), 1); 443 return 0; 444 } 445 446 static int gcm_encrypt_continue(struct aead_request *req, u32 flags) 447 { 448 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 449 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 450 451 gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst); 452 gctx->cryptlen = req->cryptlen; 453 gctx->complete = gcm_enc_copy_hash; 454 455 return gcm_hash(req, flags); 456 } 457 458 static void gcm_encrypt_done(struct crypto_async_request *areq, int err) 459 { 460 struct aead_request *req = areq->data; 461 462 if (err) 463 goto out; 464 465 err = gcm_encrypt_continue(req, 0); 466 if (err == -EINPROGRESS) 467 return; 468 469 out: 470 aead_request_complete(req, err); 471 } 472 473 static int crypto_gcm_encrypt(struct aead_request *req) 474 { 475 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 476 struct skcipher_request *skreq = &pctx->u.skreq; 477 u32 flags = aead_request_flags(req); 478 479 crypto_gcm_init_common(req); 480 crypto_gcm_init_crypt(req, req->cryptlen); 481 skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req); 482 483 return crypto_skcipher_encrypt(skreq) ?: 484 gcm_encrypt_continue(req, flags); 485 } 486 487 static int crypto_gcm_verify(struct aead_request *req) 488 { 489 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 490 struct crypto_aead *aead = crypto_aead_reqtfm(req); 491 u8 *auth_tag = pctx->auth_tag; 492 u8 *iauth_tag = pctx->iauth_tag; 493 unsigned int authsize = crypto_aead_authsize(aead); 494 unsigned int cryptlen = req->cryptlen - authsize; 495 496 crypto_xor(auth_tag, iauth_tag, 16); 497 scatterwalk_map_and_copy(iauth_tag, req->src, 498 req->assoclen + cryptlen, authsize, 0); 499 return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0; 500 } 501 502 static void gcm_decrypt_done(struct crypto_async_request *areq, int err) 503 { 504 struct aead_request *req = areq->data; 505 506 if (!err) 507 err = crypto_gcm_verify(req); 508 509 aead_request_complete(req, err); 510 } 511 512 static int gcm_dec_hash_continue(struct aead_request *req, u32 flags) 513 { 514 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 515 struct skcipher_request *skreq = &pctx->u.skreq; 516 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 517 518 crypto_gcm_init_crypt(req, gctx->cryptlen); 519 skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req); 520 return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req); 521 } 522 523 static int crypto_gcm_decrypt(struct aead_request *req) 524 { 525 struct crypto_aead *aead = crypto_aead_reqtfm(req); 526 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 527 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 528 unsigned int authsize = crypto_aead_authsize(aead); 529 unsigned int cryptlen = req->cryptlen; 530 u32 flags = aead_request_flags(req); 531 532 cryptlen -= authsize; 533 534 crypto_gcm_init_common(req); 535 536 gctx->src = sg_next(pctx->src); 537 gctx->cryptlen = cryptlen; 538 gctx->complete = gcm_dec_hash_continue; 539 540 return gcm_hash(req, flags); 541 } 542 543 static int crypto_gcm_init_tfm(struct crypto_aead *tfm) 544 { 545 struct aead_instance *inst = aead_alg_instance(tfm); 546 struct gcm_instance_ctx *ictx = aead_instance_ctx(inst); 547 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm); 548 struct crypto_skcipher *ctr; 549 struct crypto_ahash *ghash; 550 unsigned long align; 551 int err; 552 553 ghash = crypto_spawn_ahash(&ictx->ghash); 554 if (IS_ERR(ghash)) 555 return PTR_ERR(ghash); 556 557 ctr = crypto_spawn_skcipher(&ictx->ctr); 558 err = PTR_ERR(ctr); 559 if (IS_ERR(ctr)) 560 goto err_free_hash; 561 562 ctx->ctr = ctr; 563 ctx->ghash = ghash; 564 565 align = crypto_aead_alignmask(tfm); 566 align &= ~(crypto_tfm_ctx_alignment() - 1); 567 crypto_aead_set_reqsize(tfm, 568 align + offsetof(struct crypto_gcm_req_priv_ctx, u) + 569 max(sizeof(struct skcipher_request) + 570 crypto_skcipher_reqsize(ctr), 571 sizeof(struct ahash_request) + 572 crypto_ahash_reqsize(ghash))); 573 574 return 0; 575 576 err_free_hash: 577 crypto_free_ahash(ghash); 578 return err; 579 } 580 581 static void crypto_gcm_exit_tfm(struct crypto_aead *tfm) 582 { 583 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm); 584 585 crypto_free_ahash(ctx->ghash); 586 crypto_free_skcipher(ctx->ctr); 587 } 588 589 static void crypto_gcm_free(struct aead_instance *inst) 590 { 591 struct gcm_instance_ctx *ctx = aead_instance_ctx(inst); 592 593 crypto_drop_skcipher(&ctx->ctr); 594 crypto_drop_ahash(&ctx->ghash); 595 kfree(inst); 596 } 597 598 static int crypto_gcm_create_common(struct crypto_template *tmpl, 599 struct rtattr **tb, 600 const char *full_name, 601 const char *ctr_name, 602 const char *ghash_name) 603 { 604 struct crypto_attr_type *algt; 605 struct aead_instance *inst; 606 struct skcipher_alg *ctr; 607 struct crypto_alg *ghash_alg; 608 struct hash_alg_common *ghash; 609 struct gcm_instance_ctx *ctx; 610 int err; 611 612 algt = crypto_get_attr_type(tb); 613 if (IS_ERR(algt)) 614 return PTR_ERR(algt); 615 616 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 617 return -EINVAL; 618 619 ghash_alg = crypto_find_alg(ghash_name, &crypto_ahash_type, 620 CRYPTO_ALG_TYPE_HASH, 621 CRYPTO_ALG_TYPE_AHASH_MASK | 622 crypto_requires_sync(algt->type, 623 algt->mask)); 624 if (IS_ERR(ghash_alg)) 625 return PTR_ERR(ghash_alg); 626 627 ghash = __crypto_hash_alg_common(ghash_alg); 628 629 err = -ENOMEM; 630 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 631 if (!inst) 632 goto out_put_ghash; 633 634 ctx = aead_instance_ctx(inst); 635 err = crypto_init_ahash_spawn(&ctx->ghash, ghash, 636 aead_crypto_instance(inst)); 637 if (err) 638 goto err_free_inst; 639 640 err = -EINVAL; 641 if (ghash->digestsize != 16) 642 goto err_drop_ghash; 643 644 crypto_set_skcipher_spawn(&ctx->ctr, aead_crypto_instance(inst)); 645 err = crypto_grab_skcipher(&ctx->ctr, ctr_name, 0, 646 crypto_requires_sync(algt->type, 647 algt->mask)); 648 if (err) 649 goto err_drop_ghash; 650 651 ctr = crypto_spawn_skcipher_alg(&ctx->ctr); 652 653 /* We only support 16-byte blocks. */ 654 err = -EINVAL; 655 if (crypto_skcipher_alg_ivsize(ctr) != 16) 656 goto out_put_ctr; 657 658 /* Not a stream cipher? */ 659 if (ctr->base.cra_blocksize != 1) 660 goto out_put_ctr; 661 662 err = -ENAMETOOLONG; 663 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 664 "gcm_base(%s,%s)", ctr->base.cra_driver_name, 665 ghash_alg->cra_driver_name) >= 666 CRYPTO_MAX_ALG_NAME) 667 goto out_put_ctr; 668 669 memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME); 670 671 inst->alg.base.cra_flags = (ghash->base.cra_flags | 672 ctr->base.cra_flags) & CRYPTO_ALG_ASYNC; 673 inst->alg.base.cra_priority = (ghash->base.cra_priority + 674 ctr->base.cra_priority) / 2; 675 inst->alg.base.cra_blocksize = 1; 676 inst->alg.base.cra_alignmask = ghash->base.cra_alignmask | 677 ctr->base.cra_alignmask; 678 inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx); 679 inst->alg.ivsize = GCM_AES_IV_SIZE; 680 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr); 681 inst->alg.maxauthsize = 16; 682 inst->alg.init = crypto_gcm_init_tfm; 683 inst->alg.exit = crypto_gcm_exit_tfm; 684 inst->alg.setkey = crypto_gcm_setkey; 685 inst->alg.setauthsize = crypto_gcm_setauthsize; 686 inst->alg.encrypt = crypto_gcm_encrypt; 687 inst->alg.decrypt = crypto_gcm_decrypt; 688 689 inst->free = crypto_gcm_free; 690 691 err = aead_register_instance(tmpl, inst); 692 if (err) 693 goto out_put_ctr; 694 695 out_put_ghash: 696 crypto_mod_put(ghash_alg); 697 return err; 698 699 out_put_ctr: 700 crypto_drop_skcipher(&ctx->ctr); 701 err_drop_ghash: 702 crypto_drop_ahash(&ctx->ghash); 703 err_free_inst: 704 kfree(inst); 705 goto out_put_ghash; 706 } 707 708 static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb) 709 { 710 const char *cipher_name; 711 char ctr_name[CRYPTO_MAX_ALG_NAME]; 712 char full_name[CRYPTO_MAX_ALG_NAME]; 713 714 cipher_name = crypto_attr_alg_name(tb[1]); 715 if (IS_ERR(cipher_name)) 716 return PTR_ERR(cipher_name); 717 718 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >= 719 CRYPTO_MAX_ALG_NAME) 720 return -ENAMETOOLONG; 721 722 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >= 723 CRYPTO_MAX_ALG_NAME) 724 return -ENAMETOOLONG; 725 726 return crypto_gcm_create_common(tmpl, tb, full_name, 727 ctr_name, "ghash"); 728 } 729 730 static int crypto_gcm_base_create(struct crypto_template *tmpl, 731 struct rtattr **tb) 732 { 733 const char *ctr_name; 734 const char *ghash_name; 735 char full_name[CRYPTO_MAX_ALG_NAME]; 736 737 ctr_name = crypto_attr_alg_name(tb[1]); 738 if (IS_ERR(ctr_name)) 739 return PTR_ERR(ctr_name); 740 741 ghash_name = crypto_attr_alg_name(tb[2]); 742 if (IS_ERR(ghash_name)) 743 return PTR_ERR(ghash_name); 744 745 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s,%s)", 746 ctr_name, ghash_name) >= CRYPTO_MAX_ALG_NAME) 747 return -ENAMETOOLONG; 748 749 return crypto_gcm_create_common(tmpl, tb, full_name, 750 ctr_name, ghash_name); 751 } 752 753 static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key, 754 unsigned int keylen) 755 { 756 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); 757 struct crypto_aead *child = ctx->child; 758 int err; 759 760 if (keylen < 4) 761 return -EINVAL; 762 763 keylen -= 4; 764 memcpy(ctx->nonce, key + keylen, 4); 765 766 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 767 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 768 CRYPTO_TFM_REQ_MASK); 769 err = crypto_aead_setkey(child, key, keylen); 770 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) & 771 CRYPTO_TFM_RES_MASK); 772 773 return err; 774 } 775 776 static int crypto_rfc4106_setauthsize(struct crypto_aead *parent, 777 unsigned int authsize) 778 { 779 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); 780 781 switch (authsize) { 782 case 8: 783 case 12: 784 case 16: 785 break; 786 default: 787 return -EINVAL; 788 } 789 790 return crypto_aead_setauthsize(ctx->child, authsize); 791 } 792 793 static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req) 794 { 795 struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req); 796 struct crypto_aead *aead = crypto_aead_reqtfm(req); 797 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead); 798 struct aead_request *subreq = &rctx->subreq; 799 struct crypto_aead *child = ctx->child; 800 struct scatterlist *sg; 801 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child), 802 crypto_aead_alignmask(child) + 1); 803 804 scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0); 805 806 memcpy(iv, ctx->nonce, 4); 807 memcpy(iv + 4, req->iv, 8); 808 809 sg_init_table(rctx->src, 3); 810 sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8); 811 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen); 812 if (sg != rctx->src + 1) 813 sg_chain(rctx->src, 2, sg); 814 815 if (req->src != req->dst) { 816 sg_init_table(rctx->dst, 3); 817 sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8); 818 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen); 819 if (sg != rctx->dst + 1) 820 sg_chain(rctx->dst, 2, sg); 821 } 822 823 aead_request_set_tfm(subreq, child); 824 aead_request_set_callback(subreq, req->base.flags, req->base.complete, 825 req->base.data); 826 aead_request_set_crypt(subreq, rctx->src, 827 req->src == req->dst ? rctx->src : rctx->dst, 828 req->cryptlen, iv); 829 aead_request_set_ad(subreq, req->assoclen - 8); 830 831 return subreq; 832 } 833 834 static int crypto_rfc4106_encrypt(struct aead_request *req) 835 { 836 if (req->assoclen != 16 && req->assoclen != 20) 837 return -EINVAL; 838 839 req = crypto_rfc4106_crypt(req); 840 841 return crypto_aead_encrypt(req); 842 } 843 844 static int crypto_rfc4106_decrypt(struct aead_request *req) 845 { 846 if (req->assoclen != 16 && req->assoclen != 20) 847 return -EINVAL; 848 849 req = crypto_rfc4106_crypt(req); 850 851 return crypto_aead_decrypt(req); 852 } 853 854 static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm) 855 { 856 struct aead_instance *inst = aead_alg_instance(tfm); 857 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst); 858 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm); 859 struct crypto_aead *aead; 860 unsigned long align; 861 862 aead = crypto_spawn_aead(spawn); 863 if (IS_ERR(aead)) 864 return PTR_ERR(aead); 865 866 ctx->child = aead; 867 868 align = crypto_aead_alignmask(aead); 869 align &= ~(crypto_tfm_ctx_alignment() - 1); 870 crypto_aead_set_reqsize( 871 tfm, 872 sizeof(struct crypto_rfc4106_req_ctx) + 873 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + 874 align + 24); 875 876 return 0; 877 } 878 879 static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm) 880 { 881 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm); 882 883 crypto_free_aead(ctx->child); 884 } 885 886 static void crypto_rfc4106_free(struct aead_instance *inst) 887 { 888 crypto_drop_aead(aead_instance_ctx(inst)); 889 kfree(inst); 890 } 891 892 static int crypto_rfc4106_create(struct crypto_template *tmpl, 893 struct rtattr **tb) 894 { 895 struct crypto_attr_type *algt; 896 struct aead_instance *inst; 897 struct crypto_aead_spawn *spawn; 898 struct aead_alg *alg; 899 const char *ccm_name; 900 int err; 901 902 algt = crypto_get_attr_type(tb); 903 if (IS_ERR(algt)) 904 return PTR_ERR(algt); 905 906 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 907 return -EINVAL; 908 909 ccm_name = crypto_attr_alg_name(tb[1]); 910 if (IS_ERR(ccm_name)) 911 return PTR_ERR(ccm_name); 912 913 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 914 if (!inst) 915 return -ENOMEM; 916 917 spawn = aead_instance_ctx(inst); 918 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst)); 919 err = crypto_grab_aead(spawn, ccm_name, 0, 920 crypto_requires_sync(algt->type, algt->mask)); 921 if (err) 922 goto out_free_inst; 923 924 alg = crypto_spawn_aead_alg(spawn); 925 926 err = -EINVAL; 927 928 /* Underlying IV size must be 12. */ 929 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE) 930 goto out_drop_alg; 931 932 /* Not a stream cipher? */ 933 if (alg->base.cra_blocksize != 1) 934 goto out_drop_alg; 935 936 err = -ENAMETOOLONG; 937 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 938 "rfc4106(%s)", alg->base.cra_name) >= 939 CRYPTO_MAX_ALG_NAME || 940 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 941 "rfc4106(%s)", alg->base.cra_driver_name) >= 942 CRYPTO_MAX_ALG_NAME) 943 goto out_drop_alg; 944 945 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC; 946 inst->alg.base.cra_priority = alg->base.cra_priority; 947 inst->alg.base.cra_blocksize = 1; 948 inst->alg.base.cra_alignmask = alg->base.cra_alignmask; 949 950 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx); 951 952 inst->alg.ivsize = GCM_RFC4106_IV_SIZE; 953 inst->alg.chunksize = crypto_aead_alg_chunksize(alg); 954 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg); 955 956 inst->alg.init = crypto_rfc4106_init_tfm; 957 inst->alg.exit = crypto_rfc4106_exit_tfm; 958 959 inst->alg.setkey = crypto_rfc4106_setkey; 960 inst->alg.setauthsize = crypto_rfc4106_setauthsize; 961 inst->alg.encrypt = crypto_rfc4106_encrypt; 962 inst->alg.decrypt = crypto_rfc4106_decrypt; 963 964 inst->free = crypto_rfc4106_free; 965 966 err = aead_register_instance(tmpl, inst); 967 if (err) 968 goto out_drop_alg; 969 970 out: 971 return err; 972 973 out_drop_alg: 974 crypto_drop_aead(spawn); 975 out_free_inst: 976 kfree(inst); 977 goto out; 978 } 979 980 static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key, 981 unsigned int keylen) 982 { 983 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent); 984 struct crypto_aead *child = ctx->child; 985 int err; 986 987 if (keylen < 4) 988 return -EINVAL; 989 990 keylen -= 4; 991 memcpy(ctx->nonce, key + keylen, 4); 992 993 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 994 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 995 CRYPTO_TFM_REQ_MASK); 996 err = crypto_aead_setkey(child, key, keylen); 997 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) & 998 CRYPTO_TFM_RES_MASK); 999 1000 return err; 1001 } 1002 1003 static int crypto_rfc4543_setauthsize(struct crypto_aead *parent, 1004 unsigned int authsize) 1005 { 1006 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent); 1007 1008 if (authsize != 16) 1009 return -EINVAL; 1010 1011 return crypto_aead_setauthsize(ctx->child, authsize); 1012 } 1013 1014 static int crypto_rfc4543_crypt(struct aead_request *req, bool enc) 1015 { 1016 struct crypto_aead *aead = crypto_aead_reqtfm(req); 1017 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead); 1018 struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req); 1019 struct aead_request *subreq = &rctx->subreq; 1020 unsigned int authsize = crypto_aead_authsize(aead); 1021 u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child), 1022 crypto_aead_alignmask(ctx->child) + 1); 1023 int err; 1024 1025 if (req->src != req->dst) { 1026 err = crypto_rfc4543_copy_src_to_dst(req, enc); 1027 if (err) 1028 return err; 1029 } 1030 1031 memcpy(iv, ctx->nonce, 4); 1032 memcpy(iv + 4, req->iv, 8); 1033 1034 aead_request_set_tfm(subreq, ctx->child); 1035 aead_request_set_callback(subreq, req->base.flags, 1036 req->base.complete, req->base.data); 1037 aead_request_set_crypt(subreq, req->src, req->dst, 1038 enc ? 0 : authsize, iv); 1039 aead_request_set_ad(subreq, req->assoclen + req->cryptlen - 1040 subreq->cryptlen); 1041 1042 return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq); 1043 } 1044 1045 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc) 1046 { 1047 struct crypto_aead *aead = crypto_aead_reqtfm(req); 1048 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead); 1049 unsigned int authsize = crypto_aead_authsize(aead); 1050 unsigned int nbytes = req->assoclen + req->cryptlen - 1051 (enc ? 0 : authsize); 1052 SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null); 1053 1054 skcipher_request_set_sync_tfm(nreq, ctx->null); 1055 skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL); 1056 skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL); 1057 1058 return crypto_skcipher_encrypt(nreq); 1059 } 1060 1061 static int crypto_rfc4543_encrypt(struct aead_request *req) 1062 { 1063 return crypto_rfc4543_crypt(req, true); 1064 } 1065 1066 static int crypto_rfc4543_decrypt(struct aead_request *req) 1067 { 1068 return crypto_rfc4543_crypt(req, false); 1069 } 1070 1071 static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm) 1072 { 1073 struct aead_instance *inst = aead_alg_instance(tfm); 1074 struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst); 1075 struct crypto_aead_spawn *spawn = &ictx->aead; 1076 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); 1077 struct crypto_aead *aead; 1078 struct crypto_sync_skcipher *null; 1079 unsigned long align; 1080 int err = 0; 1081 1082 aead = crypto_spawn_aead(spawn); 1083 if (IS_ERR(aead)) 1084 return PTR_ERR(aead); 1085 1086 null = crypto_get_default_null_skcipher(); 1087 err = PTR_ERR(null); 1088 if (IS_ERR(null)) 1089 goto err_free_aead; 1090 1091 ctx->child = aead; 1092 ctx->null = null; 1093 1094 align = crypto_aead_alignmask(aead); 1095 align &= ~(crypto_tfm_ctx_alignment() - 1); 1096 crypto_aead_set_reqsize( 1097 tfm, 1098 sizeof(struct crypto_rfc4543_req_ctx) + 1099 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + 1100 align + GCM_AES_IV_SIZE); 1101 1102 return 0; 1103 1104 err_free_aead: 1105 crypto_free_aead(aead); 1106 return err; 1107 } 1108 1109 static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm) 1110 { 1111 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); 1112 1113 crypto_free_aead(ctx->child); 1114 crypto_put_default_null_skcipher(); 1115 } 1116 1117 static void crypto_rfc4543_free(struct aead_instance *inst) 1118 { 1119 struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst); 1120 1121 crypto_drop_aead(&ctx->aead); 1122 1123 kfree(inst); 1124 } 1125 1126 static int crypto_rfc4543_create(struct crypto_template *tmpl, 1127 struct rtattr **tb) 1128 { 1129 struct crypto_attr_type *algt; 1130 struct aead_instance *inst; 1131 struct crypto_aead_spawn *spawn; 1132 struct aead_alg *alg; 1133 struct crypto_rfc4543_instance_ctx *ctx; 1134 const char *ccm_name; 1135 int err; 1136 1137 algt = crypto_get_attr_type(tb); 1138 if (IS_ERR(algt)) 1139 return PTR_ERR(algt); 1140 1141 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 1142 return -EINVAL; 1143 1144 ccm_name = crypto_attr_alg_name(tb[1]); 1145 if (IS_ERR(ccm_name)) 1146 return PTR_ERR(ccm_name); 1147 1148 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 1149 if (!inst) 1150 return -ENOMEM; 1151 1152 ctx = aead_instance_ctx(inst); 1153 spawn = &ctx->aead; 1154 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst)); 1155 err = crypto_grab_aead(spawn, ccm_name, 0, 1156 crypto_requires_sync(algt->type, algt->mask)); 1157 if (err) 1158 goto out_free_inst; 1159 1160 alg = crypto_spawn_aead_alg(spawn); 1161 1162 err = -EINVAL; 1163 1164 /* Underlying IV size must be 12. */ 1165 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE) 1166 goto out_drop_alg; 1167 1168 /* Not a stream cipher? */ 1169 if (alg->base.cra_blocksize != 1) 1170 goto out_drop_alg; 1171 1172 err = -ENAMETOOLONG; 1173 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 1174 "rfc4543(%s)", alg->base.cra_name) >= 1175 CRYPTO_MAX_ALG_NAME || 1176 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 1177 "rfc4543(%s)", alg->base.cra_driver_name) >= 1178 CRYPTO_MAX_ALG_NAME) 1179 goto out_drop_alg; 1180 1181 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC; 1182 inst->alg.base.cra_priority = alg->base.cra_priority; 1183 inst->alg.base.cra_blocksize = 1; 1184 inst->alg.base.cra_alignmask = alg->base.cra_alignmask; 1185 1186 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx); 1187 1188 inst->alg.ivsize = GCM_RFC4543_IV_SIZE; 1189 inst->alg.chunksize = crypto_aead_alg_chunksize(alg); 1190 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg); 1191 1192 inst->alg.init = crypto_rfc4543_init_tfm; 1193 inst->alg.exit = crypto_rfc4543_exit_tfm; 1194 1195 inst->alg.setkey = crypto_rfc4543_setkey; 1196 inst->alg.setauthsize = crypto_rfc4543_setauthsize; 1197 inst->alg.encrypt = crypto_rfc4543_encrypt; 1198 inst->alg.decrypt = crypto_rfc4543_decrypt; 1199 1200 inst->free = crypto_rfc4543_free, 1201 1202 err = aead_register_instance(tmpl, inst); 1203 if (err) 1204 goto out_drop_alg; 1205 1206 out: 1207 return err; 1208 1209 out_drop_alg: 1210 crypto_drop_aead(spawn); 1211 out_free_inst: 1212 kfree(inst); 1213 goto out; 1214 } 1215 1216 static struct crypto_template crypto_gcm_tmpls[] = { 1217 { 1218 .name = "gcm_base", 1219 .create = crypto_gcm_base_create, 1220 .module = THIS_MODULE, 1221 }, { 1222 .name = "gcm", 1223 .create = crypto_gcm_create, 1224 .module = THIS_MODULE, 1225 }, { 1226 .name = "rfc4106", 1227 .create = crypto_rfc4106_create, 1228 .module = THIS_MODULE, 1229 }, { 1230 .name = "rfc4543", 1231 .create = crypto_rfc4543_create, 1232 .module = THIS_MODULE, 1233 }, 1234 }; 1235 1236 static int __init crypto_gcm_module_init(void) 1237 { 1238 int err; 1239 1240 gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL); 1241 if (!gcm_zeroes) 1242 return -ENOMEM; 1243 1244 sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf)); 1245 1246 err = crypto_register_templates(crypto_gcm_tmpls, 1247 ARRAY_SIZE(crypto_gcm_tmpls)); 1248 if (err) 1249 kfree(gcm_zeroes); 1250 1251 return err; 1252 } 1253 1254 static void __exit crypto_gcm_module_exit(void) 1255 { 1256 kfree(gcm_zeroes); 1257 crypto_unregister_templates(crypto_gcm_tmpls, 1258 ARRAY_SIZE(crypto_gcm_tmpls)); 1259 } 1260 1261 module_init(crypto_gcm_module_init); 1262 module_exit(crypto_gcm_module_exit); 1263 1264 MODULE_LICENSE("GPL"); 1265 MODULE_DESCRIPTION("Galois/Counter Mode"); 1266 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>"); 1267 MODULE_ALIAS_CRYPTO("gcm_base"); 1268 MODULE_ALIAS_CRYPTO("rfc4106"); 1269 MODULE_ALIAS_CRYPTO("rfc4543"); 1270 MODULE_ALIAS_CRYPTO("gcm"); 1271