1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * GCM: Galois/Counter Mode. 4 * 5 * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi> 6 */ 7 8 #include <crypto/gf128mul.h> 9 #include <crypto/internal/aead.h> 10 #include <crypto/internal/skcipher.h> 11 #include <crypto/internal/hash.h> 12 #include <crypto/null.h> 13 #include <crypto/scatterwalk.h> 14 #include <crypto/gcm.h> 15 #include <crypto/hash.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 struct gcm_instance_ctx { 23 struct crypto_skcipher_spawn ctr; 24 struct crypto_ahash_spawn ghash; 25 }; 26 27 struct crypto_gcm_ctx { 28 struct crypto_skcipher *ctr; 29 struct crypto_ahash *ghash; 30 }; 31 32 struct crypto_rfc4106_ctx { 33 struct crypto_aead *child; 34 u8 nonce[4]; 35 }; 36 37 struct crypto_rfc4106_req_ctx { 38 struct scatterlist src[3]; 39 struct scatterlist dst[3]; 40 struct aead_request subreq; 41 }; 42 43 struct crypto_rfc4543_instance_ctx { 44 struct crypto_aead_spawn aead; 45 }; 46 47 struct crypto_rfc4543_ctx { 48 struct crypto_aead *child; 49 struct crypto_sync_skcipher *null; 50 u8 nonce[4]; 51 }; 52 53 struct crypto_rfc4543_req_ctx { 54 struct aead_request subreq; 55 }; 56 57 struct crypto_gcm_ghash_ctx { 58 unsigned int cryptlen; 59 struct scatterlist *src; 60 int (*complete)(struct aead_request *req, u32 flags); 61 }; 62 63 struct crypto_gcm_req_priv_ctx { 64 u8 iv[16]; 65 u8 auth_tag[16]; 66 u8 iauth_tag[16]; 67 struct scatterlist src[3]; 68 struct scatterlist dst[3]; 69 struct scatterlist sg; 70 struct crypto_gcm_ghash_ctx ghash_ctx; 71 union { 72 struct ahash_request ahreq; 73 struct skcipher_request skreq; 74 } u; 75 }; 76 77 static struct { 78 u8 buf[16]; 79 struct scatterlist sg; 80 } *gcm_zeroes; 81 82 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc); 83 84 static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx( 85 struct aead_request *req) 86 { 87 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); 88 89 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); 90 } 91 92 static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key, 93 unsigned int keylen) 94 { 95 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); 96 struct crypto_ahash *ghash = ctx->ghash; 97 struct crypto_skcipher *ctr = ctx->ctr; 98 struct { 99 be128 hash; 100 u8 iv[16]; 101 102 struct crypto_wait wait; 103 104 struct scatterlist sg[1]; 105 struct skcipher_request req; 106 } *data; 107 int err; 108 109 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); 110 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) & 111 CRYPTO_TFM_REQ_MASK); 112 err = crypto_skcipher_setkey(ctr, key, keylen); 113 if (err) 114 return err; 115 116 data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr), 117 GFP_KERNEL); 118 if (!data) 119 return -ENOMEM; 120 121 crypto_init_wait(&data->wait); 122 sg_init_one(data->sg, &data->hash, sizeof(data->hash)); 123 skcipher_request_set_tfm(&data->req, ctr); 124 skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP | 125 CRYPTO_TFM_REQ_MAY_BACKLOG, 126 crypto_req_done, 127 &data->wait); 128 skcipher_request_set_crypt(&data->req, data->sg, data->sg, 129 sizeof(data->hash), data->iv); 130 131 err = crypto_wait_req(crypto_skcipher_encrypt(&data->req), 132 &data->wait); 133 134 if (err) 135 goto out; 136 137 crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK); 138 crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) & 139 CRYPTO_TFM_REQ_MASK); 140 err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128)); 141 out: 142 kfree_sensitive(data); 143 return err; 144 } 145 146 static int crypto_gcm_setauthsize(struct crypto_aead *tfm, 147 unsigned int authsize) 148 { 149 return crypto_gcm_check_authsize(authsize); 150 } 151 152 static void crypto_gcm_init_common(struct aead_request *req) 153 { 154 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 155 __be32 counter = cpu_to_be32(1); 156 struct scatterlist *sg; 157 158 memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag)); 159 memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE); 160 memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4); 161 162 sg_init_table(pctx->src, 3); 163 sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag)); 164 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen); 165 if (sg != pctx->src + 1) 166 sg_chain(pctx->src, 2, sg); 167 168 if (req->src != req->dst) { 169 sg_init_table(pctx->dst, 3); 170 sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag)); 171 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen); 172 if (sg != pctx->dst + 1) 173 sg_chain(pctx->dst, 2, sg); 174 } 175 } 176 177 static void crypto_gcm_init_crypt(struct aead_request *req, 178 unsigned int cryptlen) 179 { 180 struct crypto_aead *aead = crypto_aead_reqtfm(req); 181 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); 182 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 183 struct skcipher_request *skreq = &pctx->u.skreq; 184 struct scatterlist *dst; 185 186 dst = req->src == req->dst ? pctx->src : pctx->dst; 187 188 skcipher_request_set_tfm(skreq, ctx->ctr); 189 skcipher_request_set_crypt(skreq, pctx->src, dst, 190 cryptlen + sizeof(pctx->auth_tag), 191 pctx->iv); 192 } 193 194 static inline unsigned int gcm_remain(unsigned int len) 195 { 196 len &= 0xfU; 197 return len ? 16 - len : 0; 198 } 199 200 static void gcm_hash_len_done(struct crypto_async_request *areq, int err); 201 202 static int gcm_hash_update(struct aead_request *req, 203 crypto_completion_t compl, 204 struct scatterlist *src, 205 unsigned int len, u32 flags) 206 { 207 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 208 struct ahash_request *ahreq = &pctx->u.ahreq; 209 210 ahash_request_set_callback(ahreq, flags, compl, req); 211 ahash_request_set_crypt(ahreq, src, NULL, len); 212 213 return crypto_ahash_update(ahreq); 214 } 215 216 static int gcm_hash_remain(struct aead_request *req, 217 unsigned int remain, 218 crypto_completion_t compl, u32 flags) 219 { 220 return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags); 221 } 222 223 static int gcm_hash_len(struct aead_request *req, u32 flags) 224 { 225 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 226 struct ahash_request *ahreq = &pctx->u.ahreq; 227 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 228 be128 lengths; 229 230 lengths.a = cpu_to_be64(req->assoclen * 8); 231 lengths.b = cpu_to_be64(gctx->cryptlen * 8); 232 memcpy(pctx->iauth_tag, &lengths, 16); 233 sg_init_one(&pctx->sg, pctx->iauth_tag, 16); 234 ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req); 235 ahash_request_set_crypt(ahreq, &pctx->sg, 236 pctx->iauth_tag, sizeof(lengths)); 237 238 return crypto_ahash_finup(ahreq); 239 } 240 241 static int gcm_hash_len_continue(struct aead_request *req, u32 flags) 242 { 243 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 244 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 245 246 return gctx->complete(req, flags); 247 } 248 249 static void gcm_hash_len_done(struct crypto_async_request *areq, int err) 250 { 251 struct aead_request *req = areq->data; 252 253 if (err) 254 goto out; 255 256 err = gcm_hash_len_continue(req, 0); 257 if (err == -EINPROGRESS) 258 return; 259 260 out: 261 aead_request_complete(req, err); 262 } 263 264 static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags) 265 { 266 return gcm_hash_len(req, flags) ?: 267 gcm_hash_len_continue(req, flags); 268 } 269 270 static void gcm_hash_crypt_remain_done(struct crypto_async_request *areq, 271 int err) 272 { 273 struct aead_request *req = areq->data; 274 275 if (err) 276 goto out; 277 278 err = gcm_hash_crypt_remain_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_continue(struct aead_request *req, u32 flags) 287 { 288 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 289 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 290 unsigned int remain; 291 292 remain = gcm_remain(gctx->cryptlen); 293 if (remain) 294 return gcm_hash_remain(req, remain, 295 gcm_hash_crypt_remain_done, flags) ?: 296 gcm_hash_crypt_remain_continue(req, flags); 297 298 return gcm_hash_crypt_remain_continue(req, flags); 299 } 300 301 static void gcm_hash_crypt_done(struct crypto_async_request *areq, int err) 302 { 303 struct aead_request *req = areq->data; 304 305 if (err) 306 goto out; 307 308 err = gcm_hash_crypt_continue(req, 0); 309 if (err == -EINPROGRESS) 310 return; 311 312 out: 313 aead_request_complete(req, err); 314 } 315 316 static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags) 317 { 318 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 319 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 320 321 if (gctx->cryptlen) 322 return gcm_hash_update(req, gcm_hash_crypt_done, 323 gctx->src, gctx->cryptlen, flags) ?: 324 gcm_hash_crypt_continue(req, flags); 325 326 return gcm_hash_crypt_remain_continue(req, flags); 327 } 328 329 static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq, 330 int err) 331 { 332 struct aead_request *req = areq->data; 333 334 if (err) 335 goto out; 336 337 err = gcm_hash_assoc_remain_continue(req, 0); 338 if (err == -EINPROGRESS) 339 return; 340 341 out: 342 aead_request_complete(req, err); 343 } 344 345 static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags) 346 { 347 unsigned int remain; 348 349 remain = gcm_remain(req->assoclen); 350 if (remain) 351 return gcm_hash_remain(req, remain, 352 gcm_hash_assoc_remain_done, flags) ?: 353 gcm_hash_assoc_remain_continue(req, flags); 354 355 return gcm_hash_assoc_remain_continue(req, flags); 356 } 357 358 static void gcm_hash_assoc_done(struct crypto_async_request *areq, int err) 359 { 360 struct aead_request *req = areq->data; 361 362 if (err) 363 goto out; 364 365 err = gcm_hash_assoc_continue(req, 0); 366 if (err == -EINPROGRESS) 367 return; 368 369 out: 370 aead_request_complete(req, err); 371 } 372 373 static int gcm_hash_init_continue(struct aead_request *req, u32 flags) 374 { 375 if (req->assoclen) 376 return gcm_hash_update(req, gcm_hash_assoc_done, 377 req->src, req->assoclen, flags) ?: 378 gcm_hash_assoc_continue(req, flags); 379 380 return gcm_hash_assoc_remain_continue(req, flags); 381 } 382 383 static void gcm_hash_init_done(struct crypto_async_request *areq, int err) 384 { 385 struct aead_request *req = areq->data; 386 387 if (err) 388 goto out; 389 390 err = gcm_hash_init_continue(req, 0); 391 if (err == -EINPROGRESS) 392 return; 393 394 out: 395 aead_request_complete(req, err); 396 } 397 398 static int gcm_hash(struct aead_request *req, u32 flags) 399 { 400 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 401 struct ahash_request *ahreq = &pctx->u.ahreq; 402 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); 403 404 ahash_request_set_tfm(ahreq, ctx->ghash); 405 406 ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req); 407 return crypto_ahash_init(ahreq) ?: 408 gcm_hash_init_continue(req, flags); 409 } 410 411 static int gcm_enc_copy_hash(struct aead_request *req, u32 flags) 412 { 413 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 414 struct crypto_aead *aead = crypto_aead_reqtfm(req); 415 u8 *auth_tag = pctx->auth_tag; 416 417 crypto_xor(auth_tag, pctx->iauth_tag, 16); 418 scatterwalk_map_and_copy(auth_tag, req->dst, 419 req->assoclen + req->cryptlen, 420 crypto_aead_authsize(aead), 1); 421 return 0; 422 } 423 424 static int gcm_encrypt_continue(struct aead_request *req, u32 flags) 425 { 426 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 427 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 428 429 gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst); 430 gctx->cryptlen = req->cryptlen; 431 gctx->complete = gcm_enc_copy_hash; 432 433 return gcm_hash(req, flags); 434 } 435 436 static void gcm_encrypt_done(struct crypto_async_request *areq, int err) 437 { 438 struct aead_request *req = areq->data; 439 440 if (err) 441 goto out; 442 443 err = gcm_encrypt_continue(req, 0); 444 if (err == -EINPROGRESS) 445 return; 446 447 out: 448 aead_request_complete(req, err); 449 } 450 451 static int crypto_gcm_encrypt(struct aead_request *req) 452 { 453 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 454 struct skcipher_request *skreq = &pctx->u.skreq; 455 u32 flags = aead_request_flags(req); 456 457 crypto_gcm_init_common(req); 458 crypto_gcm_init_crypt(req, req->cryptlen); 459 skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req); 460 461 return crypto_skcipher_encrypt(skreq) ?: 462 gcm_encrypt_continue(req, flags); 463 } 464 465 static int crypto_gcm_verify(struct aead_request *req) 466 { 467 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 468 struct crypto_aead *aead = crypto_aead_reqtfm(req); 469 u8 *auth_tag = pctx->auth_tag; 470 u8 *iauth_tag = pctx->iauth_tag; 471 unsigned int authsize = crypto_aead_authsize(aead); 472 unsigned int cryptlen = req->cryptlen - authsize; 473 474 crypto_xor(auth_tag, iauth_tag, 16); 475 scatterwalk_map_and_copy(iauth_tag, req->src, 476 req->assoclen + cryptlen, authsize, 0); 477 return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0; 478 } 479 480 static void gcm_decrypt_done(struct crypto_async_request *areq, int err) 481 { 482 struct aead_request *req = areq->data; 483 484 if (!err) 485 err = crypto_gcm_verify(req); 486 487 aead_request_complete(req, err); 488 } 489 490 static int gcm_dec_hash_continue(struct aead_request *req, u32 flags) 491 { 492 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 493 struct skcipher_request *skreq = &pctx->u.skreq; 494 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 495 496 crypto_gcm_init_crypt(req, gctx->cryptlen); 497 skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req); 498 return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req); 499 } 500 501 static int crypto_gcm_decrypt(struct aead_request *req) 502 { 503 struct crypto_aead *aead = crypto_aead_reqtfm(req); 504 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 505 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx; 506 unsigned int authsize = crypto_aead_authsize(aead); 507 unsigned int cryptlen = req->cryptlen; 508 u32 flags = aead_request_flags(req); 509 510 cryptlen -= authsize; 511 512 crypto_gcm_init_common(req); 513 514 gctx->src = sg_next(pctx->src); 515 gctx->cryptlen = cryptlen; 516 gctx->complete = gcm_dec_hash_continue; 517 518 return gcm_hash(req, flags); 519 } 520 521 static int crypto_gcm_init_tfm(struct crypto_aead *tfm) 522 { 523 struct aead_instance *inst = aead_alg_instance(tfm); 524 struct gcm_instance_ctx *ictx = aead_instance_ctx(inst); 525 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm); 526 struct crypto_skcipher *ctr; 527 struct crypto_ahash *ghash; 528 unsigned long align; 529 int err; 530 531 ghash = crypto_spawn_ahash(&ictx->ghash); 532 if (IS_ERR(ghash)) 533 return PTR_ERR(ghash); 534 535 ctr = crypto_spawn_skcipher(&ictx->ctr); 536 err = PTR_ERR(ctr); 537 if (IS_ERR(ctr)) 538 goto err_free_hash; 539 540 ctx->ctr = ctr; 541 ctx->ghash = ghash; 542 543 align = crypto_aead_alignmask(tfm); 544 align &= ~(crypto_tfm_ctx_alignment() - 1); 545 crypto_aead_set_reqsize(tfm, 546 align + offsetof(struct crypto_gcm_req_priv_ctx, u) + 547 max(sizeof(struct skcipher_request) + 548 crypto_skcipher_reqsize(ctr), 549 sizeof(struct ahash_request) + 550 crypto_ahash_reqsize(ghash))); 551 552 return 0; 553 554 err_free_hash: 555 crypto_free_ahash(ghash); 556 return err; 557 } 558 559 static void crypto_gcm_exit_tfm(struct crypto_aead *tfm) 560 { 561 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm); 562 563 crypto_free_ahash(ctx->ghash); 564 crypto_free_skcipher(ctx->ctr); 565 } 566 567 static void crypto_gcm_free(struct aead_instance *inst) 568 { 569 struct gcm_instance_ctx *ctx = aead_instance_ctx(inst); 570 571 crypto_drop_skcipher(&ctx->ctr); 572 crypto_drop_ahash(&ctx->ghash); 573 kfree(inst); 574 } 575 576 static int crypto_gcm_create_common(struct crypto_template *tmpl, 577 struct rtattr **tb, 578 const char *ctr_name, 579 const char *ghash_name) 580 { 581 u32 mask; 582 struct aead_instance *inst; 583 struct gcm_instance_ctx *ctx; 584 struct skcipher_alg *ctr; 585 struct hash_alg_common *ghash; 586 int err; 587 588 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); 589 if (err) 590 return err; 591 592 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 593 if (!inst) 594 return -ENOMEM; 595 ctx = aead_instance_ctx(inst); 596 597 err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst), 598 ghash_name, 0, mask); 599 if (err) 600 goto err_free_inst; 601 ghash = crypto_spawn_ahash_alg(&ctx->ghash); 602 603 err = -EINVAL; 604 if (strcmp(ghash->base.cra_name, "ghash") != 0 || 605 ghash->digestsize != 16) 606 goto err_free_inst; 607 608 err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst), 609 ctr_name, 0, mask); 610 if (err) 611 goto err_free_inst; 612 ctr = crypto_spawn_skcipher_alg(&ctx->ctr); 613 614 /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */ 615 err = -EINVAL; 616 if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 || 617 crypto_skcipher_alg_ivsize(ctr) != 16 || 618 ctr->base.cra_blocksize != 1) 619 goto err_free_inst; 620 621 err = -ENAMETOOLONG; 622 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 623 "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME) 624 goto err_free_inst; 625 626 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 627 "gcm_base(%s,%s)", ctr->base.cra_driver_name, 628 ghash->base.cra_driver_name) >= 629 CRYPTO_MAX_ALG_NAME) 630 goto err_free_inst; 631 632 inst->alg.base.cra_priority = (ghash->base.cra_priority + 633 ctr->base.cra_priority) / 2; 634 inst->alg.base.cra_blocksize = 1; 635 inst->alg.base.cra_alignmask = ghash->base.cra_alignmask | 636 ctr->base.cra_alignmask; 637 inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx); 638 inst->alg.ivsize = GCM_AES_IV_SIZE; 639 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr); 640 inst->alg.maxauthsize = 16; 641 inst->alg.init = crypto_gcm_init_tfm; 642 inst->alg.exit = crypto_gcm_exit_tfm; 643 inst->alg.setkey = crypto_gcm_setkey; 644 inst->alg.setauthsize = crypto_gcm_setauthsize; 645 inst->alg.encrypt = crypto_gcm_encrypt; 646 inst->alg.decrypt = crypto_gcm_decrypt; 647 648 inst->free = crypto_gcm_free; 649 650 err = aead_register_instance(tmpl, inst); 651 if (err) { 652 err_free_inst: 653 crypto_gcm_free(inst); 654 } 655 return err; 656 } 657 658 static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb) 659 { 660 const char *cipher_name; 661 char ctr_name[CRYPTO_MAX_ALG_NAME]; 662 663 cipher_name = crypto_attr_alg_name(tb[1]); 664 if (IS_ERR(cipher_name)) 665 return PTR_ERR(cipher_name); 666 667 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >= 668 CRYPTO_MAX_ALG_NAME) 669 return -ENAMETOOLONG; 670 671 return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash"); 672 } 673 674 static int crypto_gcm_base_create(struct crypto_template *tmpl, 675 struct rtattr **tb) 676 { 677 const char *ctr_name; 678 const char *ghash_name; 679 680 ctr_name = crypto_attr_alg_name(tb[1]); 681 if (IS_ERR(ctr_name)) 682 return PTR_ERR(ctr_name); 683 684 ghash_name = crypto_attr_alg_name(tb[2]); 685 if (IS_ERR(ghash_name)) 686 return PTR_ERR(ghash_name); 687 688 return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name); 689 } 690 691 static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key, 692 unsigned int keylen) 693 { 694 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); 695 struct crypto_aead *child = ctx->child; 696 697 if (keylen < 4) 698 return -EINVAL; 699 700 keylen -= 4; 701 memcpy(ctx->nonce, key + keylen, 4); 702 703 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 704 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 705 CRYPTO_TFM_REQ_MASK); 706 return crypto_aead_setkey(child, key, keylen); 707 } 708 709 static int crypto_rfc4106_setauthsize(struct crypto_aead *parent, 710 unsigned int authsize) 711 { 712 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); 713 int err; 714 715 err = crypto_rfc4106_check_authsize(authsize); 716 if (err) 717 return err; 718 719 return crypto_aead_setauthsize(ctx->child, authsize); 720 } 721 722 static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req) 723 { 724 struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req); 725 struct crypto_aead *aead = crypto_aead_reqtfm(req); 726 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead); 727 struct aead_request *subreq = &rctx->subreq; 728 struct crypto_aead *child = ctx->child; 729 struct scatterlist *sg; 730 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child), 731 crypto_aead_alignmask(child) + 1); 732 733 scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0); 734 735 memcpy(iv, ctx->nonce, 4); 736 memcpy(iv + 4, req->iv, 8); 737 738 sg_init_table(rctx->src, 3); 739 sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8); 740 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen); 741 if (sg != rctx->src + 1) 742 sg_chain(rctx->src, 2, sg); 743 744 if (req->src != req->dst) { 745 sg_init_table(rctx->dst, 3); 746 sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8); 747 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen); 748 if (sg != rctx->dst + 1) 749 sg_chain(rctx->dst, 2, sg); 750 } 751 752 aead_request_set_tfm(subreq, child); 753 aead_request_set_callback(subreq, req->base.flags, req->base.complete, 754 req->base.data); 755 aead_request_set_crypt(subreq, rctx->src, 756 req->src == req->dst ? rctx->src : rctx->dst, 757 req->cryptlen, iv); 758 aead_request_set_ad(subreq, req->assoclen - 8); 759 760 return subreq; 761 } 762 763 static int crypto_rfc4106_encrypt(struct aead_request *req) 764 { 765 int err; 766 767 err = crypto_ipsec_check_assoclen(req->assoclen); 768 if (err) 769 return err; 770 771 req = crypto_rfc4106_crypt(req); 772 773 return crypto_aead_encrypt(req); 774 } 775 776 static int crypto_rfc4106_decrypt(struct aead_request *req) 777 { 778 int err; 779 780 err = crypto_ipsec_check_assoclen(req->assoclen); 781 if (err) 782 return err; 783 784 req = crypto_rfc4106_crypt(req); 785 786 return crypto_aead_decrypt(req); 787 } 788 789 static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm) 790 { 791 struct aead_instance *inst = aead_alg_instance(tfm); 792 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst); 793 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm); 794 struct crypto_aead *aead; 795 unsigned long align; 796 797 aead = crypto_spawn_aead(spawn); 798 if (IS_ERR(aead)) 799 return PTR_ERR(aead); 800 801 ctx->child = aead; 802 803 align = crypto_aead_alignmask(aead); 804 align &= ~(crypto_tfm_ctx_alignment() - 1); 805 crypto_aead_set_reqsize( 806 tfm, 807 sizeof(struct crypto_rfc4106_req_ctx) + 808 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + 809 align + 24); 810 811 return 0; 812 } 813 814 static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm) 815 { 816 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm); 817 818 crypto_free_aead(ctx->child); 819 } 820 821 static void crypto_rfc4106_free(struct aead_instance *inst) 822 { 823 crypto_drop_aead(aead_instance_ctx(inst)); 824 kfree(inst); 825 } 826 827 static int crypto_rfc4106_create(struct crypto_template *tmpl, 828 struct rtattr **tb) 829 { 830 u32 mask; 831 struct aead_instance *inst; 832 struct crypto_aead_spawn *spawn; 833 struct aead_alg *alg; 834 int err; 835 836 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); 837 if (err) 838 return err; 839 840 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 841 if (!inst) 842 return -ENOMEM; 843 844 spawn = aead_instance_ctx(inst); 845 err = crypto_grab_aead(spawn, aead_crypto_instance(inst), 846 crypto_attr_alg_name(tb[1]), 0, mask); 847 if (err) 848 goto err_free_inst; 849 850 alg = crypto_spawn_aead_alg(spawn); 851 852 err = -EINVAL; 853 854 /* Underlying IV size must be 12. */ 855 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE) 856 goto err_free_inst; 857 858 /* Not a stream cipher? */ 859 if (alg->base.cra_blocksize != 1) 860 goto err_free_inst; 861 862 err = -ENAMETOOLONG; 863 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 864 "rfc4106(%s)", alg->base.cra_name) >= 865 CRYPTO_MAX_ALG_NAME || 866 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 867 "rfc4106(%s)", alg->base.cra_driver_name) >= 868 CRYPTO_MAX_ALG_NAME) 869 goto err_free_inst; 870 871 inst->alg.base.cra_priority = alg->base.cra_priority; 872 inst->alg.base.cra_blocksize = 1; 873 inst->alg.base.cra_alignmask = alg->base.cra_alignmask; 874 875 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx); 876 877 inst->alg.ivsize = GCM_RFC4106_IV_SIZE; 878 inst->alg.chunksize = crypto_aead_alg_chunksize(alg); 879 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg); 880 881 inst->alg.init = crypto_rfc4106_init_tfm; 882 inst->alg.exit = crypto_rfc4106_exit_tfm; 883 884 inst->alg.setkey = crypto_rfc4106_setkey; 885 inst->alg.setauthsize = crypto_rfc4106_setauthsize; 886 inst->alg.encrypt = crypto_rfc4106_encrypt; 887 inst->alg.decrypt = crypto_rfc4106_decrypt; 888 889 inst->free = crypto_rfc4106_free; 890 891 err = aead_register_instance(tmpl, inst); 892 if (err) { 893 err_free_inst: 894 crypto_rfc4106_free(inst); 895 } 896 return err; 897 } 898 899 static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key, 900 unsigned int keylen) 901 { 902 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent); 903 struct crypto_aead *child = ctx->child; 904 905 if (keylen < 4) 906 return -EINVAL; 907 908 keylen -= 4; 909 memcpy(ctx->nonce, key + keylen, 4); 910 911 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 912 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 913 CRYPTO_TFM_REQ_MASK); 914 return crypto_aead_setkey(child, key, keylen); 915 } 916 917 static int crypto_rfc4543_setauthsize(struct crypto_aead *parent, 918 unsigned int authsize) 919 { 920 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent); 921 922 if (authsize != 16) 923 return -EINVAL; 924 925 return crypto_aead_setauthsize(ctx->child, authsize); 926 } 927 928 static int crypto_rfc4543_crypt(struct aead_request *req, bool enc) 929 { 930 struct crypto_aead *aead = crypto_aead_reqtfm(req); 931 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead); 932 struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req); 933 struct aead_request *subreq = &rctx->subreq; 934 unsigned int authsize = crypto_aead_authsize(aead); 935 u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child), 936 crypto_aead_alignmask(ctx->child) + 1); 937 int err; 938 939 if (req->src != req->dst) { 940 err = crypto_rfc4543_copy_src_to_dst(req, enc); 941 if (err) 942 return err; 943 } 944 945 memcpy(iv, ctx->nonce, 4); 946 memcpy(iv + 4, req->iv, 8); 947 948 aead_request_set_tfm(subreq, ctx->child); 949 aead_request_set_callback(subreq, req->base.flags, 950 req->base.complete, req->base.data); 951 aead_request_set_crypt(subreq, req->src, req->dst, 952 enc ? 0 : authsize, iv); 953 aead_request_set_ad(subreq, req->assoclen + req->cryptlen - 954 subreq->cryptlen); 955 956 return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq); 957 } 958 959 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc) 960 { 961 struct crypto_aead *aead = crypto_aead_reqtfm(req); 962 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead); 963 unsigned int authsize = crypto_aead_authsize(aead); 964 unsigned int nbytes = req->assoclen + req->cryptlen - 965 (enc ? 0 : authsize); 966 SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null); 967 968 skcipher_request_set_sync_tfm(nreq, ctx->null); 969 skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL); 970 skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL); 971 972 return crypto_skcipher_encrypt(nreq); 973 } 974 975 static int crypto_rfc4543_encrypt(struct aead_request *req) 976 { 977 return crypto_ipsec_check_assoclen(req->assoclen) ?: 978 crypto_rfc4543_crypt(req, true); 979 } 980 981 static int crypto_rfc4543_decrypt(struct aead_request *req) 982 { 983 return crypto_ipsec_check_assoclen(req->assoclen) ?: 984 crypto_rfc4543_crypt(req, false); 985 } 986 987 static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm) 988 { 989 struct aead_instance *inst = aead_alg_instance(tfm); 990 struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst); 991 struct crypto_aead_spawn *spawn = &ictx->aead; 992 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); 993 struct crypto_aead *aead; 994 struct crypto_sync_skcipher *null; 995 unsigned long align; 996 int err = 0; 997 998 aead = crypto_spawn_aead(spawn); 999 if (IS_ERR(aead)) 1000 return PTR_ERR(aead); 1001 1002 null = crypto_get_default_null_skcipher(); 1003 err = PTR_ERR(null); 1004 if (IS_ERR(null)) 1005 goto err_free_aead; 1006 1007 ctx->child = aead; 1008 ctx->null = null; 1009 1010 align = crypto_aead_alignmask(aead); 1011 align &= ~(crypto_tfm_ctx_alignment() - 1); 1012 crypto_aead_set_reqsize( 1013 tfm, 1014 sizeof(struct crypto_rfc4543_req_ctx) + 1015 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + 1016 align + GCM_AES_IV_SIZE); 1017 1018 return 0; 1019 1020 err_free_aead: 1021 crypto_free_aead(aead); 1022 return err; 1023 } 1024 1025 static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm) 1026 { 1027 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); 1028 1029 crypto_free_aead(ctx->child); 1030 crypto_put_default_null_skcipher(); 1031 } 1032 1033 static void crypto_rfc4543_free(struct aead_instance *inst) 1034 { 1035 struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst); 1036 1037 crypto_drop_aead(&ctx->aead); 1038 1039 kfree(inst); 1040 } 1041 1042 static int crypto_rfc4543_create(struct crypto_template *tmpl, 1043 struct rtattr **tb) 1044 { 1045 u32 mask; 1046 struct aead_instance *inst; 1047 struct aead_alg *alg; 1048 struct crypto_rfc4543_instance_ctx *ctx; 1049 int err; 1050 1051 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); 1052 if (err) 1053 return err; 1054 1055 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 1056 if (!inst) 1057 return -ENOMEM; 1058 1059 ctx = aead_instance_ctx(inst); 1060 err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst), 1061 crypto_attr_alg_name(tb[1]), 0, mask); 1062 if (err) 1063 goto err_free_inst; 1064 1065 alg = crypto_spawn_aead_alg(&ctx->aead); 1066 1067 err = -EINVAL; 1068 1069 /* Underlying IV size must be 12. */ 1070 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE) 1071 goto err_free_inst; 1072 1073 /* Not a stream cipher? */ 1074 if (alg->base.cra_blocksize != 1) 1075 goto err_free_inst; 1076 1077 err = -ENAMETOOLONG; 1078 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 1079 "rfc4543(%s)", alg->base.cra_name) >= 1080 CRYPTO_MAX_ALG_NAME || 1081 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 1082 "rfc4543(%s)", alg->base.cra_driver_name) >= 1083 CRYPTO_MAX_ALG_NAME) 1084 goto err_free_inst; 1085 1086 inst->alg.base.cra_priority = alg->base.cra_priority; 1087 inst->alg.base.cra_blocksize = 1; 1088 inst->alg.base.cra_alignmask = alg->base.cra_alignmask; 1089 1090 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx); 1091 1092 inst->alg.ivsize = GCM_RFC4543_IV_SIZE; 1093 inst->alg.chunksize = crypto_aead_alg_chunksize(alg); 1094 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg); 1095 1096 inst->alg.init = crypto_rfc4543_init_tfm; 1097 inst->alg.exit = crypto_rfc4543_exit_tfm; 1098 1099 inst->alg.setkey = crypto_rfc4543_setkey; 1100 inst->alg.setauthsize = crypto_rfc4543_setauthsize; 1101 inst->alg.encrypt = crypto_rfc4543_encrypt; 1102 inst->alg.decrypt = crypto_rfc4543_decrypt; 1103 1104 inst->free = crypto_rfc4543_free; 1105 1106 err = aead_register_instance(tmpl, inst); 1107 if (err) { 1108 err_free_inst: 1109 crypto_rfc4543_free(inst); 1110 } 1111 return err; 1112 } 1113 1114 static struct crypto_template crypto_gcm_tmpls[] = { 1115 { 1116 .name = "gcm_base", 1117 .create = crypto_gcm_base_create, 1118 .module = THIS_MODULE, 1119 }, { 1120 .name = "gcm", 1121 .create = crypto_gcm_create, 1122 .module = THIS_MODULE, 1123 }, { 1124 .name = "rfc4106", 1125 .create = crypto_rfc4106_create, 1126 .module = THIS_MODULE, 1127 }, { 1128 .name = "rfc4543", 1129 .create = crypto_rfc4543_create, 1130 .module = THIS_MODULE, 1131 }, 1132 }; 1133 1134 static int __init crypto_gcm_module_init(void) 1135 { 1136 int err; 1137 1138 gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL); 1139 if (!gcm_zeroes) 1140 return -ENOMEM; 1141 1142 sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf)); 1143 1144 err = crypto_register_templates(crypto_gcm_tmpls, 1145 ARRAY_SIZE(crypto_gcm_tmpls)); 1146 if (err) 1147 kfree(gcm_zeroes); 1148 1149 return err; 1150 } 1151 1152 static void __exit crypto_gcm_module_exit(void) 1153 { 1154 kfree(gcm_zeroes); 1155 crypto_unregister_templates(crypto_gcm_tmpls, 1156 ARRAY_SIZE(crypto_gcm_tmpls)); 1157 } 1158 1159 subsys_initcall(crypto_gcm_module_init); 1160 module_exit(crypto_gcm_module_exit); 1161 1162 MODULE_LICENSE("GPL"); 1163 MODULE_DESCRIPTION("Galois/Counter Mode"); 1164 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>"); 1165 MODULE_ALIAS_CRYPTO("gcm_base"); 1166 MODULE_ALIAS_CRYPTO("rfc4106"); 1167 MODULE_ALIAS_CRYPTO("rfc4543"); 1168 MODULE_ALIAS_CRYPTO("gcm"); 1169