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/scatterwalk.h> 15 #include <linux/completion.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 }; 25 26 struct crypto_gcm_ctx { 27 struct crypto_ablkcipher *ctr; 28 struct gf128mul_4k *gf128; 29 }; 30 31 struct crypto_rfc4106_ctx { 32 struct crypto_aead *child; 33 u8 nonce[4]; 34 }; 35 36 struct crypto_gcm_ghash_ctx { 37 u32 bytes; 38 u32 flags; 39 struct gf128mul_4k *gf128; 40 u8 buffer[16]; 41 }; 42 43 struct crypto_gcm_req_priv_ctx { 44 u8 auth_tag[16]; 45 u8 iauth_tag[16]; 46 struct scatterlist src[2]; 47 struct scatterlist dst[2]; 48 struct crypto_gcm_ghash_ctx ghash; 49 struct ablkcipher_request abreq; 50 }; 51 52 struct crypto_gcm_setkey_result { 53 int err; 54 struct completion completion; 55 }; 56 57 static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx( 58 struct aead_request *req) 59 { 60 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); 61 62 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); 63 } 64 65 static void crypto_gcm_ghash_init(struct crypto_gcm_ghash_ctx *ctx, u32 flags, 66 struct gf128mul_4k *gf128) 67 { 68 ctx->bytes = 0; 69 ctx->flags = flags; 70 ctx->gf128 = gf128; 71 memset(ctx->buffer, 0, 16); 72 } 73 74 static void crypto_gcm_ghash_update(struct crypto_gcm_ghash_ctx *ctx, 75 const u8 *src, unsigned int srclen) 76 { 77 u8 *dst = ctx->buffer; 78 79 if (ctx->bytes) { 80 int n = min(srclen, ctx->bytes); 81 u8 *pos = dst + (16 - ctx->bytes); 82 83 ctx->bytes -= n; 84 srclen -= n; 85 86 while (n--) 87 *pos++ ^= *src++; 88 89 if (!ctx->bytes) 90 gf128mul_4k_lle((be128 *)dst, ctx->gf128); 91 } 92 93 while (srclen >= 16) { 94 crypto_xor(dst, src, 16); 95 gf128mul_4k_lle((be128 *)dst, ctx->gf128); 96 src += 16; 97 srclen -= 16; 98 } 99 100 if (srclen) { 101 ctx->bytes = 16 - srclen; 102 while (srclen--) 103 *dst++ ^= *src++; 104 } 105 } 106 107 static void crypto_gcm_ghash_update_sg(struct crypto_gcm_ghash_ctx *ctx, 108 struct scatterlist *sg, int len) 109 { 110 struct scatter_walk walk; 111 u8 *src; 112 int n; 113 114 if (!len) 115 return; 116 117 scatterwalk_start(&walk, sg); 118 119 while (len) { 120 n = scatterwalk_clamp(&walk, len); 121 122 if (!n) { 123 scatterwalk_start(&walk, scatterwalk_sg_next(walk.sg)); 124 n = scatterwalk_clamp(&walk, len); 125 } 126 127 src = scatterwalk_map(&walk, 0); 128 129 crypto_gcm_ghash_update(ctx, src, n); 130 len -= n; 131 132 scatterwalk_unmap(src, 0); 133 scatterwalk_advance(&walk, n); 134 scatterwalk_done(&walk, 0, len); 135 if (len) 136 crypto_yield(ctx->flags); 137 } 138 } 139 140 static void crypto_gcm_ghash_flush(struct crypto_gcm_ghash_ctx *ctx) 141 { 142 u8 *dst = ctx->buffer; 143 144 if (ctx->bytes) { 145 u8 *tmp = dst + (16 - ctx->bytes); 146 147 while (ctx->bytes--) 148 *tmp++ ^= 0; 149 150 gf128mul_4k_lle((be128 *)dst, ctx->gf128); 151 } 152 153 ctx->bytes = 0; 154 } 155 156 static void crypto_gcm_ghash_final_xor(struct crypto_gcm_ghash_ctx *ctx, 157 unsigned int authlen, 158 unsigned int cryptlen, u8 *dst) 159 { 160 u8 *buf = ctx->buffer; 161 u128 lengths; 162 163 lengths.a = cpu_to_be64(authlen * 8); 164 lengths.b = cpu_to_be64(cryptlen * 8); 165 166 crypto_gcm_ghash_flush(ctx); 167 crypto_xor(buf, (u8 *)&lengths, 16); 168 gf128mul_4k_lle((be128 *)buf, ctx->gf128); 169 crypto_xor(dst, buf, 16); 170 } 171 172 static void crypto_gcm_setkey_done(struct crypto_async_request *req, int err) 173 { 174 struct crypto_gcm_setkey_result *result = req->data; 175 176 if (err == -EINPROGRESS) 177 return; 178 179 result->err = err; 180 complete(&result->completion); 181 } 182 183 static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key, 184 unsigned int keylen) 185 { 186 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); 187 struct crypto_ablkcipher *ctr = ctx->ctr; 188 struct { 189 be128 hash; 190 u8 iv[8]; 191 192 struct crypto_gcm_setkey_result result; 193 194 struct scatterlist sg[1]; 195 struct ablkcipher_request req; 196 } *data; 197 int err; 198 199 crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); 200 crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) & 201 CRYPTO_TFM_REQ_MASK); 202 203 err = crypto_ablkcipher_setkey(ctr, key, keylen); 204 if (err) 205 return err; 206 207 crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) & 208 CRYPTO_TFM_RES_MASK); 209 210 data = kzalloc(sizeof(*data) + crypto_ablkcipher_reqsize(ctr), 211 GFP_KERNEL); 212 if (!data) 213 return -ENOMEM; 214 215 init_completion(&data->result.completion); 216 sg_init_one(data->sg, &data->hash, sizeof(data->hash)); 217 ablkcipher_request_set_tfm(&data->req, ctr); 218 ablkcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP | 219 CRYPTO_TFM_REQ_MAY_BACKLOG, 220 crypto_gcm_setkey_done, 221 &data->result); 222 ablkcipher_request_set_crypt(&data->req, data->sg, data->sg, 223 sizeof(data->hash), data->iv); 224 225 err = crypto_ablkcipher_encrypt(&data->req); 226 if (err == -EINPROGRESS || err == -EBUSY) { 227 err = wait_for_completion_interruptible( 228 &data->result.completion); 229 if (!err) 230 err = data->result.err; 231 } 232 233 if (err) 234 goto out; 235 236 if (ctx->gf128 != NULL) 237 gf128mul_free_4k(ctx->gf128); 238 239 ctx->gf128 = gf128mul_init_4k_lle(&data->hash); 240 241 if (ctx->gf128 == NULL) 242 err = -ENOMEM; 243 244 out: 245 kfree(data); 246 return err; 247 } 248 249 static int crypto_gcm_setauthsize(struct crypto_aead *tfm, 250 unsigned int authsize) 251 { 252 switch (authsize) { 253 case 4: 254 case 8: 255 case 12: 256 case 13: 257 case 14: 258 case 15: 259 case 16: 260 break; 261 default: 262 return -EINVAL; 263 } 264 265 return 0; 266 } 267 268 static void crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req, 269 struct aead_request *req, 270 unsigned int cryptlen) 271 { 272 struct crypto_aead *aead = crypto_aead_reqtfm(req); 273 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); 274 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 275 u32 flags = req->base.tfm->crt_flags; 276 struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; 277 struct scatterlist *dst; 278 __be32 counter = cpu_to_be32(1); 279 280 memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag)); 281 memcpy(req->iv + 12, &counter, 4); 282 283 sg_init_table(pctx->src, 2); 284 sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag)); 285 scatterwalk_sg_chain(pctx->src, 2, req->src); 286 287 dst = pctx->src; 288 if (req->src != req->dst) { 289 sg_init_table(pctx->dst, 2); 290 sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag)); 291 scatterwalk_sg_chain(pctx->dst, 2, req->dst); 292 dst = pctx->dst; 293 } 294 295 ablkcipher_request_set_tfm(ablk_req, ctx->ctr); 296 ablkcipher_request_set_crypt(ablk_req, pctx->src, dst, 297 cryptlen + sizeof(pctx->auth_tag), 298 req->iv); 299 300 crypto_gcm_ghash_init(ghash, flags, ctx->gf128); 301 302 crypto_gcm_ghash_update_sg(ghash, req->assoc, req->assoclen); 303 crypto_gcm_ghash_flush(ghash); 304 } 305 306 static int crypto_gcm_hash(struct aead_request *req) 307 { 308 struct crypto_aead *aead = crypto_aead_reqtfm(req); 309 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 310 u8 *auth_tag = pctx->auth_tag; 311 struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; 312 313 crypto_gcm_ghash_update_sg(ghash, req->dst, req->cryptlen); 314 crypto_gcm_ghash_final_xor(ghash, req->assoclen, req->cryptlen, 315 auth_tag); 316 317 scatterwalk_map_and_copy(auth_tag, req->dst, req->cryptlen, 318 crypto_aead_authsize(aead), 1); 319 return 0; 320 } 321 322 static void crypto_gcm_encrypt_done(struct crypto_async_request *areq, int err) 323 { 324 struct aead_request *req = areq->data; 325 326 if (!err) 327 err = crypto_gcm_hash(req); 328 329 aead_request_complete(req, err); 330 } 331 332 static int crypto_gcm_encrypt(struct aead_request *req) 333 { 334 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 335 struct ablkcipher_request *abreq = &pctx->abreq; 336 int err; 337 338 crypto_gcm_init_crypt(abreq, req, req->cryptlen); 339 ablkcipher_request_set_callback(abreq, aead_request_flags(req), 340 crypto_gcm_encrypt_done, req); 341 342 err = crypto_ablkcipher_encrypt(abreq); 343 if (err) 344 return err; 345 346 return crypto_gcm_hash(req); 347 } 348 349 static int crypto_gcm_verify(struct aead_request *req) 350 { 351 struct crypto_aead *aead = crypto_aead_reqtfm(req); 352 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 353 struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; 354 u8 *auth_tag = pctx->auth_tag; 355 u8 *iauth_tag = pctx->iauth_tag; 356 unsigned int authsize = crypto_aead_authsize(aead); 357 unsigned int cryptlen = req->cryptlen - authsize; 358 359 crypto_gcm_ghash_final_xor(ghash, req->assoclen, cryptlen, auth_tag); 360 361 authsize = crypto_aead_authsize(aead); 362 scatterwalk_map_and_copy(iauth_tag, req->src, cryptlen, authsize, 0); 363 return memcmp(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0; 364 } 365 366 static void crypto_gcm_decrypt_done(struct crypto_async_request *areq, int err) 367 { 368 struct aead_request *req = areq->data; 369 370 if (!err) 371 err = crypto_gcm_verify(req); 372 373 aead_request_complete(req, err); 374 } 375 376 static int crypto_gcm_decrypt(struct aead_request *req) 377 { 378 struct crypto_aead *aead = crypto_aead_reqtfm(req); 379 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 380 struct ablkcipher_request *abreq = &pctx->abreq; 381 struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash; 382 unsigned int cryptlen = req->cryptlen; 383 unsigned int authsize = crypto_aead_authsize(aead); 384 int err; 385 386 if (cryptlen < authsize) 387 return -EINVAL; 388 cryptlen -= authsize; 389 390 crypto_gcm_init_crypt(abreq, req, cryptlen); 391 ablkcipher_request_set_callback(abreq, aead_request_flags(req), 392 crypto_gcm_decrypt_done, req); 393 394 crypto_gcm_ghash_update_sg(ghash, req->src, cryptlen); 395 396 err = crypto_ablkcipher_decrypt(abreq); 397 if (err) 398 return err; 399 400 return crypto_gcm_verify(req); 401 } 402 403 static int crypto_gcm_init_tfm(struct crypto_tfm *tfm) 404 { 405 struct crypto_instance *inst = (void *)tfm->__crt_alg; 406 struct gcm_instance_ctx *ictx = crypto_instance_ctx(inst); 407 struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm); 408 struct crypto_ablkcipher *ctr; 409 unsigned long align; 410 int err; 411 412 ctr = crypto_spawn_skcipher(&ictx->ctr); 413 err = PTR_ERR(ctr); 414 if (IS_ERR(ctr)) 415 return err; 416 417 ctx->ctr = ctr; 418 ctx->gf128 = NULL; 419 420 align = crypto_tfm_alg_alignmask(tfm); 421 align &= ~(crypto_tfm_ctx_alignment() - 1); 422 tfm->crt_aead.reqsize = align + 423 sizeof(struct crypto_gcm_req_priv_ctx) + 424 crypto_ablkcipher_reqsize(ctr); 425 426 return 0; 427 } 428 429 static void crypto_gcm_exit_tfm(struct crypto_tfm *tfm) 430 { 431 struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm); 432 433 if (ctx->gf128 != NULL) 434 gf128mul_free_4k(ctx->gf128); 435 436 crypto_free_ablkcipher(ctx->ctr); 437 } 438 439 static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb, 440 const char *full_name, 441 const char *ctr_name) 442 { 443 struct crypto_attr_type *algt; 444 struct crypto_instance *inst; 445 struct crypto_alg *ctr; 446 struct gcm_instance_ctx *ctx; 447 int err; 448 449 algt = crypto_get_attr_type(tb); 450 err = PTR_ERR(algt); 451 if (IS_ERR(algt)) 452 return ERR_PTR(err); 453 454 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 455 return ERR_PTR(-EINVAL); 456 457 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 458 if (!inst) 459 return ERR_PTR(-ENOMEM); 460 461 ctx = crypto_instance_ctx(inst); 462 crypto_set_skcipher_spawn(&ctx->ctr, inst); 463 err = crypto_grab_skcipher(&ctx->ctr, ctr_name, 0, 464 crypto_requires_sync(algt->type, 465 algt->mask)); 466 if (err) 467 goto err_free_inst; 468 469 ctr = crypto_skcipher_spawn_alg(&ctx->ctr); 470 471 /* We only support 16-byte blocks. */ 472 if (ctr->cra_ablkcipher.ivsize != 16) 473 goto out_put_ctr; 474 475 /* Not a stream cipher? */ 476 err = -EINVAL; 477 if (ctr->cra_blocksize != 1) 478 goto out_put_ctr; 479 480 err = -ENAMETOOLONG; 481 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, 482 "gcm_base(%s)", ctr->cra_driver_name) >= 483 CRYPTO_MAX_ALG_NAME) 484 goto out_put_ctr; 485 486 memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME); 487 488 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD; 489 inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC; 490 inst->alg.cra_priority = ctr->cra_priority; 491 inst->alg.cra_blocksize = 1; 492 inst->alg.cra_alignmask = ctr->cra_alignmask | (__alignof__(u64) - 1); 493 inst->alg.cra_type = &crypto_aead_type; 494 inst->alg.cra_aead.ivsize = 16; 495 inst->alg.cra_aead.maxauthsize = 16; 496 inst->alg.cra_ctxsize = sizeof(struct crypto_gcm_ctx); 497 inst->alg.cra_init = crypto_gcm_init_tfm; 498 inst->alg.cra_exit = crypto_gcm_exit_tfm; 499 inst->alg.cra_aead.setkey = crypto_gcm_setkey; 500 inst->alg.cra_aead.setauthsize = crypto_gcm_setauthsize; 501 inst->alg.cra_aead.encrypt = crypto_gcm_encrypt; 502 inst->alg.cra_aead.decrypt = crypto_gcm_decrypt; 503 504 out: 505 return inst; 506 507 out_put_ctr: 508 crypto_drop_skcipher(&ctx->ctr); 509 err_free_inst: 510 kfree(inst); 511 inst = ERR_PTR(err); 512 goto out; 513 } 514 515 static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb) 516 { 517 int err; 518 const char *cipher_name; 519 char ctr_name[CRYPTO_MAX_ALG_NAME]; 520 char full_name[CRYPTO_MAX_ALG_NAME]; 521 522 cipher_name = crypto_attr_alg_name(tb[1]); 523 err = PTR_ERR(cipher_name); 524 if (IS_ERR(cipher_name)) 525 return ERR_PTR(err); 526 527 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >= 528 CRYPTO_MAX_ALG_NAME) 529 return ERR_PTR(-ENAMETOOLONG); 530 531 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >= 532 CRYPTO_MAX_ALG_NAME) 533 return ERR_PTR(-ENAMETOOLONG); 534 535 return crypto_gcm_alloc_common(tb, full_name, ctr_name); 536 } 537 538 static void crypto_gcm_free(struct crypto_instance *inst) 539 { 540 struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst); 541 542 crypto_drop_skcipher(&ctx->ctr); 543 kfree(inst); 544 } 545 546 static struct crypto_template crypto_gcm_tmpl = { 547 .name = "gcm", 548 .alloc = crypto_gcm_alloc, 549 .free = crypto_gcm_free, 550 .module = THIS_MODULE, 551 }; 552 553 static struct crypto_instance *crypto_gcm_base_alloc(struct rtattr **tb) 554 { 555 int err; 556 const char *ctr_name; 557 char full_name[CRYPTO_MAX_ALG_NAME]; 558 559 ctr_name = crypto_attr_alg_name(tb[1]); 560 err = PTR_ERR(ctr_name); 561 if (IS_ERR(ctr_name)) 562 return ERR_PTR(err); 563 564 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s)", 565 ctr_name) >= CRYPTO_MAX_ALG_NAME) 566 return ERR_PTR(-ENAMETOOLONG); 567 568 return crypto_gcm_alloc_common(tb, full_name, ctr_name); 569 } 570 571 static struct crypto_template crypto_gcm_base_tmpl = { 572 .name = "gcm_base", 573 .alloc = crypto_gcm_base_alloc, 574 .free = crypto_gcm_free, 575 .module = THIS_MODULE, 576 }; 577 578 static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key, 579 unsigned int keylen) 580 { 581 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); 582 struct crypto_aead *child = ctx->child; 583 int err; 584 585 if (keylen < 4) 586 return -EINVAL; 587 588 keylen -= 4; 589 memcpy(ctx->nonce, key + keylen, 4); 590 591 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 592 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 593 CRYPTO_TFM_REQ_MASK); 594 err = crypto_aead_setkey(child, key, keylen); 595 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) & 596 CRYPTO_TFM_RES_MASK); 597 598 return err; 599 } 600 601 static int crypto_rfc4106_setauthsize(struct crypto_aead *parent, 602 unsigned int authsize) 603 { 604 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); 605 606 switch (authsize) { 607 case 8: 608 case 12: 609 case 16: 610 break; 611 default: 612 return -EINVAL; 613 } 614 615 return crypto_aead_setauthsize(ctx->child, authsize); 616 } 617 618 static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req) 619 { 620 struct aead_request *subreq = aead_request_ctx(req); 621 struct crypto_aead *aead = crypto_aead_reqtfm(req); 622 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead); 623 struct crypto_aead *child = ctx->child; 624 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child), 625 crypto_aead_alignmask(child) + 1); 626 627 memcpy(iv, ctx->nonce, 4); 628 memcpy(iv + 4, req->iv, 8); 629 630 aead_request_set_tfm(subreq, child); 631 aead_request_set_callback(subreq, req->base.flags, req->base.complete, 632 req->base.data); 633 aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv); 634 aead_request_set_assoc(subreq, req->assoc, req->assoclen); 635 636 return subreq; 637 } 638 639 static int crypto_rfc4106_encrypt(struct aead_request *req) 640 { 641 req = crypto_rfc4106_crypt(req); 642 643 return crypto_aead_encrypt(req); 644 } 645 646 static int crypto_rfc4106_decrypt(struct aead_request *req) 647 { 648 req = crypto_rfc4106_crypt(req); 649 650 return crypto_aead_decrypt(req); 651 } 652 653 static int crypto_rfc4106_init_tfm(struct crypto_tfm *tfm) 654 { 655 struct crypto_instance *inst = (void *)tfm->__crt_alg; 656 struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst); 657 struct crypto_rfc4106_ctx *ctx = crypto_tfm_ctx(tfm); 658 struct crypto_aead *aead; 659 unsigned long align; 660 661 aead = crypto_spawn_aead(spawn); 662 if (IS_ERR(aead)) 663 return PTR_ERR(aead); 664 665 ctx->child = aead; 666 667 align = crypto_aead_alignmask(aead); 668 align &= ~(crypto_tfm_ctx_alignment() - 1); 669 tfm->crt_aead.reqsize = sizeof(struct aead_request) + 670 ALIGN(crypto_aead_reqsize(aead), 671 crypto_tfm_ctx_alignment()) + 672 align + 16; 673 674 return 0; 675 } 676 677 static void crypto_rfc4106_exit_tfm(struct crypto_tfm *tfm) 678 { 679 struct crypto_rfc4106_ctx *ctx = crypto_tfm_ctx(tfm); 680 681 crypto_free_aead(ctx->child); 682 } 683 684 static struct crypto_instance *crypto_rfc4106_alloc(struct rtattr **tb) 685 { 686 struct crypto_attr_type *algt; 687 struct crypto_instance *inst; 688 struct crypto_aead_spawn *spawn; 689 struct crypto_alg *alg; 690 const char *ccm_name; 691 int err; 692 693 algt = crypto_get_attr_type(tb); 694 err = PTR_ERR(algt); 695 if (IS_ERR(algt)) 696 return ERR_PTR(err); 697 698 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 699 return ERR_PTR(-EINVAL); 700 701 ccm_name = crypto_attr_alg_name(tb[1]); 702 err = PTR_ERR(ccm_name); 703 if (IS_ERR(ccm_name)) 704 return ERR_PTR(err); 705 706 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 707 if (!inst) 708 return ERR_PTR(-ENOMEM); 709 710 spawn = crypto_instance_ctx(inst); 711 crypto_set_aead_spawn(spawn, inst); 712 err = crypto_grab_aead(spawn, ccm_name, 0, 713 crypto_requires_sync(algt->type, algt->mask)); 714 if (err) 715 goto out_free_inst; 716 717 alg = crypto_aead_spawn_alg(spawn); 718 719 err = -EINVAL; 720 721 /* We only support 16-byte blocks. */ 722 if (alg->cra_aead.ivsize != 16) 723 goto out_drop_alg; 724 725 /* Not a stream cipher? */ 726 if (alg->cra_blocksize != 1) 727 goto out_drop_alg; 728 729 err = -ENAMETOOLONG; 730 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, 731 "rfc4106(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME || 732 snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, 733 "rfc4106(%s)", alg->cra_driver_name) >= 734 CRYPTO_MAX_ALG_NAME) 735 goto out_drop_alg; 736 737 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD; 738 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC; 739 inst->alg.cra_priority = alg->cra_priority; 740 inst->alg.cra_blocksize = 1; 741 inst->alg.cra_alignmask = alg->cra_alignmask; 742 inst->alg.cra_type = &crypto_nivaead_type; 743 744 inst->alg.cra_aead.ivsize = 8; 745 inst->alg.cra_aead.maxauthsize = 16; 746 747 inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx); 748 749 inst->alg.cra_init = crypto_rfc4106_init_tfm; 750 inst->alg.cra_exit = crypto_rfc4106_exit_tfm; 751 752 inst->alg.cra_aead.setkey = crypto_rfc4106_setkey; 753 inst->alg.cra_aead.setauthsize = crypto_rfc4106_setauthsize; 754 inst->alg.cra_aead.encrypt = crypto_rfc4106_encrypt; 755 inst->alg.cra_aead.decrypt = crypto_rfc4106_decrypt; 756 757 inst->alg.cra_aead.geniv = "seqiv"; 758 759 out: 760 return inst; 761 762 out_drop_alg: 763 crypto_drop_aead(spawn); 764 out_free_inst: 765 kfree(inst); 766 inst = ERR_PTR(err); 767 goto out; 768 } 769 770 static void crypto_rfc4106_free(struct crypto_instance *inst) 771 { 772 crypto_drop_spawn(crypto_instance_ctx(inst)); 773 kfree(inst); 774 } 775 776 static struct crypto_template crypto_rfc4106_tmpl = { 777 .name = "rfc4106", 778 .alloc = crypto_rfc4106_alloc, 779 .free = crypto_rfc4106_free, 780 .module = THIS_MODULE, 781 }; 782 783 static int __init crypto_gcm_module_init(void) 784 { 785 int err; 786 787 err = crypto_register_template(&crypto_gcm_base_tmpl); 788 if (err) 789 goto out; 790 791 err = crypto_register_template(&crypto_gcm_tmpl); 792 if (err) 793 goto out_undo_base; 794 795 err = crypto_register_template(&crypto_rfc4106_tmpl); 796 if (err) 797 goto out_undo_gcm; 798 799 out: 800 return err; 801 802 out_undo_gcm: 803 crypto_unregister_template(&crypto_gcm_tmpl); 804 out_undo_base: 805 crypto_unregister_template(&crypto_gcm_base_tmpl); 806 goto out; 807 } 808 809 static void __exit crypto_gcm_module_exit(void) 810 { 811 crypto_unregister_template(&crypto_rfc4106_tmpl); 812 crypto_unregister_template(&crypto_gcm_tmpl); 813 crypto_unregister_template(&crypto_gcm_base_tmpl); 814 } 815 816 module_init(crypto_gcm_module_init); 817 module_exit(crypto_gcm_module_exit); 818 819 MODULE_LICENSE("GPL"); 820 MODULE_DESCRIPTION("Galois/Counter Mode"); 821 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>"); 822 MODULE_ALIAS("gcm_base"); 823 MODULE_ALIAS("rfc4106"); 824