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/internal/aead.h> 9 #include <crypto/internal/skcipher.h> 10 #include <crypto/scatterwalk.h> 11 #include <crypto/gcm.h> 12 #include <crypto/gf128hash.h> 13 #include <linux/err.h> 14 #include <linux/init.h> 15 #include <linux/kernel.h> 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 19 struct gcm_instance_ctx { 20 struct crypto_skcipher_spawn ctr; 21 }; 22 23 struct crypto_gcm_ctx { 24 struct crypto_skcipher *ctr; 25 struct ghash_key ghash; 26 }; 27 28 struct crypto_rfc4106_ctx { 29 struct crypto_aead *child; 30 u8 nonce[4]; 31 }; 32 33 struct crypto_rfc4106_req_ctx { 34 struct scatterlist src[3]; 35 struct scatterlist dst[3]; 36 struct aead_request subreq; 37 }; 38 39 struct crypto_rfc4543_instance_ctx { 40 struct crypto_aead_spawn aead; 41 }; 42 43 struct crypto_rfc4543_ctx { 44 struct crypto_aead *child; 45 u8 nonce[4]; 46 }; 47 48 struct crypto_rfc4543_req_ctx { 49 struct aead_request subreq; 50 }; 51 52 struct crypto_gcm_req_priv_ctx { 53 u8 iv[16]; 54 u8 auth_tag[16]; 55 u8 iauth_tag[16]; 56 struct scatterlist src[3]; 57 struct scatterlist dst[3]; 58 struct skcipher_request skreq; /* Must be last */ 59 }; 60 61 static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx( 62 struct aead_request *req) 63 { 64 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req)); 65 66 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1); 67 } 68 69 static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key, 70 unsigned int keylen) 71 { 72 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); 73 struct crypto_skcipher *ctr = ctx->ctr; 74 struct { 75 u8 h[GHASH_BLOCK_SIZE]; 76 u8 iv[16]; 77 78 struct crypto_wait wait; 79 80 struct scatterlist sg[1]; 81 struct skcipher_request req; 82 } *data; 83 int err; 84 85 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK); 86 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) & 87 CRYPTO_TFM_REQ_MASK); 88 err = crypto_skcipher_setkey(ctr, key, keylen); 89 if (err) 90 return err; 91 92 data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr), 93 GFP_KERNEL); 94 if (!data) 95 return -ENOMEM; 96 97 crypto_init_wait(&data->wait); 98 sg_init_one(data->sg, data->h, sizeof(data->h)); 99 skcipher_request_set_tfm(&data->req, ctr); 100 skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP | 101 CRYPTO_TFM_REQ_MAY_BACKLOG, 102 crypto_req_done, 103 &data->wait); 104 skcipher_request_set_crypt(&data->req, data->sg, data->sg, 105 sizeof(data->h), data->iv); 106 107 err = crypto_wait_req(crypto_skcipher_encrypt(&data->req), 108 &data->wait); 109 110 if (err) 111 goto out; 112 113 ghash_preparekey(&ctx->ghash, data->h); 114 out: 115 kfree_sensitive(data); 116 return err; 117 } 118 119 static int crypto_gcm_setauthsize(struct crypto_aead *tfm, 120 unsigned int authsize) 121 { 122 return crypto_gcm_check_authsize(authsize); 123 } 124 125 static void crypto_gcm_init_common(struct aead_request *req) 126 { 127 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 128 __be32 counter = cpu_to_be32(1); 129 struct scatterlist *sg; 130 131 memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag)); 132 memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE); 133 memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4); 134 135 sg_init_table(pctx->src, 3); 136 sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag)); 137 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen); 138 if (sg != pctx->src + 1) 139 sg_chain(pctx->src, 2, sg); 140 141 if (req->src != req->dst) { 142 sg_init_table(pctx->dst, 3); 143 sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag)); 144 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen); 145 if (sg != pctx->dst + 1) 146 sg_chain(pctx->dst, 2, sg); 147 } 148 } 149 150 static void crypto_gcm_init_crypt(struct aead_request *req, 151 unsigned int cryptlen) 152 { 153 struct crypto_aead *aead = crypto_aead_reqtfm(req); 154 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead); 155 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 156 struct skcipher_request *skreq = &pctx->skreq; 157 struct scatterlist *dst; 158 159 dst = req->src == req->dst ? pctx->src : pctx->dst; 160 161 skcipher_request_set_tfm(skreq, ctx->ctr); 162 skcipher_request_set_crypt(skreq, pctx->src, dst, 163 cryptlen + sizeof(pctx->auth_tag), 164 pctx->iv); 165 } 166 167 static void ghash_update_sg_and_pad(struct ghash_ctx *ghash, 168 struct scatterlist *sg, unsigned int len) 169 { 170 static const u8 zeroes[GHASH_BLOCK_SIZE]; 171 172 if (len) { 173 unsigned int pad_len = -len % GHASH_BLOCK_SIZE; 174 struct scatter_walk walk; 175 176 scatterwalk_start(&walk, sg); 177 do { 178 unsigned int n = scatterwalk_next(&walk, len); 179 180 ghash_update(ghash, walk.addr, n); 181 scatterwalk_done_src(&walk, n); 182 len -= n; 183 } while (len); 184 185 if (pad_len) 186 ghash_update(ghash, zeroes, pad_len); 187 } 188 } 189 190 static void gcm_hash(struct aead_request *req, struct scatterlist *ctext, 191 unsigned int datalen, u8 out[GHASH_BLOCK_SIZE]) 192 { 193 const struct crypto_gcm_ctx *ctx = 194 crypto_aead_ctx(crypto_aead_reqtfm(req)); 195 __be64 lengths[2] = { 196 cpu_to_be64(8 * (u64)req->assoclen), 197 cpu_to_be64(8 * (u64)datalen), 198 }; 199 struct ghash_ctx ghash; 200 201 ghash_init(&ghash, &ctx->ghash); 202 203 /* Associated data, then zero-padding to the next 16-byte boundary */ 204 ghash_update_sg_and_pad(&ghash, req->src, req->assoclen); 205 206 /* Ciphertext, then zero-padding to the next 16-byte boundary */ 207 ghash_update_sg_and_pad(&ghash, ctext, datalen); 208 209 /* Lengths block */ 210 ghash_update(&ghash, (const u8 *)lengths, sizeof(lengths)); 211 212 ghash_final(&ghash, out); 213 } 214 215 static int gcm_add_auth_tag(struct aead_request *req) 216 { 217 struct crypto_aead *aead = crypto_aead_reqtfm(req); 218 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 219 220 gcm_hash(req, sg_next(req->src == req->dst ? pctx->src : pctx->dst), 221 req->cryptlen, pctx->iauth_tag); 222 crypto_xor(pctx->auth_tag, pctx->iauth_tag, 16); 223 memcpy_to_sglist(req->dst, req->assoclen + req->cryptlen, 224 pctx->auth_tag, crypto_aead_authsize(aead)); 225 return 0; 226 } 227 228 static void gcm_encrypt_done(void *data, int err) 229 { 230 struct aead_request *req = data; 231 232 if (err) 233 goto out; 234 235 err = gcm_add_auth_tag(req); 236 237 out: 238 aead_request_complete(req, err); 239 } 240 241 static int crypto_gcm_encrypt(struct aead_request *req) 242 { 243 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 244 struct skcipher_request *skreq = &pctx->skreq; 245 u32 flags = aead_request_flags(req); 246 247 crypto_gcm_init_common(req); 248 crypto_gcm_init_crypt(req, req->cryptlen); 249 skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req); 250 251 return crypto_skcipher_encrypt(skreq) ?: gcm_add_auth_tag(req); 252 } 253 254 static int crypto_gcm_verify(struct aead_request *req) 255 { 256 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 257 struct crypto_aead *aead = crypto_aead_reqtfm(req); 258 u8 *auth_tag = pctx->auth_tag; 259 u8 *iauth_tag = pctx->iauth_tag; 260 unsigned int authsize = crypto_aead_authsize(aead); 261 unsigned int cryptlen = req->cryptlen - authsize; 262 263 crypto_xor(auth_tag, iauth_tag, 16); 264 scatterwalk_map_and_copy(iauth_tag, req->src, 265 req->assoclen + cryptlen, authsize, 0); 266 return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0; 267 } 268 269 static void gcm_decrypt_done(void *data, int err) 270 { 271 struct aead_request *req = data; 272 273 if (!err) 274 err = crypto_gcm_verify(req); 275 276 aead_request_complete(req, err); 277 } 278 279 static int crypto_gcm_decrypt(struct aead_request *req) 280 { 281 struct crypto_aead *aead = crypto_aead_reqtfm(req); 282 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req); 283 struct skcipher_request *skreq = &pctx->skreq; 284 unsigned int datalen = req->cryptlen - crypto_aead_authsize(aead); 285 286 crypto_gcm_init_common(req); 287 288 gcm_hash(req, sg_next(pctx->src), datalen, pctx->iauth_tag); 289 290 crypto_gcm_init_crypt(req, datalen); 291 skcipher_request_set_callback(skreq, aead_request_flags(req), 292 gcm_decrypt_done, req); 293 return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req); 294 } 295 296 static int crypto_gcm_init_tfm(struct crypto_aead *tfm) 297 { 298 struct aead_instance *inst = aead_alg_instance(tfm); 299 struct gcm_instance_ctx *ictx = aead_instance_ctx(inst); 300 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm); 301 struct crypto_skcipher *ctr; 302 unsigned long align; 303 304 ctr = crypto_spawn_skcipher(&ictx->ctr); 305 if (IS_ERR(ctr)) 306 return PTR_ERR(ctr); 307 308 ctx->ctr = ctr; 309 310 align = crypto_aead_alignmask(tfm); 311 align &= ~(crypto_tfm_ctx_alignment() - 1); 312 crypto_aead_set_reqsize(tfm, 313 align + sizeof(struct crypto_gcm_req_priv_ctx) + 314 crypto_skcipher_reqsize(ctr)); 315 return 0; 316 } 317 318 static void crypto_gcm_exit_tfm(struct crypto_aead *tfm) 319 { 320 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm); 321 322 crypto_free_skcipher(ctx->ctr); 323 } 324 325 static void crypto_gcm_free(struct aead_instance *inst) 326 { 327 struct gcm_instance_ctx *ctx = aead_instance_ctx(inst); 328 329 crypto_drop_skcipher(&ctx->ctr); 330 kfree(inst); 331 } 332 333 static int crypto_gcm_create_common(struct crypto_template *tmpl, 334 struct rtattr **tb, const char *ctr_name) 335 { 336 struct skcipher_alg_common *ctr; 337 u32 mask; 338 struct aead_instance *inst; 339 struct gcm_instance_ctx *ctx; 340 int err; 341 342 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); 343 if (err) 344 return err; 345 346 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 347 if (!inst) 348 return -ENOMEM; 349 ctx = aead_instance_ctx(inst); 350 351 err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst), 352 ctr_name, 0, mask); 353 if (err) 354 goto err_free_inst; 355 ctr = crypto_spawn_skcipher_alg_common(&ctx->ctr); 356 357 /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */ 358 err = -EINVAL; 359 if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 || 360 ctr->ivsize != 16 || ctr->base.cra_blocksize != 1) 361 goto err_free_inst; 362 363 err = -ENAMETOOLONG; 364 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 365 "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME) 366 goto err_free_inst; 367 368 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 369 "gcm_base(%s,ghash-lib)", 370 ctr->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME) 371 goto err_free_inst; 372 373 inst->alg.base.cra_priority = ctr->base.cra_priority; 374 inst->alg.base.cra_blocksize = 1; 375 inst->alg.base.cra_alignmask = ctr->base.cra_alignmask; 376 inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx); 377 inst->alg.ivsize = GCM_AES_IV_SIZE; 378 inst->alg.chunksize = ctr->chunksize; 379 inst->alg.maxauthsize = 16; 380 inst->alg.init = crypto_gcm_init_tfm; 381 inst->alg.exit = crypto_gcm_exit_tfm; 382 inst->alg.setkey = crypto_gcm_setkey; 383 inst->alg.setauthsize = crypto_gcm_setauthsize; 384 inst->alg.encrypt = crypto_gcm_encrypt; 385 inst->alg.decrypt = crypto_gcm_decrypt; 386 387 inst->free = crypto_gcm_free; 388 389 err = aead_register_instance(tmpl, inst); 390 if (err) { 391 err_free_inst: 392 crypto_gcm_free(inst); 393 } 394 return err; 395 } 396 397 static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb) 398 { 399 const char *cipher_name; 400 char ctr_name[CRYPTO_MAX_ALG_NAME]; 401 402 cipher_name = crypto_attr_alg_name(tb[1]); 403 if (IS_ERR(cipher_name)) 404 return PTR_ERR(cipher_name); 405 406 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >= 407 CRYPTO_MAX_ALG_NAME) 408 return -ENAMETOOLONG; 409 410 return crypto_gcm_create_common(tmpl, tb, ctr_name); 411 } 412 413 static int crypto_gcm_base_create(struct crypto_template *tmpl, 414 struct rtattr **tb) 415 { 416 const char *ctr_name; 417 const char *ghash_name; 418 419 ctr_name = crypto_attr_alg_name(tb[1]); 420 if (IS_ERR(ctr_name)) 421 return PTR_ERR(ctr_name); 422 423 ghash_name = crypto_attr_alg_name(tb[2]); 424 if (IS_ERR(ghash_name)) 425 return PTR_ERR(ghash_name); 426 427 /* 428 * Originally this parameter allowed requesting a specific 429 * implementation of GHASH. This is no longer supported. Now the best 430 * implementation of GHASH is just always used. 431 */ 432 if (strcmp(ghash_name, "ghash") != 0 && 433 strcmp(ghash_name, "ghash-lib") != 0) 434 return -EINVAL; 435 436 return crypto_gcm_create_common(tmpl, tb, ctr_name); 437 } 438 439 static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key, 440 unsigned int keylen) 441 { 442 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); 443 struct crypto_aead *child = ctx->child; 444 445 if (keylen < 4) 446 return -EINVAL; 447 448 keylen -= 4; 449 memcpy(ctx->nonce, key + keylen, 4); 450 451 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 452 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 453 CRYPTO_TFM_REQ_MASK); 454 return crypto_aead_setkey(child, key, keylen); 455 } 456 457 static int crypto_rfc4106_setauthsize(struct crypto_aead *parent, 458 unsigned int authsize) 459 { 460 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent); 461 int err; 462 463 err = crypto_rfc4106_check_authsize(authsize); 464 if (err) 465 return err; 466 467 return crypto_aead_setauthsize(ctx->child, authsize); 468 } 469 470 static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req) 471 { 472 struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req); 473 struct crypto_aead *aead = crypto_aead_reqtfm(req); 474 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead); 475 struct aead_request *subreq = &rctx->subreq; 476 struct crypto_aead *child = ctx->child; 477 struct scatterlist *sg; 478 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child), 479 crypto_aead_alignmask(child) + 1); 480 481 scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0); 482 483 memcpy(iv, ctx->nonce, 4); 484 memcpy(iv + 4, req->iv, 8); 485 486 sg_init_table(rctx->src, 3); 487 sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8); 488 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen); 489 if (sg != rctx->src + 1) 490 sg_chain(rctx->src, 2, sg); 491 492 if (req->src != req->dst) { 493 sg_init_table(rctx->dst, 3); 494 sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8); 495 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen); 496 if (sg != rctx->dst + 1) 497 sg_chain(rctx->dst, 2, sg); 498 } 499 500 aead_request_set_tfm(subreq, child); 501 aead_request_set_callback(subreq, req->base.flags, req->base.complete, 502 req->base.data); 503 aead_request_set_crypt(subreq, rctx->src, 504 req->src == req->dst ? rctx->src : rctx->dst, 505 req->cryptlen, iv); 506 aead_request_set_ad(subreq, req->assoclen - 8); 507 508 return subreq; 509 } 510 511 static int crypto_rfc4106_encrypt(struct aead_request *req) 512 { 513 int err; 514 515 err = crypto_ipsec_check_assoclen(req->assoclen); 516 if (err) 517 return err; 518 519 req = crypto_rfc4106_crypt(req); 520 521 return crypto_aead_encrypt(req); 522 } 523 524 static int crypto_rfc4106_decrypt(struct aead_request *req) 525 { 526 int err; 527 528 err = crypto_ipsec_check_assoclen(req->assoclen); 529 if (err) 530 return err; 531 532 req = crypto_rfc4106_crypt(req); 533 534 return crypto_aead_decrypt(req); 535 } 536 537 static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm) 538 { 539 struct aead_instance *inst = aead_alg_instance(tfm); 540 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst); 541 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm); 542 struct crypto_aead *aead; 543 unsigned long align; 544 545 aead = crypto_spawn_aead(spawn); 546 if (IS_ERR(aead)) 547 return PTR_ERR(aead); 548 549 ctx->child = aead; 550 551 align = crypto_aead_alignmask(aead); 552 align &= ~(crypto_tfm_ctx_alignment() - 1); 553 crypto_aead_set_reqsize( 554 tfm, 555 sizeof(struct crypto_rfc4106_req_ctx) + 556 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + 557 align + 24); 558 559 return 0; 560 } 561 562 static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm) 563 { 564 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm); 565 566 crypto_free_aead(ctx->child); 567 } 568 569 static void crypto_rfc4106_free(struct aead_instance *inst) 570 { 571 crypto_drop_aead(aead_instance_ctx(inst)); 572 kfree(inst); 573 } 574 575 static int crypto_rfc4106_create(struct crypto_template *tmpl, 576 struct rtattr **tb) 577 { 578 u32 mask; 579 struct aead_instance *inst; 580 struct crypto_aead_spawn *spawn; 581 struct aead_alg *alg; 582 int err; 583 584 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); 585 if (err) 586 return err; 587 588 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 589 if (!inst) 590 return -ENOMEM; 591 592 spawn = aead_instance_ctx(inst); 593 err = crypto_grab_aead(spawn, aead_crypto_instance(inst), 594 crypto_attr_alg_name(tb[1]), 0, mask); 595 if (err) 596 goto err_free_inst; 597 598 alg = crypto_spawn_aead_alg(spawn); 599 600 err = -EINVAL; 601 602 /* Underlying IV size must be 12. */ 603 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE) 604 goto err_free_inst; 605 606 /* Not a stream cipher? */ 607 if (alg->base.cra_blocksize != 1) 608 goto err_free_inst; 609 610 err = -ENAMETOOLONG; 611 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 612 "rfc4106(%s)", alg->base.cra_name) >= 613 CRYPTO_MAX_ALG_NAME || 614 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 615 "rfc4106(%s)", alg->base.cra_driver_name) >= 616 CRYPTO_MAX_ALG_NAME) 617 goto err_free_inst; 618 619 inst->alg.base.cra_priority = alg->base.cra_priority; 620 inst->alg.base.cra_blocksize = 1; 621 inst->alg.base.cra_alignmask = alg->base.cra_alignmask; 622 623 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx); 624 625 inst->alg.ivsize = GCM_RFC4106_IV_SIZE; 626 inst->alg.chunksize = crypto_aead_alg_chunksize(alg); 627 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg); 628 629 inst->alg.init = crypto_rfc4106_init_tfm; 630 inst->alg.exit = crypto_rfc4106_exit_tfm; 631 632 inst->alg.setkey = crypto_rfc4106_setkey; 633 inst->alg.setauthsize = crypto_rfc4106_setauthsize; 634 inst->alg.encrypt = crypto_rfc4106_encrypt; 635 inst->alg.decrypt = crypto_rfc4106_decrypt; 636 637 inst->free = crypto_rfc4106_free; 638 639 err = aead_register_instance(tmpl, inst); 640 if (err) { 641 err_free_inst: 642 crypto_rfc4106_free(inst); 643 } 644 return err; 645 } 646 647 static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key, 648 unsigned int keylen) 649 { 650 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent); 651 struct crypto_aead *child = ctx->child; 652 653 if (keylen < 4) 654 return -EINVAL; 655 656 keylen -= 4; 657 memcpy(ctx->nonce, key + keylen, 4); 658 659 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK); 660 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) & 661 CRYPTO_TFM_REQ_MASK); 662 return crypto_aead_setkey(child, key, keylen); 663 } 664 665 static int crypto_rfc4543_setauthsize(struct crypto_aead *parent, 666 unsigned int authsize) 667 { 668 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent); 669 670 if (authsize != 16) 671 return -EINVAL; 672 673 return crypto_aead_setauthsize(ctx->child, authsize); 674 } 675 676 static int crypto_rfc4543_crypt(struct aead_request *req, bool enc) 677 { 678 struct crypto_aead *aead = crypto_aead_reqtfm(req); 679 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead); 680 struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req); 681 struct aead_request *subreq = &rctx->subreq; 682 unsigned int authsize = crypto_aead_authsize(aead); 683 u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child), 684 crypto_aead_alignmask(ctx->child) + 1); 685 686 if (req->src != req->dst) { 687 unsigned int nbytes = req->assoclen + req->cryptlen - 688 (enc ? 0 : authsize); 689 690 memcpy_sglist(req->dst, req->src, nbytes); 691 } 692 693 memcpy(iv, ctx->nonce, 4); 694 memcpy(iv + 4, req->iv, 8); 695 696 aead_request_set_tfm(subreq, ctx->child); 697 aead_request_set_callback(subreq, req->base.flags, 698 req->base.complete, req->base.data); 699 aead_request_set_crypt(subreq, req->src, req->dst, 700 enc ? 0 : authsize, iv); 701 aead_request_set_ad(subreq, req->assoclen + req->cryptlen - 702 subreq->cryptlen); 703 704 return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq); 705 } 706 707 static int crypto_rfc4543_encrypt(struct aead_request *req) 708 { 709 return crypto_ipsec_check_assoclen(req->assoclen) ?: 710 crypto_rfc4543_crypt(req, true); 711 } 712 713 static int crypto_rfc4543_decrypt(struct aead_request *req) 714 { 715 return crypto_ipsec_check_assoclen(req->assoclen) ?: 716 crypto_rfc4543_crypt(req, false); 717 } 718 719 static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm) 720 { 721 struct aead_instance *inst = aead_alg_instance(tfm); 722 struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst); 723 struct crypto_aead_spawn *spawn = &ictx->aead; 724 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); 725 struct crypto_aead *aead; 726 unsigned long align; 727 728 aead = crypto_spawn_aead(spawn); 729 if (IS_ERR(aead)) 730 return PTR_ERR(aead); 731 732 ctx->child = aead; 733 734 align = crypto_aead_alignmask(aead); 735 align &= ~(crypto_tfm_ctx_alignment() - 1); 736 crypto_aead_set_reqsize( 737 tfm, 738 sizeof(struct crypto_rfc4543_req_ctx) + 739 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) + 740 align + GCM_AES_IV_SIZE); 741 742 return 0; 743 } 744 745 static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm) 746 { 747 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); 748 749 crypto_free_aead(ctx->child); 750 } 751 752 static void crypto_rfc4543_free(struct aead_instance *inst) 753 { 754 struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst); 755 756 crypto_drop_aead(&ctx->aead); 757 758 kfree(inst); 759 } 760 761 static int crypto_rfc4543_create(struct crypto_template *tmpl, 762 struct rtattr **tb) 763 { 764 u32 mask; 765 struct aead_instance *inst; 766 struct aead_alg *alg; 767 struct crypto_rfc4543_instance_ctx *ctx; 768 int err; 769 770 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask); 771 if (err) 772 return err; 773 774 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 775 if (!inst) 776 return -ENOMEM; 777 778 ctx = aead_instance_ctx(inst); 779 err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst), 780 crypto_attr_alg_name(tb[1]), 0, mask); 781 if (err) 782 goto err_free_inst; 783 784 alg = crypto_spawn_aead_alg(&ctx->aead); 785 786 err = -EINVAL; 787 788 /* Underlying IV size must be 12. */ 789 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE) 790 goto err_free_inst; 791 792 /* Not a stream cipher? */ 793 if (alg->base.cra_blocksize != 1) 794 goto err_free_inst; 795 796 err = -ENAMETOOLONG; 797 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 798 "rfc4543(%s)", alg->base.cra_name) >= 799 CRYPTO_MAX_ALG_NAME || 800 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 801 "rfc4543(%s)", alg->base.cra_driver_name) >= 802 CRYPTO_MAX_ALG_NAME) 803 goto err_free_inst; 804 805 inst->alg.base.cra_priority = alg->base.cra_priority; 806 inst->alg.base.cra_blocksize = 1; 807 inst->alg.base.cra_alignmask = alg->base.cra_alignmask; 808 809 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx); 810 811 inst->alg.ivsize = GCM_RFC4543_IV_SIZE; 812 inst->alg.chunksize = crypto_aead_alg_chunksize(alg); 813 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg); 814 815 inst->alg.init = crypto_rfc4543_init_tfm; 816 inst->alg.exit = crypto_rfc4543_exit_tfm; 817 818 inst->alg.setkey = crypto_rfc4543_setkey; 819 inst->alg.setauthsize = crypto_rfc4543_setauthsize; 820 inst->alg.encrypt = crypto_rfc4543_encrypt; 821 inst->alg.decrypt = crypto_rfc4543_decrypt; 822 823 inst->free = crypto_rfc4543_free; 824 825 err = aead_register_instance(tmpl, inst); 826 if (err) { 827 err_free_inst: 828 crypto_rfc4543_free(inst); 829 } 830 return err; 831 } 832 833 static struct crypto_template crypto_gcm_tmpls[] = { 834 { 835 .name = "gcm_base", 836 .create = crypto_gcm_base_create, 837 .module = THIS_MODULE, 838 }, { 839 .name = "gcm", 840 .create = crypto_gcm_create, 841 .module = THIS_MODULE, 842 }, { 843 .name = "rfc4106", 844 .create = crypto_rfc4106_create, 845 .module = THIS_MODULE, 846 }, { 847 .name = "rfc4543", 848 .create = crypto_rfc4543_create, 849 .module = THIS_MODULE, 850 }, 851 }; 852 853 static int __init crypto_gcm_module_init(void) 854 { 855 return crypto_register_templates(crypto_gcm_tmpls, 856 ARRAY_SIZE(crypto_gcm_tmpls)); 857 } 858 859 static void __exit crypto_gcm_module_exit(void) 860 { 861 crypto_unregister_templates(crypto_gcm_tmpls, 862 ARRAY_SIZE(crypto_gcm_tmpls)); 863 } 864 865 module_init(crypto_gcm_module_init); 866 module_exit(crypto_gcm_module_exit); 867 868 MODULE_LICENSE("GPL"); 869 MODULE_DESCRIPTION("Galois/Counter Mode"); 870 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>"); 871 MODULE_ALIAS_CRYPTO("gcm_base"); 872 MODULE_ALIAS_CRYPTO("rfc4106"); 873 MODULE_ALIAS_CRYPTO("rfc4543"); 874 MODULE_ALIAS_CRYPTO("gcm"); 875