1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * authencesn.c - AEAD wrapper for IPsec with extended sequence numbers, 4 * derived from authenc.c 5 * 6 * Copyright (C) 2010 secunet Security Networks AG 7 * Copyright (C) 2010 Steffen Klassert <steffen.klassert@secunet.com> 8 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> 9 */ 10 11 #include <crypto/internal/aead.h> 12 #include <crypto/internal/hash.h> 13 #include <crypto/internal/skcipher.h> 14 #include <crypto/authenc.h> 15 #include <crypto/null.h> 16 #include <crypto/scatterwalk.h> 17 #include <linux/err.h> 18 #include <linux/init.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/rtnetlink.h> 22 #include <linux/slab.h> 23 #include <linux/spinlock.h> 24 25 struct authenc_esn_instance_ctx { 26 struct crypto_ahash_spawn auth; 27 struct crypto_skcipher_spawn enc; 28 }; 29 30 struct crypto_authenc_esn_ctx { 31 unsigned int reqoff; 32 struct crypto_ahash *auth; 33 struct crypto_skcipher *enc; 34 struct crypto_sync_skcipher *null; 35 }; 36 37 struct authenc_esn_request_ctx { 38 struct scatterlist src[2]; 39 struct scatterlist dst[2]; 40 char tail[]; 41 }; 42 43 static void authenc_esn_request_complete(struct aead_request *req, int err) 44 { 45 if (err != -EINPROGRESS) 46 aead_request_complete(req, err); 47 } 48 49 static int crypto_authenc_esn_setauthsize(struct crypto_aead *authenc_esn, 50 unsigned int authsize) 51 { 52 if (authsize > 0 && authsize < 4) 53 return -EINVAL; 54 55 return 0; 56 } 57 58 static int crypto_authenc_esn_setkey(struct crypto_aead *authenc_esn, const u8 *key, 59 unsigned int keylen) 60 { 61 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn); 62 struct crypto_ahash *auth = ctx->auth; 63 struct crypto_skcipher *enc = ctx->enc; 64 struct crypto_authenc_keys keys; 65 int err = -EINVAL; 66 67 if (crypto_authenc_extractkeys(&keys, key, keylen) != 0) 68 goto badkey; 69 70 crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK); 71 crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc_esn) & 72 CRYPTO_TFM_REQ_MASK); 73 err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen); 74 crypto_aead_set_flags(authenc_esn, crypto_ahash_get_flags(auth) & 75 CRYPTO_TFM_RES_MASK); 76 77 if (err) 78 goto out; 79 80 crypto_skcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK); 81 crypto_skcipher_set_flags(enc, crypto_aead_get_flags(authenc_esn) & 82 CRYPTO_TFM_REQ_MASK); 83 err = crypto_skcipher_setkey(enc, keys.enckey, keys.enckeylen); 84 crypto_aead_set_flags(authenc_esn, crypto_skcipher_get_flags(enc) & 85 CRYPTO_TFM_RES_MASK); 86 87 out: 88 memzero_explicit(&keys, sizeof(keys)); 89 return err; 90 91 badkey: 92 crypto_aead_set_flags(authenc_esn, CRYPTO_TFM_RES_BAD_KEY_LEN); 93 goto out; 94 } 95 96 static int crypto_authenc_esn_genicv_tail(struct aead_request *req, 97 unsigned int flags) 98 { 99 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req); 100 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn); 101 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req); 102 struct crypto_ahash *auth = ctx->auth; 103 u8 *hash = PTR_ALIGN((u8 *)areq_ctx->tail, 104 crypto_ahash_alignmask(auth) + 1); 105 unsigned int authsize = crypto_aead_authsize(authenc_esn); 106 unsigned int assoclen = req->assoclen; 107 unsigned int cryptlen = req->cryptlen; 108 struct scatterlist *dst = req->dst; 109 u32 tmp[2]; 110 111 /* Move high-order bits of sequence number back. */ 112 scatterwalk_map_and_copy(tmp, dst, 4, 4, 0); 113 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0); 114 scatterwalk_map_and_copy(tmp, dst, 0, 8, 1); 115 116 scatterwalk_map_and_copy(hash, dst, assoclen + cryptlen, authsize, 1); 117 return 0; 118 } 119 120 static void authenc_esn_geniv_ahash_done(struct crypto_async_request *areq, 121 int err) 122 { 123 struct aead_request *req = areq->data; 124 125 err = err ?: crypto_authenc_esn_genicv_tail(req, 0); 126 aead_request_complete(req, err); 127 } 128 129 static int crypto_authenc_esn_genicv(struct aead_request *req, 130 unsigned int flags) 131 { 132 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req); 133 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req); 134 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn); 135 struct crypto_ahash *auth = ctx->auth; 136 u8 *hash = PTR_ALIGN((u8 *)areq_ctx->tail, 137 crypto_ahash_alignmask(auth) + 1); 138 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff); 139 unsigned int authsize = crypto_aead_authsize(authenc_esn); 140 unsigned int assoclen = req->assoclen; 141 unsigned int cryptlen = req->cryptlen; 142 struct scatterlist *dst = req->dst; 143 u32 tmp[2]; 144 145 if (!authsize) 146 return 0; 147 148 /* Move high-order bits of sequence number to the end. */ 149 scatterwalk_map_and_copy(tmp, dst, 0, 8, 0); 150 scatterwalk_map_and_copy(tmp, dst, 4, 4, 1); 151 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1); 152 153 sg_init_table(areq_ctx->dst, 2); 154 dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4); 155 156 ahash_request_set_tfm(ahreq, auth); 157 ahash_request_set_crypt(ahreq, dst, hash, assoclen + cryptlen); 158 ahash_request_set_callback(ahreq, flags, 159 authenc_esn_geniv_ahash_done, req); 160 161 return crypto_ahash_digest(ahreq) ?: 162 crypto_authenc_esn_genicv_tail(req, aead_request_flags(req)); 163 } 164 165 166 static void crypto_authenc_esn_encrypt_done(struct crypto_async_request *req, 167 int err) 168 { 169 struct aead_request *areq = req->data; 170 171 if (!err) 172 err = crypto_authenc_esn_genicv(areq, 0); 173 174 authenc_esn_request_complete(areq, err); 175 } 176 177 static int crypto_authenc_esn_copy(struct aead_request *req, unsigned int len) 178 { 179 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req); 180 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn); 181 SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, ctx->null); 182 183 skcipher_request_set_sync_tfm(skreq, ctx->null); 184 skcipher_request_set_callback(skreq, aead_request_flags(req), 185 NULL, NULL); 186 skcipher_request_set_crypt(skreq, req->src, req->dst, len, NULL); 187 188 return crypto_skcipher_encrypt(skreq); 189 } 190 191 static int crypto_authenc_esn_encrypt(struct aead_request *req) 192 { 193 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req); 194 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req); 195 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn); 196 struct skcipher_request *skreq = (void *)(areq_ctx->tail + 197 ctx->reqoff); 198 struct crypto_skcipher *enc = ctx->enc; 199 unsigned int assoclen = req->assoclen; 200 unsigned int cryptlen = req->cryptlen; 201 struct scatterlist *src, *dst; 202 int err; 203 204 sg_init_table(areq_ctx->src, 2); 205 src = scatterwalk_ffwd(areq_ctx->src, req->src, assoclen); 206 dst = src; 207 208 if (req->src != req->dst) { 209 err = crypto_authenc_esn_copy(req, assoclen); 210 if (err) 211 return err; 212 213 sg_init_table(areq_ctx->dst, 2); 214 dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, assoclen); 215 } 216 217 skcipher_request_set_tfm(skreq, enc); 218 skcipher_request_set_callback(skreq, aead_request_flags(req), 219 crypto_authenc_esn_encrypt_done, req); 220 skcipher_request_set_crypt(skreq, src, dst, cryptlen, req->iv); 221 222 err = crypto_skcipher_encrypt(skreq); 223 if (err) 224 return err; 225 226 return crypto_authenc_esn_genicv(req, aead_request_flags(req)); 227 } 228 229 static int crypto_authenc_esn_decrypt_tail(struct aead_request *req, 230 unsigned int flags) 231 { 232 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req); 233 unsigned int authsize = crypto_aead_authsize(authenc_esn); 234 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req); 235 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn); 236 struct skcipher_request *skreq = (void *)(areq_ctx->tail + 237 ctx->reqoff); 238 struct crypto_ahash *auth = ctx->auth; 239 u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail, 240 crypto_ahash_alignmask(auth) + 1); 241 unsigned int cryptlen = req->cryptlen - authsize; 242 unsigned int assoclen = req->assoclen; 243 struct scatterlist *dst = req->dst; 244 u8 *ihash = ohash + crypto_ahash_digestsize(auth); 245 u32 tmp[2]; 246 247 if (!authsize) 248 goto decrypt; 249 250 /* Move high-order bits of sequence number back. */ 251 scatterwalk_map_and_copy(tmp, dst, 4, 4, 0); 252 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 0); 253 scatterwalk_map_and_copy(tmp, dst, 0, 8, 1); 254 255 if (crypto_memneq(ihash, ohash, authsize)) 256 return -EBADMSG; 257 258 decrypt: 259 260 sg_init_table(areq_ctx->dst, 2); 261 dst = scatterwalk_ffwd(areq_ctx->dst, dst, assoclen); 262 263 skcipher_request_set_tfm(skreq, ctx->enc); 264 skcipher_request_set_callback(skreq, flags, 265 req->base.complete, req->base.data); 266 skcipher_request_set_crypt(skreq, dst, dst, cryptlen, req->iv); 267 268 return crypto_skcipher_decrypt(skreq); 269 } 270 271 static void authenc_esn_verify_ahash_done(struct crypto_async_request *areq, 272 int err) 273 { 274 struct aead_request *req = areq->data; 275 276 err = err ?: crypto_authenc_esn_decrypt_tail(req, 0); 277 authenc_esn_request_complete(req, err); 278 } 279 280 static int crypto_authenc_esn_decrypt(struct aead_request *req) 281 { 282 struct crypto_aead *authenc_esn = crypto_aead_reqtfm(req); 283 struct authenc_esn_request_ctx *areq_ctx = aead_request_ctx(req); 284 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(authenc_esn); 285 struct ahash_request *ahreq = (void *)(areq_ctx->tail + ctx->reqoff); 286 unsigned int authsize = crypto_aead_authsize(authenc_esn); 287 struct crypto_ahash *auth = ctx->auth; 288 u8 *ohash = PTR_ALIGN((u8 *)areq_ctx->tail, 289 crypto_ahash_alignmask(auth) + 1); 290 unsigned int assoclen = req->assoclen; 291 unsigned int cryptlen = req->cryptlen; 292 u8 *ihash = ohash + crypto_ahash_digestsize(auth); 293 struct scatterlist *dst = req->dst; 294 u32 tmp[2]; 295 int err; 296 297 cryptlen -= authsize; 298 299 if (req->src != dst) { 300 err = crypto_authenc_esn_copy(req, assoclen + cryptlen); 301 if (err) 302 return err; 303 } 304 305 scatterwalk_map_and_copy(ihash, req->src, assoclen + cryptlen, 306 authsize, 0); 307 308 if (!authsize) 309 goto tail; 310 311 /* Move high-order bits of sequence number to the end. */ 312 scatterwalk_map_and_copy(tmp, dst, 0, 8, 0); 313 scatterwalk_map_and_copy(tmp, dst, 4, 4, 1); 314 scatterwalk_map_and_copy(tmp + 1, dst, assoclen + cryptlen, 4, 1); 315 316 sg_init_table(areq_ctx->dst, 2); 317 dst = scatterwalk_ffwd(areq_ctx->dst, dst, 4); 318 319 ahash_request_set_tfm(ahreq, auth); 320 ahash_request_set_crypt(ahreq, dst, ohash, assoclen + cryptlen); 321 ahash_request_set_callback(ahreq, aead_request_flags(req), 322 authenc_esn_verify_ahash_done, req); 323 324 err = crypto_ahash_digest(ahreq); 325 if (err) 326 return err; 327 328 tail: 329 return crypto_authenc_esn_decrypt_tail(req, aead_request_flags(req)); 330 } 331 332 static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm) 333 { 334 struct aead_instance *inst = aead_alg_instance(tfm); 335 struct authenc_esn_instance_ctx *ictx = aead_instance_ctx(inst); 336 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm); 337 struct crypto_ahash *auth; 338 struct crypto_skcipher *enc; 339 struct crypto_sync_skcipher *null; 340 int err; 341 342 auth = crypto_spawn_ahash(&ictx->auth); 343 if (IS_ERR(auth)) 344 return PTR_ERR(auth); 345 346 enc = crypto_spawn_skcipher(&ictx->enc); 347 err = PTR_ERR(enc); 348 if (IS_ERR(enc)) 349 goto err_free_ahash; 350 351 null = crypto_get_default_null_skcipher(); 352 err = PTR_ERR(null); 353 if (IS_ERR(null)) 354 goto err_free_skcipher; 355 356 ctx->auth = auth; 357 ctx->enc = enc; 358 ctx->null = null; 359 360 ctx->reqoff = ALIGN(2 * crypto_ahash_digestsize(auth), 361 crypto_ahash_alignmask(auth) + 1); 362 363 crypto_aead_set_reqsize( 364 tfm, 365 sizeof(struct authenc_esn_request_ctx) + 366 ctx->reqoff + 367 max_t(unsigned int, 368 crypto_ahash_reqsize(auth) + 369 sizeof(struct ahash_request), 370 sizeof(struct skcipher_request) + 371 crypto_skcipher_reqsize(enc))); 372 373 return 0; 374 375 err_free_skcipher: 376 crypto_free_skcipher(enc); 377 err_free_ahash: 378 crypto_free_ahash(auth); 379 return err; 380 } 381 382 static void crypto_authenc_esn_exit_tfm(struct crypto_aead *tfm) 383 { 384 struct crypto_authenc_esn_ctx *ctx = crypto_aead_ctx(tfm); 385 386 crypto_free_ahash(ctx->auth); 387 crypto_free_skcipher(ctx->enc); 388 crypto_put_default_null_skcipher(); 389 } 390 391 static void crypto_authenc_esn_free(struct aead_instance *inst) 392 { 393 struct authenc_esn_instance_ctx *ctx = aead_instance_ctx(inst); 394 395 crypto_drop_skcipher(&ctx->enc); 396 crypto_drop_ahash(&ctx->auth); 397 kfree(inst); 398 } 399 400 static int crypto_authenc_esn_create(struct crypto_template *tmpl, 401 struct rtattr **tb) 402 { 403 struct crypto_attr_type *algt; 404 struct aead_instance *inst; 405 struct hash_alg_common *auth; 406 struct crypto_alg *auth_base; 407 struct skcipher_alg *enc; 408 struct authenc_esn_instance_ctx *ctx; 409 const char *enc_name; 410 int err; 411 412 algt = crypto_get_attr_type(tb); 413 if (IS_ERR(algt)) 414 return PTR_ERR(algt); 415 416 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) 417 return -EINVAL; 418 419 auth = ahash_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH, 420 CRYPTO_ALG_TYPE_AHASH_MASK | 421 crypto_requires_sync(algt->type, algt->mask)); 422 if (IS_ERR(auth)) 423 return PTR_ERR(auth); 424 425 auth_base = &auth->base; 426 427 enc_name = crypto_attr_alg_name(tb[2]); 428 err = PTR_ERR(enc_name); 429 if (IS_ERR(enc_name)) 430 goto out_put_auth; 431 432 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 433 err = -ENOMEM; 434 if (!inst) 435 goto out_put_auth; 436 437 ctx = aead_instance_ctx(inst); 438 439 err = crypto_init_ahash_spawn(&ctx->auth, auth, 440 aead_crypto_instance(inst)); 441 if (err) 442 goto err_free_inst; 443 444 crypto_set_skcipher_spawn(&ctx->enc, aead_crypto_instance(inst)); 445 err = crypto_grab_skcipher(&ctx->enc, enc_name, 0, 446 crypto_requires_sync(algt->type, 447 algt->mask)); 448 if (err) 449 goto err_drop_auth; 450 451 enc = crypto_spawn_skcipher_alg(&ctx->enc); 452 453 err = -ENAMETOOLONG; 454 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, 455 "authencesn(%s,%s)", auth_base->cra_name, 456 enc->base.cra_name) >= CRYPTO_MAX_ALG_NAME) 457 goto err_drop_enc; 458 459 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, 460 "authencesn(%s,%s)", auth_base->cra_driver_name, 461 enc->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME) 462 goto err_drop_enc; 463 464 inst->alg.base.cra_flags = (auth_base->cra_flags | 465 enc->base.cra_flags) & CRYPTO_ALG_ASYNC; 466 inst->alg.base.cra_priority = enc->base.cra_priority * 10 + 467 auth_base->cra_priority; 468 inst->alg.base.cra_blocksize = enc->base.cra_blocksize; 469 inst->alg.base.cra_alignmask = auth_base->cra_alignmask | 470 enc->base.cra_alignmask; 471 inst->alg.base.cra_ctxsize = sizeof(struct crypto_authenc_esn_ctx); 472 473 inst->alg.ivsize = crypto_skcipher_alg_ivsize(enc); 474 inst->alg.chunksize = crypto_skcipher_alg_chunksize(enc); 475 inst->alg.maxauthsize = auth->digestsize; 476 477 inst->alg.init = crypto_authenc_esn_init_tfm; 478 inst->alg.exit = crypto_authenc_esn_exit_tfm; 479 480 inst->alg.setkey = crypto_authenc_esn_setkey; 481 inst->alg.setauthsize = crypto_authenc_esn_setauthsize; 482 inst->alg.encrypt = crypto_authenc_esn_encrypt; 483 inst->alg.decrypt = crypto_authenc_esn_decrypt; 484 485 inst->free = crypto_authenc_esn_free, 486 487 err = aead_register_instance(tmpl, inst); 488 if (err) 489 goto err_drop_enc; 490 491 out: 492 crypto_mod_put(auth_base); 493 return err; 494 495 err_drop_enc: 496 crypto_drop_skcipher(&ctx->enc); 497 err_drop_auth: 498 crypto_drop_ahash(&ctx->auth); 499 err_free_inst: 500 kfree(inst); 501 out_put_auth: 502 goto out; 503 } 504 505 static struct crypto_template crypto_authenc_esn_tmpl = { 506 .name = "authencesn", 507 .create = crypto_authenc_esn_create, 508 .module = THIS_MODULE, 509 }; 510 511 static int __init crypto_authenc_esn_module_init(void) 512 { 513 return crypto_register_template(&crypto_authenc_esn_tmpl); 514 } 515 516 static void __exit crypto_authenc_esn_module_exit(void) 517 { 518 crypto_unregister_template(&crypto_authenc_esn_tmpl); 519 } 520 521 subsys_initcall(crypto_authenc_esn_module_init); 522 module_exit(crypto_authenc_esn_module_exit); 523 524 MODULE_LICENSE("GPL"); 525 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); 526 MODULE_DESCRIPTION("AEAD wrapper for IPsec with extended sequence numbers"); 527 MODULE_ALIAS_CRYPTO("authencesn"); 528