1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Linear symmetric key cipher operations. 4 * 5 * Generic encrypt/decrypt wrapper for ciphers. 6 * 7 * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au> 8 */ 9 10 #include <linux/cryptouser.h> 11 #include <linux/err.h> 12 #include <linux/export.h> 13 #include <linux/kernel.h> 14 #include <linux/seq_file.h> 15 #include <linux/slab.h> 16 #include <linux/string.h> 17 #include <net/netlink.h> 18 #include "skcipher.h" 19 20 static inline struct crypto_lskcipher *__crypto_lskcipher_cast( 21 struct crypto_tfm *tfm) 22 { 23 return container_of(tfm, struct crypto_lskcipher, base); 24 } 25 26 static inline struct lskcipher_alg *__crypto_lskcipher_alg( 27 struct crypto_alg *alg) 28 { 29 return container_of(alg, struct lskcipher_alg, co.base); 30 } 31 32 static int lskcipher_setkey_unaligned(struct crypto_lskcipher *tfm, 33 const u8 *key, unsigned int keylen) 34 { 35 unsigned long alignmask = crypto_lskcipher_alignmask(tfm); 36 struct lskcipher_alg *cipher = crypto_lskcipher_alg(tfm); 37 u8 *buffer, *alignbuffer; 38 unsigned long absize; 39 int ret; 40 41 absize = keylen + alignmask; 42 buffer = kmalloc(absize, GFP_ATOMIC); 43 if (!buffer) 44 return -ENOMEM; 45 46 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 47 memcpy(alignbuffer, key, keylen); 48 ret = cipher->setkey(tfm, alignbuffer, keylen); 49 kfree_sensitive(buffer); 50 return ret; 51 } 52 53 int crypto_lskcipher_setkey(struct crypto_lskcipher *tfm, const u8 *key, 54 unsigned int keylen) 55 { 56 unsigned long alignmask = crypto_lskcipher_alignmask(tfm); 57 struct lskcipher_alg *cipher = crypto_lskcipher_alg(tfm); 58 59 if (keylen < cipher->co.min_keysize || keylen > cipher->co.max_keysize) 60 return -EINVAL; 61 62 if ((unsigned long)key & alignmask) 63 return lskcipher_setkey_unaligned(tfm, key, keylen); 64 else 65 return cipher->setkey(tfm, key, keylen); 66 } 67 EXPORT_SYMBOL_GPL(crypto_lskcipher_setkey); 68 69 static int crypto_lskcipher_crypt_unaligned( 70 struct crypto_lskcipher *tfm, const u8 *src, u8 *dst, unsigned len, 71 u8 *iv, int (*crypt)(struct crypto_lskcipher *tfm, const u8 *src, 72 u8 *dst, unsigned len, u8 *iv, u32 flags)) 73 { 74 unsigned statesize = crypto_lskcipher_statesize(tfm); 75 unsigned ivsize = crypto_lskcipher_ivsize(tfm); 76 unsigned bs = crypto_lskcipher_blocksize(tfm); 77 unsigned cs = crypto_lskcipher_chunksize(tfm); 78 int err; 79 u8 *tiv; 80 u8 *p; 81 82 BUILD_BUG_ON(MAX_CIPHER_BLOCKSIZE > PAGE_SIZE || 83 MAX_CIPHER_ALIGNMASK >= PAGE_SIZE); 84 85 tiv = kmalloc(PAGE_SIZE, GFP_ATOMIC); 86 if (!tiv) 87 return -ENOMEM; 88 89 memcpy(tiv, iv, ivsize + statesize); 90 91 p = kmalloc(PAGE_SIZE, GFP_ATOMIC); 92 err = -ENOMEM; 93 if (!p) 94 goto out; 95 96 while (len >= bs) { 97 unsigned chunk = min((unsigned)PAGE_SIZE, len); 98 int err; 99 100 if (chunk > cs) 101 chunk &= ~(cs - 1); 102 103 memcpy(p, src, chunk); 104 err = crypt(tfm, p, p, chunk, tiv, CRYPTO_LSKCIPHER_FLAG_FINAL); 105 if (err) 106 goto out; 107 108 memcpy(dst, p, chunk); 109 src += chunk; 110 dst += chunk; 111 len -= chunk; 112 } 113 114 err = len ? -EINVAL : 0; 115 116 out: 117 memcpy(iv, tiv, ivsize + statesize); 118 kfree_sensitive(p); 119 kfree_sensitive(tiv); 120 return err; 121 } 122 123 static int crypto_lskcipher_crypt(struct crypto_lskcipher *tfm, const u8 *src, 124 u8 *dst, unsigned len, u8 *iv, 125 int (*crypt)(struct crypto_lskcipher *tfm, 126 const u8 *src, u8 *dst, 127 unsigned len, u8 *iv, 128 u32 flags)) 129 { 130 unsigned long alignmask = crypto_lskcipher_alignmask(tfm); 131 132 if (((unsigned long)src | (unsigned long)dst | (unsigned long)iv) & 133 alignmask) 134 return crypto_lskcipher_crypt_unaligned(tfm, src, dst, len, iv, 135 crypt); 136 137 return crypt(tfm, src, dst, len, iv, CRYPTO_LSKCIPHER_FLAG_FINAL); 138 } 139 140 int crypto_lskcipher_encrypt(struct crypto_lskcipher *tfm, const u8 *src, 141 u8 *dst, unsigned len, u8 *iv) 142 { 143 struct lskcipher_alg *alg = crypto_lskcipher_alg(tfm); 144 145 return crypto_lskcipher_crypt(tfm, src, dst, len, iv, alg->encrypt); 146 } 147 EXPORT_SYMBOL_GPL(crypto_lskcipher_encrypt); 148 149 int crypto_lskcipher_decrypt(struct crypto_lskcipher *tfm, const u8 *src, 150 u8 *dst, unsigned len, u8 *iv) 151 { 152 struct lskcipher_alg *alg = crypto_lskcipher_alg(tfm); 153 154 return crypto_lskcipher_crypt(tfm, src, dst, len, iv, alg->decrypt); 155 } 156 EXPORT_SYMBOL_GPL(crypto_lskcipher_decrypt); 157 158 static int crypto_lskcipher_crypt_sg(struct skcipher_request *req, 159 int (*crypt)(struct crypto_lskcipher *tfm, 160 const u8 *src, u8 *dst, 161 unsigned len, u8 *ivs, 162 u32 flags)) 163 { 164 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 165 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher); 166 u8 *ivs = skcipher_request_ctx(req); 167 struct crypto_lskcipher *tfm = *ctx; 168 struct skcipher_walk walk; 169 unsigned ivsize; 170 u32 flags; 171 int err; 172 173 ivsize = crypto_lskcipher_ivsize(tfm); 174 ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(skcipher) + 1); 175 memcpy(ivs, req->iv, ivsize); 176 177 flags = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP; 178 179 if (req->base.flags & CRYPTO_SKCIPHER_REQ_CONT) 180 flags |= CRYPTO_LSKCIPHER_FLAG_CONT; 181 182 if (!(req->base.flags & CRYPTO_SKCIPHER_REQ_NOTFINAL)) 183 flags |= CRYPTO_LSKCIPHER_FLAG_FINAL; 184 185 err = skcipher_walk_virt(&walk, req, false); 186 187 while (walk.nbytes) { 188 err = crypt(tfm, walk.src.virt.addr, walk.dst.virt.addr, 189 walk.nbytes, ivs, 190 flags & ~(walk.nbytes == walk.total ? 191 0 : CRYPTO_LSKCIPHER_FLAG_FINAL)); 192 err = skcipher_walk_done(&walk, err); 193 flags |= CRYPTO_LSKCIPHER_FLAG_CONT; 194 } 195 196 memcpy(req->iv, ivs, ivsize); 197 198 return err; 199 } 200 201 int crypto_lskcipher_encrypt_sg(struct skcipher_request *req) 202 { 203 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 204 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher); 205 struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx); 206 207 return crypto_lskcipher_crypt_sg(req, alg->encrypt); 208 } 209 210 int crypto_lskcipher_decrypt_sg(struct skcipher_request *req) 211 { 212 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 213 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher); 214 struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx); 215 216 return crypto_lskcipher_crypt_sg(req, alg->decrypt); 217 } 218 219 static void crypto_lskcipher_exit_tfm(struct crypto_tfm *tfm) 220 { 221 struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm); 222 struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher); 223 224 alg->exit(skcipher); 225 } 226 227 static int crypto_lskcipher_init_tfm(struct crypto_tfm *tfm) 228 { 229 struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm); 230 struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher); 231 232 if (alg->exit) 233 skcipher->base.exit = crypto_lskcipher_exit_tfm; 234 235 if (alg->init) 236 return alg->init(skcipher); 237 238 return 0; 239 } 240 241 static void crypto_lskcipher_free_instance(struct crypto_instance *inst) 242 { 243 struct lskcipher_instance *skcipher = 244 container_of(inst, struct lskcipher_instance, s.base); 245 246 skcipher->free(skcipher); 247 } 248 249 static void __maybe_unused crypto_lskcipher_show( 250 struct seq_file *m, struct crypto_alg *alg) 251 { 252 struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg); 253 254 seq_printf(m, "type : lskcipher\n"); 255 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 256 seq_printf(m, "min keysize : %u\n", skcipher->co.min_keysize); 257 seq_printf(m, "max keysize : %u\n", skcipher->co.max_keysize); 258 seq_printf(m, "ivsize : %u\n", skcipher->co.ivsize); 259 seq_printf(m, "chunksize : %u\n", skcipher->co.chunksize); 260 seq_printf(m, "statesize : %u\n", skcipher->co.statesize); 261 } 262 263 static int __maybe_unused crypto_lskcipher_report( 264 struct sk_buff *skb, struct crypto_alg *alg) 265 { 266 struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg); 267 struct crypto_report_blkcipher rblkcipher; 268 269 memset(&rblkcipher, 0, sizeof(rblkcipher)); 270 271 strscpy(rblkcipher.type, "lskcipher", sizeof(rblkcipher.type)); 272 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 273 274 rblkcipher.blocksize = alg->cra_blocksize; 275 rblkcipher.min_keysize = skcipher->co.min_keysize; 276 rblkcipher.max_keysize = skcipher->co.max_keysize; 277 rblkcipher.ivsize = skcipher->co.ivsize; 278 279 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 280 sizeof(rblkcipher), &rblkcipher); 281 } 282 283 static const struct crypto_type crypto_lskcipher_type = { 284 .extsize = crypto_alg_extsize, 285 .init_tfm = crypto_lskcipher_init_tfm, 286 .free = crypto_lskcipher_free_instance, 287 #ifdef CONFIG_PROC_FS 288 .show = crypto_lskcipher_show, 289 #endif 290 #if IS_ENABLED(CONFIG_CRYPTO_USER) 291 .report = crypto_lskcipher_report, 292 #endif 293 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 294 .maskset = CRYPTO_ALG_TYPE_MASK, 295 .type = CRYPTO_ALG_TYPE_LSKCIPHER, 296 .tfmsize = offsetof(struct crypto_lskcipher, base), 297 .algsize = offsetof(struct lskcipher_alg, co.base), 298 }; 299 300 static void crypto_lskcipher_exit_tfm_sg(struct crypto_tfm *tfm) 301 { 302 struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm); 303 304 crypto_free_lskcipher(*ctx); 305 } 306 307 int crypto_init_lskcipher_ops_sg(struct crypto_tfm *tfm) 308 { 309 struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm); 310 struct crypto_alg *calg = tfm->__crt_alg; 311 struct crypto_lskcipher *skcipher; 312 313 if (!crypto_mod_get(calg)) 314 return -EAGAIN; 315 316 skcipher = crypto_create_tfm(calg, &crypto_lskcipher_type); 317 if (IS_ERR(skcipher)) { 318 crypto_mod_put(calg); 319 return PTR_ERR(skcipher); 320 } 321 322 *ctx = skcipher; 323 tfm->exit = crypto_lskcipher_exit_tfm_sg; 324 325 return 0; 326 } 327 328 int crypto_grab_lskcipher(struct crypto_lskcipher_spawn *spawn, 329 struct crypto_instance *inst, 330 const char *name, u32 type, u32 mask) 331 { 332 spawn->base.frontend = &crypto_lskcipher_type; 333 return crypto_grab_spawn(&spawn->base, inst, name, type, mask); 334 } 335 EXPORT_SYMBOL_GPL(crypto_grab_lskcipher); 336 337 struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name, 338 u32 type, u32 mask) 339 { 340 return crypto_alloc_tfm(alg_name, &crypto_lskcipher_type, type, mask); 341 } 342 EXPORT_SYMBOL_GPL(crypto_alloc_lskcipher); 343 344 static int lskcipher_prepare_alg(struct lskcipher_alg *alg) 345 { 346 struct crypto_alg *base = &alg->co.base; 347 int err; 348 349 err = skcipher_prepare_alg_common(&alg->co); 350 if (err) 351 return err; 352 353 if (alg->co.chunksize & (alg->co.chunksize - 1)) 354 return -EINVAL; 355 356 base->cra_type = &crypto_lskcipher_type; 357 base->cra_flags |= CRYPTO_ALG_TYPE_LSKCIPHER; 358 359 return 0; 360 } 361 362 int crypto_register_lskcipher(struct lskcipher_alg *alg) 363 { 364 struct crypto_alg *base = &alg->co.base; 365 int err; 366 367 err = lskcipher_prepare_alg(alg); 368 if (err) 369 return err; 370 371 return crypto_register_alg(base); 372 } 373 EXPORT_SYMBOL_GPL(crypto_register_lskcipher); 374 375 void crypto_unregister_lskcipher(struct lskcipher_alg *alg) 376 { 377 crypto_unregister_alg(&alg->co.base); 378 } 379 EXPORT_SYMBOL_GPL(crypto_unregister_lskcipher); 380 381 int crypto_register_lskciphers(struct lskcipher_alg *algs, int count) 382 { 383 int i, ret; 384 385 for (i = 0; i < count; i++) { 386 ret = crypto_register_lskcipher(&algs[i]); 387 if (ret) 388 goto err; 389 } 390 391 return 0; 392 393 err: 394 for (--i; i >= 0; --i) 395 crypto_unregister_lskcipher(&algs[i]); 396 397 return ret; 398 } 399 EXPORT_SYMBOL_GPL(crypto_register_lskciphers); 400 401 void crypto_unregister_lskciphers(struct lskcipher_alg *algs, int count) 402 { 403 int i; 404 405 for (i = count - 1; i >= 0; --i) 406 crypto_unregister_lskcipher(&algs[i]); 407 } 408 EXPORT_SYMBOL_GPL(crypto_unregister_lskciphers); 409 410 int lskcipher_register_instance(struct crypto_template *tmpl, 411 struct lskcipher_instance *inst) 412 { 413 int err; 414 415 if (WARN_ON(!inst->free)) 416 return -EINVAL; 417 418 err = lskcipher_prepare_alg(&inst->alg); 419 if (err) 420 return err; 421 422 return crypto_register_instance(tmpl, lskcipher_crypto_instance(inst)); 423 } 424 EXPORT_SYMBOL_GPL(lskcipher_register_instance); 425 426 static int lskcipher_setkey_simple(struct crypto_lskcipher *tfm, const u8 *key, 427 unsigned int keylen) 428 { 429 struct crypto_lskcipher *cipher = lskcipher_cipher_simple(tfm); 430 431 crypto_lskcipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK); 432 crypto_lskcipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) & 433 CRYPTO_TFM_REQ_MASK); 434 return crypto_lskcipher_setkey(cipher, key, keylen); 435 } 436 437 static int lskcipher_init_tfm_simple(struct crypto_lskcipher *tfm) 438 { 439 struct lskcipher_instance *inst = lskcipher_alg_instance(tfm); 440 struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm); 441 struct crypto_lskcipher_spawn *spawn; 442 struct crypto_lskcipher *cipher; 443 444 spawn = lskcipher_instance_ctx(inst); 445 cipher = crypto_spawn_lskcipher(spawn); 446 if (IS_ERR(cipher)) 447 return PTR_ERR(cipher); 448 449 *ctx = cipher; 450 return 0; 451 } 452 453 static void lskcipher_exit_tfm_simple(struct crypto_lskcipher *tfm) 454 { 455 struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm); 456 457 crypto_free_lskcipher(*ctx); 458 } 459 460 static void lskcipher_free_instance_simple(struct lskcipher_instance *inst) 461 { 462 crypto_drop_lskcipher(lskcipher_instance_ctx(inst)); 463 kfree(inst); 464 } 465 466 /** 467 * lskcipher_alloc_instance_simple - allocate instance of simple block cipher 468 * 469 * Allocate an lskcipher_instance for a simple block cipher mode of operation, 470 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn, 471 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize, 472 * alignmask, and priority are set from the underlying cipher but can be 473 * overridden if needed. The tfm context defaults to 474 * struct crypto_lskcipher *, and default ->setkey(), ->init(), and 475 * ->exit() methods are installed. 476 * 477 * @tmpl: the template being instantiated 478 * @tb: the template parameters 479 * 480 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still 481 * needs to register the instance. 482 */ 483 struct lskcipher_instance *lskcipher_alloc_instance_simple( 484 struct crypto_template *tmpl, struct rtattr **tb) 485 { 486 u32 mask; 487 struct lskcipher_instance *inst; 488 struct crypto_lskcipher_spawn *spawn; 489 char ecb_name[CRYPTO_MAX_ALG_NAME]; 490 struct lskcipher_alg *cipher_alg; 491 const char *cipher_name; 492 int err; 493 494 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask); 495 if (err) 496 return ERR_PTR(err); 497 498 cipher_name = crypto_attr_alg_name(tb[1]); 499 if (IS_ERR(cipher_name)) 500 return ERR_CAST(cipher_name); 501 502 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 503 if (!inst) 504 return ERR_PTR(-ENOMEM); 505 506 spawn = lskcipher_instance_ctx(inst); 507 err = crypto_grab_lskcipher(spawn, 508 lskcipher_crypto_instance(inst), 509 cipher_name, 0, mask); 510 511 ecb_name[0] = 0; 512 if (err == -ENOENT && !!memcmp(tmpl->name, "ecb", 4)) { 513 err = -ENAMETOOLONG; 514 if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)", 515 cipher_name) >= CRYPTO_MAX_ALG_NAME) 516 goto err_free_inst; 517 518 err = crypto_grab_lskcipher(spawn, 519 lskcipher_crypto_instance(inst), 520 ecb_name, 0, mask); 521 } 522 523 if (err) 524 goto err_free_inst; 525 526 cipher_alg = crypto_lskcipher_spawn_alg(spawn); 527 528 err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name, 529 &cipher_alg->co.base); 530 if (err) 531 goto err_free_inst; 532 533 if (ecb_name[0]) { 534 int len; 535 536 err = -EINVAL; 537 len = strscpy(ecb_name, &cipher_alg->co.base.cra_name[4], 538 sizeof(ecb_name)); 539 if (len < 2) 540 goto err_free_inst; 541 542 if (ecb_name[len - 1] != ')') 543 goto err_free_inst; 544 545 ecb_name[len - 1] = 0; 546 547 err = -ENAMETOOLONG; 548 if (snprintf(inst->alg.co.base.cra_name, CRYPTO_MAX_ALG_NAME, 549 "%s(%s)", tmpl->name, ecb_name) >= 550 CRYPTO_MAX_ALG_NAME) 551 goto err_free_inst; 552 553 if (strcmp(ecb_name, cipher_name) && 554 snprintf(inst->alg.co.base.cra_driver_name, 555 CRYPTO_MAX_ALG_NAME, 556 "%s(%s)", tmpl->name, cipher_name) >= 557 CRYPTO_MAX_ALG_NAME) 558 goto err_free_inst; 559 } else { 560 /* Don't allow nesting. */ 561 err = -ELOOP; 562 if ((cipher_alg->co.base.cra_flags & CRYPTO_ALG_INSTANCE)) 563 goto err_free_inst; 564 } 565 566 err = -EINVAL; 567 if (cipher_alg->co.ivsize) 568 goto err_free_inst; 569 570 inst->free = lskcipher_free_instance_simple; 571 572 /* Default algorithm properties, can be overridden */ 573 inst->alg.co.base.cra_blocksize = cipher_alg->co.base.cra_blocksize; 574 inst->alg.co.base.cra_alignmask = cipher_alg->co.base.cra_alignmask; 575 inst->alg.co.base.cra_priority = cipher_alg->co.base.cra_priority; 576 inst->alg.co.min_keysize = cipher_alg->co.min_keysize; 577 inst->alg.co.max_keysize = cipher_alg->co.max_keysize; 578 inst->alg.co.ivsize = cipher_alg->co.base.cra_blocksize; 579 inst->alg.co.statesize = cipher_alg->co.statesize; 580 581 /* Use struct crypto_lskcipher * by default, can be overridden */ 582 inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_lskcipher *); 583 inst->alg.setkey = lskcipher_setkey_simple; 584 inst->alg.init = lskcipher_init_tfm_simple; 585 inst->alg.exit = lskcipher_exit_tfm_simple; 586 587 return inst; 588 589 err_free_inst: 590 lskcipher_free_instance_simple(inst); 591 return ERR_PTR(err); 592 } 593 EXPORT_SYMBOL_GPL(lskcipher_alloc_instance_simple); 594