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); 175 176 flags = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP; 177 178 if (req->base.flags & CRYPTO_SKCIPHER_REQ_CONT) 179 flags |= CRYPTO_LSKCIPHER_FLAG_CONT; 180 else 181 memcpy(ivs, req->iv, ivsize); 182 183 if (!(req->base.flags & CRYPTO_SKCIPHER_REQ_NOTFINAL)) 184 flags |= CRYPTO_LSKCIPHER_FLAG_FINAL; 185 186 err = skcipher_walk_virt(&walk, req, false); 187 188 while (walk.nbytes) { 189 err = crypt(tfm, walk.src.virt.addr, walk.dst.virt.addr, 190 walk.nbytes, ivs, 191 flags & ~(walk.nbytes == walk.total ? 192 0 : CRYPTO_LSKCIPHER_FLAG_FINAL)); 193 err = skcipher_walk_done(&walk, err); 194 flags |= CRYPTO_LSKCIPHER_FLAG_CONT; 195 } 196 197 if (flags & CRYPTO_LSKCIPHER_FLAG_FINAL) 198 memcpy(req->iv, ivs, ivsize); 199 200 return err; 201 } 202 203 int crypto_lskcipher_encrypt_sg(struct skcipher_request *req) 204 { 205 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 206 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher); 207 struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx); 208 209 return crypto_lskcipher_crypt_sg(req, alg->encrypt); 210 } 211 212 int crypto_lskcipher_decrypt_sg(struct skcipher_request *req) 213 { 214 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 215 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(skcipher); 216 struct lskcipher_alg *alg = crypto_lskcipher_alg(*ctx); 217 218 return crypto_lskcipher_crypt_sg(req, alg->decrypt); 219 } 220 221 static void crypto_lskcipher_exit_tfm(struct crypto_tfm *tfm) 222 { 223 struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm); 224 struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher); 225 226 alg->exit(skcipher); 227 } 228 229 static int crypto_lskcipher_init_tfm(struct crypto_tfm *tfm) 230 { 231 struct crypto_lskcipher *skcipher = __crypto_lskcipher_cast(tfm); 232 struct lskcipher_alg *alg = crypto_lskcipher_alg(skcipher); 233 234 if (alg->exit) 235 skcipher->base.exit = crypto_lskcipher_exit_tfm; 236 237 if (alg->init) 238 return alg->init(skcipher); 239 240 return 0; 241 } 242 243 static void crypto_lskcipher_free_instance(struct crypto_instance *inst) 244 { 245 struct lskcipher_instance *skcipher = 246 container_of(inst, struct lskcipher_instance, s.base); 247 248 skcipher->free(skcipher); 249 } 250 251 static void __maybe_unused crypto_lskcipher_show( 252 struct seq_file *m, struct crypto_alg *alg) 253 { 254 struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg); 255 256 seq_printf(m, "type : lskcipher\n"); 257 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 258 seq_printf(m, "min keysize : %u\n", skcipher->co.min_keysize); 259 seq_printf(m, "max keysize : %u\n", skcipher->co.max_keysize); 260 seq_printf(m, "ivsize : %u\n", skcipher->co.ivsize); 261 seq_printf(m, "chunksize : %u\n", skcipher->co.chunksize); 262 seq_printf(m, "statesize : %u\n", skcipher->co.statesize); 263 } 264 265 static int __maybe_unused crypto_lskcipher_report( 266 struct sk_buff *skb, struct crypto_alg *alg) 267 { 268 struct lskcipher_alg *skcipher = __crypto_lskcipher_alg(alg); 269 struct crypto_report_blkcipher rblkcipher; 270 271 memset(&rblkcipher, 0, sizeof(rblkcipher)); 272 273 strscpy(rblkcipher.type, "lskcipher", sizeof(rblkcipher.type)); 274 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 275 276 rblkcipher.blocksize = alg->cra_blocksize; 277 rblkcipher.min_keysize = skcipher->co.min_keysize; 278 rblkcipher.max_keysize = skcipher->co.max_keysize; 279 rblkcipher.ivsize = skcipher->co.ivsize; 280 281 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 282 sizeof(rblkcipher), &rblkcipher); 283 } 284 285 static const struct crypto_type crypto_lskcipher_type = { 286 .extsize = crypto_alg_extsize, 287 .init_tfm = crypto_lskcipher_init_tfm, 288 .free = crypto_lskcipher_free_instance, 289 #ifdef CONFIG_PROC_FS 290 .show = crypto_lskcipher_show, 291 #endif 292 #if IS_ENABLED(CONFIG_CRYPTO_USER) 293 .report = crypto_lskcipher_report, 294 #endif 295 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 296 .maskset = CRYPTO_ALG_TYPE_MASK, 297 .type = CRYPTO_ALG_TYPE_LSKCIPHER, 298 .tfmsize = offsetof(struct crypto_lskcipher, base), 299 }; 300 301 static void crypto_lskcipher_exit_tfm_sg(struct crypto_tfm *tfm) 302 { 303 struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm); 304 305 crypto_free_lskcipher(*ctx); 306 } 307 308 int crypto_init_lskcipher_ops_sg(struct crypto_tfm *tfm) 309 { 310 struct crypto_lskcipher **ctx = crypto_tfm_ctx(tfm); 311 struct crypto_alg *calg = tfm->__crt_alg; 312 struct crypto_lskcipher *skcipher; 313 314 if (!crypto_mod_get(calg)) 315 return -EAGAIN; 316 317 skcipher = crypto_create_tfm(calg, &crypto_lskcipher_type); 318 if (IS_ERR(skcipher)) { 319 crypto_mod_put(calg); 320 return PTR_ERR(skcipher); 321 } 322 323 *ctx = skcipher; 324 tfm->exit = crypto_lskcipher_exit_tfm_sg; 325 326 return 0; 327 } 328 329 int crypto_grab_lskcipher(struct crypto_lskcipher_spawn *spawn, 330 struct crypto_instance *inst, 331 const char *name, u32 type, u32 mask) 332 { 333 spawn->base.frontend = &crypto_lskcipher_type; 334 return crypto_grab_spawn(&spawn->base, inst, name, type, mask); 335 } 336 EXPORT_SYMBOL_GPL(crypto_grab_lskcipher); 337 338 struct crypto_lskcipher *crypto_alloc_lskcipher(const char *alg_name, 339 u32 type, u32 mask) 340 { 341 return crypto_alloc_tfm(alg_name, &crypto_lskcipher_type, type, mask); 342 } 343 EXPORT_SYMBOL_GPL(crypto_alloc_lskcipher); 344 345 static int lskcipher_prepare_alg(struct lskcipher_alg *alg) 346 { 347 struct crypto_alg *base = &alg->co.base; 348 int err; 349 350 err = skcipher_prepare_alg_common(&alg->co); 351 if (err) 352 return err; 353 354 if (alg->co.chunksize & (alg->co.chunksize - 1)) 355 return -EINVAL; 356 357 base->cra_type = &crypto_lskcipher_type; 358 base->cra_flags |= CRYPTO_ALG_TYPE_LSKCIPHER; 359 360 return 0; 361 } 362 363 int crypto_register_lskcipher(struct lskcipher_alg *alg) 364 { 365 struct crypto_alg *base = &alg->co.base; 366 int err; 367 368 err = lskcipher_prepare_alg(alg); 369 if (err) 370 return err; 371 372 return crypto_register_alg(base); 373 } 374 EXPORT_SYMBOL_GPL(crypto_register_lskcipher); 375 376 void crypto_unregister_lskcipher(struct lskcipher_alg *alg) 377 { 378 crypto_unregister_alg(&alg->co.base); 379 } 380 EXPORT_SYMBOL_GPL(crypto_unregister_lskcipher); 381 382 int crypto_register_lskciphers(struct lskcipher_alg *algs, int count) 383 { 384 int i, ret; 385 386 for (i = 0; i < count; i++) { 387 ret = crypto_register_lskcipher(&algs[i]); 388 if (ret) 389 goto err; 390 } 391 392 return 0; 393 394 err: 395 for (--i; i >= 0; --i) 396 crypto_unregister_lskcipher(&algs[i]); 397 398 return ret; 399 } 400 EXPORT_SYMBOL_GPL(crypto_register_lskciphers); 401 402 void crypto_unregister_lskciphers(struct lskcipher_alg *algs, int count) 403 { 404 int i; 405 406 for (i = count - 1; i >= 0; --i) 407 crypto_unregister_lskcipher(&algs[i]); 408 } 409 EXPORT_SYMBOL_GPL(crypto_unregister_lskciphers); 410 411 int lskcipher_register_instance(struct crypto_template *tmpl, 412 struct lskcipher_instance *inst) 413 { 414 int err; 415 416 if (WARN_ON(!inst->free)) 417 return -EINVAL; 418 419 err = lskcipher_prepare_alg(&inst->alg); 420 if (err) 421 return err; 422 423 return crypto_register_instance(tmpl, lskcipher_crypto_instance(inst)); 424 } 425 EXPORT_SYMBOL_GPL(lskcipher_register_instance); 426 427 static int lskcipher_setkey_simple(struct crypto_lskcipher *tfm, const u8 *key, 428 unsigned int keylen) 429 { 430 struct crypto_lskcipher *cipher = lskcipher_cipher_simple(tfm); 431 432 crypto_lskcipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK); 433 crypto_lskcipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) & 434 CRYPTO_TFM_REQ_MASK); 435 return crypto_lskcipher_setkey(cipher, key, keylen); 436 } 437 438 static int lskcipher_init_tfm_simple(struct crypto_lskcipher *tfm) 439 { 440 struct lskcipher_instance *inst = lskcipher_alg_instance(tfm); 441 struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm); 442 struct crypto_lskcipher_spawn *spawn; 443 struct crypto_lskcipher *cipher; 444 445 spawn = lskcipher_instance_ctx(inst); 446 cipher = crypto_spawn_lskcipher(spawn); 447 if (IS_ERR(cipher)) 448 return PTR_ERR(cipher); 449 450 *ctx = cipher; 451 return 0; 452 } 453 454 static void lskcipher_exit_tfm_simple(struct crypto_lskcipher *tfm) 455 { 456 struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm); 457 458 crypto_free_lskcipher(*ctx); 459 } 460 461 static void lskcipher_free_instance_simple(struct lskcipher_instance *inst) 462 { 463 crypto_drop_lskcipher(lskcipher_instance_ctx(inst)); 464 kfree(inst); 465 } 466 467 /** 468 * lskcipher_alloc_instance_simple - allocate instance of simple block cipher 469 * 470 * Allocate an lskcipher_instance for a simple block cipher mode of operation, 471 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn, 472 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize, 473 * alignmask, and priority are set from the underlying cipher but can be 474 * overridden if needed. The tfm context defaults to 475 * struct crypto_lskcipher *, and default ->setkey(), ->init(), and 476 * ->exit() methods are installed. 477 * 478 * @tmpl: the template being instantiated 479 * @tb: the template parameters 480 * 481 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still 482 * needs to register the instance. 483 */ 484 struct lskcipher_instance *lskcipher_alloc_instance_simple( 485 struct crypto_template *tmpl, struct rtattr **tb) 486 { 487 u32 mask; 488 struct lskcipher_instance *inst; 489 struct crypto_lskcipher_spawn *spawn; 490 char ecb_name[CRYPTO_MAX_ALG_NAME]; 491 struct lskcipher_alg *cipher_alg; 492 const char *cipher_name; 493 int err; 494 495 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask); 496 if (err) 497 return ERR_PTR(err); 498 499 cipher_name = crypto_attr_alg_name(tb[1]); 500 if (IS_ERR(cipher_name)) 501 return ERR_CAST(cipher_name); 502 503 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 504 if (!inst) 505 return ERR_PTR(-ENOMEM); 506 507 spawn = lskcipher_instance_ctx(inst); 508 err = crypto_grab_lskcipher(spawn, 509 lskcipher_crypto_instance(inst), 510 cipher_name, 0, mask); 511 512 ecb_name[0] = 0; 513 if (err == -ENOENT && !!memcmp(tmpl->name, "ecb", 4)) { 514 err = -ENAMETOOLONG; 515 if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)", 516 cipher_name) >= CRYPTO_MAX_ALG_NAME) 517 goto err_free_inst; 518 519 err = crypto_grab_lskcipher(spawn, 520 lskcipher_crypto_instance(inst), 521 ecb_name, 0, mask); 522 } 523 524 if (err) 525 goto err_free_inst; 526 527 cipher_alg = crypto_lskcipher_spawn_alg(spawn); 528 529 err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name, 530 &cipher_alg->co.base); 531 if (err) 532 goto err_free_inst; 533 534 if (ecb_name[0]) { 535 int len; 536 537 err = -EINVAL; 538 len = strscpy(ecb_name, &cipher_alg->co.base.cra_name[4], 539 sizeof(ecb_name)); 540 if (len < 2) 541 goto err_free_inst; 542 543 if (ecb_name[len - 1] != ')') 544 goto err_free_inst; 545 546 ecb_name[len - 1] = 0; 547 548 err = -ENAMETOOLONG; 549 if (snprintf(inst->alg.co.base.cra_name, CRYPTO_MAX_ALG_NAME, 550 "%s(%s)", tmpl->name, ecb_name) >= 551 CRYPTO_MAX_ALG_NAME) 552 goto err_free_inst; 553 554 if (strcmp(ecb_name, cipher_name) && 555 snprintf(inst->alg.co.base.cra_driver_name, 556 CRYPTO_MAX_ALG_NAME, 557 "%s(%s)", tmpl->name, cipher_name) >= 558 CRYPTO_MAX_ALG_NAME) 559 goto err_free_inst; 560 } else { 561 /* Don't allow nesting. */ 562 err = -ELOOP; 563 if ((cipher_alg->co.base.cra_flags & CRYPTO_ALG_INSTANCE)) 564 goto err_free_inst; 565 } 566 567 err = -EINVAL; 568 if (cipher_alg->co.ivsize) 569 goto err_free_inst; 570 571 inst->free = lskcipher_free_instance_simple; 572 573 /* Default algorithm properties, can be overridden */ 574 inst->alg.co.base.cra_blocksize = cipher_alg->co.base.cra_blocksize; 575 inst->alg.co.base.cra_alignmask = cipher_alg->co.base.cra_alignmask; 576 inst->alg.co.base.cra_priority = cipher_alg->co.base.cra_priority; 577 inst->alg.co.min_keysize = cipher_alg->co.min_keysize; 578 inst->alg.co.max_keysize = cipher_alg->co.max_keysize; 579 inst->alg.co.ivsize = cipher_alg->co.base.cra_blocksize; 580 inst->alg.co.statesize = cipher_alg->co.statesize; 581 582 /* Use struct crypto_lskcipher * by default, can be overridden */ 583 inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_lskcipher *); 584 inst->alg.setkey = lskcipher_setkey_simple; 585 inst->alg.init = lskcipher_init_tfm_simple; 586 inst->alg.exit = lskcipher_exit_tfm_simple; 587 588 return inst; 589 590 err_free_inst: 591 lskcipher_free_instance_simple(inst); 592 return ERR_PTR(err); 593 } 594 EXPORT_SYMBOL_GPL(lskcipher_alloc_instance_simple); 595