1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Scatterlist Cryptographic API. 4 * 5 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> 6 * Copyright (c) 2002 David S. Miller (davem@redhat.com) 7 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au> 8 * 9 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no> 10 * and Nettle, by Niels Möller. 11 */ 12 13 #include <linux/err.h> 14 #include <linux/errno.h> 15 #include <linux/jump_label.h> 16 #include <linux/kernel.h> 17 #include <linux/kmod.h> 18 #include <linux/module.h> 19 #include <linux/param.h> 20 #include <linux/sched/signal.h> 21 #include <linux/slab.h> 22 #include <linux/string.h> 23 #include <linux/completion.h> 24 #include "internal.h" 25 26 LIST_HEAD(crypto_alg_list); 27 EXPORT_SYMBOL_GPL(crypto_alg_list); 28 DECLARE_RWSEM(crypto_alg_sem); 29 EXPORT_SYMBOL_GPL(crypto_alg_sem); 30 31 BLOCKING_NOTIFIER_HEAD(crypto_chain); 32 EXPORT_SYMBOL_GPL(crypto_chain); 33 34 #if IS_BUILTIN(CONFIG_CRYPTO_ALGAPI) && \ 35 !IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS) 36 DEFINE_STATIC_KEY_FALSE(__crypto_boot_test_finished); 37 #endif 38 39 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg); 40 static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, 41 u32 mask); 42 43 struct crypto_alg *crypto_mod_get(struct crypto_alg *alg) 44 { 45 return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL; 46 } 47 EXPORT_SYMBOL_GPL(crypto_mod_get); 48 49 void crypto_mod_put(struct crypto_alg *alg) 50 { 51 struct module *module = alg->cra_module; 52 53 crypto_alg_put(alg); 54 module_put(module); 55 } 56 EXPORT_SYMBOL_GPL(crypto_mod_put); 57 58 static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type, 59 u32 mask) 60 { 61 struct crypto_alg *q, *alg = NULL; 62 int best = -2; 63 64 list_for_each_entry(q, &crypto_alg_list, cra_list) { 65 int exact, fuzzy; 66 67 if (crypto_is_moribund(q)) 68 continue; 69 70 if ((q->cra_flags ^ type) & mask) 71 continue; 72 73 exact = !strcmp(q->cra_driver_name, name); 74 fuzzy = !strcmp(q->cra_name, name); 75 if (!exact && !(fuzzy && q->cra_priority > best)) 76 continue; 77 78 if (unlikely(!crypto_mod_get(q))) 79 continue; 80 81 best = q->cra_priority; 82 if (alg) 83 crypto_mod_put(alg); 84 alg = q; 85 86 if (exact) 87 break; 88 } 89 90 return alg; 91 } 92 93 static void crypto_larval_destroy(struct crypto_alg *alg) 94 { 95 struct crypto_larval *larval = (void *)alg; 96 97 BUG_ON(!crypto_is_larval(alg)); 98 if (!IS_ERR_OR_NULL(larval->adult)) 99 crypto_mod_put(larval->adult); 100 kfree(larval); 101 } 102 103 struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask) 104 { 105 struct crypto_larval *larval; 106 107 larval = kzalloc(sizeof(*larval), GFP_KERNEL); 108 if (!larval) 109 return ERR_PTR(-ENOMEM); 110 111 type &= ~CRYPTO_ALG_TYPE_MASK | (mask ?: CRYPTO_ALG_TYPE_MASK); 112 113 larval->mask = mask; 114 larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type; 115 larval->alg.cra_priority = -1; 116 larval->alg.cra_destroy = crypto_larval_destroy; 117 118 strscpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME); 119 init_completion(&larval->completion); 120 121 return larval; 122 } 123 EXPORT_SYMBOL_GPL(crypto_larval_alloc); 124 125 static struct crypto_alg *crypto_larval_add(const char *name, u32 type, 126 u32 mask) 127 { 128 struct crypto_alg *alg; 129 struct crypto_larval *larval; 130 131 larval = crypto_larval_alloc(name, type, mask); 132 if (IS_ERR(larval)) 133 return ERR_CAST(larval); 134 135 refcount_set(&larval->alg.cra_refcnt, 2); 136 137 down_write(&crypto_alg_sem); 138 alg = __crypto_alg_lookup(name, type, mask); 139 if (!alg) { 140 alg = &larval->alg; 141 list_add(&alg->cra_list, &crypto_alg_list); 142 } 143 up_write(&crypto_alg_sem); 144 145 if (alg != &larval->alg) { 146 kfree(larval); 147 if (crypto_is_larval(alg)) 148 alg = crypto_larval_wait(alg); 149 } 150 151 return alg; 152 } 153 154 static void crypto_larval_kill(struct crypto_larval *larval) 155 { 156 bool unlinked; 157 158 down_write(&crypto_alg_sem); 159 unlinked = list_empty(&larval->alg.cra_list); 160 if (!unlinked) 161 list_del_init(&larval->alg.cra_list); 162 up_write(&crypto_alg_sem); 163 164 if (unlinked) 165 return; 166 167 complete_all(&larval->completion); 168 crypto_alg_put(&larval->alg); 169 } 170 171 void crypto_schedule_test(struct crypto_larval *larval) 172 { 173 int err; 174 175 err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult); 176 WARN_ON_ONCE(err != NOTIFY_STOP); 177 } 178 EXPORT_SYMBOL_GPL(crypto_schedule_test); 179 180 static void crypto_start_test(struct crypto_larval *larval) 181 { 182 if (!crypto_is_test_larval(larval)) 183 return; 184 185 if (larval->test_started) 186 return; 187 188 down_write(&crypto_alg_sem); 189 if (larval->test_started) { 190 up_write(&crypto_alg_sem); 191 return; 192 } 193 194 larval->test_started = true; 195 up_write(&crypto_alg_sem); 196 197 crypto_schedule_test(larval); 198 } 199 200 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg) 201 { 202 struct crypto_larval *larval; 203 long time_left; 204 205 again: 206 larval = container_of(alg, struct crypto_larval, alg); 207 208 if (!crypto_boot_test_finished()) 209 crypto_start_test(larval); 210 211 time_left = wait_for_completion_killable_timeout( 212 &larval->completion, 60 * HZ); 213 214 alg = larval->adult; 215 if (time_left < 0) 216 alg = ERR_PTR(-EINTR); 217 else if (!time_left) { 218 if (crypto_is_test_larval(larval)) 219 crypto_larval_kill(larval); 220 alg = ERR_PTR(-ETIMEDOUT); 221 } else if (!alg) { 222 u32 type; 223 u32 mask; 224 225 alg = &larval->alg; 226 type = alg->cra_flags & ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); 227 mask = larval->mask; 228 alg = crypto_alg_lookup(alg->cra_name, type, mask) ?: 229 ERR_PTR(-EAGAIN); 230 } else if (IS_ERR(alg)) 231 ; 232 else if (crypto_is_test_larval(larval) && 233 !(alg->cra_flags & CRYPTO_ALG_TESTED)) 234 alg = ERR_PTR(-EAGAIN); 235 else if (alg->cra_flags & CRYPTO_ALG_FIPS_INTERNAL) 236 alg = ERR_PTR(-EAGAIN); 237 else if (!crypto_mod_get(alg)) 238 alg = ERR_PTR(-EAGAIN); 239 crypto_mod_put(&larval->alg); 240 241 if (!IS_ERR(alg) && crypto_is_larval(alg)) 242 goto again; 243 244 return alg; 245 } 246 247 static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, 248 u32 mask) 249 { 250 const u32 fips = CRYPTO_ALG_FIPS_INTERNAL; 251 struct crypto_alg *alg; 252 u32 test = 0; 253 254 if (!((type | mask) & CRYPTO_ALG_TESTED)) 255 test |= CRYPTO_ALG_TESTED; 256 257 down_read(&crypto_alg_sem); 258 alg = __crypto_alg_lookup(name, (type | test) & ~fips, 259 (mask | test) & ~fips); 260 if (alg) { 261 if (((type | mask) ^ fips) & fips) 262 mask |= fips; 263 mask &= fips; 264 265 if (!crypto_is_larval(alg) && 266 ((type ^ alg->cra_flags) & mask)) { 267 /* Algorithm is disallowed in FIPS mode. */ 268 crypto_mod_put(alg); 269 alg = ERR_PTR(-ENOENT); 270 } 271 } else if (test) { 272 alg = __crypto_alg_lookup(name, type, mask); 273 if (alg && !crypto_is_larval(alg)) { 274 /* Test failed */ 275 crypto_mod_put(alg); 276 alg = ERR_PTR(-ELIBBAD); 277 } 278 } 279 up_read(&crypto_alg_sem); 280 281 return alg; 282 } 283 284 static struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, 285 u32 mask) 286 { 287 struct crypto_alg *alg; 288 289 if (!name) 290 return ERR_PTR(-ENOENT); 291 292 type &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); 293 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); 294 295 alg = crypto_alg_lookup(name, type, mask); 296 if (!alg && !(mask & CRYPTO_NOLOAD)) { 297 request_module("crypto-%s", name); 298 299 if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask & 300 CRYPTO_ALG_NEED_FALLBACK)) 301 request_module("crypto-%s-all", name); 302 303 alg = crypto_alg_lookup(name, type, mask); 304 } 305 306 if (!IS_ERR_OR_NULL(alg) && crypto_is_larval(alg)) 307 alg = crypto_larval_wait(alg); 308 else if (alg) 309 ; 310 else if (!(mask & CRYPTO_ALG_TESTED)) 311 alg = crypto_larval_add(name, type, mask); 312 else 313 alg = ERR_PTR(-ENOENT); 314 315 return alg; 316 } 317 318 int crypto_probing_notify(unsigned long val, void *v) 319 { 320 int ok; 321 322 ok = blocking_notifier_call_chain(&crypto_chain, val, v); 323 if (ok == NOTIFY_DONE) { 324 request_module("cryptomgr"); 325 ok = blocking_notifier_call_chain(&crypto_chain, val, v); 326 } 327 328 return ok; 329 } 330 EXPORT_SYMBOL_GPL(crypto_probing_notify); 331 332 struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask) 333 { 334 struct crypto_alg *alg; 335 struct crypto_alg *larval; 336 int ok; 337 338 /* 339 * If the internal flag is set for a cipher, require a caller to 340 * invoke the cipher with the internal flag to use that cipher. 341 * Also, if a caller wants to allocate a cipher that may or may 342 * not be an internal cipher, use type | CRYPTO_ALG_INTERNAL and 343 * !(mask & CRYPTO_ALG_INTERNAL). 344 */ 345 if (!((type | mask) & CRYPTO_ALG_INTERNAL)) 346 mask |= CRYPTO_ALG_INTERNAL; 347 348 larval = crypto_larval_lookup(name, type, mask); 349 if (IS_ERR(larval) || !crypto_is_larval(larval)) 350 return larval; 351 352 ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval); 353 354 if (ok == NOTIFY_STOP) 355 alg = crypto_larval_wait(larval); 356 else { 357 crypto_mod_put(larval); 358 alg = ERR_PTR(-ENOENT); 359 } 360 crypto_larval_kill(container_of(larval, struct crypto_larval, alg)); 361 return alg; 362 } 363 EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup); 364 365 static void crypto_exit_ops(struct crypto_tfm *tfm) 366 { 367 const struct crypto_type *type = tfm->__crt_alg->cra_type; 368 369 if (type && tfm->exit) 370 tfm->exit(tfm); 371 } 372 373 static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask) 374 { 375 const struct crypto_type *type_obj = alg->cra_type; 376 unsigned int len; 377 378 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1); 379 if (type_obj) 380 return len + type_obj->ctxsize(alg, type, mask); 381 382 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) { 383 default: 384 BUG(); 385 386 case CRYPTO_ALG_TYPE_CIPHER: 387 len += crypto_cipher_ctxsize(alg); 388 break; 389 390 case CRYPTO_ALG_TYPE_COMPRESS: 391 len += crypto_compress_ctxsize(alg); 392 break; 393 } 394 395 return len; 396 } 397 398 void crypto_shoot_alg(struct crypto_alg *alg) 399 { 400 down_write(&crypto_alg_sem); 401 alg->cra_flags |= CRYPTO_ALG_DYING; 402 up_write(&crypto_alg_sem); 403 } 404 EXPORT_SYMBOL_GPL(crypto_shoot_alg); 405 406 struct crypto_tfm *__crypto_alloc_tfmgfp(struct crypto_alg *alg, u32 type, 407 u32 mask, gfp_t gfp) 408 { 409 struct crypto_tfm *tfm; 410 unsigned int tfm_size; 411 int err = -ENOMEM; 412 413 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask); 414 tfm = kzalloc(tfm_size, gfp); 415 if (tfm == NULL) 416 goto out_err; 417 418 tfm->__crt_alg = alg; 419 refcount_set(&tfm->refcnt, 1); 420 421 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm))) 422 goto cra_init_failed; 423 424 goto out; 425 426 cra_init_failed: 427 crypto_exit_ops(tfm); 428 if (err == -EAGAIN) 429 crypto_shoot_alg(alg); 430 kfree(tfm); 431 out_err: 432 tfm = ERR_PTR(err); 433 out: 434 return tfm; 435 } 436 EXPORT_SYMBOL_GPL(__crypto_alloc_tfmgfp); 437 438 struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type, 439 u32 mask) 440 { 441 return __crypto_alloc_tfmgfp(alg, type, mask, GFP_KERNEL); 442 } 443 EXPORT_SYMBOL_GPL(__crypto_alloc_tfm); 444 445 /* 446 * crypto_alloc_base - Locate algorithm and allocate transform 447 * @alg_name: Name of algorithm 448 * @type: Type of algorithm 449 * @mask: Mask for type comparison 450 * 451 * This function should not be used by new algorithm types. 452 * Please use crypto_alloc_tfm instead. 453 * 454 * crypto_alloc_base() will first attempt to locate an already loaded 455 * algorithm. If that fails and the kernel supports dynamically loadable 456 * modules, it will then attempt to load a module of the same name or 457 * alias. If that fails it will send a query to any loaded crypto manager 458 * to construct an algorithm on the fly. A refcount is grabbed on the 459 * algorithm which is then associated with the new transform. 460 * 461 * The returned transform is of a non-determinate type. Most people 462 * should use one of the more specific allocation functions such as 463 * crypto_alloc_skcipher(). 464 * 465 * In case of error the return value is an error pointer. 466 */ 467 struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask) 468 { 469 struct crypto_tfm *tfm; 470 int err; 471 472 for (;;) { 473 struct crypto_alg *alg; 474 475 alg = crypto_alg_mod_lookup(alg_name, type, mask); 476 if (IS_ERR(alg)) { 477 err = PTR_ERR(alg); 478 goto err; 479 } 480 481 tfm = __crypto_alloc_tfm(alg, type, mask); 482 if (!IS_ERR(tfm)) 483 return tfm; 484 485 crypto_mod_put(alg); 486 err = PTR_ERR(tfm); 487 488 err: 489 if (err != -EAGAIN) 490 break; 491 if (fatal_signal_pending(current)) { 492 err = -EINTR; 493 break; 494 } 495 } 496 497 return ERR_PTR(err); 498 } 499 EXPORT_SYMBOL_GPL(crypto_alloc_base); 500 501 static void *crypto_alloc_tfmmem(struct crypto_alg *alg, 502 const struct crypto_type *frontend, int node, 503 gfp_t gfp) 504 { 505 struct crypto_tfm *tfm; 506 unsigned int tfmsize; 507 unsigned int total; 508 char *mem; 509 510 tfmsize = frontend->tfmsize; 511 total = tfmsize + sizeof(*tfm) + frontend->extsize(alg); 512 513 mem = kzalloc_node(total, gfp, node); 514 if (mem == NULL) 515 return ERR_PTR(-ENOMEM); 516 517 tfm = (struct crypto_tfm *)(mem + tfmsize); 518 tfm->__crt_alg = alg; 519 tfm->node = node; 520 refcount_set(&tfm->refcnt, 1); 521 522 return mem; 523 } 524 525 void *crypto_create_tfm_node(struct crypto_alg *alg, 526 const struct crypto_type *frontend, 527 int node) 528 { 529 struct crypto_tfm *tfm; 530 char *mem; 531 int err; 532 533 mem = crypto_alloc_tfmmem(alg, frontend, node, GFP_KERNEL); 534 if (IS_ERR(mem)) 535 goto out; 536 537 tfm = (struct crypto_tfm *)(mem + frontend->tfmsize); 538 539 err = frontend->init_tfm(tfm); 540 if (err) 541 goto out_free_tfm; 542 543 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm))) 544 goto cra_init_failed; 545 546 goto out; 547 548 cra_init_failed: 549 crypto_exit_ops(tfm); 550 out_free_tfm: 551 if (err == -EAGAIN) 552 crypto_shoot_alg(alg); 553 kfree(mem); 554 mem = ERR_PTR(err); 555 out: 556 return mem; 557 } 558 EXPORT_SYMBOL_GPL(crypto_create_tfm_node); 559 560 void *crypto_clone_tfm(const struct crypto_type *frontend, 561 struct crypto_tfm *otfm) 562 { 563 struct crypto_alg *alg = otfm->__crt_alg; 564 struct crypto_tfm *tfm; 565 char *mem; 566 567 mem = ERR_PTR(-ESTALE); 568 if (unlikely(!crypto_mod_get(alg))) 569 goto out; 570 571 mem = crypto_alloc_tfmmem(alg, frontend, otfm->node, GFP_ATOMIC); 572 if (IS_ERR(mem)) { 573 crypto_mod_put(alg); 574 goto out; 575 } 576 577 tfm = (struct crypto_tfm *)(mem + frontend->tfmsize); 578 tfm->crt_flags = otfm->crt_flags; 579 tfm->exit = otfm->exit; 580 581 out: 582 return mem; 583 } 584 EXPORT_SYMBOL_GPL(crypto_clone_tfm); 585 586 struct crypto_alg *crypto_find_alg(const char *alg_name, 587 const struct crypto_type *frontend, 588 u32 type, u32 mask) 589 { 590 if (frontend) { 591 type &= frontend->maskclear; 592 mask &= frontend->maskclear; 593 type |= frontend->type; 594 mask |= frontend->maskset; 595 } 596 597 return crypto_alg_mod_lookup(alg_name, type, mask); 598 } 599 EXPORT_SYMBOL_GPL(crypto_find_alg); 600 601 /* 602 * crypto_alloc_tfm_node - Locate algorithm and allocate transform 603 * @alg_name: Name of algorithm 604 * @frontend: Frontend algorithm type 605 * @type: Type of algorithm 606 * @mask: Mask for type comparison 607 * @node: NUMA node in which users desire to put requests, if node is 608 * NUMA_NO_NODE, it means users have no special requirement. 609 * 610 * crypto_alloc_tfm() will first attempt to locate an already loaded 611 * algorithm. If that fails and the kernel supports dynamically loadable 612 * modules, it will then attempt to load a module of the same name or 613 * alias. If that fails it will send a query to any loaded crypto manager 614 * to construct an algorithm on the fly. A refcount is grabbed on the 615 * algorithm which is then associated with the new transform. 616 * 617 * The returned transform is of a non-determinate type. Most people 618 * should use one of the more specific allocation functions such as 619 * crypto_alloc_skcipher(). 620 * 621 * In case of error the return value is an error pointer. 622 */ 623 624 void *crypto_alloc_tfm_node(const char *alg_name, 625 const struct crypto_type *frontend, u32 type, u32 mask, 626 int node) 627 { 628 void *tfm; 629 int err; 630 631 for (;;) { 632 struct crypto_alg *alg; 633 634 alg = crypto_find_alg(alg_name, frontend, type, mask); 635 if (IS_ERR(alg)) { 636 err = PTR_ERR(alg); 637 goto err; 638 } 639 640 tfm = crypto_create_tfm_node(alg, frontend, node); 641 if (!IS_ERR(tfm)) 642 return tfm; 643 644 crypto_mod_put(alg); 645 err = PTR_ERR(tfm); 646 647 err: 648 if (err != -EAGAIN) 649 break; 650 if (fatal_signal_pending(current)) { 651 err = -EINTR; 652 break; 653 } 654 } 655 656 return ERR_PTR(err); 657 } 658 EXPORT_SYMBOL_GPL(crypto_alloc_tfm_node); 659 660 /* 661 * crypto_destroy_tfm - Free crypto transform 662 * @mem: Start of tfm slab 663 * @tfm: Transform to free 664 * 665 * This function frees up the transform and any associated resources, 666 * then drops the refcount on the associated algorithm. 667 */ 668 void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm) 669 { 670 struct crypto_alg *alg; 671 672 if (IS_ERR_OR_NULL(mem)) 673 return; 674 675 if (!refcount_dec_and_test(&tfm->refcnt)) 676 return; 677 alg = tfm->__crt_alg; 678 679 if (!tfm->exit && alg->cra_exit) 680 alg->cra_exit(tfm); 681 crypto_exit_ops(tfm); 682 crypto_mod_put(alg); 683 kfree_sensitive(mem); 684 } 685 EXPORT_SYMBOL_GPL(crypto_destroy_tfm); 686 687 int crypto_has_alg(const char *name, u32 type, u32 mask) 688 { 689 int ret = 0; 690 struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask); 691 692 if (!IS_ERR(alg)) { 693 crypto_mod_put(alg); 694 ret = 1; 695 } 696 697 return ret; 698 } 699 EXPORT_SYMBOL_GPL(crypto_has_alg); 700 701 void crypto_req_done(void *data, int err) 702 { 703 struct crypto_wait *wait = data; 704 705 if (err == -EINPROGRESS) 706 return; 707 708 wait->err = err; 709 complete(&wait->completion); 710 } 711 EXPORT_SYMBOL_GPL(crypto_req_done); 712 713 MODULE_DESCRIPTION("Cryptographic core API"); 714 MODULE_LICENSE("GPL"); 715