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