crypto/algapi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Cryptographic API for algorithms (i.e., low-level API).
   4  *
   5  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   6  */
   7
   8 #include <crypto/algapi.h>
   9 #include <linux/err.h>
  10 #include <linux/errno.h>
  11 #include <linux/fips.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/list.h>
  15 #include <linux/module.h>
  16 #include <linux/rtnetlink.h>
  17 #include <linux/slab.h>
  18 #include <linux/string.h>
  19
  20 #include "internal.h"
  21
  22 static LIST_HEAD(crypto_template_list);
  23
  24 static inline void crypto_check_module_sig(struct module *mod)
  25 {
  26         if (fips_enabled && mod && !module_sig_ok(mod))
  27                 panic("Module %s signature verification failed in FIPS mode\n",
  28                       module_name(mod));
  29 }
  30
  31 static int crypto_check_alg(struct crypto_alg *alg)
  32 {
  33         crypto_check_module_sig(alg->cra_module);
  34
  35         if (!alg->cra_name[0] || !alg->cra_driver_name[0])
  36                 return -EINVAL;
  37
  38         if (alg->cra_alignmask & (alg->cra_alignmask + 1))
  39                 return -EINVAL;
  40
  41         /* General maximums for all algs. */
  42         if (alg->cra_alignmask > MAX_ALGAPI_ALIGNMASK)
  43                 return -EINVAL;
  44
  45         if (alg->cra_blocksize > MAX_ALGAPI_BLOCKSIZE)
  46                 return -EINVAL;
  47
  48         /* Lower maximums for specific alg types. */
  49         if (!alg->cra_type && (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
  50                                CRYPTO_ALG_TYPE_CIPHER) {
  51                 if (alg->cra_alignmask > MAX_CIPHER_ALIGNMASK)
  52                         return -EINVAL;
  53
  54                 if (alg->cra_blocksize > MAX_CIPHER_BLOCKSIZE)
  55                         return -EINVAL;
  56         }
  57
  58         if (alg->cra_priority < 0)
  59                 return -EINVAL;
  60
  61         refcount_set(&alg->cra_refcnt, 1);
  62
  63         return 0;
  64 }
  65
  66 static void crypto_free_instance(struct crypto_instance *inst)
  67 {
  68         inst->alg.cra_type->free(inst);
  69 }
  70
  71 static void crypto_destroy_instance(struct crypto_alg *alg)
  72 {
  73         struct crypto_instance *inst = (void *)alg;
  74         struct crypto_template *tmpl = inst->tmpl;
  75
  76         crypto_free_instance(inst);
  77         crypto_tmpl_put(tmpl);
  78 }
  79
  80 /*
  81  * This function adds a spawn to the list secondary_spawns which
  82  * will be used at the end of crypto_remove_spawns to unregister
  83  * instances, unless the spawn happens to be one that is depended
  84  * on by the new algorithm (nalg in crypto_remove_spawns).
  85  *
  86  * This function is also responsible for resurrecting any algorithms
  87  * in the dependency chain of nalg by unsetting n->dead.
  88  */
  89 static struct list_head *crypto_more_spawns(struct crypto_alg *alg,
  90                                             struct list_head *stack,
  91                                             struct list_head *top,
  92                                             struct list_head *secondary_spawns)
  93 {
  94         struct crypto_spawn *spawn, *n;
  95
  96         spawn = list_first_entry_or_null(stack, struct crypto_spawn, list);
  97         if (!spawn)
  98                 return NULL;
  99
 100         n = list_prev_entry(spawn, list);
 101         list_move(&spawn->list, secondary_spawns);
 102
 103         if (list_is_last(&n->list, stack))
 104                 return top;
 105
 106         n = list_next_entry(n, list);
 107         if (!spawn->dead)
 108                 n->dead = false;
 109
 110         return &n->inst->alg.cra_users;
 111 }
 112
 113 static void crypto_remove_instance(struct crypto_instance *inst,
 114                                    struct list_head *list)
 115 {
 116         struct crypto_template *tmpl = inst->tmpl;
 117
 118         if (crypto_is_dead(&inst->alg))
 119                 return;
 120
 121         inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
 122
 123         if (!tmpl || !crypto_tmpl_get(tmpl))
 124                 return;
 125
 126         list_move(&inst->alg.cra_list, list);
 127         hlist_del(&inst->list);
 128         inst->alg.cra_destroy = crypto_destroy_instance;
 129
 130         BUG_ON(!list_empty(&inst->alg.cra_users));
 131 }
 132
 133 /*
 134  * Given an algorithm alg, remove all algorithms that depend on it
 135  * through spawns.  If nalg is not null, then exempt any algorithms
 136  * that is depended on by nalg.  This is useful when nalg itself
 137  * depends on alg.
 138  */
 139 void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
 140                           struct crypto_alg *nalg)
 141 {
 142         u32 new_type = (nalg ?: alg)->cra_flags;
 143         struct crypto_spawn *spawn, *n;
 144         LIST_HEAD(secondary_spawns);
 145         struct list_head *spawns;
 146         LIST_HEAD(stack);
 147         LIST_HEAD(top);
 148
 149         spawns = &alg->cra_users;
 150         list_for_each_entry_safe(spawn, n, spawns, list) {
 151                 if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
 152                         continue;
 153
 154                 list_move(&spawn->list, &top);
 155         }
 156
 157         /*
 158          * Perform a depth-first walk starting from alg through
 159          * the cra_users tree.  The list stack records the path
 160          * from alg to the current spawn.
 161          */
 162         spawns = &top;
 163         do {
 164                 while (!list_empty(spawns)) {
 165                         struct crypto_instance *inst;
 166
 167                         spawn = list_first_entry(spawns, struct crypto_spawn,
 168                                                  list);
 169                         inst = spawn->inst;
 170
 171                         list_move(&spawn->list, &stack);
 172                         spawn->dead = !spawn->registered || &inst->alg != nalg;
 173
 174                         if (!spawn->registered)
 175                                 break;
 176
 177                         BUG_ON(&inst->alg == alg);
 178
 179                         if (&inst->alg == nalg)
 180                                 break;
 181
 182                         spawns = &inst->alg.cra_users;
 183
 184                         /*
 185                          * Even if spawn->registered is true, the
 186                          * instance itself may still be unregistered.
 187                          * This is because it may have failed during
 188                          * registration.  Therefore we still need to
 189                          * make the following test.
 190                          *
 191                          * We may encounter an unregistered instance here, since
 192                          * an instance's spawns are set up prior to the instance
 193                          * being registered.  An unregistered instance will have
 194                          * NULL ->cra_users.next, since ->cra_users isn't
 195                          * properly initialized until registration.  But an
 196                          * unregistered instance cannot have any users, so treat
 197                          * it the same as ->cra_users being empty.
 198                          */
 199                         if (spawns->next == NULL)
 200                                 break;
 201                 }
 202         } while ((spawns = crypto_more_spawns(alg, &stack, &top,
 203                                               &secondary_spawns)));
 204
 205         /*
 206          * Remove all instances that are marked as dead.  Also
 207          * complete the resurrection of the others by moving them
 208          * back to the cra_users list.
 209          */
 210         list_for_each_entry_safe(spawn, n, &secondary_spawns, list) {
 211                 if (!spawn->dead)
 212                         list_move(&spawn->list, &spawn->alg->cra_users);
 213                 else if (spawn->registered)
 214                         crypto_remove_instance(spawn->inst, list);
 215         }
 216 }
 217 EXPORT_SYMBOL_GPL(crypto_remove_spawns);
 218
 219 static struct crypto_larval *crypto_alloc_test_larval(struct crypto_alg *alg)
 220 {
 221         struct crypto_larval *larval;
 222
 223         if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER))
 224                 return NULL;
 225
 226         larval = crypto_larval_alloc(alg->cra_name,
 227                                      alg->cra_flags | CRYPTO_ALG_TESTED, 0);
 228         if (IS_ERR(larval))
 229                 return larval;
 230
 231         larval->adult = crypto_mod_get(alg);
 232         if (!larval->adult) {
 233                 kfree(larval);
 234                 return ERR_PTR(-ENOENT);
 235         }
 236
 237         refcount_set(&larval->alg.cra_refcnt, 1);
 238         memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
 239                CRYPTO_MAX_ALG_NAME);
 240         larval->alg.cra_priority = alg->cra_priority;
 241
 242         return larval;
 243 }
 244
 245 static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg)
 246 {
 247         struct crypto_alg *q;
 248         struct crypto_larval *larval;
 249         int ret = -EAGAIN;
 250
 251         if (crypto_is_dead(alg))
 252                 goto err;
 253
 254         INIT_LIST_HEAD(&alg->cra_users);
 255
 256         /* No cheating! */
 257         alg->cra_flags &= ~CRYPTO_ALG_TESTED;
 258
 259         ret = -EEXIST;
 260
 261         list_for_each_entry(q, &crypto_alg_list, cra_list) {
 262                 if (q == alg)
 263                         goto err;
 264
 265                 if (crypto_is_moribund(q))
 266                         continue;
 267
 268                 if (crypto_is_larval(q)) {
 269                         if (!strcmp(alg->cra_driver_name, q->cra_driver_name))
 270                                 goto err;
 271                         continue;
 272                 }
 273
 274                 if (!strcmp(q->cra_driver_name, alg->cra_name) ||
 275                     !strcmp(q->cra_name, alg->cra_driver_name))
 276                         goto err;
 277         }
 278
 279         larval = crypto_alloc_test_larval(alg);
 280         if (IS_ERR(larval))
 281                 goto out;
 282
 283         list_add(&alg->cra_list, &crypto_alg_list);
 284
 285         if (larval)
 286                 list_add(&larval->alg.cra_list, &crypto_alg_list);
 287         else
 288                 alg->cra_flags |= CRYPTO_ALG_TESTED;
 289
 290         crypto_stats_init(alg);
 291
 292 out:
 293         return larval;
 294
 295 err:
 296         larval = ERR_PTR(ret);
 297         goto out;
 298 }
 299
 300 void crypto_alg_tested(const char *name, int err)
 301 {
 302         struct crypto_larval *test;
 303         struct crypto_alg *alg;
 304         struct crypto_alg *q;
 305         LIST_HEAD(list);
 306         bool best;
 307
 308         down_write(&crypto_alg_sem);
 309         list_for_each_entry(q, &crypto_alg_list, cra_list) {
 310                 if (crypto_is_moribund(q) || !crypto_is_larval(q))
 311                         continue;
 312
 313                 test = (struct crypto_larval *)q;
 314
 315                 if (!strcmp(q->cra_driver_name, name))
 316                         goto found;
 317         }
 318
 319         pr_err("alg: Unexpected test result for %s: %d\n", name, err);
 320         goto unlock;
 321
 322 found:
 323         q->cra_flags |= CRYPTO_ALG_DEAD;
 324         alg = test->adult;
 325         if (err || list_empty(&alg->cra_list))
 326                 goto complete;
 327
 328         alg->cra_flags |= CRYPTO_ALG_TESTED;
 329
 330         /* Only satisfy larval waiters if we are the best. */
 331         best = true;
 332         list_for_each_entry(q, &crypto_alg_list, cra_list) {
 333                 if (crypto_is_moribund(q) || !crypto_is_larval(q))
 334                         continue;
 335
 336                 if (strcmp(alg->cra_name, q->cra_name))
 337                         continue;
 338
 339                 if (q->cra_priority > alg->cra_priority) {
 340                         best = false;
 341                         break;
 342                 }
 343         }
 344
 345         list_for_each_entry(q, &crypto_alg_list, cra_list) {
 346                 if (q == alg)
 347                         continue;
 348
 349                 if (crypto_is_moribund(q))
 350                         continue;
 351
 352                 if (crypto_is_larval(q)) {
 353                         struct crypto_larval *larval = (void *)q;
 354
 355                         /*
 356                          * Check to see if either our generic name or
 357                          * specific name can satisfy the name requested
 358                          * by the larval entry q.
 359                          */
 360                         if (strcmp(alg->cra_name, q->cra_name) &&
 361                             strcmp(alg->cra_driver_name, q->cra_name))
 362                                 continue;
 363
 364                         if (larval->adult)
 365                                 continue;
 366                         if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
 367                                 continue;
 368
 369                         if (best && crypto_mod_get(alg))
 370                                 larval->adult = alg;
 371                         else
 372                                 larval->adult = ERR_PTR(-EAGAIN);
 373
 374                         continue;
 375                 }
 376
 377                 if (strcmp(alg->cra_name, q->cra_name))
 378                         continue;
 379
 380                 if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
 381                     q->cra_priority > alg->cra_priority)
 382                         continue;
 383
 384                 crypto_remove_spawns(q, &list, alg);
 385         }
 386
 387 complete:
 388         complete_all(&test->completion);
 389
 390 unlock:
 391         up_write(&crypto_alg_sem);
 392
 393         crypto_remove_final(&list);
 394 }
 395 EXPORT_SYMBOL_GPL(crypto_alg_tested);
 396
 397 void crypto_remove_final(struct list_head *list)
 398 {
 399         struct crypto_alg *alg;
 400         struct crypto_alg *n;
 401
 402         list_for_each_entry_safe(alg, n, list, cra_list) {
 403                 list_del_init(&alg->cra_list);
 404                 crypto_alg_put(alg);
 405         }
 406 }
 407 EXPORT_SYMBOL_GPL(crypto_remove_final);
 408
 409 int crypto_register_alg(struct crypto_alg *alg)
 410 {
 411         struct crypto_larval *larval;
 412         bool test_started;
 413         int err;
 414
 415         alg->cra_flags &= ~CRYPTO_ALG_DEAD;
 416         err = crypto_check_alg(alg);
 417         if (err)
 418                 return err;
 419
 420         down_write(&crypto_alg_sem);
 421         larval = __crypto_register_alg(alg);
 422         test_started = static_key_enabled(&crypto_boot_test_finished);
 423         if (!IS_ERR_OR_NULL(larval))
 424                 larval->test_started = test_started;
 425         up_write(&crypto_alg_sem);
 426
 427         if (IS_ERR_OR_NULL(larval))
 428                 return PTR_ERR(larval);
 429
 430         if (test_started)
 431                 crypto_wait_for_test(larval);
 432         return 0;
 433 }
 434 EXPORT_SYMBOL_GPL(crypto_register_alg);
 435
 436 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
 437 {
 438         if (unlikely(list_empty(&alg->cra_list)))
 439                 return -ENOENT;
 440
 441         alg->cra_flags |= CRYPTO_ALG_DEAD;
 442
 443         list_del_init(&alg->cra_list);
 444         crypto_remove_spawns(alg, list, NULL);
 445
 446         return 0;
 447 }
 448
 449 void crypto_unregister_alg(struct crypto_alg *alg)
 450 {
 451         int ret;
 452         LIST_HEAD(list);
 453
 454         down_write(&crypto_alg_sem);
 455         ret = crypto_remove_alg(alg, &list);
 456         up_write(&crypto_alg_sem);
 457
 458         if (WARN(ret, "Algorithm %s is not registered", alg->cra_driver_name))
 459                 return;
 460
 461         BUG_ON(refcount_read(&alg->cra_refcnt) != 1);
 462         if (alg->cra_destroy)
 463                 alg->cra_destroy(alg);
 464
 465         crypto_remove_final(&list);
 466 }
 467 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
 468
 469 int crypto_register_algs(struct crypto_alg *algs, int count)
 470 {
 471         int i, ret;
 472
 473         for (i = 0; i < count; i++) {
 474                 ret = crypto_register_alg(&algs[i]);
 475                 if (ret)
 476                         goto err;
 477         }
 478
 479         return 0;
 480
 481 err:
 482         for (--i; i >= 0; --i)
 483                 crypto_unregister_alg(&algs[i]);
 484
 485         return ret;
 486 }
 487 EXPORT_SYMBOL_GPL(crypto_register_algs);
 488
 489 void crypto_unregister_algs(struct crypto_alg *algs, int count)
 490 {
 491         int i;
 492
 493         for (i = 0; i < count; i++)
 494                 crypto_unregister_alg(&algs[i]);
 495 }
 496 EXPORT_SYMBOL_GPL(crypto_unregister_algs);
 497
 498 int crypto_register_template(struct crypto_template *tmpl)
 499 {
 500         struct crypto_template *q;
 501         int err = -EEXIST;
 502
 503         down_write(&crypto_alg_sem);
 504
 505         crypto_check_module_sig(tmpl->module);
 506
 507         list_for_each_entry(q, &crypto_template_list, list) {
 508                 if (q == tmpl)
 509                         goto out;
 510         }
 511
 512         list_add(&tmpl->list, &crypto_template_list);
 513         err = 0;
 514 out:
 515         up_write(&crypto_alg_sem);
 516         return err;
 517 }
 518 EXPORT_SYMBOL_GPL(crypto_register_template);
 519
 520 int crypto_register_templates(struct crypto_template *tmpls, int count)
 521 {
 522         int i, err;
 523
 524         for (i = 0; i < count; i++) {
 525                 err = crypto_register_template(&tmpls[i]);
 526                 if (err)
 527                         goto out;
 528         }
 529         return 0;
 530
 531 out:
 532         for (--i; i >= 0; --i)
 533                 crypto_unregister_template(&tmpls[i]);
 534         return err;
 535 }
 536 EXPORT_SYMBOL_GPL(crypto_register_templates);
 537
 538 void crypto_unregister_template(struct crypto_template *tmpl)
 539 {
 540         struct crypto_instance *inst;
 541         struct hlist_node *n;
 542         struct hlist_head *list;
 543         LIST_HEAD(users);
 544
 545         down_write(&crypto_alg_sem);
 546
 547         BUG_ON(list_empty(&tmpl->list));
 548         list_del_init(&tmpl->list);
 549
 550         list = &tmpl->instances;
 551         hlist_for_each_entry(inst, list, list) {
 552                 int err = crypto_remove_alg(&inst->alg, &users);
 553
 554                 BUG_ON(err);
 555         }
 556
 557         up_write(&crypto_alg_sem);
 558
 559         hlist_for_each_entry_safe(inst, n, list, list) {
 560                 BUG_ON(refcount_read(&inst->alg.cra_refcnt) != 1);
 561                 crypto_free_instance(inst);
 562         }
 563         crypto_remove_final(&users);
 564 }
 565 EXPORT_SYMBOL_GPL(crypto_unregister_template);
 566
 567 void crypto_unregister_templates(struct crypto_template *tmpls, int count)
 568 {
 569         int i;
 570
 571         for (i = count - 1; i >= 0; --i)
 572                 crypto_unregister_template(&tmpls[i]);
 573 }
 574 EXPORT_SYMBOL_GPL(crypto_unregister_templates);
 575
 576 static struct crypto_template *__crypto_lookup_template(const char *name)
 577 {
 578         struct crypto_template *q, *tmpl = NULL;
 579
 580         down_read(&crypto_alg_sem);
 581         list_for_each_entry(q, &crypto_template_list, list) {
 582                 if (strcmp(q->name, name))
 583                         continue;
 584                 if (unlikely(!crypto_tmpl_get(q)))
 585                         continue;
 586
 587                 tmpl = q;
 588                 break;
 589         }
 590         up_read(&crypto_alg_sem);
 591
 592         return tmpl;
 593 }
 594
 595 struct crypto_template *crypto_lookup_template(const char *name)
 596 {
 597         return try_then_request_module(__crypto_lookup_template(name),
 598                                        "crypto-%s", name);
 599 }
 600 EXPORT_SYMBOL_GPL(crypto_lookup_template);
 601
 602 int crypto_register_instance(struct crypto_template *tmpl,
 603                              struct crypto_instance *inst)
 604 {
 605         struct crypto_larval *larval;
 606         struct crypto_spawn *spawn;
 607         int err;
 608
 609         err = crypto_check_alg(&inst->alg);
 610         if (err)
 611                 return err;
 612
 613         inst->alg.cra_module = tmpl->module;
 614         inst->alg.cra_flags |= CRYPTO_ALG_INSTANCE;
 615
 616         down_write(&crypto_alg_sem);
 617
 618         larval = ERR_PTR(-EAGAIN);
 619         for (spawn = inst->spawns; spawn;) {
 620                 struct crypto_spawn *next;
 621
 622                 if (spawn->dead)
 623                         goto unlock;
 624
 625                 next = spawn->next;
 626                 spawn->inst = inst;
 627                 spawn->registered = true;
 628
 629                 crypto_mod_put(spawn->alg);
 630
 631                 spawn = next;
 632         }
 633
 634         larval = __crypto_register_alg(&inst->alg);
 635         if (IS_ERR(larval))
 636                 goto unlock;
 637         else if (larval)
 638                 larval->test_started = true;
 639
 640         hlist_add_head(&inst->list, &tmpl->instances);
 641         inst->tmpl = tmpl;
 642
 643 unlock:
 644         up_write(&crypto_alg_sem);
 645
 646         err = PTR_ERR(larval);
 647         if (IS_ERR_OR_NULL(larval))
 648                 goto err;
 649
 650         crypto_wait_for_test(larval);
 651         err = 0;
 652
 653 err:
 654         return err;
 655 }
 656 EXPORT_SYMBOL_GPL(crypto_register_instance);
 657
 658 void crypto_unregister_instance(struct crypto_instance *inst)
 659 {
 660         LIST_HEAD(list);
 661
 662         down_write(&crypto_alg_sem);
 663
 664         crypto_remove_spawns(&inst->alg, &list, NULL);
 665         crypto_remove_instance(inst, &list);
 666
 667         up_write(&crypto_alg_sem);
 668
 669         crypto_remove_final(&list);
 670 }
 671 EXPORT_SYMBOL_GPL(crypto_unregister_instance);
 672
 673 int crypto_grab_spawn(struct crypto_spawn *spawn, struct crypto_instance *inst,
 674                       const char *name, u32 type, u32 mask)
 675 {
 676         struct crypto_alg *alg;
 677         int err = -EAGAIN;
 678
 679         if (WARN_ON_ONCE(inst == NULL))
 680                 return -EINVAL;
 681
 682         /* Allow the result of crypto_attr_alg_name() to be passed directly */
 683         if (IS_ERR(name))
 684                 return PTR_ERR(name);
 685
 686         alg = crypto_find_alg(name, spawn->frontend, type, mask);
 687         if (IS_ERR(alg))
 688                 return PTR_ERR(alg);
 689
 690         down_write(&crypto_alg_sem);
 691         if (!crypto_is_moribund(alg)) {
 692                 list_add(&spawn->list, &alg->cra_users);
 693                 spawn->alg = alg;
 694                 spawn->mask = mask;
 695                 spawn->next = inst->spawns;
 696                 inst->spawns = spawn;
 697                 inst->alg.cra_flags |=
 698                         (alg->cra_flags & CRYPTO_ALG_INHERITED_FLAGS);
 699                 err = 0;
 700         }
 701         up_write(&crypto_alg_sem);
 702         if (err)
 703                 crypto_mod_put(alg);
 704         return err;
 705 }
 706 EXPORT_SYMBOL_GPL(crypto_grab_spawn);
 707
 708 void crypto_drop_spawn(struct crypto_spawn *spawn)
 709 {
 710         if (!spawn->alg) /* not yet initialized? */
 711                 return;
 712
 713         down_write(&crypto_alg_sem);
 714         if (!spawn->dead)
 715                 list_del(&spawn->list);
 716         up_write(&crypto_alg_sem);
 717
 718         if (!spawn->registered)
 719                 crypto_mod_put(spawn->alg);
 720 }
 721 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
 722
 723 static struct crypto_alg *crypto_spawn_alg(struct crypto_spawn *spawn)
 724 {
 725         struct crypto_alg *alg = ERR_PTR(-EAGAIN);
 726         struct crypto_alg *target;
 727         bool shoot = false;
 728
 729         down_read(&crypto_alg_sem);
 730         if (!spawn->dead) {
 731                 alg = spawn->alg;
 732                 if (!crypto_mod_get(alg)) {
 733                         target = crypto_alg_get(alg);
 734                         shoot = true;
 735                         alg = ERR_PTR(-EAGAIN);
 736                 }
 737         }
 738         up_read(&crypto_alg_sem);
 739
 740         if (shoot) {
 741                 crypto_shoot_alg(target);
 742                 crypto_alg_put(target);
 743         }
 744
 745         return alg;
 746 }
 747
 748 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
 749                                     u32 mask)
 750 {
 751         struct crypto_alg *alg;
 752         struct crypto_tfm *tfm;
 753
 754         alg = crypto_spawn_alg(spawn);
 755         if (IS_ERR(alg))
 756                 return ERR_CAST(alg);
 757
 758         tfm = ERR_PTR(-EINVAL);
 759         if (unlikely((alg->cra_flags ^ type) & mask))
 760                 goto out_put_alg;
 761
 762         tfm = __crypto_alloc_tfm(alg, type, mask);
 763         if (IS_ERR(tfm))
 764                 goto out_put_alg;
 765
 766         return tfm;
 767
 768 out_put_alg:
 769         crypto_mod_put(alg);
 770         return tfm;
 771 }
 772 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
 773
 774 void *crypto_spawn_tfm2(struct crypto_spawn *spawn)
 775 {
 776         struct crypto_alg *alg;
 777         struct crypto_tfm *tfm;
 778
 779         alg = crypto_spawn_alg(spawn);
 780         if (IS_ERR(alg))
 781                 return ERR_CAST(alg);
 782
 783         tfm = crypto_create_tfm(alg, spawn->frontend);
 784         if (IS_ERR(tfm))
 785                 goto out_put_alg;
 786
 787         return tfm;
 788
 789 out_put_alg:
 790         crypto_mod_put(alg);
 791         return tfm;
 792 }
 793 EXPORT_SYMBOL_GPL(crypto_spawn_tfm2);
 794
 795 int crypto_register_notifier(struct notifier_block *nb)
 796 {
 797         return blocking_notifier_chain_register(&crypto_chain, nb);
 798 }
 799 EXPORT_SYMBOL_GPL(crypto_register_notifier);
 800
 801 int crypto_unregister_notifier(struct notifier_block *nb)
 802 {
 803         return blocking_notifier_chain_unregister(&crypto_chain, nb);
 804 }
 805 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
 806
 807 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
 808 {
 809         struct rtattr *rta = tb[0];
 810         struct crypto_attr_type *algt;
 811
 812         if (!rta)
 813                 return ERR_PTR(-ENOENT);
 814         if (RTA_PAYLOAD(rta) < sizeof(*algt))
 815                 return ERR_PTR(-EINVAL);
 816         if (rta->rta_type != CRYPTOA_TYPE)
 817                 return ERR_PTR(-EINVAL);
 818
 819         algt = RTA_DATA(rta);
 820
 821         return algt;
 822 }
 823 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
 824
 825 /**
 826  * crypto_check_attr_type() - check algorithm type and compute inherited mask
 827  * @tb: the template parameters
 828  * @type: the algorithm type the template would be instantiated as
 829  * @mask_ret: (output) the mask that should be passed to crypto_grab_*()
 830  *            to restrict the flags of any inner algorithms
 831  *
 832  * Validate that the algorithm type the user requested is compatible with the
 833  * one the template would actually be instantiated as.  E.g., if the user is
 834  * doing crypto_alloc_shash("cbc(aes)", ...), this would return an error because
 835  * the "cbc" template creates an "skcipher" algorithm, not an "shash" algorithm.
 836  *
 837  * Also compute the mask to use to restrict the flags of any inner algorithms.
 838  *
 839  * Return: 0 on success; -errno on failure
 840  */
 841 int crypto_check_attr_type(struct rtattr **tb, u32 type, u32 *mask_ret)
 842 {
 843         struct crypto_attr_type *algt;
 844
 845         algt = crypto_get_attr_type(tb);
 846         if (IS_ERR(algt))
 847                 return PTR_ERR(algt);
 848
 849         if ((algt->type ^ type) & algt->mask)
 850                 return -EINVAL;
 851
 852         *mask_ret = crypto_algt_inherited_mask(algt);
 853         return 0;
 854 }
 855 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
 856
 857 const char *crypto_attr_alg_name(struct rtattr *rta)
 858 {
 859         struct crypto_attr_alg *alga;
 860
 861         if (!rta)
 862                 return ERR_PTR(-ENOENT);
 863         if (RTA_PAYLOAD(rta) < sizeof(*alga))
 864                 return ERR_PTR(-EINVAL);
 865         if (rta->rta_type != CRYPTOA_ALG)
 866                 return ERR_PTR(-EINVAL);
 867
 868         alga = RTA_DATA(rta);
 869         alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
 870
 871         return alga->name;
 872 }
 873 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
 874
 875 int crypto_inst_setname(struct crypto_instance *inst, const char *name,
 876                         struct crypto_alg *alg)
 877 {
 878         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
 879                      alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
 880                 return -ENAMETOOLONG;
 881
 882         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
 883                      name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 884                 return -ENAMETOOLONG;
 885
 886         return 0;
 887 }
 888 EXPORT_SYMBOL_GPL(crypto_inst_setname);
 889
 890 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
 891 {
 892         INIT_LIST_HEAD(&queue->list);
 893         queue->backlog = &queue->list;
 894         queue->qlen = 0;
 895         queue->max_qlen = max_qlen;
 896 }
 897 EXPORT_SYMBOL_GPL(crypto_init_queue);
 898
 899 int crypto_enqueue_request(struct crypto_queue *queue,
 900                            struct crypto_async_request *request)
 901 {
 902         int err = -EINPROGRESS;
 903
 904         if (unlikely(queue->qlen >= queue->max_qlen)) {
 905                 if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) {
 906                         err = -ENOSPC;
 907                         goto out;
 908                 }
 909                 err = -EBUSY;
 910                 if (queue->backlog == &queue->list)
 911                         queue->backlog = &request->list;
 912         }
 913
 914         queue->qlen++;
 915         list_add_tail(&request->list, &queue->list);
 916
 917 out:
 918         return err;
 919 }
 920 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
 921
 922 void crypto_enqueue_request_head(struct crypto_queue *queue,
 923                                  struct crypto_async_request *request)
 924 {
 925         queue->qlen++;
 926         list_add(&request->list, &queue->list);
 927 }
 928 EXPORT_SYMBOL_GPL(crypto_enqueue_request_head);
 929
 930 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
 931 {
 932         struct list_head *request;
 933
 934         if (unlikely(!queue->qlen))
 935                 return NULL;
 936
 937         queue->qlen--;
 938
 939         if (queue->backlog != &queue->list)
 940                 queue->backlog = queue->backlog->next;
 941
 942         request = queue->list.next;
 943         list_del(request);
 944
 945         return list_entry(request, struct crypto_async_request, list);
 946 }
 947 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
 948
 949 static inline void crypto_inc_byte(u8 *a, unsigned int size)
 950 {
 951         u8 *b = (a + size);
 952         u8 c;
 953
 954         for (; size; size--) {
 955                 c = *--b + 1;
 956                 *b = c;
 957                 if (c)
 958                         break;
 959         }
 960 }
 961
 962 void crypto_inc(u8 *a, unsigned int size)
 963 {
 964         __be32 *b = (__be32 *)(a + size);
 965         u32 c;
 966
 967         if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ||
 968             IS_ALIGNED((unsigned long)b, __alignof__(*b)))
 969                 for (; size >= 4; size -= 4) {
 970                         c = be32_to_cpu(*--b) + 1;
 971                         *b = cpu_to_be32(c);
 972                         if (likely(c))
 973                                 return;
 974                 }
 975
 976         crypto_inc_byte(a, size);
 977 }
 978 EXPORT_SYMBOL_GPL(crypto_inc);
 979
 980 void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int len)
 981 {
 982         int relalign = 0;
 983
 984         if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {
 985                 int size = sizeof(unsigned long);
 986                 int d = (((unsigned long)dst ^ (unsigned long)src1) |
 987                          ((unsigned long)dst ^ (unsigned long)src2)) &
 988                         (size - 1);
 989
 990                 relalign = d ? 1 << __ffs(d) : size;
 991
 992                 /*
 993                  * If we care about alignment, process as many bytes as
 994                  * needed to advance dst and src to values whose alignments
 995                  * equal their relative alignment. This will allow us to
 996                  * process the remainder of the input using optimal strides.
 997                  */
 998                 while (((unsigned long)dst & (relalign - 1)) && len > 0) {
 999                         *dst++ = *src1++ ^ *src2++;
1000                         len--;
1001                 }
1002         }
1003
1004         while (IS_ENABLED(CONFIG_64BIT) && len >= 8 && !(relalign & 7)) {
1005                 *(u64 *)dst = *(u64 *)src1 ^  *(u64 *)src2;
1006                 dst += 8;
1007                 src1 += 8;
1008                 src2 += 8;
1009                 len -= 8;
1010         }
1011
1012         while (len >= 4 && !(relalign & 3)) {
1013                 *(u32 *)dst = *(u32 *)src1 ^ *(u32 *)src2;
1014                 dst += 4;
1015                 src1 += 4;
1016                 src2 += 4;
1017                 len -= 4;
1018         }
1019
1020         while (len >= 2 && !(relalign & 1)) {
1021                 *(u16 *)dst = *(u16 *)src1 ^ *(u16 *)src2;
1022                 dst += 2;
1023                 src1 += 2;
1024                 src2 += 2;
1025                 len -= 2;
1026         }
1027
1028         while (len--)
1029                 *dst++ = *src1++ ^ *src2++;
1030 }
1031 EXPORT_SYMBOL_GPL(__crypto_xor);
1032
1033 unsigned int crypto_alg_extsize(struct crypto_alg *alg)
1034 {
1035         return alg->cra_ctxsize +
1036                (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));
1037 }
1038 EXPORT_SYMBOL_GPL(crypto_alg_extsize);
1039
1040 int crypto_type_has_alg(const char *name, const struct crypto_type *frontend,
1041                         u32 type, u32 mask)
1042 {
1043         int ret = 0;
1044         struct crypto_alg *alg = crypto_find_alg(name, frontend, type, mask);
1045
1046         if (!IS_ERR(alg)) {
1047                 crypto_mod_put(alg);
1048                 ret = 1;
1049         }
1050
1051         return ret;
1052 }
1053 EXPORT_SYMBOL_GPL(crypto_type_has_alg);
1054
1055 #ifdef CONFIG_CRYPTO_STATS
1056 void crypto_stats_init(struct crypto_alg *alg)
1057 {
1058         memset(&alg->stats, 0, sizeof(alg->stats));
1059 }
1060 EXPORT_SYMBOL_GPL(crypto_stats_init);
1061
1062 void crypto_stats_get(struct crypto_alg *alg)
1063 {
1064         crypto_alg_get(alg);
1065 }
1066 EXPORT_SYMBOL_GPL(crypto_stats_get);
1067
1068 void crypto_stats_aead_encrypt(unsigned int cryptlen, struct crypto_alg *alg,
1069                                int ret)
1070 {
1071         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1072                 atomic64_inc(&alg->stats.aead.err_cnt);
1073         } else {
1074                 atomic64_inc(&alg->stats.aead.encrypt_cnt);
1075                 atomic64_add(cryptlen, &alg->stats.aead.encrypt_tlen);
1076         }
1077         crypto_alg_put(alg);
1078 }
1079 EXPORT_SYMBOL_GPL(crypto_stats_aead_encrypt);
1080
1081 void crypto_stats_aead_decrypt(unsigned int cryptlen, struct crypto_alg *alg,
1082                                int ret)
1083 {
1084         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1085                 atomic64_inc(&alg->stats.aead.err_cnt);
1086         } else {
1087                 atomic64_inc(&alg->stats.aead.decrypt_cnt);
1088                 atomic64_add(cryptlen, &alg->stats.aead.decrypt_tlen);
1089         }
1090         crypto_alg_put(alg);
1091 }
1092 EXPORT_SYMBOL_GPL(crypto_stats_aead_decrypt);
1093
1094 void crypto_stats_akcipher_encrypt(unsigned int src_len, int ret,
1095                                    struct crypto_alg *alg)
1096 {
1097         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1098                 atomic64_inc(&alg->stats.akcipher.err_cnt);
1099         } else {
1100                 atomic64_inc(&alg->stats.akcipher.encrypt_cnt);
1101                 atomic64_add(src_len, &alg->stats.akcipher.encrypt_tlen);
1102         }
1103         crypto_alg_put(alg);
1104 }
1105 EXPORT_SYMBOL_GPL(crypto_stats_akcipher_encrypt);
1106
1107 void crypto_stats_akcipher_decrypt(unsigned int src_len, int ret,
1108                                    struct crypto_alg *alg)
1109 {
1110         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1111                 atomic64_inc(&alg->stats.akcipher.err_cnt);
1112         } else {
1113                 atomic64_inc(&alg->stats.akcipher.decrypt_cnt);
1114                 atomic64_add(src_len, &alg->stats.akcipher.decrypt_tlen);
1115         }
1116         crypto_alg_put(alg);
1117 }
1118 EXPORT_SYMBOL_GPL(crypto_stats_akcipher_decrypt);
1119
1120 void crypto_stats_akcipher_sign(int ret, struct crypto_alg *alg)
1121 {
1122         if (ret && ret != -EINPROGRESS && ret != -EBUSY)
1123                 atomic64_inc(&alg->stats.akcipher.err_cnt);
1124         else
1125                 atomic64_inc(&alg->stats.akcipher.sign_cnt);
1126         crypto_alg_put(alg);
1127 }
1128 EXPORT_SYMBOL_GPL(crypto_stats_akcipher_sign);
1129
1130 void crypto_stats_akcipher_verify(int ret, struct crypto_alg *alg)
1131 {
1132         if (ret && ret != -EINPROGRESS && ret != -EBUSY)
1133                 atomic64_inc(&alg->stats.akcipher.err_cnt);
1134         else
1135                 atomic64_inc(&alg->stats.akcipher.verify_cnt);
1136         crypto_alg_put(alg);
1137 }
1138 EXPORT_SYMBOL_GPL(crypto_stats_akcipher_verify);
1139
1140 void crypto_stats_compress(unsigned int slen, int ret, struct crypto_alg *alg)
1141 {
1142         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1143                 atomic64_inc(&alg->stats.compress.err_cnt);
1144         } else {
1145                 atomic64_inc(&alg->stats.compress.compress_cnt);
1146                 atomic64_add(slen, &alg->stats.compress.compress_tlen);
1147         }
1148         crypto_alg_put(alg);
1149 }
1150 EXPORT_SYMBOL_GPL(crypto_stats_compress);
1151
1152 void crypto_stats_decompress(unsigned int slen, int ret, struct crypto_alg *alg)
1153 {
1154         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1155                 atomic64_inc(&alg->stats.compress.err_cnt);
1156         } else {
1157                 atomic64_inc(&alg->stats.compress.decompress_cnt);
1158                 atomic64_add(slen, &alg->stats.compress.decompress_tlen);
1159         }
1160         crypto_alg_put(alg);
1161 }
1162 EXPORT_SYMBOL_GPL(crypto_stats_decompress);
1163
1164 void crypto_stats_ahash_update(unsigned int nbytes, int ret,
1165                                struct crypto_alg *alg)
1166 {
1167         if (ret && ret != -EINPROGRESS && ret != -EBUSY)
1168                 atomic64_inc(&alg->stats.hash.err_cnt);
1169         else
1170                 atomic64_add(nbytes, &alg->stats.hash.hash_tlen);
1171         crypto_alg_put(alg);
1172 }
1173 EXPORT_SYMBOL_GPL(crypto_stats_ahash_update);
1174
1175 void crypto_stats_ahash_final(unsigned int nbytes, int ret,
1176                               struct crypto_alg *alg)
1177 {
1178         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1179                 atomic64_inc(&alg->stats.hash.err_cnt);
1180         } else {
1181                 atomic64_inc(&alg->stats.hash.hash_cnt);
1182                 atomic64_add(nbytes, &alg->stats.hash.hash_tlen);
1183         }
1184         crypto_alg_put(alg);
1185 }
1186 EXPORT_SYMBOL_GPL(crypto_stats_ahash_final);
1187
1188 void crypto_stats_kpp_set_secret(struct crypto_alg *alg, int ret)
1189 {
1190         if (ret)
1191                 atomic64_inc(&alg->stats.kpp.err_cnt);
1192         else
1193                 atomic64_inc(&alg->stats.kpp.setsecret_cnt);
1194         crypto_alg_put(alg);
1195 }
1196 EXPORT_SYMBOL_GPL(crypto_stats_kpp_set_secret);
1197
1198 void crypto_stats_kpp_generate_public_key(struct crypto_alg *alg, int ret)
1199 {
1200         if (ret)
1201                 atomic64_inc(&alg->stats.kpp.err_cnt);
1202         else
1203                 atomic64_inc(&alg->stats.kpp.generate_public_key_cnt);
1204         crypto_alg_put(alg);
1205 }
1206 EXPORT_SYMBOL_GPL(crypto_stats_kpp_generate_public_key);
1207
1208 void crypto_stats_kpp_compute_shared_secret(struct crypto_alg *alg, int ret)
1209 {
1210         if (ret)
1211                 atomic64_inc(&alg->stats.kpp.err_cnt);
1212         else
1213                 atomic64_inc(&alg->stats.kpp.compute_shared_secret_cnt);
1214         crypto_alg_put(alg);
1215 }
1216 EXPORT_SYMBOL_GPL(crypto_stats_kpp_compute_shared_secret);
1217
1218 void crypto_stats_rng_seed(struct crypto_alg *alg, int ret)
1219 {
1220         if (ret && ret != -EINPROGRESS && ret != -EBUSY)
1221                 atomic64_inc(&alg->stats.rng.err_cnt);
1222         else
1223                 atomic64_inc(&alg->stats.rng.seed_cnt);
1224         crypto_alg_put(alg);
1225 }
1226 EXPORT_SYMBOL_GPL(crypto_stats_rng_seed);
1227
1228 void crypto_stats_rng_generate(struct crypto_alg *alg, unsigned int dlen,
1229                                int ret)
1230 {
1231         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1232                 atomic64_inc(&alg->stats.rng.err_cnt);
1233         } else {
1234                 atomic64_inc(&alg->stats.rng.generate_cnt);
1235                 atomic64_add(dlen, &alg->stats.rng.generate_tlen);
1236         }
1237         crypto_alg_put(alg);
1238 }
1239 EXPORT_SYMBOL_GPL(crypto_stats_rng_generate);
1240
1241 void crypto_stats_skcipher_encrypt(unsigned int cryptlen, int ret,
1242                                    struct crypto_alg *alg)
1243 {
1244         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1245                 atomic64_inc(&alg->stats.cipher.err_cnt);
1246         } else {
1247                 atomic64_inc(&alg->stats.cipher.encrypt_cnt);
1248                 atomic64_add(cryptlen, &alg->stats.cipher.encrypt_tlen);
1249         }
1250         crypto_alg_put(alg);
1251 }
1252 EXPORT_SYMBOL_GPL(crypto_stats_skcipher_encrypt);
1253
1254 void crypto_stats_skcipher_decrypt(unsigned int cryptlen, int ret,
1255                                    struct crypto_alg *alg)
1256 {
1257         if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
1258                 atomic64_inc(&alg->stats.cipher.err_cnt);
1259         } else {
1260                 atomic64_inc(&alg->stats.cipher.decrypt_cnt);
1261                 atomic64_add(cryptlen, &alg->stats.cipher.decrypt_tlen);
1262         }
1263         crypto_alg_put(alg);
1264 }
1265 EXPORT_SYMBOL_GPL(crypto_stats_skcipher_decrypt);
1266 #endif
1267
1268 static void __init crypto_start_tests(void)
1269 {
1270         for (;;) {
1271                 struct crypto_larval *larval = NULL;
1272                 struct crypto_alg *q;
1273
1274                 down_write(&crypto_alg_sem);
1275
1276                 list_for_each_entry(q, &crypto_alg_list, cra_list) {
1277                         struct crypto_larval *l;
1278
1279                         if (!crypto_is_larval(q))
1280                                 continue;
1281
1282                         l = (void *)q;
1283
1284                         if (!crypto_is_test_larval(l))
1285                                 continue;
1286
1287                         if (l->test_started)
1288                                 continue;
1289
1290                         l->test_started = true;
1291                         larval = l;
1292                         break;
1293                 }
1294
1295                 up_write(&crypto_alg_sem);
1296
1297                 if (!larval)
1298                         break;
1299
1300                 crypto_wait_for_test(larval);
1301         }
1302
1303         static_branch_enable(&crypto_boot_test_finished);
1304 }
1305
1306 static int __init crypto_algapi_init(void)
1307 {
1308         crypto_init_proc();
1309         crypto_start_tests();
1310         return 0;
1311 }
1312
1313 static void __exit crypto_algapi_exit(void)
1314 {
1315         crypto_exit_proc();
1316 }
1317
1318 /*
1319  * We run this at late_initcall so that all the built-in algorithms
1320  * have had a chance to register themselves first.
1321  */
1322 late_initcall(crypto_algapi_init);
1323 module_exit(crypto_algapi_exit);
1324
1325 MODULE_LICENSE("GPL");
1326 MODULE_DESCRIPTION("Cryptographic algorithms API");