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