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