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         bool test_started = false;
 411         LIST_HEAD(algs_to_put);
 412         int err;
 413
 414         alg->cra_flags &= ~CRYPTO_ALG_DEAD;
 415         err = crypto_check_alg(alg);
 416         if (err)
 417                 return err;
 418
 419         down_write(&crypto_alg_sem);
 420         larval = __crypto_register_alg(alg, &algs_to_put);
 421         if (!IS_ERR_OR_NULL(larval)) {
 422                 test_started = crypto_boot_test_finished();
 423                 larval->test_started = test_started;
 424         }
 425         up_write(&crypto_alg_sem);
 426
 427         if (IS_ERR(larval))
 428                 return PTR_ERR(larval);
 429
 430         if (test_started)
 431                 crypto_schedule_test(larval);
 432         else
 433                 crypto_remove_final(&algs_to_put);
 434
 435         return 0;
 436 }
 437 EXPORT_SYMBOL_GPL(crypto_register_alg);
 438
 439 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
 440 {
 441         if (unlikely(list_empty(&alg->cra_list)))
 442                 return -ENOENT;
 443
 444         alg->cra_flags |= CRYPTO_ALG_DEAD;
 445
 446         list_del_init(&alg->cra_list);
 447         crypto_remove_spawns(alg, list, NULL);
 448
 449         return 0;
 450 }
 451
 452 void crypto_unregister_alg(struct crypto_alg *alg)
 453 {
 454         int ret;
 455         LIST_HEAD(list);
 456
 457         down_write(&crypto_alg_sem);
 458         ret = crypto_remove_alg(alg, &list);
 459         up_write(&crypto_alg_sem);
 460
 461         if (WARN(ret, "Algorithm %s is not registered", alg->cra_driver_name))
 462                 return;
 463
 464         if (WARN_ON(refcount_read(&alg->cra_refcnt) != 1))
 465                 return;
 466
 467         if (alg->cra_destroy)
 468                 alg->cra_destroy(alg);
 469
 470         crypto_remove_final(&list);
 471 }
 472 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
 473
 474 int crypto_register_algs(struct crypto_alg *algs, int count)
 475 {
 476         int i, ret;
 477
 478         for (i = 0; i < count; i++) {
 479                 ret = crypto_register_alg(&algs[i]);
 480                 if (ret)
 481                         goto err;
 482         }
 483
 484         return 0;
 485
 486 err:
 487         for (--i; i >= 0; --i)
 488                 crypto_unregister_alg(&algs[i]);
 489
 490         return ret;
 491 }
 492 EXPORT_SYMBOL_GPL(crypto_register_algs);
 493
 494 void crypto_unregister_algs(struct crypto_alg *algs, int count)
 495 {
 496         int i;
 497
 498         for (i = 0; i < count; i++)
 499                 crypto_unregister_alg(&algs[i]);
 500 }
 501 EXPORT_SYMBOL_GPL(crypto_unregister_algs);
 502
 503 int crypto_register_template(struct crypto_template *tmpl)
 504 {
 505         struct crypto_template *q;
 506         int err = -EEXIST;
 507
 508         down_write(&crypto_alg_sem);
 509
 510         crypto_check_module_sig(tmpl->module);
 511
 512         list_for_each_entry(q, &crypto_template_list, list) {
 513                 if (q == tmpl)
 514                         goto out;
 515         }
 516
 517         list_add(&tmpl->list, &crypto_template_list);
 518         err = 0;
 519 out:
 520         up_write(&crypto_alg_sem);
 521         return err;
 522 }
 523 EXPORT_SYMBOL_GPL(crypto_register_template);
 524
 525 int crypto_register_templates(struct crypto_template *tmpls, int count)
 526 {
 527         int i, err;
 528
 529         for (i = 0; i < count; i++) {
 530                 err = crypto_register_template(&tmpls[i]);
 531                 if (err)
 532                         goto out;
 533         }
 534         return 0;
 535
 536 out:
 537         for (--i; i >= 0; --i)
 538                 crypto_unregister_template(&tmpls[i]);
 539         return err;
 540 }
 541 EXPORT_SYMBOL_GPL(crypto_register_templates);
 542
 543 void crypto_unregister_template(struct crypto_template *tmpl)
 544 {
 545         struct crypto_instance *inst;
 546         struct hlist_node *n;
 547         struct hlist_head *list;
 548         LIST_HEAD(users);
 549
 550         down_write(&crypto_alg_sem);
 551
 552         BUG_ON(list_empty(&tmpl->list));
 553         list_del_init(&tmpl->list);
 554
 555         list = &tmpl->instances;
 556         hlist_for_each_entry(inst, list, list) {
 557                 int err = crypto_remove_alg(&inst->alg, &users);
 558
 559                 BUG_ON(err);
 560         }
 561
 562         up_write(&crypto_alg_sem);
 563
 564         hlist_for_each_entry_safe(inst, n, list, list) {
 565                 BUG_ON(refcount_read(&inst->alg.cra_refcnt) != 1);
 566                 crypto_free_instance(inst);
 567         }
 568         crypto_remove_final(&users);
 569 }
 570 EXPORT_SYMBOL_GPL(crypto_unregister_template);
 571
 572 void crypto_unregister_templates(struct crypto_template *tmpls, int count)
 573 {
 574         int i;
 575
 576         for (i = count - 1; i >= 0; --i)
 577                 crypto_unregister_template(&tmpls[i]);
 578 }
 579 EXPORT_SYMBOL_GPL(crypto_unregister_templates);
 580
 581 static struct crypto_template *__crypto_lookup_template(const char *name)
 582 {
 583         struct crypto_template *q, *tmpl = NULL;
 584
 585         down_read(&crypto_alg_sem);
 586         list_for_each_entry(q, &crypto_template_list, list) {
 587                 if (strcmp(q->name, name))
 588                         continue;
 589                 if (unlikely(!crypto_tmpl_get(q)))
 590                         continue;
 591
 592                 tmpl = q;
 593                 break;
 594         }
 595         up_read(&crypto_alg_sem);
 596
 597         return tmpl;
 598 }
 599
 600 struct crypto_template *crypto_lookup_template(const char *name)
 601 {
 602         return try_then_request_module(__crypto_lookup_template(name),
 603                                        "crypto-%s", name);
 604 }
 605 EXPORT_SYMBOL_GPL(crypto_lookup_template);
 606
 607 int crypto_register_instance(struct crypto_template *tmpl,
 608                              struct crypto_instance *inst)
 609 {
 610         struct crypto_larval *larval;
 611         struct crypto_spawn *spawn;
 612         u32 fips_internal = 0;
 613         LIST_HEAD(algs_to_put);
 614         int err;
 615
 616         err = crypto_check_alg(&inst->alg);
 617         if (err)
 618                 return err;
 619
 620         inst->alg.cra_module = tmpl->module;
 621         inst->alg.cra_flags |= CRYPTO_ALG_INSTANCE;
 622
 623         down_write(&crypto_alg_sem);
 624
 625         larval = ERR_PTR(-EAGAIN);
 626         for (spawn = inst->spawns; spawn;) {
 627                 struct crypto_spawn *next;
 628
 629                 if (spawn->dead)
 630                         goto unlock;
 631
 632                 next = spawn->next;
 633                 spawn->inst = inst;
 634                 spawn->registered = true;
 635
 636                 fips_internal |= spawn->alg->cra_flags;
 637
 638                 crypto_mod_put(spawn->alg);
 639
 640                 spawn = next;
 641         }
 642
 643         inst->alg.cra_flags |= (fips_internal & CRYPTO_ALG_FIPS_INTERNAL);
 644
 645         larval = __crypto_register_alg(&inst->alg, &algs_to_put);
 646         if (IS_ERR(larval))
 647                 goto unlock;
 648         else if (larval)
 649                 larval->test_started = true;
 650
 651         hlist_add_head(&inst->list, &tmpl->instances);
 652         inst->tmpl = tmpl;
 653
 654 unlock:
 655         up_write(&crypto_alg_sem);
 656
 657         if (IS_ERR(larval))
 658                 return PTR_ERR(larval);
 659
 660         if (larval)
 661                 crypto_schedule_test(larval);
 662         else
 663                 crypto_remove_final(&algs_to_put);
 664
 665         return 0;
 666 }
 667 EXPORT_SYMBOL_GPL(crypto_register_instance);
 668
 669 void crypto_unregister_instance(struct crypto_instance *inst)
 670 {
 671         LIST_HEAD(list);
 672
 673         down_write(&crypto_alg_sem);
 674
 675         crypto_remove_spawns(&inst->alg, &list, NULL);
 676         crypto_remove_instance(inst, &list);
 677
 678         up_write(&crypto_alg_sem);
 679
 680         crypto_remove_final(&list);
 681 }
 682 EXPORT_SYMBOL_GPL(crypto_unregister_instance);
 683
 684 int crypto_grab_spawn(struct crypto_spawn *spawn, struct crypto_instance *inst,
 685                       const char *name, u32 type, u32 mask)
 686 {
 687         struct crypto_alg *alg;
 688         int err = -EAGAIN;
 689
 690         if (WARN_ON_ONCE(inst == NULL))
 691                 return -EINVAL;
 692
 693         /* Allow the result of crypto_attr_alg_name() to be passed directly */
 694         if (IS_ERR(name))
 695                 return PTR_ERR(name);
 696
 697         alg = crypto_find_alg(name, spawn->frontend,
 698                               type | CRYPTO_ALG_FIPS_INTERNAL, mask);
 699         if (IS_ERR(alg))
 700                 return PTR_ERR(alg);
 701
 702         down_write(&crypto_alg_sem);
 703         if (!crypto_is_moribund(alg)) {
 704                 list_add(&spawn->list, &alg->cra_users);
 705                 spawn->alg = alg;
 706                 spawn->mask = mask;
 707                 spawn->next = inst->spawns;
 708                 inst->spawns = spawn;
 709                 inst->alg.cra_flags |=
 710                         (alg->cra_flags & CRYPTO_ALG_INHERITED_FLAGS);
 711                 err = 0;
 712         }
 713         up_write(&crypto_alg_sem);
 714         if (err)
 715                 crypto_mod_put(alg);
 716         return err;
 717 }
 718 EXPORT_SYMBOL_GPL(crypto_grab_spawn);
 719
 720 void crypto_drop_spawn(struct crypto_spawn *spawn)
 721 {
 722         if (!spawn->alg) /* not yet initialized? */
 723                 return;
 724
 725         down_write(&crypto_alg_sem);
 726         if (!spawn->dead)
 727                 list_del(&spawn->list);
 728         up_write(&crypto_alg_sem);
 729
 730         if (!spawn->registered)
 731                 crypto_mod_put(spawn->alg);
 732 }
 733 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
 734
 735 static struct crypto_alg *crypto_spawn_alg(struct crypto_spawn *spawn)
 736 {
 737         struct crypto_alg *alg = ERR_PTR(-EAGAIN);
 738         struct crypto_alg *target;
 739         bool shoot = false;
 740
 741         down_read(&crypto_alg_sem);
 742         if (!spawn->dead) {
 743                 alg = spawn->alg;
 744                 if (!crypto_mod_get(alg)) {
 745                         target = crypto_alg_get(alg);
 746                         shoot = true;
 747                         alg = ERR_PTR(-EAGAIN);
 748                 }
 749         }
 750         up_read(&crypto_alg_sem);
 751
 752         if (shoot) {
 753                 crypto_shoot_alg(target);
 754                 crypto_alg_put(target);
 755         }
 756
 757         return alg;
 758 }
 759
 760 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
 761                                     u32 mask)
 762 {
 763         struct crypto_alg *alg;
 764         struct crypto_tfm *tfm;
 765
 766         alg = crypto_spawn_alg(spawn);
 767         if (IS_ERR(alg))
 768                 return ERR_CAST(alg);
 769
 770         tfm = ERR_PTR(-EINVAL);
 771         if (unlikely((alg->cra_flags ^ type) & mask))
 772                 goto out_put_alg;
 773
 774         tfm = __crypto_alloc_tfm(alg, type, mask);
 775         if (IS_ERR(tfm))
 776                 goto out_put_alg;
 777
 778         return tfm;
 779
 780 out_put_alg:
 781         crypto_mod_put(alg);
 782         return tfm;
 783 }
 784 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
 785
 786 void *crypto_spawn_tfm2(struct crypto_spawn *spawn)
 787 {
 788         struct crypto_alg *alg;
 789         struct crypto_tfm *tfm;
 790
 791         alg = crypto_spawn_alg(spawn);
 792         if (IS_ERR(alg))
 793                 return ERR_CAST(alg);
 794
 795         tfm = crypto_create_tfm(alg, spawn->frontend);
 796         if (IS_ERR(tfm))
 797                 goto out_put_alg;
 798
 799         return tfm;
 800
 801 out_put_alg:
 802         crypto_mod_put(alg);
 803         return tfm;
 804 }
 805 EXPORT_SYMBOL_GPL(crypto_spawn_tfm2);
 806
 807 int crypto_register_notifier(struct notifier_block *nb)
 808 {
 809         return blocking_notifier_chain_register(&crypto_chain, nb);
 810 }
 811 EXPORT_SYMBOL_GPL(crypto_register_notifier);
 812
 813 int crypto_unregister_notifier(struct notifier_block *nb)
 814 {
 815         return blocking_notifier_chain_unregister(&crypto_chain, nb);
 816 }
 817 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
 818
 819 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
 820 {
 821         struct rtattr *rta = tb[0];
 822         struct crypto_attr_type *algt;
 823
 824         if (!rta)
 825                 return ERR_PTR(-ENOENT);
 826         if (RTA_PAYLOAD(rta) < sizeof(*algt))
 827                 return ERR_PTR(-EINVAL);
 828         if (rta->rta_type != CRYPTOA_TYPE)
 829                 return ERR_PTR(-EINVAL);
 830
 831         algt = RTA_DATA(rta);
 832
 833         return algt;
 834 }
 835 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
 836
 837 /**
 838  * crypto_check_attr_type() - check algorithm type and compute inherited mask
 839  * @tb: the template parameters
 840  * @type: the algorithm type the template would be instantiated as
 841  * @mask_ret: (output) the mask that should be passed to crypto_grab_*()
 842  *            to restrict the flags of any inner algorithms
 843  *
 844  * Validate that the algorithm type the user requested is compatible with the
 845  * one the template would actually be instantiated as.  E.g., if the user is
 846  * doing crypto_alloc_shash("cbc(aes)", ...), this would return an error because
 847  * the "cbc" template creates an "skcipher" algorithm, not an "shash" algorithm.
 848  *
 849  * Also compute the mask to use to restrict the flags of any inner algorithms.
 850  *
 851  * Return: 0 on success; -errno on failure
 852  */
 853 int crypto_check_attr_type(struct rtattr **tb, u32 type, u32 *mask_ret)
 854 {
 855         struct crypto_attr_type *algt;
 856
 857         algt = crypto_get_attr_type(tb);
 858         if (IS_ERR(algt))
 859                 return PTR_ERR(algt);
 860
 861         if ((algt->type ^ type) & algt->mask)
 862                 return -EINVAL;
 863
 864         *mask_ret = crypto_algt_inherited_mask(algt);
 865         return 0;
 866 }
 867 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
 868
 869 const char *crypto_attr_alg_name(struct rtattr *rta)
 870 {
 871         struct crypto_attr_alg *alga;
 872
 873         if (!rta)
 874                 return ERR_PTR(-ENOENT);
 875         if (RTA_PAYLOAD(rta) < sizeof(*alga))
 876                 return ERR_PTR(-EINVAL);
 877         if (rta->rta_type != CRYPTOA_ALG)
 878                 return ERR_PTR(-EINVAL);
 879
 880         alga = RTA_DATA(rta);
 881         alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
 882
 883         return alga->name;
 884 }
 885 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
 886
 887 int crypto_inst_setname(struct crypto_instance *inst, const char *name,
 888                         struct crypto_alg *alg)
 889 {
 890         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
 891                      alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
 892                 return -ENAMETOOLONG;
 893
 894         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
 895                      name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 896                 return -ENAMETOOLONG;
 897
 898         return 0;
 899 }
 900 EXPORT_SYMBOL_GPL(crypto_inst_setname);
 901
 902 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
 903 {
 904         INIT_LIST_HEAD(&queue->list);
 905         queue->backlog = &queue->list;
 906         queue->qlen = 0;
 907         queue->max_qlen = max_qlen;
 908 }
 909 EXPORT_SYMBOL_GPL(crypto_init_queue);
 910
 911 int crypto_enqueue_request(struct crypto_queue *queue,
 912                            struct crypto_async_request *request)
 913 {
 914         int err = -EINPROGRESS;
 915
 916         if (unlikely(queue->qlen >= queue->max_qlen)) {
 917                 if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) {
 918                         err = -ENOSPC;
 919                         goto out;
 920                 }
 921                 err = -EBUSY;
 922                 if (queue->backlog == &queue->list)
 923                         queue->backlog = &request->list;
 924         }
 925
 926         queue->qlen++;
 927         list_add_tail(&request->list, &queue->list);
 928
 929 out:
 930         return err;
 931 }
 932 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
 933
 934 void crypto_enqueue_request_head(struct crypto_queue *queue,
 935                                  struct crypto_async_request *request)
 936 {
 937         if (unlikely(queue->qlen >= queue->max_qlen))
 938                 queue->backlog = queue->backlog->prev;
 939
 940         queue->qlen++;
 941         list_add(&request->list, &queue->list);
 942 }
 943 EXPORT_SYMBOL_GPL(crypto_enqueue_request_head);
 944
 945 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
 946 {
 947         struct list_head *request;
 948
 949         if (unlikely(!queue->qlen))
 950                 return NULL;
 951
 952         queue->qlen--;
 953
 954         if (queue->backlog != &queue->list)
 955                 queue->backlog = queue->backlog->next;
 956
 957         request = queue->list.next;
 958         list_del(request);
 959
 960         return list_entry(request, struct crypto_async_request, list);
 961 }
 962 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
 963
 964 static inline void crypto_inc_byte(u8 *a, unsigned int size)
 965 {
 966         u8 *b = (a + size);
 967         u8 c;
 968
 969         for (; size; size--) {
 970                 c = *--b + 1;
 971                 *b = c;
 972                 if (c)
 973                         break;
 974         }
 975 }
 976
 977 void crypto_inc(u8 *a, unsigned int size)
 978 {
 979         __be32 *b = (__be32 *)(a + size);
 980         u32 c;
 981
 982         if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ||
 983             IS_ALIGNED((unsigned long)b, __alignof__(*b)))
 984                 for (; size >= 4; size -= 4) {
 985                         c = be32_to_cpu(*--b) + 1;
 986                         *b = cpu_to_be32(c);
 987                         if (likely(c))
 988                                 return;
 989                 }
 990
 991         crypto_inc_byte(a, size);
 992 }
 993 EXPORT_SYMBOL_GPL(crypto_inc);
 994
 995 unsigned int crypto_alg_extsize(struct crypto_alg *alg)
 996 {
 997         return alg->cra_ctxsize +
 998                (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));
 999 }
1000 EXPORT_SYMBOL_GPL(crypto_alg_extsize);
1001
1002 int crypto_type_has_alg(const char *name, const struct crypto_type *frontend,
1003                         u32 type, u32 mask)
1004 {
1005         int ret = 0;
1006         struct crypto_alg *alg = crypto_find_alg(name, frontend, type, mask);
1007
1008         if (!IS_ERR(alg)) {
1009                 crypto_mod_put(alg);
1010                 ret = 1;
1011         }
1012
1013         return ret;
1014 }
1015 EXPORT_SYMBOL_GPL(crypto_type_has_alg);
1016
1017 static void __init crypto_start_tests(void)
1018 {
1019         if (!IS_BUILTIN(CONFIG_CRYPTO_ALGAPI))
1020                 return;
1021
1022         if (IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS))
1023                 return;
1024
1025         set_crypto_boot_test_finished();
1026
1027         for (;;) {
1028                 struct crypto_larval *larval = NULL;
1029                 struct crypto_alg *q;
1030
1031                 down_write(&crypto_alg_sem);
1032
1033                 list_for_each_entry(q, &crypto_alg_list, cra_list) {
1034                         struct crypto_larval *l;
1035
1036                         if (!crypto_is_larval(q))
1037                                 continue;
1038
1039                         l = (void *)q;
1040
1041                         if (!crypto_is_test_larval(l))
1042                                 continue;
1043
1044                         if (l->test_started)
1045                                 continue;
1046
1047                         l->test_started = true;
1048                         larval = l;
1049                         break;
1050                 }
1051
1052                 up_write(&crypto_alg_sem);
1053
1054                 if (!larval)
1055                         break;
1056
1057                 crypto_schedule_test(larval);
1058         }
1059 }
1060
1061 static int __init crypto_algapi_init(void)
1062 {
1063         crypto_init_proc();
1064         crypto_start_tests();
1065         return 0;
1066 }
1067
1068 static void __exit crypto_algapi_exit(void)
1069 {
1070         crypto_exit_proc();
1071 }
1072
1073 /*
1074  * We run this at late_initcall so that all the built-in algorithms
1075  * have had a chance to register themselves first.
1076  */
1077 late_initcall(crypto_algapi_init);
1078 module_exit(crypto_algapi_exit);
1079
1080 MODULE_LICENSE("GPL");
1081 MODULE_DESCRIPTION("Cryptographic algorithms API");
1082 MODULE_SOFTDEP("pre: cryptomgr");