crypto/algapi.c

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