crypto/algapi.c

   1 /*
   2  * Cryptographic API for algorithms (i.e., low-level API).
   3  *
   4  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <linux/err.h>
  14 #include <linux/errno.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/list.h>
  18 #include <linux/module.h>
  19 #include <linux/rtnetlink.h>
  20 #include <linux/string.h>
  21
  22 #include "internal.h"
  23
  24 static LIST_HEAD(crypto_template_list);
  25
  26 void crypto_larval_error(const char *name, u32 type, u32 mask)
  27 {
  28         struct crypto_alg *alg;
  29
  30         down_read(&crypto_alg_sem);
  31         alg = __crypto_alg_lookup(name, type, mask);
  32         up_read(&crypto_alg_sem);
  33
  34         if (alg) {
  35                 if (crypto_is_larval(alg)) {
  36                         struct crypto_larval *larval = (void *)alg;
  37                         complete_all(&larval->completion);
  38                 }
  39                 crypto_mod_put(alg);
  40         }
  41 }
  42 EXPORT_SYMBOL_GPL(crypto_larval_error);
  43
  44 static inline int crypto_set_driver_name(struct crypto_alg *alg)
  45 {
  46         static const char suffix[] = "-generic";
  47         char *driver_name = alg->cra_driver_name;
  48         int len;
  49
  50         if (*driver_name)
  51                 return 0;
  52
  53         len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
  54         if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
  55                 return -ENAMETOOLONG;
  56
  57         memcpy(driver_name + len, suffix, sizeof(suffix));
  58         return 0;
  59 }
  60
  61 static int crypto_check_alg(struct crypto_alg *alg)
  62 {
  63         if (alg->cra_alignmask & (alg->cra_alignmask + 1))
  64                 return -EINVAL;
  65
  66         if (alg->cra_blocksize > PAGE_SIZE / 8)
  67                 return -EINVAL;
  68
  69         if (alg->cra_priority < 0)
  70                 return -EINVAL;
  71
  72         return crypto_set_driver_name(alg);
  73 }
  74
  75 static void crypto_destroy_instance(struct crypto_alg *alg)
  76 {
  77         struct crypto_instance *inst = (void *)alg;
  78         struct crypto_template *tmpl = inst->tmpl;
  79
  80         tmpl->free(inst);
  81         crypto_tmpl_put(tmpl);
  82 }
  83
  84 static void crypto_remove_spawn(struct crypto_spawn *spawn,
  85                                 struct list_head *list,
  86                                 struct list_head *secondary_spawns)
  87 {
  88         struct crypto_instance *inst = spawn->inst;
  89         struct crypto_template *tmpl = inst->tmpl;
  90
  91         list_del_init(&spawn->list);
  92         spawn->alg = NULL;
  93
  94         if (crypto_is_dead(&inst->alg))
  95                 return;
  96
  97         inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
  98         if (hlist_unhashed(&inst->list))
  99                 return;
 100
 101         if (!tmpl || !crypto_tmpl_get(tmpl))
 102                 return;
 103
 104         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
 105         list_move(&inst->alg.cra_list, list);
 106         hlist_del(&inst->list);
 107         inst->alg.cra_destroy = crypto_destroy_instance;
 108
 109         list_splice(&inst->alg.cra_users, secondary_spawns);
 110 }
 111
 112 static void crypto_remove_spawns(struct list_head *spawns,
 113                                  struct list_head *list, u32 new_type)
 114 {
 115         struct crypto_spawn *spawn, *n;
 116         LIST_HEAD(secondary_spawns);
 117
 118         list_for_each_entry_safe(spawn, n, spawns, list) {
 119                 if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
 120                         continue;
 121
 122                 crypto_remove_spawn(spawn, list, &secondary_spawns);
 123         }
 124
 125         while (!list_empty(&secondary_spawns)) {
 126                 list_for_each_entry_safe(spawn, n, &secondary_spawns, list)
 127                         crypto_remove_spawn(spawn, list, &secondary_spawns);
 128         }
 129 }
 130
 131 static int __crypto_register_alg(struct crypto_alg *alg,
 132                                  struct list_head *list)
 133 {
 134         struct crypto_alg *q;
 135         int ret = -EAGAIN;
 136
 137         if (crypto_is_dead(alg))
 138                 goto out;
 139
 140         INIT_LIST_HEAD(&alg->cra_users);
 141
 142         ret = -EEXIST;
 143
 144         atomic_set(&alg->cra_refcnt, 1);
 145         list_for_each_entry(q, &crypto_alg_list, cra_list) {
 146                 if (q == alg)
 147                         goto out;
 148
 149                 if (crypto_is_moribund(q))
 150                         continue;
 151
 152                 if (crypto_is_larval(q)) {
 153                         struct crypto_larval *larval = (void *)q;
 154
 155                         /*
 156                          * Check to see if either our generic name or
 157                          * specific name can satisfy the name requested
 158                          * by the larval entry q.
 159                          */
 160                         if (strcmp(alg->cra_name, q->cra_name) &&
 161                             strcmp(alg->cra_driver_name, q->cra_name))
 162                                 continue;
 163
 164                         if (larval->adult)
 165                                 continue;
 166                         if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
 167                                 continue;
 168                         if (!crypto_mod_get(alg))
 169                                 continue;
 170
 171                         larval->adult = alg;
 172                         complete_all(&larval->completion);
 173                         continue;
 174                 }
 175
 176                 if (strcmp(alg->cra_name, q->cra_name))
 177                         continue;
 178
 179                 if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
 180                     q->cra_priority > alg->cra_priority)
 181                         continue;
 182
 183                 crypto_remove_spawns(&q->cra_users, list, alg->cra_flags);
 184         }
 185
 186         list_add(&alg->cra_list, &crypto_alg_list);
 187
 188         crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg);
 189         ret = 0;
 190
 191 out:
 192         return ret;
 193 }
 194
 195 static void crypto_remove_final(struct list_head *list)
 196 {
 197         struct crypto_alg *alg;
 198         struct crypto_alg *n;
 199
 200         list_for_each_entry_safe(alg, n, list, cra_list) {
 201                 list_del_init(&alg->cra_list);
 202                 crypto_alg_put(alg);
 203         }
 204 }
 205
 206 int crypto_register_alg(struct crypto_alg *alg)
 207 {
 208         LIST_HEAD(list);
 209         int err;
 210
 211         err = crypto_check_alg(alg);
 212         if (err)
 213                 return err;
 214
 215         down_write(&crypto_alg_sem);
 216         err = __crypto_register_alg(alg, &list);
 217         up_write(&crypto_alg_sem);
 218
 219         crypto_remove_final(&list);
 220         return err;
 221 }
 222 EXPORT_SYMBOL_GPL(crypto_register_alg);
 223
 224 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
 225 {
 226         if (unlikely(list_empty(&alg->cra_list)))
 227                 return -ENOENT;
 228
 229         alg->cra_flags |= CRYPTO_ALG_DEAD;
 230
 231         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
 232         list_del_init(&alg->cra_list);
 233         crypto_remove_spawns(&alg->cra_users, list, alg->cra_flags);
 234
 235         return 0;
 236 }
 237
 238 int crypto_unregister_alg(struct crypto_alg *alg)
 239 {
 240         int ret;
 241         LIST_HEAD(list);
 242
 243         down_write(&crypto_alg_sem);
 244         ret = crypto_remove_alg(alg, &list);
 245         up_write(&crypto_alg_sem);
 246
 247         if (ret)
 248                 return ret;
 249
 250         BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
 251         if (alg->cra_destroy)
 252                 alg->cra_destroy(alg);
 253
 254         crypto_remove_final(&list);
 255         return 0;
 256 }
 257 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
 258
 259 int crypto_register_template(struct crypto_template *tmpl)
 260 {
 261         struct crypto_template *q;
 262         int err = -EEXIST;
 263
 264         down_write(&crypto_alg_sem);
 265
 266         list_for_each_entry(q, &crypto_template_list, list) {
 267                 if (q == tmpl)
 268                         goto out;
 269         }
 270
 271         list_add(&tmpl->list, &crypto_template_list);
 272         crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
 273         err = 0;
 274 out:
 275         up_write(&crypto_alg_sem);
 276         return err;
 277 }
 278 EXPORT_SYMBOL_GPL(crypto_register_template);
 279
 280 void crypto_unregister_template(struct crypto_template *tmpl)
 281 {
 282         struct crypto_instance *inst;
 283         struct hlist_node *p, *n;
 284         struct hlist_head *list;
 285         LIST_HEAD(users);
 286
 287         down_write(&crypto_alg_sem);
 288
 289         BUG_ON(list_empty(&tmpl->list));
 290         list_del_init(&tmpl->list);
 291
 292         list = &tmpl->instances;
 293         hlist_for_each_entry(inst, p, list, list) {
 294                 int err = crypto_remove_alg(&inst->alg, &users);
 295                 BUG_ON(err);
 296         }
 297
 298         crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
 299
 300         up_write(&crypto_alg_sem);
 301
 302         hlist_for_each_entry_safe(inst, p, n, list, list) {
 303                 BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
 304                 tmpl->free(inst);
 305         }
 306         crypto_remove_final(&users);
 307 }
 308 EXPORT_SYMBOL_GPL(crypto_unregister_template);
 309
 310 static struct crypto_template *__crypto_lookup_template(const char *name)
 311 {
 312         struct crypto_template *q, *tmpl = NULL;
 313
 314         down_read(&crypto_alg_sem);
 315         list_for_each_entry(q, &crypto_template_list, list) {
 316                 if (strcmp(q->name, name))
 317                         continue;
 318                 if (unlikely(!crypto_tmpl_get(q)))
 319                         continue;
 320
 321                 tmpl = q;
 322                 break;
 323         }
 324         up_read(&crypto_alg_sem);
 325
 326         return tmpl;
 327 }
 328
 329 struct crypto_template *crypto_lookup_template(const char *name)
 330 {
 331         return try_then_request_module(__crypto_lookup_template(name), name);
 332 }
 333 EXPORT_SYMBOL_GPL(crypto_lookup_template);
 334
 335 int crypto_register_instance(struct crypto_template *tmpl,
 336                              struct crypto_instance *inst)
 337 {
 338         LIST_HEAD(list);
 339         int err = -EINVAL;
 340
 341         err = crypto_check_alg(&inst->alg);
 342         if (err)
 343                 goto err;
 344
 345         inst->alg.cra_module = tmpl->module;
 346
 347         down_write(&crypto_alg_sem);
 348
 349         err = __crypto_register_alg(&inst->alg, &list);
 350         if (err)
 351                 goto unlock;
 352
 353         hlist_add_head(&inst->list, &tmpl->instances);
 354         inst->tmpl = tmpl;
 355
 356 unlock:
 357         up_write(&crypto_alg_sem);
 358
 359         crypto_remove_final(&list);
 360
 361 err:
 362         return err;
 363 }
 364 EXPORT_SYMBOL_GPL(crypto_register_instance);
 365
 366 int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
 367                       struct crypto_instance *inst, u32 mask)
 368 {
 369         int err = -EAGAIN;
 370
 371         spawn->inst = inst;
 372         spawn->mask = mask;
 373
 374         down_write(&crypto_alg_sem);
 375         if (!crypto_is_moribund(alg)) {
 376                 list_add(&spawn->list, &alg->cra_users);
 377                 spawn->alg = alg;
 378                 err = 0;
 379         }
 380         up_write(&crypto_alg_sem);
 381
 382         return err;
 383 }
 384 EXPORT_SYMBOL_GPL(crypto_init_spawn);
 385
 386 void crypto_drop_spawn(struct crypto_spawn *spawn)
 387 {
 388         down_write(&crypto_alg_sem);
 389         list_del(&spawn->list);
 390         up_write(&crypto_alg_sem);
 391 }
 392 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
 393
 394 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
 395                                     u32 mask)
 396 {
 397         struct crypto_alg *alg;
 398         struct crypto_alg *alg2;
 399         struct crypto_tfm *tfm;
 400
 401         down_read(&crypto_alg_sem);
 402         alg = spawn->alg;
 403         alg2 = alg;
 404         if (alg2)
 405                 alg2 = crypto_mod_get(alg2);
 406         up_read(&crypto_alg_sem);
 407
 408         if (!alg2) {
 409                 if (alg)
 410                         crypto_shoot_alg(alg);
 411                 return ERR_PTR(-EAGAIN);
 412         }
 413
 414         tfm = ERR_PTR(-EINVAL);
 415         if (unlikely((alg->cra_flags ^ type) & mask))
 416                 goto out_put_alg;
 417
 418         tfm = __crypto_alloc_tfm(alg, type, mask);
 419         if (IS_ERR(tfm))
 420                 goto out_put_alg;
 421
 422         return tfm;
 423
 424 out_put_alg:
 425         crypto_mod_put(alg);
 426         return tfm;
 427 }
 428 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
 429
 430 int crypto_register_notifier(struct notifier_block *nb)
 431 {
 432         return blocking_notifier_chain_register(&crypto_chain, nb);
 433 }
 434 EXPORT_SYMBOL_GPL(crypto_register_notifier);
 435
 436 int crypto_unregister_notifier(struct notifier_block *nb)
 437 {
 438         return blocking_notifier_chain_unregister(&crypto_chain, nb);
 439 }
 440 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
 441
 442 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
 443 {
 444         struct rtattr *rta = tb[0];
 445         struct crypto_attr_type *algt;
 446
 447         if (!rta)
 448                 return ERR_PTR(-ENOENT);
 449         if (RTA_PAYLOAD(rta) < sizeof(*algt))
 450                 return ERR_PTR(-EINVAL);
 451         if (rta->rta_type != CRYPTOA_TYPE)
 452                 return ERR_PTR(-EINVAL);
 453
 454         algt = RTA_DATA(rta);
 455
 456         return algt;
 457 }
 458 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
 459
 460 int crypto_check_attr_type(struct rtattr **tb, u32 type)
 461 {
 462         struct crypto_attr_type *algt;
 463
 464         algt = crypto_get_attr_type(tb);
 465         if (IS_ERR(algt))
 466                 return PTR_ERR(algt);
 467
 468         if ((algt->type ^ type) & algt->mask)
 469                 return -EINVAL;
 470
 471         return 0;
 472 }
 473 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
 474
 475 const char *crypto_attr_alg_name(struct rtattr *rta)
 476 {
 477         struct crypto_attr_alg *alga;
 478
 479         if (!rta)
 480                 return ERR_PTR(-ENOENT);
 481         if (RTA_PAYLOAD(rta) < sizeof(*alga))
 482                 return ERR_PTR(-EINVAL);
 483         if (rta->rta_type != CRYPTOA_ALG)
 484                 return ERR_PTR(-EINVAL);
 485
 486         alga = RTA_DATA(rta);
 487         alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
 488
 489         return alga->name;
 490 }
 491 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
 492
 493 struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 494 {
 495         const char *name;
 496         int err;
 497
 498         name = crypto_attr_alg_name(rta);
 499         err = PTR_ERR(name);
 500         if (IS_ERR(name))
 501                 return ERR_PTR(err);
 502
 503         return crypto_alg_mod_lookup(name, type, mask);
 504 }
 505 EXPORT_SYMBOL_GPL(crypto_attr_alg);
 506
 507 int crypto_attr_u32(struct rtattr *rta, u32 *num)
 508 {
 509         struct crypto_attr_u32 *nu32;
 510
 511         if (!rta)
 512                 return -ENOENT;
 513         if (RTA_PAYLOAD(rta) < sizeof(*nu32))
 514                 return -EINVAL;
 515         if (rta->rta_type != CRYPTOA_U32)
 516                 return -EINVAL;
 517
 518         nu32 = RTA_DATA(rta);
 519         *num = nu32->num;
 520
 521         return 0;
 522 }
 523 EXPORT_SYMBOL_GPL(crypto_attr_u32);
 524
 525 struct crypto_instance *crypto_alloc_instance(const char *name,
 526                                               struct crypto_alg *alg)
 527 {
 528         struct crypto_instance *inst;
 529         struct crypto_spawn *spawn;
 530         int err;
 531
 532         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 533         if (!inst)
 534                 return ERR_PTR(-ENOMEM);
 535
 536         err = -ENAMETOOLONG;
 537         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
 538                      alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
 539                 goto err_free_inst;
 540
 541         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
 542                      name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 543                 goto err_free_inst;
 544
 545         spawn = crypto_instance_ctx(inst);
 546         err = crypto_init_spawn(spawn, alg, inst,
 547                                 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
 548
 549         if (err)
 550                 goto err_free_inst;
 551
 552         return inst;
 553
 554 err_free_inst:
 555         kfree(inst);
 556         return ERR_PTR(err);
 557 }
 558 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
 559
 560 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
 561 {
 562         INIT_LIST_HEAD(&queue->list);
 563         queue->backlog = &queue->list;
 564         queue->qlen = 0;
 565         queue->max_qlen = max_qlen;
 566 }
 567 EXPORT_SYMBOL_GPL(crypto_init_queue);
 568
 569 int crypto_enqueue_request(struct crypto_queue *queue,
 570                            struct crypto_async_request *request)
 571 {
 572         int err = -EINPROGRESS;
 573
 574         if (unlikely(queue->qlen >= queue->max_qlen)) {
 575                 err = -EBUSY;
 576                 if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
 577                         goto out;
 578                 if (queue->backlog == &queue->list)
 579                         queue->backlog = &request->list;
 580         }
 581
 582         queue->qlen++;
 583         list_add_tail(&request->list, &queue->list);
 584
 585 out:
 586         return err;
 587 }
 588 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
 589
 590 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
 591 {
 592         struct list_head *request;
 593
 594         if (unlikely(!queue->qlen))
 595                 return NULL;
 596
 597         queue->qlen--;
 598
 599         if (queue->backlog != &queue->list)
 600                 queue->backlog = queue->backlog->next;
 601
 602         request = queue->list.next;
 603         list_del(request);
 604
 605         return list_entry(request, struct crypto_async_request, list);
 606 }
 607 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
 608
 609 int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
 610 {
 611         struct crypto_async_request *req;
 612
 613         list_for_each_entry(req, &queue->list, list) {
 614                 if (req->tfm == tfm)
 615                         return 1;
 616         }
 617
 618         return 0;
 619 }
 620 EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
 621
 622 static inline void crypto_inc_byte(u8 *a, unsigned int size)
 623 {
 624         u8 *b = (a + size);
 625         u8 c;
 626
 627         for (; size; size--) {
 628                 c = *--b + 1;
 629                 *b = c;
 630                 if (c)
 631                         break;
 632         }
 633 }
 634
 635 void crypto_inc(u8 *a, unsigned int size)
 636 {
 637         __be32 *b = (__be32 *)(a + size);
 638         u32 c;
 639
 640         for (; size >= 4; size -= 4) {
 641                 c = be32_to_cpu(*--b) + 1;
 642                 *b = cpu_to_be32(c);
 643                 if (c)
 644                         return;
 645         }
 646
 647         crypto_inc_byte(a, size);
 648 }
 649 EXPORT_SYMBOL_GPL(crypto_inc);
 650
 651 static inline void crypto_xor_byte(u8 *a, const u8 *b, unsigned int size)
 652 {
 653         for (; size; size--)
 654                 *a++ ^= *b++;
 655 }
 656
 657 void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
 658 {
 659         u32 *a = (u32 *)dst;
 660         u32 *b = (u32 *)src;
 661
 662         for (; size >= 4; size -= 4)
 663                 *a++ ^= *b++;
 664
 665         crypto_xor_byte((u8 *)a, (u8 *)b, size);
 666 }
 667 EXPORT_SYMBOL_GPL(crypto_xor);
 668
 669 static int __init crypto_algapi_init(void)
 670 {
 671         crypto_init_proc();
 672         return 0;
 673 }
 674
 675 static void __exit crypto_algapi_exit(void)
 676 {
 677         crypto_exit_proc();
 678 }
 679
 680 module_init(crypto_algapi_init);
 681 module_exit(crypto_algapi_exit);
 682
 683 MODULE_LICENSE("GPL");
 684 MODULE_DESCRIPTION("Cryptographic algorithms API");