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