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