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                         /*
 153                          * Check to see if either our generic name or
 154                          * specific name can satisfy the name requested
 155                          * by the larval entry q.
 156                          */
 157                         if (strcmp(alg->cra_name, q->cra_name) &&
 158                             strcmp(alg->cra_driver_name, q->cra_name))
 159                                 continue;
 160
 161                         if (larval->adult)
 162                                 continue;
 163                         if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
 164                                 continue;
 165                         if (!crypto_mod_get(alg))
 166                                 continue;
 167
 168                         larval->adult = alg;
 169                         complete_all(&larval->completion);
 170                         continue;
 171                 }
 172
 173                 if (strcmp(alg->cra_name, q->cra_name))
 174                         continue;
 175
 176                 if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
 177                     q->cra_priority > alg->cra_priority)
 178                         continue;
 179
 180                 crypto_remove_spawns(&q->cra_users, list, alg->cra_flags);
 181         }
 182
 183         list_add(&alg->cra_list, &crypto_alg_list);
 184
 185         crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg);
 186         ret = 0;
 187
 188 out:
 189         return ret;
 190 }
 191
 192 static void crypto_remove_final(struct list_head *list)
 193 {
 194         struct crypto_alg *alg;
 195         struct crypto_alg *n;
 196
 197         list_for_each_entry_safe(alg, n, list, cra_list) {
 198                 list_del_init(&alg->cra_list);
 199                 crypto_alg_put(alg);
 200         }
 201 }
 202
 203 int crypto_register_alg(struct crypto_alg *alg)
 204 {
 205         LIST_HEAD(list);
 206         int err;
 207
 208         err = crypto_check_alg(alg);
 209         if (err)
 210                 return err;
 211
 212         down_write(&crypto_alg_sem);
 213         err = __crypto_register_alg(alg, &list);
 214         up_write(&crypto_alg_sem);
 215
 216         crypto_remove_final(&list);
 217         return err;
 218 }
 219 EXPORT_SYMBOL_GPL(crypto_register_alg);
 220
 221 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
 222 {
 223         if (unlikely(list_empty(&alg->cra_list)))
 224                 return -ENOENT;
 225
 226         alg->cra_flags |= CRYPTO_ALG_DEAD;
 227
 228         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
 229         list_del_init(&alg->cra_list);
 230         crypto_remove_spawns(&alg->cra_users, list, alg->cra_flags);
 231
 232         return 0;
 233 }
 234
 235 int crypto_unregister_alg(struct crypto_alg *alg)
 236 {
 237         int ret;
 238         LIST_HEAD(list);
 239
 240         down_write(&crypto_alg_sem);
 241         ret = crypto_remove_alg(alg, &list);
 242         up_write(&crypto_alg_sem);
 243
 244         if (ret)
 245                 return ret;
 246
 247         BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
 248         if (alg->cra_destroy)
 249                 alg->cra_destroy(alg);
 250
 251         crypto_remove_final(&list);
 252         return 0;
 253 }
 254 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
 255
 256 int crypto_register_template(struct crypto_template *tmpl)
 257 {
 258         struct crypto_template *q;
 259         int err = -EEXIST;
 260
 261         down_write(&crypto_alg_sem);
 262
 263         list_for_each_entry(q, &crypto_template_list, list) {
 264                 if (q == tmpl)
 265                         goto out;
 266         }
 267
 268         list_add(&tmpl->list, &crypto_template_list);
 269         crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
 270         err = 0;
 271 out:
 272         up_write(&crypto_alg_sem);
 273         return err;
 274 }
 275 EXPORT_SYMBOL_GPL(crypto_register_template);
 276
 277 void crypto_unregister_template(struct crypto_template *tmpl)
 278 {
 279         struct crypto_instance *inst;
 280         struct hlist_node *p, *n;
 281         struct hlist_head *list;
 282         LIST_HEAD(users);
 283
 284         down_write(&crypto_alg_sem);
 285
 286         BUG_ON(list_empty(&tmpl->list));
 287         list_del_init(&tmpl->list);
 288
 289         list = &tmpl->instances;
 290         hlist_for_each_entry(inst, p, list, list) {
 291                 int err = crypto_remove_alg(&inst->alg, &users);
 292                 BUG_ON(err);
 293         }
 294
 295         crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
 296
 297         up_write(&crypto_alg_sem);
 298
 299         hlist_for_each_entry_safe(inst, p, n, list, list) {
 300                 BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
 301                 tmpl->free(inst);
 302         }
 303         crypto_remove_final(&users);
 304 }
 305 EXPORT_SYMBOL_GPL(crypto_unregister_template);
 306
 307 static struct crypto_template *__crypto_lookup_template(const char *name)
 308 {
 309         struct crypto_template *q, *tmpl = NULL;
 310
 311         down_read(&crypto_alg_sem);
 312         list_for_each_entry(q, &crypto_template_list, list) {
 313                 if (strcmp(q->name, name))
 314                         continue;
 315                 if (unlikely(!crypto_tmpl_get(q)))
 316                         continue;
 317
 318                 tmpl = q;
 319                 break;
 320         }
 321         up_read(&crypto_alg_sem);
 322
 323         return tmpl;
 324 }
 325
 326 struct crypto_template *crypto_lookup_template(const char *name)
 327 {
 328         return try_then_request_module(__crypto_lookup_template(name), name);
 329 }
 330 EXPORT_SYMBOL_GPL(crypto_lookup_template);
 331
 332 int crypto_register_instance(struct crypto_template *tmpl,
 333                              struct crypto_instance *inst)
 334 {
 335         LIST_HEAD(list);
 336         int err = -EINVAL;
 337
 338         if (inst->alg.cra_destroy)
 339                 goto err;
 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 struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 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 crypto_alg_mod_lookup(alga->name, type, mask);
 490 }
 491 EXPORT_SYMBOL_GPL(crypto_attr_alg);
 492
 493 int crypto_attr_u32(struct rtattr *rta, u32 *num)
 494 {
 495         struct crypto_attr_u32 *nu32;
 496
 497         if (!rta)
 498                 return -ENOENT;
 499         if (RTA_PAYLOAD(rta) < sizeof(*nu32))
 500                 return -EINVAL;
 501         if (rta->rta_type != CRYPTOA_U32)
 502                 return -EINVAL;
 503
 504         nu32 = RTA_DATA(rta);
 505         *num = nu32->num;
 506
 507         return 0;
 508 }
 509 EXPORT_SYMBOL_GPL(crypto_attr_u32);
 510
 511 struct crypto_instance *crypto_alloc_instance(const char *name,
 512                                               struct crypto_alg *alg)
 513 {
 514         struct crypto_instance *inst;
 515         struct crypto_spawn *spawn;
 516         int err;
 517
 518         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 519         if (!inst)
 520                 return ERR_PTR(-ENOMEM);
 521
 522         err = -ENAMETOOLONG;
 523         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
 524                      alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
 525                 goto err_free_inst;
 526
 527         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
 528                      name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 529                 goto err_free_inst;
 530
 531         spawn = crypto_instance_ctx(inst);
 532         err = crypto_init_spawn(spawn, alg, inst,
 533                                 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
 534
 535         if (err)
 536                 goto err_free_inst;
 537
 538         return inst;
 539
 540 err_free_inst:
 541         kfree(inst);
 542         return ERR_PTR(err);
 543 }
 544 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
 545
 546 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
 547 {
 548         INIT_LIST_HEAD(&queue->list);
 549         queue->backlog = &queue->list;
 550         queue->qlen = 0;
 551         queue->max_qlen = max_qlen;
 552 }
 553 EXPORT_SYMBOL_GPL(crypto_init_queue);
 554
 555 int crypto_enqueue_request(struct crypto_queue *queue,
 556                            struct crypto_async_request *request)
 557 {
 558         int err = -EINPROGRESS;
 559
 560         if (unlikely(queue->qlen >= queue->max_qlen)) {
 561                 err = -EBUSY;
 562                 if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
 563                         goto out;
 564                 if (queue->backlog == &queue->list)
 565                         queue->backlog = &request->list;
 566         }
 567
 568         queue->qlen++;
 569         list_add_tail(&request->list, &queue->list);
 570
 571 out:
 572         return err;
 573 }
 574 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
 575
 576 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
 577 {
 578         struct list_head *request;
 579
 580         if (unlikely(!queue->qlen))
 581                 return NULL;
 582
 583         queue->qlen--;
 584
 585         if (queue->backlog != &queue->list)
 586                 queue->backlog = queue->backlog->next;
 587
 588         request = queue->list.next;
 589         list_del(request);
 590
 591         return list_entry(request, struct crypto_async_request, list);
 592 }
 593 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
 594
 595 int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
 596 {
 597         struct crypto_async_request *req;
 598
 599         list_for_each_entry(req, &queue->list, list) {
 600                 if (req->tfm == tfm)
 601                         return 1;
 602         }
 603
 604         return 0;
 605 }
 606 EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
 607
 608 static int __init crypto_algapi_init(void)
 609 {
 610         crypto_init_proc();
 611         return 0;
 612 }
 613
 614 static void __exit crypto_algapi_exit(void)
 615 {
 616         crypto_exit_proc();
 617 }
 618
 619 module_init(crypto_algapi_init);
 620 module_exit(crypto_algapi_exit);
 621
 622 MODULE_LICENSE("GPL");
 623 MODULE_DESCRIPTION("Cryptographic algorithms API");