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(&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_alignmask & alg->cra_blocksize)
  67                 return -EINVAL;
  68
  69         if (alg->cra_blocksize > PAGE_SIZE / 8)
  70                 return -EINVAL;
  71
  72         if (alg->cra_priority < 0)
  73                 return -EINVAL;
  74
  75         return crypto_set_driver_name(alg);
  76 }
  77
  78 static void crypto_destroy_instance(struct crypto_alg *alg)
  79 {
  80         struct crypto_instance *inst = (void *)alg;
  81         struct crypto_template *tmpl = inst->tmpl;
  82
  83         tmpl->free(inst);
  84         crypto_tmpl_put(tmpl);
  85 }
  86
  87 static void crypto_remove_spawn(struct crypto_spawn *spawn,
  88                                 struct list_head *list,
  89                                 struct list_head *secondary_spawns)
  90 {
  91         struct crypto_instance *inst = spawn->inst;
  92         struct crypto_template *tmpl = inst->tmpl;
  93
  94         list_del_init(&spawn->list);
  95         spawn->alg = NULL;
  96
  97         if (crypto_is_dead(&inst->alg))
  98                 return;
  99
 100         inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
 101         if (hlist_unhashed(&inst->list))
 102                 return;
 103
 104         if (!tmpl || !crypto_tmpl_get(tmpl))
 105                 return;
 106
 107         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
 108         list_move(&inst->alg.cra_list, list);
 109         hlist_del(&inst->list);
 110         inst->alg.cra_destroy = crypto_destroy_instance;
 111
 112         list_splice(&inst->alg.cra_users, secondary_spawns);
 113 }
 114
 115 static void crypto_remove_spawns(struct list_head *spawns,
 116                                  struct list_head *list, u32 new_type)
 117 {
 118         struct crypto_spawn *spawn, *n;
 119         LIST_HEAD(secondary_spawns);
 120
 121         list_for_each_entry_safe(spawn, n, spawns, list) {
 122                 if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
 123                         continue;
 124
 125                 crypto_remove_spawn(spawn, list, &secondary_spawns);
 126         }
 127
 128         while (!list_empty(&secondary_spawns)) {
 129                 list_for_each_entry_safe(spawn, n, &secondary_spawns, list)
 130                         crypto_remove_spawn(spawn, list, &secondary_spawns);
 131         }
 132 }
 133
 134 static int __crypto_register_alg(struct crypto_alg *alg,
 135                                  struct list_head *list)
 136 {
 137         struct crypto_alg *q;
 138         int ret = -EAGAIN;
 139
 140         if (crypto_is_dead(alg))
 141                 goto out;
 142
 143         INIT_LIST_HEAD(&alg->cra_users);
 144
 145         ret = -EEXIST;
 146
 147         atomic_set(&alg->cra_refcnt, 1);
 148         list_for_each_entry(q, &crypto_alg_list, cra_list) {
 149                 if (q == alg)
 150                         goto out;
 151
 152                 if (crypto_is_moribund(q))
 153                         continue;
 154
 155                 if (crypto_is_larval(q)) {
 156                         struct crypto_larval *larval = (void *)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(&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[CRYPTOA_TYPE - 1];
 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
 450         algt = RTA_DATA(rta);
 451
 452         return algt;
 453 }
 454 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
 455
 456 int crypto_check_attr_type(struct rtattr **tb, u32 type)
 457 {
 458         struct crypto_attr_type *algt;
 459
 460         algt = crypto_get_attr_type(tb);
 461         if (IS_ERR(algt))
 462                 return PTR_ERR(algt);
 463
 464         if ((algt->type ^ type) & algt->mask)
 465                 return -EINVAL;
 466
 467         return 0;
 468 }
 469 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
 470
 471 struct crypto_alg *crypto_get_attr_alg(struct rtattr **tb, u32 type, u32 mask)
 472 {
 473         struct rtattr *rta = tb[CRYPTOA_ALG - 1];
 474         struct crypto_attr_alg *alga;
 475
 476         if (!rta)
 477                 return ERR_PTR(-ENOENT);
 478         if (RTA_PAYLOAD(rta) < sizeof(*alga))
 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_get_attr_alg);
 487
 488 struct crypto_instance *crypto_alloc_instance(const char *name,
 489                                               struct crypto_alg *alg)
 490 {
 491         struct crypto_instance *inst;
 492         struct crypto_spawn *spawn;
 493         int err;
 494
 495         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 496         if (!inst)
 497                 return ERR_PTR(-ENOMEM);
 498
 499         err = -ENAMETOOLONG;
 500         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
 501                      alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
 502                 goto err_free_inst;
 503
 504         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
 505                      name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
 506                 goto err_free_inst;
 507
 508         spawn = crypto_instance_ctx(inst);
 509         err = crypto_init_spawn(spawn, alg, inst,
 510                                 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
 511
 512         if (err)
 513                 goto err_free_inst;
 514
 515         return inst;
 516
 517 err_free_inst:
 518         kfree(inst);
 519         return ERR_PTR(err);
 520 }
 521 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
 522
 523 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
 524 {
 525         INIT_LIST_HEAD(&queue->list);
 526         queue->backlog = &queue->list;
 527         queue->qlen = 0;
 528         queue->max_qlen = max_qlen;
 529 }
 530 EXPORT_SYMBOL_GPL(crypto_init_queue);
 531
 532 int crypto_enqueue_request(struct crypto_queue *queue,
 533                            struct crypto_async_request *request)
 534 {
 535         int err = -EINPROGRESS;
 536
 537         if (unlikely(queue->qlen >= queue->max_qlen)) {
 538                 err = -EBUSY;
 539                 if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
 540                         goto out;
 541                 if (queue->backlog == &queue->list)
 542                         queue->backlog = &request->list;
 543         }
 544
 545         queue->qlen++;
 546         list_add_tail(&request->list, &queue->list);
 547
 548 out:
 549         return err;
 550 }
 551 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
 552
 553 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
 554 {
 555         struct list_head *request;
 556
 557         if (unlikely(!queue->qlen))
 558                 return NULL;
 559
 560         queue->qlen--;
 561
 562         if (queue->backlog != &queue->list)
 563                 queue->backlog = queue->backlog->next;
 564
 565         request = queue->list.next;
 566         list_del(request);
 567
 568         return list_entry(request, struct crypto_async_request, list);
 569 }
 570 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
 571
 572 int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
 573 {
 574         struct crypto_async_request *req;
 575
 576         list_for_each_entry(req, &queue->list, list) {
 577                 if (req->tfm == tfm)
 578                         return 1;
 579         }
 580
 581         return 0;
 582 }
 583 EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
 584
 585 static int __init crypto_algapi_init(void)
 586 {
 587         crypto_init_proc();
 588         return 0;
 589 }
 590
 591 static void __exit crypto_algapi_exit(void)
 592 {
 593         crypto_exit_proc();
 594 }
 595
 596 module_init(crypto_algapi_init);
 597 module_exit(crypto_algapi_exit);
 598
 599 MODULE_LICENSE("GPL");
 600 MODULE_DESCRIPTION("Cryptographic algorithms API");