linux/crypto/algapi.c
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   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
  24static LIST_HEAD(crypto_template_list);
  25
  26void 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}
  42EXPORT_SYMBOL_GPL(crypto_larval_error);
  43
  44static 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
  61static 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
  75static 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
  84static 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
 112static 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
 131static 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
 191out:    
 192        return ret;
 193}
 194
 195static 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
 206int 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}
 222EXPORT_SYMBOL_GPL(crypto_register_alg);
 223
 224static 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
 238int 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}
 257EXPORT_SYMBOL_GPL(crypto_unregister_alg);
 258
 259int 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;
 274out:
 275        up_write(&crypto_alg_sem);
 276        return err;
 277}
 278EXPORT_SYMBOL_GPL(crypto_register_template);
 279
 280void 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}
 308EXPORT_SYMBOL_GPL(crypto_unregister_template);
 309
 310static 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
 329struct crypto_template *crypto_lookup_template(const char *name)
 330{
 331        return try_then_request_module(__crypto_lookup_template(name), name);
 332}
 333EXPORT_SYMBOL_GPL(crypto_lookup_template);
 334
 335int 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
 356unlock:
 357        up_write(&crypto_alg_sem);
 358
 359        crypto_remove_final(&list);
 360
 361err:
 362        return err;
 363}
 364EXPORT_SYMBOL_GPL(crypto_register_instance);
 365
 366int 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}
 384EXPORT_SYMBOL_GPL(crypto_init_spawn);
 385
 386void 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}
 392EXPORT_SYMBOL_GPL(crypto_drop_spawn);
 393
 394struct 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
 424out_put_alg:
 425        crypto_mod_put(alg);
 426        return tfm;
 427}
 428EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
 429
 430int crypto_register_notifier(struct notifier_block *nb)
 431{
 432        return blocking_notifier_chain_register(&crypto_chain, nb);
 433}
 434EXPORT_SYMBOL_GPL(crypto_register_notifier);
 435
 436int crypto_unregister_notifier(struct notifier_block *nb)
 437{
 438        return blocking_notifier_chain_unregister(&crypto_chain, nb);
 439}
 440EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
 441
 442struct 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}
 458EXPORT_SYMBOL_GPL(crypto_get_attr_type);
 459
 460int 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}
 473EXPORT_SYMBOL_GPL(crypto_check_attr_type);
 474
 475struct 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}
 491EXPORT_SYMBOL_GPL(crypto_attr_alg);
 492
 493int 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}
 509EXPORT_SYMBOL_GPL(crypto_attr_u32);
 510
 511struct 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
 540err_free_inst:
 541        kfree(inst);
 542        return ERR_PTR(err);
 543}
 544EXPORT_SYMBOL_GPL(crypto_alloc_instance);
 545
 546void 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}
 553EXPORT_SYMBOL_GPL(crypto_init_queue);
 554
 555int 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
 571out:
 572        return err;
 573}
 574EXPORT_SYMBOL_GPL(crypto_enqueue_request);
 575
 576struct 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}
 593EXPORT_SYMBOL_GPL(crypto_dequeue_request);
 594
 595int 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}
 606EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
 607
 608static int __init crypto_algapi_init(void)
 609{
 610        crypto_init_proc();
 611        return 0;
 612}
 613
 614static void __exit crypto_algapi_exit(void)
 615{
 616        crypto_exit_proc();
 617}
 618
 619module_init(crypto_algapi_init);
 620module_exit(crypto_algapi_exit);
 621
 622MODULE_LICENSE("GPL");
 623MODULE_DESCRIPTION("Cryptographic algorithms API");
 624