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"); 624