Update stable tree documentation
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / crypto / algapi.c
blob7c41e7405c41a4392791cc4a01a22cce52f983b0
1 /*
2 * Cryptographic API for algorithms (i.e., low-level API).
4 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
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.
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>
22 #include "internal.h"
24 static void crypto_remove_final(struct list_head *list);
26 static LIST_HEAD(crypto_template_list);
28 void crypto_larval_error(const char *name, u32 type, u32 mask)
30 struct crypto_alg *alg;
32 alg = crypto_alg_lookup(name, type, mask);
34 if (alg) {
35 if (crypto_is_larval(alg)) {
36 struct crypto_larval *larval = (void *)alg;
37 complete_all(&larval->completion);
39 crypto_mod_put(alg);
42 EXPORT_SYMBOL_GPL(crypto_larval_error);
44 static inline int crypto_set_driver_name(struct crypto_alg *alg)
46 static const char suffix[] = "-generic";
47 char *driver_name = alg->cra_driver_name;
48 int len;
50 if (*driver_name)
51 return 0;
53 len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
54 if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
55 return -ENAMETOOLONG;
57 memcpy(driver_name + len, suffix, sizeof(suffix));
58 return 0;
61 static int crypto_check_alg(struct crypto_alg *alg)
63 if (alg->cra_alignmask & (alg->cra_alignmask + 1))
64 return -EINVAL;
66 if (alg->cra_blocksize > PAGE_SIZE / 8)
67 return -EINVAL;
69 if (alg->cra_priority < 0)
70 return -EINVAL;
72 return crypto_set_driver_name(alg);
75 static void crypto_destroy_instance(struct crypto_alg *alg)
77 struct crypto_instance *inst = (void *)alg;
78 struct crypto_template *tmpl = inst->tmpl;
80 tmpl->free(inst);
81 crypto_tmpl_put(tmpl);
84 static void crypto_remove_spawn(struct crypto_spawn *spawn,
85 struct list_head *list,
86 struct list_head *secondary_spawns)
88 struct crypto_instance *inst = spawn->inst;
89 struct crypto_template *tmpl = inst->tmpl;
91 list_del_init(&spawn->list);
92 spawn->alg = NULL;
94 if (crypto_is_dead(&inst->alg))
95 return;
97 inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
98 if (hlist_unhashed(&inst->list))
99 return;
101 if (!tmpl || !crypto_tmpl_get(tmpl))
102 return;
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;
109 list_splice(&inst->alg.cra_users, secondary_spawns);
112 static void crypto_remove_spawns(struct list_head *spawns,
113 struct list_head *list, u32 new_type)
115 struct crypto_spawn *spawn, *n;
116 LIST_HEAD(secondary_spawns);
118 list_for_each_entry_safe(spawn, n, spawns, list) {
119 if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
120 continue;
122 crypto_remove_spawn(spawn, list, &secondary_spawns);
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);
131 static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg)
133 struct crypto_alg *q;
134 struct crypto_larval *larval;
135 int ret = -EAGAIN;
137 if (crypto_is_dead(alg))
138 goto err;
140 INIT_LIST_HEAD(&alg->cra_users);
142 /* No cheating! */
143 alg->cra_flags &= ~CRYPTO_ALG_TESTED;
145 ret = -EEXIST;
147 atomic_set(&alg->cra_refcnt, 1);
148 list_for_each_entry(q, &crypto_alg_list, cra_list) {
149 if (q == alg)
150 goto err;
152 if (crypto_is_larval(q)) {
153 if (!strcmp(alg->cra_driver_name, q->cra_driver_name))
154 goto err;
155 continue;
158 if (!strcmp(q->cra_driver_name, alg->cra_name) ||
159 !strcmp(q->cra_name, alg->cra_driver_name))
160 goto err;
163 larval = crypto_larval_alloc(alg->cra_name,
164 alg->cra_flags | CRYPTO_ALG_TESTED, 0);
165 if (IS_ERR(larval))
166 goto out;
168 ret = -ENOENT;
169 larval->adult = crypto_mod_get(alg);
170 if (!larval->adult)
171 goto free_larval;
173 atomic_set(&larval->alg.cra_refcnt, 1);
174 memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
175 CRYPTO_MAX_ALG_NAME);
176 larval->alg.cra_priority = alg->cra_priority;
178 list_add(&alg->cra_list, &crypto_alg_list);
179 list_add(&larval->alg.cra_list, &crypto_alg_list);
181 out:
182 return larval;
184 free_larval:
185 kfree(larval);
186 err:
187 larval = ERR_PTR(ret);
188 goto out;
191 void crypto_alg_tested(const char *name, int err)
193 struct crypto_larval *test;
194 struct crypto_alg *alg;
195 struct crypto_alg *q;
196 LIST_HEAD(list);
198 down_write(&crypto_alg_sem);
199 list_for_each_entry(q, &crypto_alg_list, cra_list) {
200 if (!crypto_is_larval(q))
201 continue;
203 test = (struct crypto_larval *)q;
205 if (!strcmp(q->cra_driver_name, name))
206 goto found;
209 printk(KERN_ERR "alg: Unexpected test result for %s: %d\n", name, err);
210 goto unlock;
212 found:
213 alg = test->adult;
214 if (err || list_empty(&alg->cra_list))
215 goto complete;
217 alg->cra_flags |= CRYPTO_ALG_TESTED;
219 list_for_each_entry(q, &crypto_alg_list, cra_list) {
220 if (q == alg)
221 continue;
223 if (crypto_is_moribund(q))
224 continue;
226 if (crypto_is_larval(q)) {
227 struct crypto_larval *larval = (void *)q;
230 * Check to see if either our generic name or
231 * specific name can satisfy the name requested
232 * by the larval entry q.
234 if (strcmp(alg->cra_name, q->cra_name) &&
235 strcmp(alg->cra_driver_name, q->cra_name))
236 continue;
238 if (larval->adult)
239 continue;
240 if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
241 continue;
242 if (!crypto_mod_get(alg))
243 continue;
245 larval->adult = alg;
246 complete_all(&larval->completion);
247 continue;
250 if (strcmp(alg->cra_name, q->cra_name))
251 continue;
253 if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
254 q->cra_priority > alg->cra_priority)
255 continue;
257 crypto_remove_spawns(&q->cra_users, &list, alg->cra_flags);
260 complete:
261 complete_all(&test->completion);
263 unlock:
264 up_write(&crypto_alg_sem);
266 crypto_remove_final(&list);
268 EXPORT_SYMBOL_GPL(crypto_alg_tested);
270 static void crypto_remove_final(struct list_head *list)
272 struct crypto_alg *alg;
273 struct crypto_alg *n;
275 list_for_each_entry_safe(alg, n, list, cra_list) {
276 list_del_init(&alg->cra_list);
277 crypto_alg_put(alg);
281 static void crypto_wait_for_test(struct crypto_larval *larval)
283 int err;
285 err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
286 if (err != NOTIFY_STOP) {
287 if (WARN_ON(err != NOTIFY_DONE))
288 goto out;
289 crypto_alg_tested(larval->alg.cra_driver_name, 0);
292 err = wait_for_completion_interruptible(&larval->completion);
293 WARN_ON(err);
295 out:
296 crypto_larval_kill(&larval->alg);
299 int crypto_register_alg(struct crypto_alg *alg)
301 struct crypto_larval *larval;
302 int err;
304 err = crypto_check_alg(alg);
305 if (err)
306 return err;
308 down_write(&crypto_alg_sem);
309 larval = __crypto_register_alg(alg);
310 up_write(&crypto_alg_sem);
312 if (IS_ERR(larval))
313 return PTR_ERR(larval);
315 crypto_wait_for_test(larval);
316 return 0;
318 EXPORT_SYMBOL_GPL(crypto_register_alg);
320 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
322 if (unlikely(list_empty(&alg->cra_list)))
323 return -ENOENT;
325 alg->cra_flags |= CRYPTO_ALG_DEAD;
327 crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
328 list_del_init(&alg->cra_list);
329 crypto_remove_spawns(&alg->cra_users, list, alg->cra_flags);
331 return 0;
334 int crypto_unregister_alg(struct crypto_alg *alg)
336 int ret;
337 LIST_HEAD(list);
339 down_write(&crypto_alg_sem);
340 ret = crypto_remove_alg(alg, &list);
341 up_write(&crypto_alg_sem);
343 if (ret)
344 return ret;
346 BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
347 if (alg->cra_destroy)
348 alg->cra_destroy(alg);
350 crypto_remove_final(&list);
351 return 0;
353 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
355 int crypto_register_template(struct crypto_template *tmpl)
357 struct crypto_template *q;
358 int err = -EEXIST;
360 down_write(&crypto_alg_sem);
362 list_for_each_entry(q, &crypto_template_list, list) {
363 if (q == tmpl)
364 goto out;
367 list_add(&tmpl->list, &crypto_template_list);
368 crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
369 err = 0;
370 out:
371 up_write(&crypto_alg_sem);
372 return err;
374 EXPORT_SYMBOL_GPL(crypto_register_template);
376 void crypto_unregister_template(struct crypto_template *tmpl)
378 struct crypto_instance *inst;
379 struct hlist_node *p, *n;
380 struct hlist_head *list;
381 LIST_HEAD(users);
383 down_write(&crypto_alg_sem);
385 BUG_ON(list_empty(&tmpl->list));
386 list_del_init(&tmpl->list);
388 list = &tmpl->instances;
389 hlist_for_each_entry(inst, p, list, list) {
390 int err = crypto_remove_alg(&inst->alg, &users);
391 BUG_ON(err);
394 crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
396 up_write(&crypto_alg_sem);
398 hlist_for_each_entry_safe(inst, p, n, list, list) {
399 BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
400 tmpl->free(inst);
402 crypto_remove_final(&users);
404 EXPORT_SYMBOL_GPL(crypto_unregister_template);
406 static struct crypto_template *__crypto_lookup_template(const char *name)
408 struct crypto_template *q, *tmpl = NULL;
410 down_read(&crypto_alg_sem);
411 list_for_each_entry(q, &crypto_template_list, list) {
412 if (strcmp(q->name, name))
413 continue;
414 if (unlikely(!crypto_tmpl_get(q)))
415 continue;
417 tmpl = q;
418 break;
420 up_read(&crypto_alg_sem);
422 return tmpl;
425 struct crypto_template *crypto_lookup_template(const char *name)
427 return try_then_request_module(__crypto_lookup_template(name), name);
429 EXPORT_SYMBOL_GPL(crypto_lookup_template);
431 int crypto_register_instance(struct crypto_template *tmpl,
432 struct crypto_instance *inst)
434 struct crypto_larval *larval;
435 int err;
437 err = crypto_check_alg(&inst->alg);
438 if (err)
439 goto err;
441 inst->alg.cra_module = tmpl->module;
443 down_write(&crypto_alg_sem);
445 larval = __crypto_register_alg(&inst->alg);
446 if (IS_ERR(larval))
447 goto unlock;
449 hlist_add_head(&inst->list, &tmpl->instances);
450 inst->tmpl = tmpl;
452 unlock:
453 up_write(&crypto_alg_sem);
455 err = PTR_ERR(larval);
456 if (IS_ERR(larval))
457 goto err;
459 crypto_wait_for_test(larval);
460 err = 0;
462 err:
463 return err;
465 EXPORT_SYMBOL_GPL(crypto_register_instance);
467 int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
468 struct crypto_instance *inst, u32 mask)
470 int err = -EAGAIN;
472 spawn->inst = inst;
473 spawn->mask = mask;
475 down_write(&crypto_alg_sem);
476 if (!crypto_is_moribund(alg)) {
477 list_add(&spawn->list, &alg->cra_users);
478 spawn->alg = alg;
479 err = 0;
481 up_write(&crypto_alg_sem);
483 return err;
485 EXPORT_SYMBOL_GPL(crypto_init_spawn);
487 void crypto_drop_spawn(struct crypto_spawn *spawn)
489 down_write(&crypto_alg_sem);
490 list_del(&spawn->list);
491 up_write(&crypto_alg_sem);
493 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
495 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
496 u32 mask)
498 struct crypto_alg *alg;
499 struct crypto_alg *alg2;
500 struct crypto_tfm *tfm;
502 down_read(&crypto_alg_sem);
503 alg = spawn->alg;
504 alg2 = alg;
505 if (alg2)
506 alg2 = crypto_mod_get(alg2);
507 up_read(&crypto_alg_sem);
509 if (!alg2) {
510 if (alg)
511 crypto_shoot_alg(alg);
512 return ERR_PTR(-EAGAIN);
515 tfm = ERR_PTR(-EINVAL);
516 if (unlikely((alg->cra_flags ^ type) & mask))
517 goto out_put_alg;
519 tfm = __crypto_alloc_tfm(alg, type, mask);
520 if (IS_ERR(tfm))
521 goto out_put_alg;
523 return tfm;
525 out_put_alg:
526 crypto_mod_put(alg);
527 return tfm;
529 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
531 int crypto_register_notifier(struct notifier_block *nb)
533 return blocking_notifier_chain_register(&crypto_chain, nb);
535 EXPORT_SYMBOL_GPL(crypto_register_notifier);
537 int crypto_unregister_notifier(struct notifier_block *nb)
539 return blocking_notifier_chain_unregister(&crypto_chain, nb);
541 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
543 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
545 struct rtattr *rta = tb[0];
546 struct crypto_attr_type *algt;
548 if (!rta)
549 return ERR_PTR(-ENOENT);
550 if (RTA_PAYLOAD(rta) < sizeof(*algt))
551 return ERR_PTR(-EINVAL);
552 if (rta->rta_type != CRYPTOA_TYPE)
553 return ERR_PTR(-EINVAL);
555 algt = RTA_DATA(rta);
557 return algt;
559 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
561 int crypto_check_attr_type(struct rtattr **tb, u32 type)
563 struct crypto_attr_type *algt;
565 algt = crypto_get_attr_type(tb);
566 if (IS_ERR(algt))
567 return PTR_ERR(algt);
569 if ((algt->type ^ type) & algt->mask)
570 return -EINVAL;
572 return 0;
574 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
576 const char *crypto_attr_alg_name(struct rtattr *rta)
578 struct crypto_attr_alg *alga;
580 if (!rta)
581 return ERR_PTR(-ENOENT);
582 if (RTA_PAYLOAD(rta) < sizeof(*alga))
583 return ERR_PTR(-EINVAL);
584 if (rta->rta_type != CRYPTOA_ALG)
585 return ERR_PTR(-EINVAL);
587 alga = RTA_DATA(rta);
588 alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
590 return alga->name;
592 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
594 struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask)
596 const char *name;
597 int err;
599 name = crypto_attr_alg_name(rta);
600 err = PTR_ERR(name);
601 if (IS_ERR(name))
602 return ERR_PTR(err);
604 return crypto_alg_mod_lookup(name, type, mask);
606 EXPORT_SYMBOL_GPL(crypto_attr_alg);
608 int crypto_attr_u32(struct rtattr *rta, u32 *num)
610 struct crypto_attr_u32 *nu32;
612 if (!rta)
613 return -ENOENT;
614 if (RTA_PAYLOAD(rta) < sizeof(*nu32))
615 return -EINVAL;
616 if (rta->rta_type != CRYPTOA_U32)
617 return -EINVAL;
619 nu32 = RTA_DATA(rta);
620 *num = nu32->num;
622 return 0;
624 EXPORT_SYMBOL_GPL(crypto_attr_u32);
626 struct crypto_instance *crypto_alloc_instance(const char *name,
627 struct crypto_alg *alg)
629 struct crypto_instance *inst;
630 struct crypto_spawn *spawn;
631 int err;
633 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
634 if (!inst)
635 return ERR_PTR(-ENOMEM);
637 err = -ENAMETOOLONG;
638 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
639 alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
640 goto err_free_inst;
642 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
643 name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
644 goto err_free_inst;
646 spawn = crypto_instance_ctx(inst);
647 err = crypto_init_spawn(spawn, alg, inst,
648 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
650 if (err)
651 goto err_free_inst;
653 return inst;
655 err_free_inst:
656 kfree(inst);
657 return ERR_PTR(err);
659 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
661 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
663 INIT_LIST_HEAD(&queue->list);
664 queue->backlog = &queue->list;
665 queue->qlen = 0;
666 queue->max_qlen = max_qlen;
668 EXPORT_SYMBOL_GPL(crypto_init_queue);
670 int crypto_enqueue_request(struct crypto_queue *queue,
671 struct crypto_async_request *request)
673 int err = -EINPROGRESS;
675 if (unlikely(queue->qlen >= queue->max_qlen)) {
676 err = -EBUSY;
677 if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
678 goto out;
679 if (queue->backlog == &queue->list)
680 queue->backlog = &request->list;
683 queue->qlen++;
684 list_add_tail(&request->list, &queue->list);
686 out:
687 return err;
689 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
691 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
693 struct list_head *request;
695 if (unlikely(!queue->qlen))
696 return NULL;
698 queue->qlen--;
700 if (queue->backlog != &queue->list)
701 queue->backlog = queue->backlog->next;
703 request = queue->list.next;
704 list_del(request);
706 return list_entry(request, struct crypto_async_request, list);
708 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
710 int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
712 struct crypto_async_request *req;
714 list_for_each_entry(req, &queue->list, list) {
715 if (req->tfm == tfm)
716 return 1;
719 return 0;
721 EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
723 static inline void crypto_inc_byte(u8 *a, unsigned int size)
725 u8 *b = (a + size);
726 u8 c;
728 for (; size; size--) {
729 c = *--b + 1;
730 *b = c;
731 if (c)
732 break;
736 void crypto_inc(u8 *a, unsigned int size)
738 __be32 *b = (__be32 *)(a + size);
739 u32 c;
741 for (; size >= 4; size -= 4) {
742 c = be32_to_cpu(*--b) + 1;
743 *b = cpu_to_be32(c);
744 if (c)
745 return;
748 crypto_inc_byte(a, size);
750 EXPORT_SYMBOL_GPL(crypto_inc);
752 static inline void crypto_xor_byte(u8 *a, const u8 *b, unsigned int size)
754 for (; size; size--)
755 *a++ ^= *b++;
758 void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
760 u32 *a = (u32 *)dst;
761 u32 *b = (u32 *)src;
763 for (; size >= 4; size -= 4)
764 *a++ ^= *b++;
766 crypto_xor_byte((u8 *)a, (u8 *)b, size);
768 EXPORT_SYMBOL_GPL(crypto_xor);
770 static int __init crypto_algapi_init(void)
772 crypto_init_proc();
773 return 0;
776 static void __exit crypto_algapi_exit(void)
778 crypto_exit_proc();
781 module_init(crypto_algapi_init);
782 module_exit(crypto_algapi_exit);
784 MODULE_LICENSE("GPL");
785 MODULE_DESCRIPTION("Cryptographic algorithms API");