xref: /openbmc/linux/crypto/algapi.c (revision 22246614)
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 (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 
112 static 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 
131 static 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 
191 out:
192 	return ret;
193 }
194 
195 static 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 
206 int 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 }
222 EXPORT_SYMBOL_GPL(crypto_register_alg);
223 
224 static 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 
238 int 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 }
257 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
258 
259 int 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;
274 out:
275 	up_write(&crypto_alg_sem);
276 	return err;
277 }
278 EXPORT_SYMBOL_GPL(crypto_register_template);
279 
280 void 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 }
308 EXPORT_SYMBOL_GPL(crypto_unregister_template);
309 
310 static 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 
329 struct crypto_template *crypto_lookup_template(const char *name)
330 {
331 	return try_then_request_module(__crypto_lookup_template(name), name);
332 }
333 EXPORT_SYMBOL_GPL(crypto_lookup_template);
334 
335 int 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 
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 const char *crypto_attr_alg_name(struct rtattr *rta)
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 alga->name;
490 }
491 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
492 
493 struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask)
494 {
495 	const char *name;
496 	int err;
497 
498 	name = crypto_attr_alg_name(rta);
499 	err = PTR_ERR(name);
500 	if (IS_ERR(name))
501 		return ERR_PTR(err);
502 
503 	return crypto_alg_mod_lookup(name, type, mask);
504 }
505 EXPORT_SYMBOL_GPL(crypto_attr_alg);
506 
507 int crypto_attr_u32(struct rtattr *rta, u32 *num)
508 {
509 	struct crypto_attr_u32 *nu32;
510 
511 	if (!rta)
512 		return -ENOENT;
513 	if (RTA_PAYLOAD(rta) < sizeof(*nu32))
514 		return -EINVAL;
515 	if (rta->rta_type != CRYPTOA_U32)
516 		return -EINVAL;
517 
518 	nu32 = RTA_DATA(rta);
519 	*num = nu32->num;
520 
521 	return 0;
522 }
523 EXPORT_SYMBOL_GPL(crypto_attr_u32);
524 
525 struct crypto_instance *crypto_alloc_instance(const char *name,
526 					      struct crypto_alg *alg)
527 {
528 	struct crypto_instance *inst;
529 	struct crypto_spawn *spawn;
530 	int err;
531 
532 	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
533 	if (!inst)
534 		return ERR_PTR(-ENOMEM);
535 
536 	err = -ENAMETOOLONG;
537 	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
538 		     alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
539 		goto err_free_inst;
540 
541 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
542 		     name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
543 		goto err_free_inst;
544 
545 	spawn = crypto_instance_ctx(inst);
546 	err = crypto_init_spawn(spawn, alg, inst,
547 				CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
548 
549 	if (err)
550 		goto err_free_inst;
551 
552 	return inst;
553 
554 err_free_inst:
555 	kfree(inst);
556 	return ERR_PTR(err);
557 }
558 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
559 
560 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
561 {
562 	INIT_LIST_HEAD(&queue->list);
563 	queue->backlog = &queue->list;
564 	queue->qlen = 0;
565 	queue->max_qlen = max_qlen;
566 }
567 EXPORT_SYMBOL_GPL(crypto_init_queue);
568 
569 int crypto_enqueue_request(struct crypto_queue *queue,
570 			   struct crypto_async_request *request)
571 {
572 	int err = -EINPROGRESS;
573 
574 	if (unlikely(queue->qlen >= queue->max_qlen)) {
575 		err = -EBUSY;
576 		if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
577 			goto out;
578 		if (queue->backlog == &queue->list)
579 			queue->backlog = &request->list;
580 	}
581 
582 	queue->qlen++;
583 	list_add_tail(&request->list, &queue->list);
584 
585 out:
586 	return err;
587 }
588 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
589 
590 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
591 {
592 	struct list_head *request;
593 
594 	if (unlikely(!queue->qlen))
595 		return NULL;
596 
597 	queue->qlen--;
598 
599 	if (queue->backlog != &queue->list)
600 		queue->backlog = queue->backlog->next;
601 
602 	request = queue->list.next;
603 	list_del(request);
604 
605 	return list_entry(request, struct crypto_async_request, list);
606 }
607 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
608 
609 int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
610 {
611 	struct crypto_async_request *req;
612 
613 	list_for_each_entry(req, &queue->list, list) {
614 		if (req->tfm == tfm)
615 			return 1;
616 	}
617 
618 	return 0;
619 }
620 EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
621 
622 static inline void crypto_inc_byte(u8 *a, unsigned int size)
623 {
624 	u8 *b = (a + size);
625 	u8 c;
626 
627 	for (; size; size--) {
628 		c = *--b + 1;
629 		*b = c;
630 		if (c)
631 			break;
632 	}
633 }
634 
635 void crypto_inc(u8 *a, unsigned int size)
636 {
637 	__be32 *b = (__be32 *)(a + size);
638 	u32 c;
639 
640 	for (; size >= 4; size -= 4) {
641 		c = be32_to_cpu(*--b) + 1;
642 		*b = cpu_to_be32(c);
643 		if (c)
644 			return;
645 	}
646 
647 	crypto_inc_byte(a, size);
648 }
649 EXPORT_SYMBOL_GPL(crypto_inc);
650 
651 static inline void crypto_xor_byte(u8 *a, const u8 *b, unsigned int size)
652 {
653 	for (; size; size--)
654 		*a++ ^= *b++;
655 }
656 
657 void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
658 {
659 	u32 *a = (u32 *)dst;
660 	u32 *b = (u32 *)src;
661 
662 	for (; size >= 4; size -= 4)
663 		*a++ ^= *b++;
664 
665 	crypto_xor_byte((u8 *)a, (u8 *)b, size);
666 }
667 EXPORT_SYMBOL_GPL(crypto_xor);
668 
669 static int __init crypto_algapi_init(void)
670 {
671 	crypto_init_proc();
672 	return 0;
673 }
674 
675 static void __exit crypto_algapi_exit(void)
676 {
677 	crypto_exit_proc();
678 }
679 
680 module_init(crypto_algapi_init);
681 module_exit(crypto_algapi_exit);
682 
683 MODULE_LICENSE("GPL");
684 MODULE_DESCRIPTION("Cryptographic algorithms API");
685