xref: /linux/crypto/algapi.c (revision 06a130e42a5bfc84795464bff023bff4c16f58c5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Cryptographic API for algorithms (i.e., low-level API).
4  *
5  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
6  */
7 
8 #include <crypto/algapi.h>
9 #include <crypto/internal/simd.h>
10 #include <linux/err.h>
11 #include <linux/errno.h>
12 #include <linux/fips.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/workqueue.h>
21 
22 #include "internal.h"
23 
24 static LIST_HEAD(crypto_template_list);
25 
26 #ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
27 DEFINE_PER_CPU(bool, crypto_simd_disabled_for_test);
28 EXPORT_PER_CPU_SYMBOL_GPL(crypto_simd_disabled_for_test);
29 #endif
30 
31 static inline void crypto_check_module_sig(struct module *mod)
32 {
33 	if (fips_enabled && mod && !module_sig_ok(mod))
34 		panic("Module %s signature verification failed in FIPS mode\n",
35 		      module_name(mod));
36 }
37 
38 static int crypto_check_alg(struct crypto_alg *alg)
39 {
40 	crypto_check_module_sig(alg->cra_module);
41 
42 	if (!alg->cra_name[0] || !alg->cra_driver_name[0])
43 		return -EINVAL;
44 
45 	if (alg->cra_alignmask & (alg->cra_alignmask + 1))
46 		return -EINVAL;
47 
48 	/* General maximums for all algs. */
49 	if (alg->cra_alignmask > MAX_ALGAPI_ALIGNMASK)
50 		return -EINVAL;
51 
52 	if (alg->cra_blocksize > MAX_ALGAPI_BLOCKSIZE)
53 		return -EINVAL;
54 
55 	/* Lower maximums for specific alg types. */
56 	if (!alg->cra_type && (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
57 			       CRYPTO_ALG_TYPE_CIPHER) {
58 		if (alg->cra_alignmask > MAX_CIPHER_ALIGNMASK)
59 			return -EINVAL;
60 
61 		if (alg->cra_blocksize > MAX_CIPHER_BLOCKSIZE)
62 			return -EINVAL;
63 	}
64 
65 	if (alg->cra_priority < 0)
66 		return -EINVAL;
67 
68 	refcount_set(&alg->cra_refcnt, 1);
69 
70 	return 0;
71 }
72 
73 static void crypto_free_instance(struct crypto_instance *inst)
74 {
75 	inst->alg.cra_type->free(inst);
76 }
77 
78 static void crypto_destroy_instance_workfn(struct work_struct *w)
79 {
80 	struct crypto_instance *inst = container_of(w, struct crypto_instance,
81 						    free_work);
82 	struct crypto_template *tmpl = inst->tmpl;
83 
84 	crypto_free_instance(inst);
85 	crypto_tmpl_put(tmpl);
86 }
87 
88 static void crypto_destroy_instance(struct crypto_alg *alg)
89 {
90 	struct crypto_instance *inst = container_of(alg,
91 						    struct crypto_instance,
92 						    alg);
93 
94 	INIT_WORK(&inst->free_work, crypto_destroy_instance_workfn);
95 	schedule_work(&inst->free_work);
96 }
97 
98 /*
99  * This function adds a spawn to the list secondary_spawns which
100  * will be used at the end of crypto_remove_spawns to unregister
101  * instances, unless the spawn happens to be one that is depended
102  * on by the new algorithm (nalg in crypto_remove_spawns).
103  *
104  * This function is also responsible for resurrecting any algorithms
105  * in the dependency chain of nalg by unsetting n->dead.
106  */
107 static struct list_head *crypto_more_spawns(struct crypto_alg *alg,
108 					    struct list_head *stack,
109 					    struct list_head *top,
110 					    struct list_head *secondary_spawns)
111 {
112 	struct crypto_spawn *spawn, *n;
113 
114 	spawn = list_first_entry_or_null(stack, struct crypto_spawn, list);
115 	if (!spawn)
116 		return NULL;
117 
118 	n = list_prev_entry(spawn, list);
119 	list_move(&spawn->list, secondary_spawns);
120 
121 	if (list_is_last(&n->list, stack))
122 		return top;
123 
124 	n = list_next_entry(n, list);
125 	if (!spawn->dead)
126 		n->dead = false;
127 
128 	return &n->inst->alg.cra_users;
129 }
130 
131 static void crypto_remove_instance(struct crypto_instance *inst,
132 				   struct list_head *list)
133 {
134 	struct crypto_template *tmpl = inst->tmpl;
135 
136 	if (crypto_is_dead(&inst->alg))
137 		return;
138 
139 	inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
140 
141 	if (!tmpl || !crypto_tmpl_get(tmpl))
142 		return;
143 
144 	list_move(&inst->alg.cra_list, list);
145 	hlist_del(&inst->list);
146 	inst->alg.cra_destroy = crypto_destroy_instance;
147 
148 	BUG_ON(!list_empty(&inst->alg.cra_users));
149 }
150 
151 /*
152  * Given an algorithm alg, remove all algorithms that depend on it
153  * through spawns.  If nalg is not null, then exempt any algorithms
154  * that is depended on by nalg.  This is useful when nalg itself
155  * depends on alg.
156  */
157 void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
158 			  struct crypto_alg *nalg)
159 {
160 	u32 new_type = (nalg ?: alg)->cra_flags;
161 	struct crypto_spawn *spawn, *n;
162 	LIST_HEAD(secondary_spawns);
163 	struct list_head *spawns;
164 	LIST_HEAD(stack);
165 	LIST_HEAD(top);
166 
167 	spawns = &alg->cra_users;
168 	list_for_each_entry_safe(spawn, n, spawns, list) {
169 		if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
170 			continue;
171 
172 		list_move(&spawn->list, &top);
173 	}
174 
175 	/*
176 	 * Perform a depth-first walk starting from alg through
177 	 * the cra_users tree.  The list stack records the path
178 	 * from alg to the current spawn.
179 	 */
180 	spawns = &top;
181 	do {
182 		while (!list_empty(spawns)) {
183 			struct crypto_instance *inst;
184 
185 			spawn = list_first_entry(spawns, struct crypto_spawn,
186 						 list);
187 			inst = spawn->inst;
188 
189 			list_move(&spawn->list, &stack);
190 			spawn->dead = !spawn->registered || &inst->alg != nalg;
191 
192 			if (!spawn->registered)
193 				break;
194 
195 			BUG_ON(&inst->alg == alg);
196 
197 			if (&inst->alg == nalg)
198 				break;
199 
200 			spawns = &inst->alg.cra_users;
201 
202 			/*
203 			 * Even if spawn->registered is true, the
204 			 * instance itself may still be unregistered.
205 			 * This is because it may have failed during
206 			 * registration.  Therefore we still need to
207 			 * make the following test.
208 			 *
209 			 * We may encounter an unregistered instance here, since
210 			 * an instance's spawns are set up prior to the instance
211 			 * being registered.  An unregistered instance will have
212 			 * NULL ->cra_users.next, since ->cra_users isn't
213 			 * properly initialized until registration.  But an
214 			 * unregistered instance cannot have any users, so treat
215 			 * it the same as ->cra_users being empty.
216 			 */
217 			if (spawns->next == NULL)
218 				break;
219 		}
220 	} while ((spawns = crypto_more_spawns(alg, &stack, &top,
221 					      &secondary_spawns)));
222 
223 	/*
224 	 * Remove all instances that are marked as dead.  Also
225 	 * complete the resurrection of the others by moving them
226 	 * back to the cra_users list.
227 	 */
228 	list_for_each_entry_safe(spawn, n, &secondary_spawns, list) {
229 		if (!spawn->dead)
230 			list_move(&spawn->list, &spawn->alg->cra_users);
231 		else if (spawn->registered)
232 			crypto_remove_instance(spawn->inst, list);
233 	}
234 }
235 EXPORT_SYMBOL_GPL(crypto_remove_spawns);
236 
237 static void crypto_alg_finish_registration(struct crypto_alg *alg,
238 					   struct list_head *algs_to_put)
239 {
240 	struct crypto_alg *q;
241 
242 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
243 		if (q == alg)
244 			continue;
245 
246 		if (crypto_is_moribund(q))
247 			continue;
248 
249 		if (crypto_is_larval(q))
250 			continue;
251 
252 		if (strcmp(alg->cra_name, q->cra_name))
253 			continue;
254 
255 		if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
256 		    q->cra_priority > alg->cra_priority)
257 			continue;
258 
259 		crypto_remove_spawns(q, algs_to_put, alg);
260 	}
261 
262 	crypto_notify(CRYPTO_MSG_ALG_LOADED, alg);
263 }
264 
265 static struct crypto_larval *crypto_alloc_test_larval(struct crypto_alg *alg)
266 {
267 	struct crypto_larval *larval;
268 
269 	if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER) ||
270 	    IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS) ||
271 	    (alg->cra_flags & CRYPTO_ALG_INTERNAL))
272 		return NULL; /* No self-test needed */
273 
274 	larval = crypto_larval_alloc(alg->cra_name,
275 				     alg->cra_flags | CRYPTO_ALG_TESTED, 0);
276 	if (IS_ERR(larval))
277 		return larval;
278 
279 	larval->adult = crypto_mod_get(alg);
280 	if (!larval->adult) {
281 		kfree(larval);
282 		return ERR_PTR(-ENOENT);
283 	}
284 
285 	refcount_set(&larval->alg.cra_refcnt, 1);
286 	memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
287 	       CRYPTO_MAX_ALG_NAME);
288 	larval->alg.cra_priority = alg->cra_priority;
289 
290 	return larval;
291 }
292 
293 static struct crypto_larval *
294 __crypto_register_alg(struct crypto_alg *alg, struct list_head *algs_to_put)
295 {
296 	struct crypto_alg *q;
297 	struct crypto_larval *larval;
298 	int ret = -EAGAIN;
299 
300 	if (crypto_is_dead(alg))
301 		goto err;
302 
303 	INIT_LIST_HEAD(&alg->cra_users);
304 
305 	ret = -EEXIST;
306 
307 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
308 		if (q == alg)
309 			goto err;
310 
311 		if (crypto_is_moribund(q))
312 			continue;
313 
314 		if (crypto_is_larval(q)) {
315 			if (!strcmp(alg->cra_driver_name, q->cra_driver_name))
316 				goto err;
317 			continue;
318 		}
319 
320 		if (!strcmp(q->cra_driver_name, alg->cra_name) ||
321 		    !strcmp(q->cra_driver_name, alg->cra_driver_name) ||
322 		    !strcmp(q->cra_name, alg->cra_driver_name))
323 			goto err;
324 	}
325 
326 	larval = crypto_alloc_test_larval(alg);
327 	if (IS_ERR(larval))
328 		goto out;
329 
330 	list_add(&alg->cra_list, &crypto_alg_list);
331 
332 	if (larval) {
333 		/* No cheating! */
334 		alg->cra_flags &= ~CRYPTO_ALG_TESTED;
335 
336 		list_add(&larval->alg.cra_list, &crypto_alg_list);
337 	} else {
338 		alg->cra_flags |= CRYPTO_ALG_TESTED;
339 		crypto_alg_finish_registration(alg, algs_to_put);
340 	}
341 
342 out:
343 	return larval;
344 
345 err:
346 	larval = ERR_PTR(ret);
347 	goto out;
348 }
349 
350 void crypto_alg_tested(const char *name, int err)
351 {
352 	struct crypto_larval *test;
353 	struct crypto_alg *alg;
354 	struct crypto_alg *q;
355 	LIST_HEAD(list);
356 
357 	down_write(&crypto_alg_sem);
358 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
359 		if (crypto_is_moribund(q) || !crypto_is_larval(q))
360 			continue;
361 
362 		test = (struct crypto_larval *)q;
363 
364 		if (!strcmp(q->cra_driver_name, name))
365 			goto found;
366 	}
367 
368 	pr_err("alg: Unexpected test result for %s: %d\n", name, err);
369 	up_write(&crypto_alg_sem);
370 	return;
371 
372 found:
373 	q->cra_flags |= CRYPTO_ALG_DEAD;
374 	alg = test->adult;
375 
376 	if (crypto_is_dead(alg))
377 		goto complete;
378 
379 	if (err == -ECANCELED)
380 		alg->cra_flags |= CRYPTO_ALG_FIPS_INTERNAL;
381 	else if (err)
382 		goto complete;
383 	else
384 		alg->cra_flags &= ~CRYPTO_ALG_FIPS_INTERNAL;
385 
386 	alg->cra_flags |= CRYPTO_ALG_TESTED;
387 
388 	crypto_alg_finish_registration(alg, &list);
389 
390 complete:
391 	list_del_init(&test->alg.cra_list);
392 	complete_all(&test->completion);
393 
394 	up_write(&crypto_alg_sem);
395 
396 	crypto_alg_put(&test->alg);
397 	crypto_remove_final(&list);
398 }
399 EXPORT_SYMBOL_GPL(crypto_alg_tested);
400 
401 void crypto_remove_final(struct list_head *list)
402 {
403 	struct crypto_alg *alg;
404 	struct crypto_alg *n;
405 
406 	list_for_each_entry_safe(alg, n, list, cra_list) {
407 		list_del_init(&alg->cra_list);
408 		crypto_alg_put(alg);
409 	}
410 }
411 EXPORT_SYMBOL_GPL(crypto_remove_final);
412 
413 int crypto_register_alg(struct crypto_alg *alg)
414 {
415 	struct crypto_larval *larval;
416 	LIST_HEAD(algs_to_put);
417 	int err;
418 
419 	alg->cra_flags &= ~CRYPTO_ALG_DEAD;
420 	err = crypto_check_alg(alg);
421 	if (err)
422 		return err;
423 
424 	down_write(&crypto_alg_sem);
425 	larval = __crypto_register_alg(alg, &algs_to_put);
426 	if (!IS_ERR_OR_NULL(larval)) {
427 		bool test_started = crypto_boot_test_finished();
428 
429 		larval->test_started = test_started;
430 		if (test_started)
431 			crypto_schedule_test(larval);
432 	}
433 	up_write(&crypto_alg_sem);
434 
435 	if (IS_ERR(larval))
436 		return PTR_ERR(larval);
437 	crypto_remove_final(&algs_to_put);
438 	return 0;
439 }
440 EXPORT_SYMBOL_GPL(crypto_register_alg);
441 
442 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
443 {
444 	if (unlikely(list_empty(&alg->cra_list)))
445 		return -ENOENT;
446 
447 	alg->cra_flags |= CRYPTO_ALG_DEAD;
448 
449 	list_del_init(&alg->cra_list);
450 	crypto_remove_spawns(alg, list, NULL);
451 
452 	return 0;
453 }
454 
455 void crypto_unregister_alg(struct crypto_alg *alg)
456 {
457 	int ret;
458 	LIST_HEAD(list);
459 
460 	down_write(&crypto_alg_sem);
461 	ret = crypto_remove_alg(alg, &list);
462 	up_write(&crypto_alg_sem);
463 
464 	if (WARN(ret, "Algorithm %s is not registered", alg->cra_driver_name))
465 		return;
466 
467 	if (WARN_ON(refcount_read(&alg->cra_refcnt) != 1))
468 		return;
469 
470 	if (alg->cra_destroy)
471 		alg->cra_destroy(alg);
472 
473 	crypto_remove_final(&list);
474 }
475 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
476 
477 int crypto_register_algs(struct crypto_alg *algs, int count)
478 {
479 	int i, ret;
480 
481 	for (i = 0; i < count; i++) {
482 		ret = crypto_register_alg(&algs[i]);
483 		if (ret)
484 			goto err;
485 	}
486 
487 	return 0;
488 
489 err:
490 	for (--i; i >= 0; --i)
491 		crypto_unregister_alg(&algs[i]);
492 
493 	return ret;
494 }
495 EXPORT_SYMBOL_GPL(crypto_register_algs);
496 
497 void crypto_unregister_algs(struct crypto_alg *algs, int count)
498 {
499 	int i;
500 
501 	for (i = 0; i < count; i++)
502 		crypto_unregister_alg(&algs[i]);
503 }
504 EXPORT_SYMBOL_GPL(crypto_unregister_algs);
505 
506 int crypto_register_template(struct crypto_template *tmpl)
507 {
508 	struct crypto_template *q;
509 	int err = -EEXIST;
510 
511 	down_write(&crypto_alg_sem);
512 
513 	crypto_check_module_sig(tmpl->module);
514 
515 	list_for_each_entry(q, &crypto_template_list, list) {
516 		if (q == tmpl)
517 			goto out;
518 	}
519 
520 	list_add(&tmpl->list, &crypto_template_list);
521 	err = 0;
522 out:
523 	up_write(&crypto_alg_sem);
524 	return err;
525 }
526 EXPORT_SYMBOL_GPL(crypto_register_template);
527 
528 int crypto_register_templates(struct crypto_template *tmpls, int count)
529 {
530 	int i, err;
531 
532 	for (i = 0; i < count; i++) {
533 		err = crypto_register_template(&tmpls[i]);
534 		if (err)
535 			goto out;
536 	}
537 	return 0;
538 
539 out:
540 	for (--i; i >= 0; --i)
541 		crypto_unregister_template(&tmpls[i]);
542 	return err;
543 }
544 EXPORT_SYMBOL_GPL(crypto_register_templates);
545 
546 void crypto_unregister_template(struct crypto_template *tmpl)
547 {
548 	struct crypto_instance *inst;
549 	struct hlist_node *n;
550 	struct hlist_head *list;
551 	LIST_HEAD(users);
552 
553 	down_write(&crypto_alg_sem);
554 
555 	BUG_ON(list_empty(&tmpl->list));
556 	list_del_init(&tmpl->list);
557 
558 	list = &tmpl->instances;
559 	hlist_for_each_entry(inst, list, list) {
560 		int err = crypto_remove_alg(&inst->alg, &users);
561 
562 		BUG_ON(err);
563 	}
564 
565 	up_write(&crypto_alg_sem);
566 
567 	hlist_for_each_entry_safe(inst, n, list, list) {
568 		BUG_ON(refcount_read(&inst->alg.cra_refcnt) != 1);
569 		crypto_free_instance(inst);
570 	}
571 	crypto_remove_final(&users);
572 }
573 EXPORT_SYMBOL_GPL(crypto_unregister_template);
574 
575 void crypto_unregister_templates(struct crypto_template *tmpls, int count)
576 {
577 	int i;
578 
579 	for (i = count - 1; i >= 0; --i)
580 		crypto_unregister_template(&tmpls[i]);
581 }
582 EXPORT_SYMBOL_GPL(crypto_unregister_templates);
583 
584 static struct crypto_template *__crypto_lookup_template(const char *name)
585 {
586 	struct crypto_template *q, *tmpl = NULL;
587 
588 	down_read(&crypto_alg_sem);
589 	list_for_each_entry(q, &crypto_template_list, list) {
590 		if (strcmp(q->name, name))
591 			continue;
592 		if (unlikely(!crypto_tmpl_get(q)))
593 			continue;
594 
595 		tmpl = q;
596 		break;
597 	}
598 	up_read(&crypto_alg_sem);
599 
600 	return tmpl;
601 }
602 
603 struct crypto_template *crypto_lookup_template(const char *name)
604 {
605 	return try_then_request_module(__crypto_lookup_template(name),
606 				       "crypto-%s", name);
607 }
608 EXPORT_SYMBOL_GPL(crypto_lookup_template);
609 
610 int crypto_register_instance(struct crypto_template *tmpl,
611 			     struct crypto_instance *inst)
612 {
613 	struct crypto_larval *larval;
614 	struct crypto_spawn *spawn;
615 	u32 fips_internal = 0;
616 	LIST_HEAD(algs_to_put);
617 	int err;
618 
619 	err = crypto_check_alg(&inst->alg);
620 	if (err)
621 		return err;
622 
623 	inst->alg.cra_module = tmpl->module;
624 	inst->alg.cra_flags |= CRYPTO_ALG_INSTANCE;
625 
626 	down_write(&crypto_alg_sem);
627 
628 	larval = ERR_PTR(-EAGAIN);
629 	for (spawn = inst->spawns; spawn;) {
630 		struct crypto_spawn *next;
631 
632 		if (spawn->dead)
633 			goto unlock;
634 
635 		next = spawn->next;
636 		spawn->inst = inst;
637 		spawn->registered = true;
638 
639 		fips_internal |= spawn->alg->cra_flags;
640 
641 		crypto_mod_put(spawn->alg);
642 
643 		spawn = next;
644 	}
645 
646 	inst->alg.cra_flags |= (fips_internal & CRYPTO_ALG_FIPS_INTERNAL);
647 
648 	larval = __crypto_register_alg(&inst->alg, &algs_to_put);
649 	if (IS_ERR(larval))
650 		goto unlock;
651 	else if (larval) {
652 		larval->test_started = true;
653 		crypto_schedule_test(larval);
654 	}
655 
656 	hlist_add_head(&inst->list, &tmpl->instances);
657 	inst->tmpl = tmpl;
658 
659 unlock:
660 	up_write(&crypto_alg_sem);
661 
662 	if (IS_ERR(larval))
663 		return PTR_ERR(larval);
664 	crypto_remove_final(&algs_to_put);
665 	return 0;
666 }
667 EXPORT_SYMBOL_GPL(crypto_register_instance);
668 
669 void crypto_unregister_instance(struct crypto_instance *inst)
670 {
671 	LIST_HEAD(list);
672 
673 	down_write(&crypto_alg_sem);
674 
675 	crypto_remove_spawns(&inst->alg, &list, NULL);
676 	crypto_remove_instance(inst, &list);
677 
678 	up_write(&crypto_alg_sem);
679 
680 	crypto_remove_final(&list);
681 }
682 EXPORT_SYMBOL_GPL(crypto_unregister_instance);
683 
684 int crypto_grab_spawn(struct crypto_spawn *spawn, struct crypto_instance *inst,
685 		      const char *name, u32 type, u32 mask)
686 {
687 	struct crypto_alg *alg;
688 	int err = -EAGAIN;
689 
690 	if (WARN_ON_ONCE(inst == NULL))
691 		return -EINVAL;
692 
693 	/* Allow the result of crypto_attr_alg_name() to be passed directly */
694 	if (IS_ERR(name))
695 		return PTR_ERR(name);
696 
697 	alg = crypto_find_alg(name, spawn->frontend,
698 			      type | CRYPTO_ALG_FIPS_INTERNAL, mask);
699 	if (IS_ERR(alg))
700 		return PTR_ERR(alg);
701 
702 	down_write(&crypto_alg_sem);
703 	if (!crypto_is_moribund(alg)) {
704 		list_add(&spawn->list, &alg->cra_users);
705 		spawn->alg = alg;
706 		spawn->mask = mask;
707 		spawn->next = inst->spawns;
708 		inst->spawns = spawn;
709 		inst->alg.cra_flags |=
710 			(alg->cra_flags & CRYPTO_ALG_INHERITED_FLAGS);
711 		err = 0;
712 	}
713 	up_write(&crypto_alg_sem);
714 	if (err)
715 		crypto_mod_put(alg);
716 	return err;
717 }
718 EXPORT_SYMBOL_GPL(crypto_grab_spawn);
719 
720 void crypto_drop_spawn(struct crypto_spawn *spawn)
721 {
722 	if (!spawn->alg) /* not yet initialized? */
723 		return;
724 
725 	down_write(&crypto_alg_sem);
726 	if (!spawn->dead)
727 		list_del(&spawn->list);
728 	up_write(&crypto_alg_sem);
729 
730 	if (!spawn->registered)
731 		crypto_mod_put(spawn->alg);
732 }
733 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
734 
735 static struct crypto_alg *crypto_spawn_alg(struct crypto_spawn *spawn)
736 {
737 	struct crypto_alg *alg = ERR_PTR(-EAGAIN);
738 	struct crypto_alg *target;
739 	bool shoot = false;
740 
741 	down_read(&crypto_alg_sem);
742 	if (!spawn->dead) {
743 		alg = spawn->alg;
744 		if (!crypto_mod_get(alg)) {
745 			target = crypto_alg_get(alg);
746 			shoot = true;
747 			alg = ERR_PTR(-EAGAIN);
748 		}
749 	}
750 	up_read(&crypto_alg_sem);
751 
752 	if (shoot) {
753 		crypto_shoot_alg(target);
754 		crypto_alg_put(target);
755 	}
756 
757 	return alg;
758 }
759 
760 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
761 				    u32 mask)
762 {
763 	struct crypto_alg *alg;
764 	struct crypto_tfm *tfm;
765 
766 	alg = crypto_spawn_alg(spawn);
767 	if (IS_ERR(alg))
768 		return ERR_CAST(alg);
769 
770 	tfm = ERR_PTR(-EINVAL);
771 	if (unlikely((alg->cra_flags ^ type) & mask))
772 		goto out_put_alg;
773 
774 	tfm = __crypto_alloc_tfm(alg, type, mask);
775 	if (IS_ERR(tfm))
776 		goto out_put_alg;
777 
778 	return tfm;
779 
780 out_put_alg:
781 	crypto_mod_put(alg);
782 	return tfm;
783 }
784 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
785 
786 void *crypto_spawn_tfm2(struct crypto_spawn *spawn)
787 {
788 	struct crypto_alg *alg;
789 	struct crypto_tfm *tfm;
790 
791 	alg = crypto_spawn_alg(spawn);
792 	if (IS_ERR(alg))
793 		return ERR_CAST(alg);
794 
795 	tfm = crypto_create_tfm(alg, spawn->frontend);
796 	if (IS_ERR(tfm))
797 		goto out_put_alg;
798 
799 	return tfm;
800 
801 out_put_alg:
802 	crypto_mod_put(alg);
803 	return tfm;
804 }
805 EXPORT_SYMBOL_GPL(crypto_spawn_tfm2);
806 
807 int crypto_register_notifier(struct notifier_block *nb)
808 {
809 	return blocking_notifier_chain_register(&crypto_chain, nb);
810 }
811 EXPORT_SYMBOL_GPL(crypto_register_notifier);
812 
813 int crypto_unregister_notifier(struct notifier_block *nb)
814 {
815 	return blocking_notifier_chain_unregister(&crypto_chain, nb);
816 }
817 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
818 
819 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
820 {
821 	struct rtattr *rta = tb[0];
822 	struct crypto_attr_type *algt;
823 
824 	if (!rta)
825 		return ERR_PTR(-ENOENT);
826 	if (RTA_PAYLOAD(rta) < sizeof(*algt))
827 		return ERR_PTR(-EINVAL);
828 	if (rta->rta_type != CRYPTOA_TYPE)
829 		return ERR_PTR(-EINVAL);
830 
831 	algt = RTA_DATA(rta);
832 
833 	return algt;
834 }
835 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
836 
837 /**
838  * crypto_check_attr_type() - check algorithm type and compute inherited mask
839  * @tb: the template parameters
840  * @type: the algorithm type the template would be instantiated as
841  * @mask_ret: (output) the mask that should be passed to crypto_grab_*()
842  *	      to restrict the flags of any inner algorithms
843  *
844  * Validate that the algorithm type the user requested is compatible with the
845  * one the template would actually be instantiated as.  E.g., if the user is
846  * doing crypto_alloc_shash("cbc(aes)", ...), this would return an error because
847  * the "cbc" template creates an "skcipher" algorithm, not an "shash" algorithm.
848  *
849  * Also compute the mask to use to restrict the flags of any inner algorithms.
850  *
851  * Return: 0 on success; -errno on failure
852  */
853 int crypto_check_attr_type(struct rtattr **tb, u32 type, u32 *mask_ret)
854 {
855 	struct crypto_attr_type *algt;
856 
857 	algt = crypto_get_attr_type(tb);
858 	if (IS_ERR(algt))
859 		return PTR_ERR(algt);
860 
861 	if ((algt->type ^ type) & algt->mask)
862 		return -EINVAL;
863 
864 	*mask_ret = crypto_algt_inherited_mask(algt);
865 	return 0;
866 }
867 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
868 
869 const char *crypto_attr_alg_name(struct rtattr *rta)
870 {
871 	struct crypto_attr_alg *alga;
872 
873 	if (!rta)
874 		return ERR_PTR(-ENOENT);
875 	if (RTA_PAYLOAD(rta) < sizeof(*alga))
876 		return ERR_PTR(-EINVAL);
877 	if (rta->rta_type != CRYPTOA_ALG)
878 		return ERR_PTR(-EINVAL);
879 
880 	alga = RTA_DATA(rta);
881 	alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
882 
883 	return alga->name;
884 }
885 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
886 
887 int crypto_inst_setname(struct crypto_instance *inst, const char *name,
888 			struct crypto_alg *alg)
889 {
890 	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
891 		     alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
892 		return -ENAMETOOLONG;
893 
894 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
895 		     name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
896 		return -ENAMETOOLONG;
897 
898 	return 0;
899 }
900 EXPORT_SYMBOL_GPL(crypto_inst_setname);
901 
902 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
903 {
904 	INIT_LIST_HEAD(&queue->list);
905 	queue->backlog = &queue->list;
906 	queue->qlen = 0;
907 	queue->max_qlen = max_qlen;
908 }
909 EXPORT_SYMBOL_GPL(crypto_init_queue);
910 
911 int crypto_enqueue_request(struct crypto_queue *queue,
912 			   struct crypto_async_request *request)
913 {
914 	int err = -EINPROGRESS;
915 
916 	if (unlikely(queue->qlen >= queue->max_qlen)) {
917 		if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) {
918 			err = -ENOSPC;
919 			goto out;
920 		}
921 		err = -EBUSY;
922 		if (queue->backlog == &queue->list)
923 			queue->backlog = &request->list;
924 	}
925 
926 	queue->qlen++;
927 	list_add_tail(&request->list, &queue->list);
928 
929 out:
930 	return err;
931 }
932 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
933 
934 void crypto_enqueue_request_head(struct crypto_queue *queue,
935 				 struct crypto_async_request *request)
936 {
937 	if (unlikely(queue->qlen >= queue->max_qlen))
938 		queue->backlog = queue->backlog->prev;
939 
940 	queue->qlen++;
941 	list_add(&request->list, &queue->list);
942 }
943 EXPORT_SYMBOL_GPL(crypto_enqueue_request_head);
944 
945 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
946 {
947 	struct list_head *request;
948 
949 	if (unlikely(!queue->qlen))
950 		return NULL;
951 
952 	queue->qlen--;
953 
954 	if (queue->backlog != &queue->list)
955 		queue->backlog = queue->backlog->next;
956 
957 	request = queue->list.next;
958 	list_del(request);
959 
960 	return list_entry(request, struct crypto_async_request, list);
961 }
962 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
963 
964 static inline void crypto_inc_byte(u8 *a, unsigned int size)
965 {
966 	u8 *b = (a + size);
967 	u8 c;
968 
969 	for (; size; size--) {
970 		c = *--b + 1;
971 		*b = c;
972 		if (c)
973 			break;
974 	}
975 }
976 
977 void crypto_inc(u8 *a, unsigned int size)
978 {
979 	__be32 *b = (__be32 *)(a + size);
980 	u32 c;
981 
982 	if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ||
983 	    IS_ALIGNED((unsigned long)b, __alignof__(*b)))
984 		for (; size >= 4; size -= 4) {
985 			c = be32_to_cpu(*--b) + 1;
986 			*b = cpu_to_be32(c);
987 			if (likely(c))
988 				return;
989 		}
990 
991 	crypto_inc_byte(a, size);
992 }
993 EXPORT_SYMBOL_GPL(crypto_inc);
994 
995 unsigned int crypto_alg_extsize(struct crypto_alg *alg)
996 {
997 	return alg->cra_ctxsize +
998 	       (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));
999 }
1000 EXPORT_SYMBOL_GPL(crypto_alg_extsize);
1001 
1002 int crypto_type_has_alg(const char *name, const struct crypto_type *frontend,
1003 			u32 type, u32 mask)
1004 {
1005 	int ret = 0;
1006 	struct crypto_alg *alg = crypto_find_alg(name, frontend, type, mask);
1007 
1008 	if (!IS_ERR(alg)) {
1009 		crypto_mod_put(alg);
1010 		ret = 1;
1011 	}
1012 
1013 	return ret;
1014 }
1015 EXPORT_SYMBOL_GPL(crypto_type_has_alg);
1016 
1017 static void __init crypto_start_tests(void)
1018 {
1019 	if (!IS_BUILTIN(CONFIG_CRYPTO_ALGAPI))
1020 		return;
1021 
1022 	if (IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS))
1023 		return;
1024 
1025 	for (;;) {
1026 		struct crypto_larval *larval = NULL;
1027 		struct crypto_alg *q;
1028 
1029 		down_write(&crypto_alg_sem);
1030 
1031 		list_for_each_entry(q, &crypto_alg_list, cra_list) {
1032 			struct crypto_larval *l;
1033 
1034 			if (!crypto_is_larval(q))
1035 				continue;
1036 
1037 			l = (void *)q;
1038 
1039 			if (!crypto_is_test_larval(l))
1040 				continue;
1041 
1042 			if (l->test_started)
1043 				continue;
1044 
1045 			l->test_started = true;
1046 			larval = l;
1047 			crypto_schedule_test(larval);
1048 			break;
1049 		}
1050 
1051 		up_write(&crypto_alg_sem);
1052 
1053 		if (!larval)
1054 			break;
1055 	}
1056 
1057 	set_crypto_boot_test_finished();
1058 }
1059 
1060 static int __init crypto_algapi_init(void)
1061 {
1062 	crypto_init_proc();
1063 	crypto_start_tests();
1064 	return 0;
1065 }
1066 
1067 static void __exit crypto_algapi_exit(void)
1068 {
1069 	crypto_exit_proc();
1070 }
1071 
1072 /*
1073  * We run this at late_initcall so that all the built-in algorithms
1074  * have had a chance to register themselves first.
1075  */
1076 late_initcall(crypto_algapi_init);
1077 module_exit(crypto_algapi_exit);
1078 
1079 MODULE_LICENSE("GPL");
1080 MODULE_DESCRIPTION("Cryptographic algorithms API");
1081 MODULE_SOFTDEP("pre: cryptomgr");
1082