xref: /linux/crypto/api.c (revision 85ffc6e4ed3712f8b3fedb3fbe42afae644a699c)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Scatterlist Cryptographic API.
4  *
5  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
6  * Copyright (c) 2002 David S. Miller (davem@redhat.com)
7  * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
8  *
9  * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
10  * and Nettle, by Niels Möller.
11  */
12 
13 #include <linux/err.h>
14 #include <linux/errno.h>
15 #include <linux/jump_label.h>
16 #include <linux/kernel.h>
17 #include <linux/kmod.h>
18 #include <linux/module.h>
19 #include <linux/param.h>
20 #include <linux/sched/signal.h>
21 #include <linux/slab.h>
22 #include <linux/string.h>
23 #include <linux/completion.h>
24 #include "internal.h"
25 
26 LIST_HEAD(crypto_alg_list);
27 EXPORT_SYMBOL_GPL(crypto_alg_list);
28 DECLARE_RWSEM(crypto_alg_sem);
29 EXPORT_SYMBOL_GPL(crypto_alg_sem);
30 
31 BLOCKING_NOTIFIER_HEAD(crypto_chain);
32 EXPORT_SYMBOL_GPL(crypto_chain);
33 
34 #if IS_BUILTIN(CONFIG_CRYPTO_ALGAPI) && \
35     !IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS)
36 DEFINE_STATIC_KEY_FALSE(__crypto_boot_test_finished);
37 #endif
38 
39 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
40 static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
41 					    u32 mask);
42 
crypto_mod_get(struct crypto_alg * alg)43 struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
44 {
45 	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
46 }
47 EXPORT_SYMBOL_GPL(crypto_mod_get);
48 
crypto_mod_put(struct crypto_alg * alg)49 void crypto_mod_put(struct crypto_alg *alg)
50 {
51 	struct module *module = alg->cra_module;
52 
53 	crypto_alg_put(alg);
54 	module_put(module);
55 }
56 EXPORT_SYMBOL_GPL(crypto_mod_put);
57 
__crypto_alg_lookup(const char * name,u32 type,u32 mask)58 static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
59 					      u32 mask)
60 {
61 	struct crypto_alg *q, *alg = NULL;
62 	int best = -2;
63 
64 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
65 		int exact, fuzzy;
66 
67 		if (crypto_is_moribund(q))
68 			continue;
69 
70 		if ((q->cra_flags ^ type) & mask)
71 			continue;
72 
73 		exact = !strcmp(q->cra_driver_name, name);
74 		fuzzy = !strcmp(q->cra_name, name);
75 		if (!exact && !(fuzzy && q->cra_priority > best))
76 			continue;
77 
78 		if (unlikely(!crypto_mod_get(q)))
79 			continue;
80 
81 		best = q->cra_priority;
82 		if (alg)
83 			crypto_mod_put(alg);
84 		alg = q;
85 
86 		if (exact)
87 			break;
88 	}
89 
90 	return alg;
91 }
92 
crypto_larval_destroy(struct crypto_alg * alg)93 static void crypto_larval_destroy(struct crypto_alg *alg)
94 {
95 	struct crypto_larval *larval = (void *)alg;
96 
97 	BUG_ON(!crypto_is_larval(alg));
98 	if (!IS_ERR_OR_NULL(larval->adult))
99 		crypto_mod_put(larval->adult);
100 	kfree(larval);
101 }
102 
crypto_larval_alloc(const char * name,u32 type,u32 mask)103 struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
104 {
105 	struct crypto_larval *larval;
106 
107 	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
108 	if (!larval)
109 		return ERR_PTR(-ENOMEM);
110 
111 	type &= ~CRYPTO_ALG_TYPE_MASK | (mask ?: CRYPTO_ALG_TYPE_MASK);
112 
113 	larval->mask = mask;
114 	larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
115 	larval->alg.cra_priority = -1;
116 	larval->alg.cra_destroy = crypto_larval_destroy;
117 
118 	strscpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
119 	init_completion(&larval->completion);
120 
121 	return larval;
122 }
123 EXPORT_SYMBOL_GPL(crypto_larval_alloc);
124 
crypto_larval_add(const char * name,u32 type,u32 mask)125 static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
126 					    u32 mask)
127 {
128 	struct crypto_alg *alg;
129 	struct crypto_larval *larval;
130 
131 	larval = crypto_larval_alloc(name, type, mask);
132 	if (IS_ERR(larval))
133 		return ERR_CAST(larval);
134 
135 	refcount_set(&larval->alg.cra_refcnt, 2);
136 
137 	down_write(&crypto_alg_sem);
138 	alg = __crypto_alg_lookup(name, type, mask);
139 	if (!alg) {
140 		alg = &larval->alg;
141 		list_add(&alg->cra_list, &crypto_alg_list);
142 	}
143 	up_write(&crypto_alg_sem);
144 
145 	if (alg != &larval->alg) {
146 		kfree(larval);
147 		if (crypto_is_larval(alg))
148 			alg = crypto_larval_wait(alg);
149 	}
150 
151 	return alg;
152 }
153 
crypto_larval_kill(struct crypto_larval * larval)154 static void crypto_larval_kill(struct crypto_larval *larval)
155 {
156 	bool unlinked;
157 
158 	down_write(&crypto_alg_sem);
159 	unlinked = list_empty(&larval->alg.cra_list);
160 	if (!unlinked)
161 		list_del_init(&larval->alg.cra_list);
162 	up_write(&crypto_alg_sem);
163 
164 	if (unlinked)
165 		return;
166 
167 	complete_all(&larval->completion);
168 	crypto_alg_put(&larval->alg);
169 }
170 
crypto_schedule_test(struct crypto_larval * larval)171 void crypto_schedule_test(struct crypto_larval *larval)
172 {
173 	int err;
174 
175 	err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
176 	WARN_ON_ONCE(err != NOTIFY_STOP);
177 }
178 EXPORT_SYMBOL_GPL(crypto_schedule_test);
179 
crypto_start_test(struct crypto_larval * larval)180 static void crypto_start_test(struct crypto_larval *larval)
181 {
182 	if (!crypto_is_test_larval(larval))
183 		return;
184 
185 	if (larval->test_started)
186 		return;
187 
188 	down_write(&crypto_alg_sem);
189 	if (larval->test_started) {
190 		up_write(&crypto_alg_sem);
191 		return;
192 	}
193 
194 	larval->test_started = true;
195 	up_write(&crypto_alg_sem);
196 
197 	crypto_schedule_test(larval);
198 }
199 
crypto_larval_wait(struct crypto_alg * alg)200 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
201 {
202 	struct crypto_larval *larval;
203 	long time_left;
204 
205 again:
206 	larval = container_of(alg, struct crypto_larval, alg);
207 
208 	if (!crypto_boot_test_finished())
209 		crypto_start_test(larval);
210 
211 	time_left = wait_for_completion_killable_timeout(
212 		&larval->completion, 60 * HZ);
213 
214 	alg = larval->adult;
215 	if (time_left < 0)
216 		alg = ERR_PTR(-EINTR);
217 	else if (!time_left) {
218 		if (crypto_is_test_larval(larval))
219 			crypto_larval_kill(larval);
220 		alg = ERR_PTR(-ETIMEDOUT);
221 	} else if (!alg) {
222 		u32 type;
223 		u32 mask;
224 
225 		alg = &larval->alg;
226 		type = alg->cra_flags & ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
227 		mask = larval->mask;
228 		alg = crypto_alg_lookup(alg->cra_name, type, mask) ?:
229 		      ERR_PTR(-EAGAIN);
230 	} else if (IS_ERR(alg))
231 		;
232 	else if (crypto_is_test_larval(larval) &&
233 		 !(alg->cra_flags & CRYPTO_ALG_TESTED))
234 		alg = ERR_PTR(-EAGAIN);
235 	else if (alg->cra_flags & CRYPTO_ALG_FIPS_INTERNAL)
236 		alg = ERR_PTR(-EAGAIN);
237 	else if (!crypto_mod_get(alg))
238 		alg = ERR_PTR(-EAGAIN);
239 	crypto_mod_put(&larval->alg);
240 
241 	if (!IS_ERR(alg) && crypto_is_larval(alg))
242 		goto again;
243 
244 	return alg;
245 }
246 
crypto_alg_lookup(const char * name,u32 type,u32 mask)247 static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
248 					    u32 mask)
249 {
250 	const u32 fips = CRYPTO_ALG_FIPS_INTERNAL;
251 	struct crypto_alg *alg;
252 	u32 test = 0;
253 
254 	if (!((type | mask) & CRYPTO_ALG_TESTED))
255 		test |= CRYPTO_ALG_TESTED;
256 
257 	down_read(&crypto_alg_sem);
258 	alg = __crypto_alg_lookup(name, (type | test) & ~fips,
259 				  (mask | test) & ~fips);
260 	if (alg) {
261 		if (((type | mask) ^ fips) & fips)
262 			mask |= fips;
263 		mask &= fips;
264 
265 		if (!crypto_is_larval(alg) &&
266 		    ((type ^ alg->cra_flags) & mask)) {
267 			/* Algorithm is disallowed in FIPS mode. */
268 			crypto_mod_put(alg);
269 			alg = ERR_PTR(-ENOENT);
270 		}
271 	} else if (test) {
272 		alg = __crypto_alg_lookup(name, type, mask);
273 		if (alg && !crypto_is_larval(alg)) {
274 			/* Test failed */
275 			crypto_mod_put(alg);
276 			alg = ERR_PTR(-ELIBBAD);
277 		}
278 	}
279 	up_read(&crypto_alg_sem);
280 
281 	return alg;
282 }
283 
crypto_larval_lookup(const char * name,u32 type,u32 mask)284 static struct crypto_alg *crypto_larval_lookup(const char *name, u32 type,
285 					       u32 mask)
286 {
287 	struct crypto_alg *alg;
288 
289 	if (!name)
290 		return ERR_PTR(-ENOENT);
291 
292 	type &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
293 	mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
294 
295 	alg = crypto_alg_lookup(name, type, mask);
296 	if (!alg && !(mask & CRYPTO_NOLOAD)) {
297 		request_module("crypto-%s", name);
298 
299 		if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
300 		      CRYPTO_ALG_NEED_FALLBACK))
301 			request_module("crypto-%s-all", name);
302 
303 		alg = crypto_alg_lookup(name, type, mask);
304 	}
305 
306 	if (!IS_ERR_OR_NULL(alg) && crypto_is_larval(alg))
307 		alg = crypto_larval_wait(alg);
308 	else if (alg)
309 		;
310 	else if (!(mask & CRYPTO_ALG_TESTED))
311 		alg = crypto_larval_add(name, type, mask);
312 	else
313 		alg = ERR_PTR(-ENOENT);
314 
315 	return alg;
316 }
317 
crypto_probing_notify(unsigned long val,void * v)318 int crypto_probing_notify(unsigned long val, void *v)
319 {
320 	int ok;
321 
322 	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
323 	if (ok == NOTIFY_DONE) {
324 		request_module("cryptomgr");
325 		ok = blocking_notifier_call_chain(&crypto_chain, val, v);
326 	}
327 
328 	return ok;
329 }
330 EXPORT_SYMBOL_GPL(crypto_probing_notify);
331 
crypto_alg_mod_lookup(const char * name,u32 type,u32 mask)332 struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
333 {
334 	struct crypto_alg *alg;
335 	struct crypto_alg *larval;
336 	int ok;
337 
338 	/*
339 	 * If the internal flag is set for a cipher, require a caller to
340 	 * invoke the cipher with the internal flag to use that cipher.
341 	 * Also, if a caller wants to allocate a cipher that may or may
342 	 * not be an internal cipher, use type | CRYPTO_ALG_INTERNAL and
343 	 * !(mask & CRYPTO_ALG_INTERNAL).
344 	 */
345 	if (!((type | mask) & CRYPTO_ALG_INTERNAL))
346 		mask |= CRYPTO_ALG_INTERNAL;
347 
348 	larval = crypto_larval_lookup(name, type, mask);
349 	if (IS_ERR(larval) || !crypto_is_larval(larval))
350 		return larval;
351 
352 	ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
353 
354 	if (ok == NOTIFY_STOP)
355 		alg = crypto_larval_wait(larval);
356 	else {
357 		crypto_mod_put(larval);
358 		alg = ERR_PTR(-ENOENT);
359 	}
360 	crypto_larval_kill(container_of(larval, struct crypto_larval, alg));
361 	return alg;
362 }
363 EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
364 
crypto_exit_ops(struct crypto_tfm * tfm)365 static void crypto_exit_ops(struct crypto_tfm *tfm)
366 {
367 	const struct crypto_type *type = tfm->__crt_alg->cra_type;
368 
369 	if (type && tfm->exit)
370 		tfm->exit(tfm);
371 }
372 
crypto_ctxsize(struct crypto_alg * alg,u32 type,u32 mask)373 static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
374 {
375 	const struct crypto_type *type_obj = alg->cra_type;
376 	unsigned int len;
377 
378 	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
379 	if (type_obj)
380 		return len + type_obj->ctxsize(alg, type, mask);
381 
382 	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
383 	default:
384 		BUG();
385 
386 	case CRYPTO_ALG_TYPE_CIPHER:
387 		len += crypto_cipher_ctxsize(alg);
388 		break;
389 
390 	case CRYPTO_ALG_TYPE_COMPRESS:
391 		len += crypto_compress_ctxsize(alg);
392 		break;
393 	}
394 
395 	return len;
396 }
397 
crypto_shoot_alg(struct crypto_alg * alg)398 void crypto_shoot_alg(struct crypto_alg *alg)
399 {
400 	down_write(&crypto_alg_sem);
401 	alg->cra_flags |= CRYPTO_ALG_DYING;
402 	up_write(&crypto_alg_sem);
403 }
404 EXPORT_SYMBOL_GPL(crypto_shoot_alg);
405 
__crypto_alloc_tfmgfp(struct crypto_alg * alg,u32 type,u32 mask,gfp_t gfp)406 struct crypto_tfm *__crypto_alloc_tfmgfp(struct crypto_alg *alg, u32 type,
407 					 u32 mask, gfp_t gfp)
408 {
409 	struct crypto_tfm *tfm;
410 	unsigned int tfm_size;
411 	int err = -ENOMEM;
412 
413 	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
414 	tfm = kzalloc(tfm_size, gfp);
415 	if (tfm == NULL)
416 		goto out_err;
417 
418 	tfm->__crt_alg = alg;
419 	refcount_set(&tfm->refcnt, 1);
420 
421 	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
422 		goto cra_init_failed;
423 
424 	goto out;
425 
426 cra_init_failed:
427 	crypto_exit_ops(tfm);
428 	if (err == -EAGAIN)
429 		crypto_shoot_alg(alg);
430 	kfree(tfm);
431 out_err:
432 	tfm = ERR_PTR(err);
433 out:
434 	return tfm;
435 }
436 EXPORT_SYMBOL_GPL(__crypto_alloc_tfmgfp);
437 
__crypto_alloc_tfm(struct crypto_alg * alg,u32 type,u32 mask)438 struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
439 				      u32 mask)
440 {
441 	return __crypto_alloc_tfmgfp(alg, type, mask, GFP_KERNEL);
442 }
443 EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
444 
445 /*
446  *	crypto_alloc_base - Locate algorithm and allocate transform
447  *	@alg_name: Name of algorithm
448  *	@type: Type of algorithm
449  *	@mask: Mask for type comparison
450  *
451  *	This function should not be used by new algorithm types.
452  *	Please use crypto_alloc_tfm instead.
453  *
454  *	crypto_alloc_base() will first attempt to locate an already loaded
455  *	algorithm.  If that fails and the kernel supports dynamically loadable
456  *	modules, it will then attempt to load a module of the same name or
457  *	alias.  If that fails it will send a query to any loaded crypto manager
458  *	to construct an algorithm on the fly.  A refcount is grabbed on the
459  *	algorithm which is then associated with the new transform.
460  *
461  *	The returned transform is of a non-determinate type.  Most people
462  *	should use one of the more specific allocation functions such as
463  *	crypto_alloc_skcipher().
464  *
465  *	In case of error the return value is an error pointer.
466  */
crypto_alloc_base(const char * alg_name,u32 type,u32 mask)467 struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
468 {
469 	struct crypto_tfm *tfm;
470 	int err;
471 
472 	for (;;) {
473 		struct crypto_alg *alg;
474 
475 		alg = crypto_alg_mod_lookup(alg_name, type, mask);
476 		if (IS_ERR(alg)) {
477 			err = PTR_ERR(alg);
478 			goto err;
479 		}
480 
481 		tfm = __crypto_alloc_tfm(alg, type, mask);
482 		if (!IS_ERR(tfm))
483 			return tfm;
484 
485 		crypto_mod_put(alg);
486 		err = PTR_ERR(tfm);
487 
488 err:
489 		if (err != -EAGAIN)
490 			break;
491 		if (fatal_signal_pending(current)) {
492 			err = -EINTR;
493 			break;
494 		}
495 	}
496 
497 	return ERR_PTR(err);
498 }
499 EXPORT_SYMBOL_GPL(crypto_alloc_base);
500 
crypto_alloc_tfmmem(struct crypto_alg * alg,const struct crypto_type * frontend,int node,gfp_t gfp)501 static void *crypto_alloc_tfmmem(struct crypto_alg *alg,
502 				 const struct crypto_type *frontend, int node,
503 				 gfp_t gfp)
504 {
505 	struct crypto_tfm *tfm;
506 	unsigned int tfmsize;
507 	unsigned int total;
508 	char *mem;
509 
510 	tfmsize = frontend->tfmsize;
511 	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
512 
513 	mem = kzalloc_node(total, gfp, node);
514 	if (mem == NULL)
515 		return ERR_PTR(-ENOMEM);
516 
517 	tfm = (struct crypto_tfm *)(mem + tfmsize);
518 	tfm->__crt_alg = alg;
519 	tfm->node = node;
520 	refcount_set(&tfm->refcnt, 1);
521 
522 	return mem;
523 }
524 
crypto_create_tfm_node(struct crypto_alg * alg,const struct crypto_type * frontend,int node)525 void *crypto_create_tfm_node(struct crypto_alg *alg,
526 			     const struct crypto_type *frontend,
527 			     int node)
528 {
529 	struct crypto_tfm *tfm;
530 	char *mem;
531 	int err;
532 
533 	mem = crypto_alloc_tfmmem(alg, frontend, node, GFP_KERNEL);
534 	if (IS_ERR(mem))
535 		goto out;
536 
537 	tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
538 
539 	err = frontend->init_tfm(tfm);
540 	if (err)
541 		goto out_free_tfm;
542 
543 	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
544 		goto cra_init_failed;
545 
546 	goto out;
547 
548 cra_init_failed:
549 	crypto_exit_ops(tfm);
550 out_free_tfm:
551 	if (err == -EAGAIN)
552 		crypto_shoot_alg(alg);
553 	kfree(mem);
554 	mem = ERR_PTR(err);
555 out:
556 	return mem;
557 }
558 EXPORT_SYMBOL_GPL(crypto_create_tfm_node);
559 
crypto_clone_tfm(const struct crypto_type * frontend,struct crypto_tfm * otfm)560 void *crypto_clone_tfm(const struct crypto_type *frontend,
561 		       struct crypto_tfm *otfm)
562 {
563 	struct crypto_alg *alg = otfm->__crt_alg;
564 	struct crypto_tfm *tfm;
565 	char *mem;
566 
567 	mem = ERR_PTR(-ESTALE);
568 	if (unlikely(!crypto_mod_get(alg)))
569 		goto out;
570 
571 	mem = crypto_alloc_tfmmem(alg, frontend, otfm->node, GFP_ATOMIC);
572 	if (IS_ERR(mem)) {
573 		crypto_mod_put(alg);
574 		goto out;
575 	}
576 
577 	tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
578 	tfm->crt_flags = otfm->crt_flags;
579 	tfm->exit = otfm->exit;
580 
581 out:
582 	return mem;
583 }
584 EXPORT_SYMBOL_GPL(crypto_clone_tfm);
585 
crypto_find_alg(const char * alg_name,const struct crypto_type * frontend,u32 type,u32 mask)586 struct crypto_alg *crypto_find_alg(const char *alg_name,
587 				   const struct crypto_type *frontend,
588 				   u32 type, u32 mask)
589 {
590 	if (frontend) {
591 		type &= frontend->maskclear;
592 		mask &= frontend->maskclear;
593 		type |= frontend->type;
594 		mask |= frontend->maskset;
595 	}
596 
597 	return crypto_alg_mod_lookup(alg_name, type, mask);
598 }
599 EXPORT_SYMBOL_GPL(crypto_find_alg);
600 
601 /*
602  *	crypto_alloc_tfm_node - Locate algorithm and allocate transform
603  *	@alg_name: Name of algorithm
604  *	@frontend: Frontend algorithm type
605  *	@type: Type of algorithm
606  *	@mask: Mask for type comparison
607  *	@node: NUMA node in which users desire to put requests, if node is
608  *		NUMA_NO_NODE, it means users have no special requirement.
609  *
610  *	crypto_alloc_tfm() will first attempt to locate an already loaded
611  *	algorithm.  If that fails and the kernel supports dynamically loadable
612  *	modules, it will then attempt to load a module of the same name or
613  *	alias.  If that fails it will send a query to any loaded crypto manager
614  *	to construct an algorithm on the fly.  A refcount is grabbed on the
615  *	algorithm which is then associated with the new transform.
616  *
617  *	The returned transform is of a non-determinate type.  Most people
618  *	should use one of the more specific allocation functions such as
619  *	crypto_alloc_skcipher().
620  *
621  *	In case of error the return value is an error pointer.
622  */
623 
crypto_alloc_tfm_node(const char * alg_name,const struct crypto_type * frontend,u32 type,u32 mask,int node)624 void *crypto_alloc_tfm_node(const char *alg_name,
625 		       const struct crypto_type *frontend, u32 type, u32 mask,
626 		       int node)
627 {
628 	void *tfm;
629 	int err;
630 
631 	for (;;) {
632 		struct crypto_alg *alg;
633 
634 		alg = crypto_find_alg(alg_name, frontend, type, mask);
635 		if (IS_ERR(alg)) {
636 			err = PTR_ERR(alg);
637 			goto err;
638 		}
639 
640 		tfm = crypto_create_tfm_node(alg, frontend, node);
641 		if (!IS_ERR(tfm))
642 			return tfm;
643 
644 		crypto_mod_put(alg);
645 		err = PTR_ERR(tfm);
646 
647 err:
648 		if (err != -EAGAIN)
649 			break;
650 		if (fatal_signal_pending(current)) {
651 			err = -EINTR;
652 			break;
653 		}
654 	}
655 
656 	return ERR_PTR(err);
657 }
658 EXPORT_SYMBOL_GPL(crypto_alloc_tfm_node);
659 
660 /*
661  *	crypto_destroy_tfm - Free crypto transform
662  *	@mem: Start of tfm slab
663  *	@tfm: Transform to free
664  *
665  *	This function frees up the transform and any associated resources,
666  *	then drops the refcount on the associated algorithm.
667  */
crypto_destroy_tfm(void * mem,struct crypto_tfm * tfm)668 void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
669 {
670 	struct crypto_alg *alg;
671 
672 	if (IS_ERR_OR_NULL(mem))
673 		return;
674 
675 	if (!refcount_dec_and_test(&tfm->refcnt))
676 		return;
677 	alg = tfm->__crt_alg;
678 
679 	if (!tfm->exit && alg->cra_exit)
680 		alg->cra_exit(tfm);
681 	crypto_exit_ops(tfm);
682 	crypto_mod_put(alg);
683 	kfree_sensitive(mem);
684 }
685 EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
686 
crypto_has_alg(const char * name,u32 type,u32 mask)687 int crypto_has_alg(const char *name, u32 type, u32 mask)
688 {
689 	int ret = 0;
690 	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
691 
692 	if (!IS_ERR(alg)) {
693 		crypto_mod_put(alg);
694 		ret = 1;
695 	}
696 
697 	return ret;
698 }
699 EXPORT_SYMBOL_GPL(crypto_has_alg);
700 
crypto_req_done(void * data,int err)701 void crypto_req_done(void *data, int err)
702 {
703 	struct crypto_wait *wait = data;
704 
705 	if (err == -EINPROGRESS)
706 		return;
707 
708 	wait->err = err;
709 	complete(&wait->completion);
710 }
711 EXPORT_SYMBOL_GPL(crypto_req_done);
712 
713 MODULE_DESCRIPTION("Cryptographic core API");
714 MODULE_LICENSE("GPL");
715