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v6.8
  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
 26LIST_HEAD(crypto_alg_list);
 27EXPORT_SYMBOL_GPL(crypto_alg_list);
 28DECLARE_RWSEM(crypto_alg_sem);
 29EXPORT_SYMBOL_GPL(crypto_alg_sem);
 30
 31BLOCKING_NOTIFIER_HEAD(crypto_chain);
 32EXPORT_SYMBOL_GPL(crypto_chain);
 33
 34#ifndef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS
 35DEFINE_STATIC_KEY_FALSE(__crypto_boot_test_finished);
 36EXPORT_SYMBOL_GPL(__crypto_boot_test_finished);
 37#endif
 38
 39static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
 40
 41struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
 42{
 43	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
 44}
 45EXPORT_SYMBOL_GPL(crypto_mod_get);
 46
 47void crypto_mod_put(struct crypto_alg *alg)
 48{
 49	struct module *module = alg->cra_module;
 50
 51	crypto_alg_put(alg);
 52	module_put(module);
 53}
 54EXPORT_SYMBOL_GPL(crypto_mod_put);
 55
 
 
 
 
 
 56static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
 57					      u32 mask)
 58{
 59	struct crypto_alg *q, *alg = NULL;
 60	int best = -2;
 61
 62	list_for_each_entry(q, &crypto_alg_list, cra_list) {
 63		int exact, fuzzy;
 64
 65		if (crypto_is_moribund(q))
 66			continue;
 67
 68		if ((q->cra_flags ^ type) & mask)
 69			continue;
 70
 71		if (crypto_is_larval(q) &&
 72		    !crypto_is_test_larval((struct crypto_larval *)q) &&
 73		    ((struct crypto_larval *)q)->mask != mask)
 74			continue;
 75
 76		exact = !strcmp(q->cra_driver_name, name);
 77		fuzzy = !strcmp(q->cra_name, name);
 78		if (!exact && !(fuzzy && q->cra_priority > best))
 79			continue;
 80
 81		if (unlikely(!crypto_mod_get(q)))
 82			continue;
 83
 84		best = q->cra_priority;
 85		if (alg)
 86			crypto_mod_put(alg);
 87		alg = q;
 88
 89		if (exact)
 90			break;
 91	}
 92
 93	return alg;
 94}
 95
 96static void crypto_larval_destroy(struct crypto_alg *alg)
 97{
 98	struct crypto_larval *larval = (void *)alg;
 99
100	BUG_ON(!crypto_is_larval(alg));
101	if (!IS_ERR_OR_NULL(larval->adult))
102		crypto_mod_put(larval->adult);
103	kfree(larval);
104}
105
106struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
107{
108	struct crypto_larval *larval;
109
110	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
111	if (!larval)
112		return ERR_PTR(-ENOMEM);
113
114	larval->mask = mask;
115	larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
116	larval->alg.cra_priority = -1;
117	larval->alg.cra_destroy = crypto_larval_destroy;
118
119	strscpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
120	init_completion(&larval->completion);
121
122	return larval;
123}
124EXPORT_SYMBOL_GPL(crypto_larval_alloc);
125
126static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
127					    u32 mask)
128{
129	struct crypto_alg *alg;
130	struct crypto_larval *larval;
131
132	larval = crypto_larval_alloc(name, type, mask);
133	if (IS_ERR(larval))
134		return ERR_CAST(larval);
135
136	refcount_set(&larval->alg.cra_refcnt, 2);
137
138	down_write(&crypto_alg_sem);
139	alg = __crypto_alg_lookup(name, type, mask);
140	if (!alg) {
141		alg = &larval->alg;
142		list_add(&alg->cra_list, &crypto_alg_list);
143	}
144	up_write(&crypto_alg_sem);
145
146	if (alg != &larval->alg) {
147		kfree(larval);
148		if (crypto_is_larval(alg))
149			alg = crypto_larval_wait(alg);
150	}
151
152	return alg;
153}
154
155void crypto_larval_kill(struct crypto_alg *alg)
156{
157	struct crypto_larval *larval = (void *)alg;
158
159	down_write(&crypto_alg_sem);
160	list_del(&alg->cra_list);
161	up_write(&crypto_alg_sem);
162	complete_all(&larval->completion);
163	crypto_alg_put(alg);
164}
165EXPORT_SYMBOL_GPL(crypto_larval_kill);
166
167void crypto_wait_for_test(struct crypto_larval *larval)
168{
169	int err;
170
171	err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
172	if (WARN_ON_ONCE(err != NOTIFY_STOP))
173		goto out;
174
175	err = wait_for_completion_killable(&larval->completion);
176	WARN_ON(err);
177out:
178	crypto_larval_kill(&larval->alg);
179}
180EXPORT_SYMBOL_GPL(crypto_wait_for_test);
181
182static void crypto_start_test(struct crypto_larval *larval)
183{
184	if (!crypto_is_test_larval(larval))
185		return;
186
187	if (larval->test_started)
188		return;
189
190	down_write(&crypto_alg_sem);
191	if (larval->test_started) {
192		up_write(&crypto_alg_sem);
193		return;
194	}
195
196	larval->test_started = true;
197	up_write(&crypto_alg_sem);
198
199	crypto_wait_for_test(larval);
200}
201
202static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
203{
204	struct crypto_larval *larval = (void *)alg;
205	long timeout;
206
207	if (!crypto_boot_test_finished())
208		crypto_start_test(larval);
209
210	timeout = wait_for_completion_killable_timeout(
211		&larval->completion, 60 * HZ);
212
213	alg = larval->adult;
214	if (timeout < 0)
215		alg = ERR_PTR(-EINTR);
216	else if (!timeout)
217		alg = ERR_PTR(-ETIMEDOUT);
218	else if (!alg)
219		alg = ERR_PTR(-ENOENT);
220	else if (IS_ERR(alg))
221		;
222	else if (crypto_is_test_larval(larval) &&
223		 !(alg->cra_flags & CRYPTO_ALG_TESTED))
224		alg = ERR_PTR(-EAGAIN);
225	else if (alg->cra_flags & CRYPTO_ALG_FIPS_INTERNAL)
226		alg = ERR_PTR(-EAGAIN);
227	else if (!crypto_mod_get(alg))
228		alg = ERR_PTR(-EAGAIN);
229	crypto_mod_put(&larval->alg);
230
231	return alg;
232}
233
234static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
235					    u32 mask)
236{
237	const u32 fips = CRYPTO_ALG_FIPS_INTERNAL;
238	struct crypto_alg *alg;
239	u32 test = 0;
240
241	if (!((type | mask) & CRYPTO_ALG_TESTED))
242		test |= CRYPTO_ALG_TESTED;
243
244	down_read(&crypto_alg_sem);
245	alg = __crypto_alg_lookup(name, (type | test) & ~fips,
246				  (mask | test) & ~fips);
247	if (alg) {
248		if (((type | mask) ^ fips) & fips)
249			mask |= fips;
250		mask &= fips;
251
252		if (!crypto_is_larval(alg) &&
253		    ((type ^ alg->cra_flags) & mask)) {
254			/* Algorithm is disallowed in FIPS mode. */
255			crypto_mod_put(alg);
256			alg = ERR_PTR(-ENOENT);
257		}
258	} else if (test) {
259		alg = __crypto_alg_lookup(name, type, mask);
260		if (alg && !crypto_is_larval(alg)) {
261			/* Test failed */
262			crypto_mod_put(alg);
263			alg = ERR_PTR(-ELIBBAD);
264		}
265	}
266	up_read(&crypto_alg_sem);
267
268	return alg;
269}
 
270
271static struct crypto_alg *crypto_larval_lookup(const char *name, u32 type,
272					       u32 mask)
273{
274	struct crypto_alg *alg;
275
276	if (!name)
277		return ERR_PTR(-ENOENT);
278
279	type &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
280	mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
 
281
282	alg = crypto_alg_lookup(name, type, mask);
283	if (!alg && !(mask & CRYPTO_NOLOAD)) {
284		request_module("crypto-%s", name);
285
286		if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
287		      CRYPTO_ALG_NEED_FALLBACK))
288			request_module("crypto-%s-all", name);
289
290		alg = crypto_alg_lookup(name, type, mask);
291	}
292
293	if (!IS_ERR_OR_NULL(alg) && crypto_is_larval(alg))
294		alg = crypto_larval_wait(alg);
295	else if (!alg)
296		alg = crypto_larval_add(name, type, mask);
297
298	return alg;
299}
 
300
301int crypto_probing_notify(unsigned long val, void *v)
302{
303	int ok;
304
305	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
306	if (ok == NOTIFY_DONE) {
307		request_module("cryptomgr");
308		ok = blocking_notifier_call_chain(&crypto_chain, val, v);
309	}
310
311	return ok;
312}
313EXPORT_SYMBOL_GPL(crypto_probing_notify);
314
315struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
316{
317	struct crypto_alg *alg;
318	struct crypto_alg *larval;
319	int ok;
320
321	/*
322	 * If the internal flag is set for a cipher, require a caller to
323	 * invoke the cipher with the internal flag to use that cipher.
324	 * Also, if a caller wants to allocate a cipher that may or may
325	 * not be an internal cipher, use type | CRYPTO_ALG_INTERNAL and
326	 * !(mask & CRYPTO_ALG_INTERNAL).
327	 */
328	if (!((type | mask) & CRYPTO_ALG_INTERNAL))
329		mask |= CRYPTO_ALG_INTERNAL;
330
331	larval = crypto_larval_lookup(name, type, mask);
332	if (IS_ERR(larval) || !crypto_is_larval(larval))
333		return larval;
334
335	ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
336
337	if (ok == NOTIFY_STOP)
338		alg = crypto_larval_wait(larval);
339	else {
340		crypto_mod_put(larval);
341		alg = ERR_PTR(-ENOENT);
342	}
343	crypto_larval_kill(larval);
344	return alg;
345}
346EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
347
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
348static void crypto_exit_ops(struct crypto_tfm *tfm)
349{
350	const struct crypto_type *type = tfm->__crt_alg->cra_type;
351
352	if (type && tfm->exit)
353		tfm->exit(tfm);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
354}
355
356static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
357{
358	const struct crypto_type *type_obj = alg->cra_type;
359	unsigned int len;
360
361	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
362	if (type_obj)
363		return len + type_obj->ctxsize(alg, type, mask);
364
365	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
366	default:
367		BUG();
368
369	case CRYPTO_ALG_TYPE_CIPHER:
370		len += crypto_cipher_ctxsize(alg);
371		break;
372
373	case CRYPTO_ALG_TYPE_COMPRESS:
374		len += crypto_compress_ctxsize(alg);
375		break;
376	}
377
378	return len;
379}
380
381void crypto_shoot_alg(struct crypto_alg *alg)
382{
383	down_write(&crypto_alg_sem);
384	alg->cra_flags |= CRYPTO_ALG_DYING;
385	up_write(&crypto_alg_sem);
386}
387EXPORT_SYMBOL_GPL(crypto_shoot_alg);
388
389struct crypto_tfm *__crypto_alloc_tfmgfp(struct crypto_alg *alg, u32 type,
390					 u32 mask, gfp_t gfp)
391{
392	struct crypto_tfm *tfm;
393	unsigned int tfm_size;
394	int err = -ENOMEM;
395
396	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
397	tfm = kzalloc(tfm_size, gfp);
398	if (tfm == NULL)
399		goto out_err;
400
401	tfm->__crt_alg = alg;
402	refcount_set(&tfm->refcnt, 1);
 
 
 
403
404	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
405		goto cra_init_failed;
406
407	goto out;
408
409cra_init_failed:
410	crypto_exit_ops(tfm);
 
411	if (err == -EAGAIN)
412		crypto_shoot_alg(alg);
413	kfree(tfm);
414out_err:
415	tfm = ERR_PTR(err);
416out:
417	return tfm;
418}
419EXPORT_SYMBOL_GPL(__crypto_alloc_tfmgfp);
420
421struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
422				      u32 mask)
423{
424	return __crypto_alloc_tfmgfp(alg, type, mask, GFP_KERNEL);
425}
426EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
427
428/*
429 *	crypto_alloc_base - Locate algorithm and allocate transform
430 *	@alg_name: Name of algorithm
431 *	@type: Type of algorithm
432 *	@mask: Mask for type comparison
433 *
434 *	This function should not be used by new algorithm types.
435 *	Please use crypto_alloc_tfm instead.
436 *
437 *	crypto_alloc_base() will first attempt to locate an already loaded
438 *	algorithm.  If that fails and the kernel supports dynamically loadable
439 *	modules, it will then attempt to load a module of the same name or
440 *	alias.  If that fails it will send a query to any loaded crypto manager
441 *	to construct an algorithm on the fly.  A refcount is grabbed on the
442 *	algorithm which is then associated with the new transform.
443 *
444 *	The returned transform is of a non-determinate type.  Most people
445 *	should use one of the more specific allocation functions such as
446 *	crypto_alloc_skcipher().
447 *
448 *	In case of error the return value is an error pointer.
449 */
450struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
451{
452	struct crypto_tfm *tfm;
453	int err;
454
455	for (;;) {
456		struct crypto_alg *alg;
457
458		alg = crypto_alg_mod_lookup(alg_name, type, mask);
459		if (IS_ERR(alg)) {
460			err = PTR_ERR(alg);
461			goto err;
462		}
463
464		tfm = __crypto_alloc_tfm(alg, type, mask);
465		if (!IS_ERR(tfm))
466			return tfm;
467
468		crypto_mod_put(alg);
469		err = PTR_ERR(tfm);
470
471err:
472		if (err != -EAGAIN)
473			break;
474		if (fatal_signal_pending(current)) {
475			err = -EINTR;
476			break;
477		}
478	}
479
480	return ERR_PTR(err);
481}
482EXPORT_SYMBOL_GPL(crypto_alloc_base);
483
484static void *crypto_alloc_tfmmem(struct crypto_alg *alg,
485				 const struct crypto_type *frontend, int node,
486				 gfp_t gfp)
487{
488	struct crypto_tfm *tfm;
 
489	unsigned int tfmsize;
490	unsigned int total;
491	char *mem;
492
493	tfmsize = frontend->tfmsize;
494	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
495
496	mem = kzalloc_node(total, gfp, node);
497	if (mem == NULL)
498		return ERR_PTR(-ENOMEM);
499
500	tfm = (struct crypto_tfm *)(mem + tfmsize);
501	tfm->__crt_alg = alg;
502	tfm->node = node;
503	refcount_set(&tfm->refcnt, 1);
504
505	return mem;
506}
507
508void *crypto_create_tfm_node(struct crypto_alg *alg,
509			     const struct crypto_type *frontend,
510			     int node)
511{
512	struct crypto_tfm *tfm;
513	char *mem;
514	int err;
515
516	mem = crypto_alloc_tfmmem(alg, frontend, node, GFP_KERNEL);
517	if (IS_ERR(mem))
518		goto out;
519
520	tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
521
522	err = frontend->init_tfm(tfm);
523	if (err)
524		goto out_free_tfm;
525
526	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
527		goto cra_init_failed;
528
529	goto out;
530
531cra_init_failed:
532	crypto_exit_ops(tfm);
533out_free_tfm:
534	if (err == -EAGAIN)
535		crypto_shoot_alg(alg);
536	kfree(mem);
 
537	mem = ERR_PTR(err);
538out:
539	return mem;
540}
541EXPORT_SYMBOL_GPL(crypto_create_tfm_node);
542
543void *crypto_clone_tfm(const struct crypto_type *frontend,
544		       struct crypto_tfm *otfm)
545{
546	struct crypto_alg *alg = otfm->__crt_alg;
547	struct crypto_tfm *tfm;
548	char *mem;
549
550	mem = ERR_PTR(-ESTALE);
551	if (unlikely(!crypto_mod_get(alg)))
552		goto out;
553
554	mem = crypto_alloc_tfmmem(alg, frontend, otfm->node, GFP_ATOMIC);
555	if (IS_ERR(mem)) {
556		crypto_mod_put(alg);
557		goto out;
558	}
559
560	tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
561	tfm->crt_flags = otfm->crt_flags;
562	tfm->exit = otfm->exit;
563
564out:
565	return mem;
566}
567EXPORT_SYMBOL_GPL(crypto_clone_tfm);
568
569struct crypto_alg *crypto_find_alg(const char *alg_name,
570				   const struct crypto_type *frontend,
571				   u32 type, u32 mask)
572{
 
 
 
573	if (frontend) {
574		type &= frontend->maskclear;
575		mask &= frontend->maskclear;
576		type |= frontend->type;
577		mask |= frontend->maskset;
 
 
 
578	}
579
580	return crypto_alg_mod_lookup(alg_name, type, mask);
581}
582EXPORT_SYMBOL_GPL(crypto_find_alg);
583
584/*
585 *	crypto_alloc_tfm_node - Locate algorithm and allocate transform
586 *	@alg_name: Name of algorithm
587 *	@frontend: Frontend algorithm type
588 *	@type: Type of algorithm
589 *	@mask: Mask for type comparison
590 *	@node: NUMA node in which users desire to put requests, if node is
591 *		NUMA_NO_NODE, it means users have no special requirement.
592 *
593 *	crypto_alloc_tfm() will first attempt to locate an already loaded
594 *	algorithm.  If that fails and the kernel supports dynamically loadable
595 *	modules, it will then attempt to load a module of the same name or
596 *	alias.  If that fails it will send a query to any loaded crypto manager
597 *	to construct an algorithm on the fly.  A refcount is grabbed on the
598 *	algorithm which is then associated with the new transform.
599 *
600 *	The returned transform is of a non-determinate type.  Most people
601 *	should use one of the more specific allocation functions such as
602 *	crypto_alloc_skcipher().
603 *
604 *	In case of error the return value is an error pointer.
605 */
606
607void *crypto_alloc_tfm_node(const char *alg_name,
608		       const struct crypto_type *frontend, u32 type, u32 mask,
609		       int node)
610{
611	void *tfm;
612	int err;
613
614	for (;;) {
615		struct crypto_alg *alg;
616
617		alg = crypto_find_alg(alg_name, frontend, type, mask);
618		if (IS_ERR(alg)) {
619			err = PTR_ERR(alg);
620			goto err;
621		}
622
623		tfm = crypto_create_tfm_node(alg, frontend, node);
624		if (!IS_ERR(tfm))
625			return tfm;
626
627		crypto_mod_put(alg);
628		err = PTR_ERR(tfm);
629
630err:
631		if (err != -EAGAIN)
632			break;
633		if (fatal_signal_pending(current)) {
634			err = -EINTR;
635			break;
636		}
637	}
638
639	return ERR_PTR(err);
640}
641EXPORT_SYMBOL_GPL(crypto_alloc_tfm_node);
642
643/*
644 *	crypto_destroy_tfm - Free crypto transform
645 *	@mem: Start of tfm slab
646 *	@tfm: Transform to free
647 *
648 *	This function frees up the transform and any associated resources,
649 *	then drops the refcount on the associated algorithm.
650 */
651void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
652{
653	struct crypto_alg *alg;
654
655	if (IS_ERR_OR_NULL(mem))
656		return;
657
658	if (!refcount_dec_and_test(&tfm->refcnt))
659		return;
660	alg = tfm->__crt_alg;
661
662	if (!tfm->exit && alg->cra_exit)
663		alg->cra_exit(tfm);
664	crypto_exit_ops(tfm);
665	crypto_mod_put(alg);
666	kfree_sensitive(mem);
667}
668EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
669
670int crypto_has_alg(const char *name, u32 type, u32 mask)
671{
672	int ret = 0;
673	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
674
675	if (!IS_ERR(alg)) {
676		crypto_mod_put(alg);
677		ret = 1;
678	}
679
680	return ret;
681}
682EXPORT_SYMBOL_GPL(crypto_has_alg);
683
684void crypto_req_done(void *data, int err)
685{
686	struct crypto_wait *wait = data;
687
688	if (err == -EINPROGRESS)
689		return;
690
691	wait->err = err;
692	complete(&wait->completion);
693}
694EXPORT_SYMBOL_GPL(crypto_req_done);
695
696MODULE_DESCRIPTION("Cryptographic core API");
697MODULE_LICENSE("GPL");
v3.15
 
  1/*
  2 * Scatterlist Cryptographic API.
  3 *
  4 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  5 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
  6 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
  7 *
  8 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
  9 * and Nettle, by Niels Möller.
 10 *
 11 * This program is free software; you can redistribute it and/or modify it
 12 * under the terms of the GNU General Public License as published by the Free
 13 * Software Foundation; either version 2 of the License, or (at your option)
 14 * any later version.
 15 *
 16 */
 17
 18#include <linux/err.h>
 19#include <linux/errno.h>
 
 20#include <linux/kernel.h>
 21#include <linux/kmod.h>
 22#include <linux/module.h>
 23#include <linux/param.h>
 24#include <linux/sched.h>
 25#include <linux/slab.h>
 26#include <linux/string.h>
 
 27#include "internal.h"
 28
 29LIST_HEAD(crypto_alg_list);
 30EXPORT_SYMBOL_GPL(crypto_alg_list);
 31DECLARE_RWSEM(crypto_alg_sem);
 32EXPORT_SYMBOL_GPL(crypto_alg_sem);
 33
 34BLOCKING_NOTIFIER_HEAD(crypto_chain);
 35EXPORT_SYMBOL_GPL(crypto_chain);
 36
 
 
 
 
 
 37static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
 38
 39struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
 40{
 41	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
 42}
 43EXPORT_SYMBOL_GPL(crypto_mod_get);
 44
 45void crypto_mod_put(struct crypto_alg *alg)
 46{
 47	struct module *module = alg->cra_module;
 48
 49	crypto_alg_put(alg);
 50	module_put(module);
 51}
 52EXPORT_SYMBOL_GPL(crypto_mod_put);
 53
 54static inline int crypto_is_test_larval(struct crypto_larval *larval)
 55{
 56	return larval->alg.cra_driver_name[0];
 57}
 58
 59static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
 60					      u32 mask)
 61{
 62	struct crypto_alg *q, *alg = NULL;
 63	int best = -2;
 64
 65	list_for_each_entry(q, &crypto_alg_list, cra_list) {
 66		int exact, fuzzy;
 67
 68		if (crypto_is_moribund(q))
 69			continue;
 70
 71		if ((q->cra_flags ^ type) & mask)
 72			continue;
 73
 74		if (crypto_is_larval(q) &&
 75		    !crypto_is_test_larval((struct crypto_larval *)q) &&
 76		    ((struct crypto_larval *)q)->mask != mask)
 77			continue;
 78
 79		exact = !strcmp(q->cra_driver_name, name);
 80		fuzzy = !strcmp(q->cra_name, name);
 81		if (!exact && !(fuzzy && q->cra_priority > best))
 82			continue;
 83
 84		if (unlikely(!crypto_mod_get(q)))
 85			continue;
 86
 87		best = q->cra_priority;
 88		if (alg)
 89			crypto_mod_put(alg);
 90		alg = q;
 91
 92		if (exact)
 93			break;
 94	}
 95
 96	return alg;
 97}
 98
 99static void crypto_larval_destroy(struct crypto_alg *alg)
100{
101	struct crypto_larval *larval = (void *)alg;
102
103	BUG_ON(!crypto_is_larval(alg));
104	if (larval->adult)
105		crypto_mod_put(larval->adult);
106	kfree(larval);
107}
108
109struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
110{
111	struct crypto_larval *larval;
112
113	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
114	if (!larval)
115		return ERR_PTR(-ENOMEM);
116
117	larval->mask = mask;
118	larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
119	larval->alg.cra_priority = -1;
120	larval->alg.cra_destroy = crypto_larval_destroy;
121
122	strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
123	init_completion(&larval->completion);
124
125	return larval;
126}
127EXPORT_SYMBOL_GPL(crypto_larval_alloc);
128
129static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
130					    u32 mask)
131{
132	struct crypto_alg *alg;
133	struct crypto_larval *larval;
134
135	larval = crypto_larval_alloc(name, type, mask);
136	if (IS_ERR(larval))
137		return ERR_CAST(larval);
138
139	atomic_set(&larval->alg.cra_refcnt, 2);
140
141	down_write(&crypto_alg_sem);
142	alg = __crypto_alg_lookup(name, type, mask);
143	if (!alg) {
144		alg = &larval->alg;
145		list_add(&alg->cra_list, &crypto_alg_list);
146	}
147	up_write(&crypto_alg_sem);
148
149	if (alg != &larval->alg) {
150		kfree(larval);
151		if (crypto_is_larval(alg))
152			alg = crypto_larval_wait(alg);
153	}
154
155	return alg;
156}
157
158void crypto_larval_kill(struct crypto_alg *alg)
159{
160	struct crypto_larval *larval = (void *)alg;
161
162	down_write(&crypto_alg_sem);
163	list_del(&alg->cra_list);
164	up_write(&crypto_alg_sem);
165	complete_all(&larval->completion);
166	crypto_alg_put(alg);
167}
168EXPORT_SYMBOL_GPL(crypto_larval_kill);
169
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
170static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
171{
172	struct crypto_larval *larval = (void *)alg;
173	long timeout;
174
175	timeout = wait_for_completion_interruptible_timeout(
 
 
 
176		&larval->completion, 60 * HZ);
177
178	alg = larval->adult;
179	if (timeout < 0)
180		alg = ERR_PTR(-EINTR);
181	else if (!timeout)
182		alg = ERR_PTR(-ETIMEDOUT);
183	else if (!alg)
184		alg = ERR_PTR(-ENOENT);
 
 
185	else if (crypto_is_test_larval(larval) &&
186		 !(alg->cra_flags & CRYPTO_ALG_TESTED))
187		alg = ERR_PTR(-EAGAIN);
 
 
188	else if (!crypto_mod_get(alg))
189		alg = ERR_PTR(-EAGAIN);
190	crypto_mod_put(&larval->alg);
191
192	return alg;
193}
194
195struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask)
 
196{
 
197	struct crypto_alg *alg;
 
 
 
 
198
199	down_read(&crypto_alg_sem);
200	alg = __crypto_alg_lookup(name, type, mask);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
201	up_read(&crypto_alg_sem);
202
203	return alg;
204}
205EXPORT_SYMBOL_GPL(crypto_alg_lookup);
206
207struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
 
208{
209	struct crypto_alg *alg;
210
211	if (!name)
212		return ERR_PTR(-ENOENT);
213
 
214	mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
215	type &= mask;
216
217	alg = crypto_alg_lookup(name, type, mask);
218	if (!alg) {
219		request_module("%s", name);
220
221		if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
222		      CRYPTO_ALG_NEED_FALLBACK))
223			request_module("%s-all", name);
224
225		alg = crypto_alg_lookup(name, type, mask);
226	}
227
228	if (alg)
229		return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
 
 
230
231	return crypto_larval_add(name, type, mask);
232}
233EXPORT_SYMBOL_GPL(crypto_larval_lookup);
234
235int crypto_probing_notify(unsigned long val, void *v)
236{
237	int ok;
238
239	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
240	if (ok == NOTIFY_DONE) {
241		request_module("cryptomgr");
242		ok = blocking_notifier_call_chain(&crypto_chain, val, v);
243	}
244
245	return ok;
246}
247EXPORT_SYMBOL_GPL(crypto_probing_notify);
248
249struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
250{
251	struct crypto_alg *alg;
252	struct crypto_alg *larval;
253	int ok;
254
255	if (!((type | mask) & CRYPTO_ALG_TESTED)) {
256		type |= CRYPTO_ALG_TESTED;
257		mask |= CRYPTO_ALG_TESTED;
258	}
 
 
 
 
 
259
260	larval = crypto_larval_lookup(name, type, mask);
261	if (IS_ERR(larval) || !crypto_is_larval(larval))
262		return larval;
263
264	ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
265
266	if (ok == NOTIFY_STOP)
267		alg = crypto_larval_wait(larval);
268	else {
269		crypto_mod_put(larval);
270		alg = ERR_PTR(-ENOENT);
271	}
272	crypto_larval_kill(larval);
273	return alg;
274}
275EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
276
277static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
278{
279	const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
280
281	if (type_obj)
282		return type_obj->init(tfm, type, mask);
283
284	switch (crypto_tfm_alg_type(tfm)) {
285	case CRYPTO_ALG_TYPE_CIPHER:
286		return crypto_init_cipher_ops(tfm);
287
288	case CRYPTO_ALG_TYPE_COMPRESS:
289		return crypto_init_compress_ops(tfm);
290
291	default:
292		break;
293	}
294
295	BUG();
296	return -EINVAL;
297}
298
299static void crypto_exit_ops(struct crypto_tfm *tfm)
300{
301	const struct crypto_type *type = tfm->__crt_alg->cra_type;
302
303	if (type) {
304		if (tfm->exit)
305			tfm->exit(tfm);
306		return;
307	}
308
309	switch (crypto_tfm_alg_type(tfm)) {
310	case CRYPTO_ALG_TYPE_CIPHER:
311		crypto_exit_cipher_ops(tfm);
312		break;
313
314	case CRYPTO_ALG_TYPE_COMPRESS:
315		crypto_exit_compress_ops(tfm);
316		break;
317
318	default:
319		BUG();
320	}
321}
322
323static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
324{
325	const struct crypto_type *type_obj = alg->cra_type;
326	unsigned int len;
327
328	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
329	if (type_obj)
330		return len + type_obj->ctxsize(alg, type, mask);
331
332	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
333	default:
334		BUG();
335
336	case CRYPTO_ALG_TYPE_CIPHER:
337		len += crypto_cipher_ctxsize(alg);
338		break;
339
340	case CRYPTO_ALG_TYPE_COMPRESS:
341		len += crypto_compress_ctxsize(alg);
342		break;
343	}
344
345	return len;
346}
347
348void crypto_shoot_alg(struct crypto_alg *alg)
349{
350	down_write(&crypto_alg_sem);
351	alg->cra_flags |= CRYPTO_ALG_DYING;
352	up_write(&crypto_alg_sem);
353}
354EXPORT_SYMBOL_GPL(crypto_shoot_alg);
355
356struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
357				      u32 mask)
358{
359	struct crypto_tfm *tfm = NULL;
360	unsigned int tfm_size;
361	int err = -ENOMEM;
362
363	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
364	tfm = kzalloc(tfm_size, GFP_KERNEL);
365	if (tfm == NULL)
366		goto out_err;
367
368	tfm->__crt_alg = alg;
369
370	err = crypto_init_ops(tfm, type, mask);
371	if (err)
372		goto out_free_tfm;
373
374	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
375		goto cra_init_failed;
376
377	goto out;
378
379cra_init_failed:
380	crypto_exit_ops(tfm);
381out_free_tfm:
382	if (err == -EAGAIN)
383		crypto_shoot_alg(alg);
384	kfree(tfm);
385out_err:
386	tfm = ERR_PTR(err);
387out:
388	return tfm;
389}
 
 
 
 
 
 
 
390EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
391
392/*
393 *	crypto_alloc_base - Locate algorithm and allocate transform
394 *	@alg_name: Name of algorithm
395 *	@type: Type of algorithm
396 *	@mask: Mask for type comparison
397 *
398 *	This function should not be used by new algorithm types.
399 *	Please use crypto_alloc_tfm instead.
400 *
401 *	crypto_alloc_base() will first attempt to locate an already loaded
402 *	algorithm.  If that fails and the kernel supports dynamically loadable
403 *	modules, it will then attempt to load a module of the same name or
404 *	alias.  If that fails it will send a query to any loaded crypto manager
405 *	to construct an algorithm on the fly.  A refcount is grabbed on the
406 *	algorithm which is then associated with the new transform.
407 *
408 *	The returned transform is of a non-determinate type.  Most people
409 *	should use one of the more specific allocation functions such as
410 *	crypto_alloc_blkcipher.
411 *
412 *	In case of error the return value is an error pointer.
413 */
414struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
415{
416	struct crypto_tfm *tfm;
417	int err;
418
419	for (;;) {
420		struct crypto_alg *alg;
421
422		alg = crypto_alg_mod_lookup(alg_name, type, mask);
423		if (IS_ERR(alg)) {
424			err = PTR_ERR(alg);
425			goto err;
426		}
427
428		tfm = __crypto_alloc_tfm(alg, type, mask);
429		if (!IS_ERR(tfm))
430			return tfm;
431
432		crypto_mod_put(alg);
433		err = PTR_ERR(tfm);
434
435err:
436		if (err != -EAGAIN)
437			break;
438		if (signal_pending(current)) {
439			err = -EINTR;
440			break;
441		}
442	}
443
444	return ERR_PTR(err);
445}
446EXPORT_SYMBOL_GPL(crypto_alloc_base);
447
448void *crypto_create_tfm(struct crypto_alg *alg,
449			const struct crypto_type *frontend)
 
450{
451	char *mem;
452	struct crypto_tfm *tfm = NULL;
453	unsigned int tfmsize;
454	unsigned int total;
455	int err = -ENOMEM;
456
457	tfmsize = frontend->tfmsize;
458	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
459
460	mem = kzalloc(total, GFP_KERNEL);
461	if (mem == NULL)
462		goto out_err;
463
464	tfm = (struct crypto_tfm *)(mem + tfmsize);
465	tfm->__crt_alg = alg;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
466
467	err = frontend->init_tfm(tfm);
468	if (err)
469		goto out_free_tfm;
470
471	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
472		goto cra_init_failed;
473
474	goto out;
475
476cra_init_failed:
477	crypto_exit_ops(tfm);
478out_free_tfm:
479	if (err == -EAGAIN)
480		crypto_shoot_alg(alg);
481	kfree(mem);
482out_err:
483	mem = ERR_PTR(err);
484out:
485	return mem;
486}
487EXPORT_SYMBOL_GPL(crypto_create_tfm);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
488
489struct crypto_alg *crypto_find_alg(const char *alg_name,
490				   const struct crypto_type *frontend,
491				   u32 type, u32 mask)
492{
493	struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask) =
494		crypto_alg_mod_lookup;
495
496	if (frontend) {
497		type &= frontend->maskclear;
498		mask &= frontend->maskclear;
499		type |= frontend->type;
500		mask |= frontend->maskset;
501
502		if (frontend->lookup)
503			lookup = frontend->lookup;
504	}
505
506	return lookup(alg_name, type, mask);
507}
508EXPORT_SYMBOL_GPL(crypto_find_alg);
509
510/*
511 *	crypto_alloc_tfm - Locate algorithm and allocate transform
512 *	@alg_name: Name of algorithm
513 *	@frontend: Frontend algorithm type
514 *	@type: Type of algorithm
515 *	@mask: Mask for type comparison
 
 
516 *
517 *	crypto_alloc_tfm() will first attempt to locate an already loaded
518 *	algorithm.  If that fails and the kernel supports dynamically loadable
519 *	modules, it will then attempt to load a module of the same name or
520 *	alias.  If that fails it will send a query to any loaded crypto manager
521 *	to construct an algorithm on the fly.  A refcount is grabbed on the
522 *	algorithm which is then associated with the new transform.
523 *
524 *	The returned transform is of a non-determinate type.  Most people
525 *	should use one of the more specific allocation functions such as
526 *	crypto_alloc_blkcipher.
527 *
528 *	In case of error the return value is an error pointer.
529 */
530void *crypto_alloc_tfm(const char *alg_name,
531		       const struct crypto_type *frontend, u32 type, u32 mask)
 
 
532{
533	void *tfm;
534	int err;
535
536	for (;;) {
537		struct crypto_alg *alg;
538
539		alg = crypto_find_alg(alg_name, frontend, type, mask);
540		if (IS_ERR(alg)) {
541			err = PTR_ERR(alg);
542			goto err;
543		}
544
545		tfm = crypto_create_tfm(alg, frontend);
546		if (!IS_ERR(tfm))
547			return tfm;
548
549		crypto_mod_put(alg);
550		err = PTR_ERR(tfm);
551
552err:
553		if (err != -EAGAIN)
554			break;
555		if (signal_pending(current)) {
556			err = -EINTR;
557			break;
558		}
559	}
560
561	return ERR_PTR(err);
562}
563EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
564
565/*
566 *	crypto_destroy_tfm - Free crypto transform
567 *	@mem: Start of tfm slab
568 *	@tfm: Transform to free
569 *
570 *	This function frees up the transform and any associated resources,
571 *	then drops the refcount on the associated algorithm.
572 */
573void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
574{
575	struct crypto_alg *alg;
576
577	if (unlikely(!mem))
578		return;
579
 
 
580	alg = tfm->__crt_alg;
581
582	if (!tfm->exit && alg->cra_exit)
583		alg->cra_exit(tfm);
584	crypto_exit_ops(tfm);
585	crypto_mod_put(alg);
586	kzfree(mem);
587}
588EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
589
590int crypto_has_alg(const char *name, u32 type, u32 mask)
591{
592	int ret = 0;
593	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
594
595	if (!IS_ERR(alg)) {
596		crypto_mod_put(alg);
597		ret = 1;
598	}
599
600	return ret;
601}
602EXPORT_SYMBOL_GPL(crypto_has_alg);
 
 
 
 
 
 
 
 
 
 
 
 
603
604MODULE_DESCRIPTION("Cryptographic core API");
605MODULE_LICENSE("GPL");