[linux-block.git] / crypto / api.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Scatterlist Cryptographic API.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
 * and Nettle, by Niels Möller.
 */

#include <linux/err.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/module.h>
#include <linux/param.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/completion.h>
#include "internal.h"

LIST_HEAD(crypto_alg_list);
EXPORT_SYMBOL_GPL(crypto_alg_list);
DECLARE_RWSEM(crypto_alg_sem);
EXPORT_SYMBOL_GPL(crypto_alg_sem);

BLOCKING_NOTIFIER_HEAD(crypto_chain);
EXPORT_SYMBOL_GPL(crypto_chain);

static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);

struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
{
	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
}
EXPORT_SYMBOL_GPL(crypto_mod_get);

void crypto_mod_put(struct crypto_alg *alg)
{
	struct module *module = alg->cra_module;

	crypto_alg_put(alg);
	module_put(module);
}
EXPORT_SYMBOL_GPL(crypto_mod_put);

static inline int crypto_is_test_larval(struct crypto_larval *larval)
{
	return larval->alg.cra_driver_name[0];
}

static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
					      u32 mask)
{
	struct crypto_alg *q, *alg = NULL;
	int best = -2;

	list_for_each_entry(q, &crypto_alg_list, cra_list) {
		int exact, fuzzy;

		if (crypto_is_moribund(q))
			continue;

		if ((q->cra_flags ^ type) & mask)
			continue;

		if (crypto_is_larval(q) &&
		    !crypto_is_test_larval((struct crypto_larval *)q) &&
		    ((struct crypto_larval *)q)->mask != mask)
			continue;

		exact = !strcmp(q->cra_driver_name, name);
		fuzzy = !strcmp(q->cra_name, name);
		if (!exact && !(fuzzy && q->cra_priority > best))
			continue;

		if (unlikely(!crypto_mod_get(q)))
			continue;

		best = q->cra_priority;
		if (alg)
			crypto_mod_put(alg);
		alg = q;

		if (exact)
			break;
	}

	return alg;
}

static void crypto_larval_destroy(struct crypto_alg *alg)
{
	struct crypto_larval *larval = (void *)alg;

	BUG_ON(!crypto_is_larval(alg));
	if (!IS_ERR_OR_NULL(larval->adult))
		crypto_mod_put(larval->adult);
	kfree(larval);
}

struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
{
	struct crypto_larval *larval;

	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
	if (!larval)
		return ERR_PTR(-ENOMEM);

	larval->mask = mask;
	larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
	larval->alg.cra_priority = -1;
	larval->alg.cra_destroy = crypto_larval_destroy;

	strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
	init_completion(&larval->completion);

	return larval;
}
EXPORT_SYMBOL_GPL(crypto_larval_alloc);

static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
					    u32 mask)
{
	struct crypto_alg *alg;
	struct crypto_larval *larval;

	larval = crypto_larval_alloc(name, type, mask);
	if (IS_ERR(larval))
		return ERR_CAST(larval);

	refcount_set(&larval->alg.cra_refcnt, 2);

	down_write(&crypto_alg_sem);
	alg = __crypto_alg_lookup(name, type, mask);
	if (!alg) {
		alg = &larval->alg;
		list_add(&alg->cra_list, &crypto_alg_list);
	}
	up_write(&crypto_alg_sem);

	if (alg != &larval->alg) {
		kfree(larval);
		if (crypto_is_larval(alg))
			alg = crypto_larval_wait(alg);
	}

	return alg;
}

void crypto_larval_kill(struct crypto_alg *alg)
{
	struct crypto_larval *larval = (void *)alg;

	down_write(&crypto_alg_sem);
	list_del(&alg->cra_list);
	up_write(&crypto_alg_sem);
	complete_all(&larval->completion);
	crypto_alg_put(alg);
}
EXPORT_SYMBOL_GPL(crypto_larval_kill);

static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
{
	struct crypto_larval *larval = (void *)alg;
	long timeout;

	timeout = wait_for_completion_killable_timeout(
		&larval->completion, 60 * HZ);

	alg = larval->adult;
	if (timeout < 0)
		alg = ERR_PTR(-EINTR);
	else if (!timeout)
		alg = ERR_PTR(-ETIMEDOUT);
	else if (!alg)
		alg = ERR_PTR(-ENOENT);
	else if (IS_ERR(alg))
		;
	else if (crypto_is_test_larval(larval) &&
		 !(alg->cra_flags & CRYPTO_ALG_TESTED))
		alg = ERR_PTR(-EAGAIN);
	else if (!crypto_mod_get(alg))
		alg = ERR_PTR(-EAGAIN);
	crypto_mod_put(&larval->alg);

	return alg;
}

static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
					    u32 mask)
{
	struct crypto_alg *alg;
	u32 test = 0;

	if (!((type | mask) & CRYPTO_ALG_TESTED))
		test |= CRYPTO_ALG_TESTED;

	down_read(&crypto_alg_sem);
	alg = __crypto_alg_lookup(name, type | test, mask | test);
	if (!alg && test) {
		alg = __crypto_alg_lookup(name, type, mask);
		if (alg && !crypto_is_larval(alg)) {
			/* Test failed */
			crypto_mod_put(alg);
			alg = ERR_PTR(-ELIBBAD);
		}
	}
	up_read(&crypto_alg_sem);

	return alg;
}

static struct crypto_alg *crypto_larval_lookup(const char *name, u32 type,
					       u32 mask)
{
	struct crypto_alg *alg;

	if (!name)
		return ERR_PTR(-ENOENT);

	type &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
	mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);

	alg = crypto_alg_lookup(name, type, mask);
	if (!alg && !(mask & CRYPTO_NOLOAD)) {
		request_module("crypto-%s", name);

		if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
		      CRYPTO_ALG_NEED_FALLBACK))
			request_module("crypto-%s-all", name);

		alg = crypto_alg_lookup(name, type, mask);
	}

	if (!IS_ERR_OR_NULL(alg) && crypto_is_larval(alg))
		alg = crypto_larval_wait(alg);
	else if (!alg)
		alg = crypto_larval_add(name, type, mask);

	return alg;
}

int crypto_probing_notify(unsigned long val, void *v)
{
	int ok;

	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
	if (ok == NOTIFY_DONE) {
		request_module("cryptomgr");
		ok = blocking_notifier_call_chain(&crypto_chain, val, v);
	}

	return ok;
}
EXPORT_SYMBOL_GPL(crypto_probing_notify);

struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
{
	struct crypto_alg *alg;
	struct crypto_alg *larval;
	int ok;

	/*
	 * If the internal flag is set for a cipher, require a caller to
	 * to invoke the cipher with the internal flag to use that cipher.
	 * Also, if a caller wants to allocate a cipher that may or may
	 * not be an internal cipher, use type | CRYPTO_ALG_INTERNAL and
	 * !(mask & CRYPTO_ALG_INTERNAL).
	 */
	if (!((type | mask) & CRYPTO_ALG_INTERNAL))
		mask |= CRYPTO_ALG_INTERNAL;

	larval = crypto_larval_lookup(name, type, mask);
	if (IS_ERR(larval) || !crypto_is_larval(larval))
		return larval;

	ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);

	if (ok == NOTIFY_STOP)
		alg = crypto_larval_wait(larval);
	else {
		crypto_mod_put(larval);
		alg = ERR_PTR(-ENOENT);
	}
	crypto_larval_kill(larval);
	return alg;
}
EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);

static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
	const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;

	if (type_obj)
		return type_obj->init(tfm, type, mask);
	return 0;
}

static void crypto_exit_ops(struct crypto_tfm *tfm)
{
	const struct crypto_type *type = tfm->__crt_alg->cra_type;

	if (type && tfm->exit)
		tfm->exit(tfm);
}

static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
{
	const struct crypto_type *type_obj = alg->cra_type;
	unsigned int len;

	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
	if (type_obj)
		return len + type_obj->ctxsize(alg, type, mask);

	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
	default:
		BUG();

	case CRYPTO_ALG_TYPE_CIPHER:
		len += crypto_cipher_ctxsize(alg);
		break;

	case CRYPTO_ALG_TYPE_COMPRESS:
		len += crypto_compress_ctxsize(alg);
		break;
	}

	return len;
}

static void crypto_shoot_alg(struct crypto_alg *alg)
{
	down_write(&crypto_alg_sem);
	alg->cra_flags |= CRYPTO_ALG_DYING;
	up_write(&crypto_alg_sem);
}

struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
				      u32 mask)
{
	struct crypto_tfm *tfm = NULL;
	unsigned int tfm_size;
	int err = -ENOMEM;

	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
	tfm = kzalloc(tfm_size, GFP_KERNEL);
	if (tfm == NULL)
		goto out_err;

	tfm->__crt_alg = alg;

	err = crypto_init_ops(tfm, type, mask);
	if (err)
		goto out_free_tfm;

	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
		goto cra_init_failed;

	goto out;

cra_init_failed:
	crypto_exit_ops(tfm);
out_free_tfm:
	if (err == -EAGAIN)
		crypto_shoot_alg(alg);
	kfree(tfm);
out_err:
	tfm = ERR_PTR(err);
out:
	return tfm;
}
EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);

/*
 *	crypto_alloc_base - Locate algorithm and allocate transform
 *	@alg_name: Name of algorithm
 *	@type: Type of algorithm
 *	@mask: Mask for type comparison
 *
 *	This function should not be used by new algorithm types.
 *	Please use crypto_alloc_tfm instead.
 *
 *	crypto_alloc_base() will first attempt to locate an already loaded
 *	algorithm.  If that fails and the kernel supports dynamically loadable
 *	modules, it will then attempt to load a module of the same name or
 *	alias.  If that fails it will send a query to any loaded crypto manager
 *	to construct an algorithm on the fly.  A refcount is grabbed on the
 *	algorithm which is then associated with the new transform.
 *
 *	The returned transform is of a non-determinate type.  Most people
 *	should use one of the more specific allocation functions such as
 *	crypto_alloc_skcipher().
 *
 *	In case of error the return value is an error pointer.
 */
struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
{
	struct crypto_tfm *tfm;
	int err;

	for (;;) {
		struct crypto_alg *alg;

		alg = crypto_alg_mod_lookup(alg_name, type, mask);
		if (IS_ERR(alg)) {
			err = PTR_ERR(alg);
			goto err;
		}

		tfm = __crypto_alloc_tfm(alg, type, mask);
		if (!IS_ERR(tfm))
			return tfm;

		crypto_mod_put(alg);
		err = PTR_ERR(tfm);

err:
		if (err != -EAGAIN)
			break;
		if (fatal_signal_pending(current)) {
			err = -EINTR;
			break;
		}
	}

	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_base);

void *crypto_create_tfm(struct crypto_alg *alg,
			const struct crypto_type *frontend)
{
	char *mem;
	struct crypto_tfm *tfm = NULL;
	unsigned int tfmsize;
	unsigned int total;
	int err = -ENOMEM;

	tfmsize = frontend->tfmsize;
	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);

	mem = kzalloc(total, GFP_KERNEL);
	if (mem == NULL)
		goto out_err;

	tfm = (struct crypto_tfm *)(mem + tfmsize);
	tfm->__crt_alg = alg;

	err = frontend->init_tfm(tfm);
	if (err)
		goto out_free_tfm;

	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
		goto cra_init_failed;

	goto out;

cra_init_failed:
	crypto_exit_ops(tfm);
out_free_tfm:
	if (err == -EAGAIN)
		crypto_shoot_alg(alg);
	kfree(mem);
out_err:
	mem = ERR_PTR(err);
out:
	return mem;
}
EXPORT_SYMBOL_GPL(crypto_create_tfm);

struct crypto_alg *crypto_find_alg(const char *alg_name,
				   const struct crypto_type *frontend,
				   u32 type, u32 mask)
{
	if (frontend) {
		type &= frontend->maskclear;
		mask &= frontend->maskclear;
		type |= frontend->type;
		mask |= frontend->maskset;
	}

	return crypto_alg_mod_lookup(alg_name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_find_alg);

/*
 *	crypto_alloc_tfm - Locate algorithm and allocate transform
 *	@alg_name: Name of algorithm
 *	@frontend: Frontend algorithm type
 *	@type: Type of algorithm
 *	@mask: Mask for type comparison
 *
 *	crypto_alloc_tfm() will first attempt to locate an already loaded
 *	algorithm.  If that fails and the kernel supports dynamically loadable
 *	modules, it will then attempt to load a module of the same name or
 *	alias.  If that fails it will send a query to any loaded crypto manager
 *	to construct an algorithm on the fly.  A refcount is grabbed on the
 *	algorithm which is then associated with the new transform.
 *
 *	The returned transform is of a non-determinate type.  Most people
 *	should use one of the more specific allocation functions such as
 *	crypto_alloc_skcipher().
 *
 *	In case of error the return value is an error pointer.
 */
void *crypto_alloc_tfm(const char *alg_name,
		       const struct crypto_type *frontend, u32 type, u32 mask)
{
	void *tfm;
	int err;

	for (;;) {
		struct crypto_alg *alg;

		alg = crypto_find_alg(alg_name, frontend, type, mask);
		if (IS_ERR(alg)) {
			err = PTR_ERR(alg);
			goto err;
		}

		tfm = crypto_create_tfm(alg, frontend);
		if (!IS_ERR(tfm))
			return tfm;

		crypto_mod_put(alg);
		err = PTR_ERR(tfm);

err:
		if (err != -EAGAIN)
			break;
		if (fatal_signal_pending(current)) {
			err = -EINTR;
			break;
		}
	}

	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_tfm);

/*
 *	crypto_destroy_tfm - Free crypto transform
 *	@mem: Start of tfm slab
 *	@tfm: Transform to free
 *
 *	This function frees up the transform and any associated resources,
 *	then drops the refcount on the associated algorithm.
 */
void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
{
	struct crypto_alg *alg;

	if (unlikely(!mem))
		return;

	alg = tfm->__crt_alg;

	if (!tfm->exit && alg->cra_exit)
		alg->cra_exit(tfm);
	crypto_exit_ops(tfm);
	crypto_mod_put(alg);
	kzfree(mem);
}
EXPORT_SYMBOL_GPL(crypto_destroy_tfm);

int crypto_has_alg(const char *name, u32 type, u32 mask)
{
	int ret = 0;
	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);

	if (!IS_ERR(alg)) {
		crypto_mod_put(alg);
		ret = 1;
	}

	return ret;
}
EXPORT_SYMBOL_GPL(crypto_has_alg);

void crypto_req_done(struct crypto_async_request *req, int err)
{
	struct crypto_wait *wait = req->data;

	if (err == -EINPROGRESS)
		return;

	wait->err = err;
	complete(&wait->completion);
}
EXPORT_SYMBOL_GPL(crypto_req_done);

MODULE_DESCRIPTION("Cryptographic core API");
MODULE_LICENSE("GPL");
MODULE_SOFTDEP("pre: cryptomgr");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	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)
5cb1454b	7	* Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
1da177e4 LT	8	*
1da177e4 LT	9	* Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
991d1740	10	* and Nettle, by Niels Möller.
1da177e4	11	*/
a61cc448	12
6bfd4809	13	#include <linux/err.h>
1da177e4	14	#include <linux/errno.h>
5cb1454b	15	#include <linux/kernel.h>
176c3652	16	#include <linux/kmod.h>
2b8c19db	17	#include <linux/module.h>
2825982d	18	#include <linux/param.h>
174cd4b1	19	#include <linux/sched/signal.h>
1da177e4	20	#include <linux/slab.h>
5cb1454b	21	#include <linux/string.h>
ada69a16	22	#include <linux/completion.h>
1da177e4 LT	23	#include "internal.h"
	24
	25	LIST_HEAD(crypto_alg_list);
cce9e06d	26	EXPORT_SYMBOL_GPL(crypto_alg_list);
1da177e4	27	DECLARE_RWSEM(crypto_alg_sem);
cce9e06d	28	EXPORT_SYMBOL_GPL(crypto_alg_sem);
1da177e4	29
2825982d HX	30	BLOCKING_NOTIFIER_HEAD(crypto_chain);
	31	EXPORT_SYMBOL_GPL(crypto_chain);
	32
77dbd7a9 HX	33	static struct crypto_alg crypto_larval_wait(struct crypto_alg alg);
77dbd7a9 HX	34
2825982d	35	struct crypto_alg crypto_mod_get(struct crypto_alg alg)
6521f302 HX	36	{
6521f302 HX	37	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
1da177e4	38	}
2825982d	39	EXPORT_SYMBOL_GPL(crypto_mod_get);
1da177e4	40
2825982d	41	void crypto_mod_put(struct crypto_alg *alg)
1da177e4	42	{
da7cd59a HX	43	struct module *module = alg->cra_module;
da7cd59a HX	44
6521f302	45	crypto_alg_put(alg);
da7cd59a	46	module_put(module);
1da177e4	47	}
2825982d	48	EXPORT_SYMBOL_GPL(crypto_mod_put);
1da177e4	49
73d3864a HX	50	static inline int crypto_is_test_larval(struct crypto_larval *larval)
	51	{
	52	return larval->alg.cra_driver_name[0];
	53	}
	54
c51b6c81 HX	55	static struct crypto_alg __crypto_alg_lookup(const char name, u32 type,
c51b6c81 HX	56	u32 mask)
1da177e4 LT	57	{
1da177e4 LT	58	struct crypto_alg q, alg = NULL;
2825982d	59	int best = -2;
1da177e4	60
1da177e4	61	list_for_each_entry(q, &crypto_alg_list, cra_list) {
5cb1454b HX	62	int exact, fuzzy;
5cb1454b HX	63
6bfd4809 HX	64	if (crypto_is_moribund(q))
	65	continue;
	66
492e2b63 HX	67	if ((q->cra_flags ^ type) & mask)
	68	continue;
	69
	70	if (crypto_is_larval(q) &&
73d3864a	71	!crypto_is_test_larval((struct crypto_larval *)q) &&
492e2b63 HX	72	((struct crypto_larval *)q)->mask != mask)
	73	continue;
	74
5cb1454b HX	75	exact = !strcmp(q->cra_driver_name, name);
	76	fuzzy = !strcmp(q->cra_name, name);
	77	if (!exact && !(fuzzy && q->cra_priority > best))
	78	continue;
	79
72fa4919	80	if (unlikely(!crypto_mod_get(q)))
5cb1454b HX	81	continue;
	82
	83	best = q->cra_priority;
	84	if (alg)
72fa4919	85	crypto_mod_put(alg);
5cb1454b HX	86	alg = q;
	87
	88	if (exact)
1da177e4	89	break;
1da177e4	90	}
2825982d HX	91
	92	return alg;
	93	}
2825982d HX	94
	95	static void crypto_larval_destroy(struct crypto_alg *alg)
	96	{
	97	struct crypto_larval larval = (void )alg;
	98
	99	BUG_ON(!crypto_is_larval(alg));
2bbb3375	100	if (!IS_ERR_OR_NULL(larval->adult))
2825982d HX	101	crypto_mod_put(larval->adult);
	102	kfree(larval);
	103	}
	104
73d3864a	105	struct crypto_larval crypto_larval_alloc(const char name, u32 type, u32 mask)
2825982d	106	{
2825982d HX	107	struct crypto_larval *larval;
	108
	109	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
	110	if (!larval)
6bfd4809	111	return ERR_PTR(-ENOMEM);
2825982d	112
492e2b63 HX	113	larval->mask = mask;
492e2b63 HX	114	larval->alg.cra_flags = CRYPTO_ALG_LARVAL \| type;
2825982d HX	115	larval->alg.cra_priority = -1;
	116	larval->alg.cra_destroy = crypto_larval_destroy;
	117
2825982d HX	118	strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
	119	init_completion(&larval->completion);
	120
73d3864a HX	121	return larval;
	122	}
	123	EXPORT_SYMBOL_GPL(crypto_larval_alloc);
	124
	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
ce8614a3	135	refcount_set(&larval->alg.cra_refcnt, 2);
73d3864a	136
2825982d	137	down_write(&crypto_alg_sem);
492e2b63	138	alg = __crypto_alg_lookup(name, type, mask);
2825982d HX	139	if (!alg) {
	140	alg = &larval->alg;
	141	list_add(&alg->cra_list, &crypto_alg_list);
	142	}
	143	up_write(&crypto_alg_sem);
	144
77dbd7a9	145	if (alg != &larval->alg) {
2825982d	146	kfree(larval);
77dbd7a9 HX	147	if (crypto_is_larval(alg))
	148	alg = crypto_larval_wait(alg);
	149	}
2825982d HX	150
	151	return alg;
	152	}
	153
b9c55aa4	154	void crypto_larval_kill(struct crypto_alg *alg)
2825982d HX	155	{
	156	struct crypto_larval larval = (void )alg;
	157
	158	down_write(&crypto_alg_sem);
	159	list_del(&alg->cra_list);
	160	up_write(&crypto_alg_sem);
fe3c5206	161	complete_all(&larval->completion);
2825982d HX	162	crypto_alg_put(alg);
2825982d HX	163	}
b9c55aa4	164	EXPORT_SYMBOL_GPL(crypto_larval_kill);
2825982d HX	165
	166	static struct crypto_alg crypto_larval_wait(struct crypto_alg alg)
	167	{
	168	struct crypto_larval larval = (void )alg;
73d3864a HX	169	long timeout;
73d3864a HX	170
3fc89adb	171	timeout = wait_for_completion_killable_timeout(
73d3864a	172	&larval->completion, 60 * HZ);
2825982d	173
2825982d	174	alg = larval->adult;
73d3864a HX	175	if (timeout < 0)
	176	alg = ERR_PTR(-EINTR);
	177	else if (!timeout)
	178	alg = ERR_PTR(-ETIMEDOUT);
	179	else if (!alg)
6bfd4809	180	alg = ERR_PTR(-ENOENT);
2bbb3375 HX	181	else if (IS_ERR(alg))
2bbb3375 HX	182	;
73d3864a HX	183	else if (crypto_is_test_larval(larval) &&
	184	!(alg->cra_flags & CRYPTO_ALG_TESTED))
	185	alg = ERR_PTR(-EAGAIN);
	186	else if (!crypto_mod_get(alg))
	187	alg = ERR_PTR(-EAGAIN);
2825982d HX	188	crypto_mod_put(&larval->alg);
	189
	190	return alg;
	191	}
	192
3ca1e994 HX	193	static struct crypto_alg crypto_alg_lookup(const char name, u32 type,
3ca1e994 HX	194	u32 mask)
2825982d HX	195	{
2825982d HX	196	struct crypto_alg *alg;
eb02c38f HX	197	u32 test = 0;
	198
	199	if (!((type \| mask) & CRYPTO_ALG_TESTED))
	200	test \|= CRYPTO_ALG_TESTED;
2825982d	201
2825982d	202	down_read(&crypto_alg_sem);
eb02c38f	203	alg = __crypto_alg_lookup(name, type \| test, mask \| test);
b346e492 EB	204	if (!alg && test) {
	205	alg = __crypto_alg_lookup(name, type, mask);
	206	if (alg && !crypto_is_larval(alg)) {
	207	/* Test failed */
	208	crypto_mod_put(alg);
	209	alg = ERR_PTR(-ELIBBAD);
	210	}
	211	}
1da177e4	212	up_read(&crypto_alg_sem);
2825982d	213
1da177e4 LT	214	return alg;
	215	}
	216
cadc9ab5 EB	217	static struct crypto_alg crypto_larval_lookup(const char name, u32 type,
cadc9ab5 EB	218	u32 mask)
176c3652	219	{
2825982d	220	struct crypto_alg *alg;
2825982d	221
6bfd4809 HX	222	if (!name)
	223	return ERR_PTR(-ENOENT);
	224
430b441c	225	type &= ~(CRYPTO_ALG_LARVAL \| CRYPTO_ALG_DEAD);
6bfd4809	226	mask &= ~(CRYPTO_ALG_LARVAL \| CRYPTO_ALG_DEAD);
492e2b63	227
a760a665	228	alg = crypto_alg_lookup(name, type, mask);
e2861fa7	229	if (!alg && !(mask & CRYPTO_NOLOAD)) {
5d26a105	230	request_module("crypto-%s", name);
a760a665	231
37fc334c	232	if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
aa07a699	233	CRYPTO_ALG_NEED_FALLBACK))
5d26a105	234	request_module("crypto-%s-all", name);
a760a665 HX	235
	236	alg = crypto_alg_lookup(name, type, mask);
	237	}
	238
eb02c38f HX	239	if (!IS_ERR_OR_NULL(alg) && crypto_is_larval(alg))
	240	alg = crypto_larval_wait(alg);
	241	else if (!alg)
	242	alg = crypto_larval_add(name, type, mask);
2825982d	243
eb02c38f	244	return alg;
b9c55aa4	245	}
b9c55aa4	246
73d3864a HX	247	int crypto_probing_notify(unsigned long val, void *v)
	248	{
	249	int ok;
	250
	251	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
	252	if (ok == NOTIFY_DONE) {
	253	request_module("cryptomgr");
	254	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
	255	}
	256
	257	return ok;
	258	}
	259	EXPORT_SYMBOL_GPL(crypto_probing_notify);
	260
b9c55aa4 HX	261	struct crypto_alg crypto_alg_mod_lookup(const char name, u32 type, u32 mask)
	262	{
	263	struct crypto_alg *alg;
	264	struct crypto_alg *larval;
	265	int ok;
	266
06ca7f68 SM	267	/*
	268	* If the internal flag is set for a cipher, require a caller to
	269	* to invoke the cipher with the internal flag to use that cipher.
	270	* Also, if a caller wants to allocate a cipher that may or may
	271	* not be an internal cipher, use type \| CRYPTO_ALG_INTERNAL and
	272	* !(mask & CRYPTO_ALG_INTERNAL).
	273	*/
	274	if (!((type \| mask) & CRYPTO_ALG_INTERNAL))
	275	mask \|= CRYPTO_ALG_INTERNAL;
	276
b9c55aa4	277	larval = crypto_larval_lookup(name, type, mask);
6bfd4809	278	if (IS_ERR(larval) \|\| !crypto_is_larval(larval))
2825982d HX	279	return larval;
2825982d HX	280
73d3864a	281	ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
2b8c19db HX	282
2b8c19db HX	283	if (ok == NOTIFY_STOP)
2825982d HX	284	alg = crypto_larval_wait(larval);
	285	else {
	286	crypto_mod_put(larval);
6bfd4809	287	alg = ERR_PTR(-ENOENT);
2825982d HX	288	}
	289	crypto_larval_kill(larval);
	290	return alg;
176c3652	291	}
492e2b63	292	EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
176c3652	293
27d2a330	294	static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
1da177e4	295	{
27d2a330	296	const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
e853c3cf	297
27d2a330 HX	298	if (type_obj)
27d2a330 HX	299	return type_obj->init(tfm, type, mask);
e8cfed5e	300	return 0;
1da177e4 LT	301	}
	302
	303	static void crypto_exit_ops(struct crypto_tfm *tfm)
	304	{
e853c3cf HX	305	const struct crypto_type *type = tfm->__crt_alg->cra_type;
e853c3cf HX	306
9c8ae17b EB	307	if (type && tfm->exit)
9c8ae17b EB	308	tfm->exit(tfm);
1da177e4 LT	309	}
1da177e4 LT	310
27d2a330	311	static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
fbdae9f3	312	{
27d2a330	313	const struct crypto_type *type_obj = alg->cra_type;
fbdae9f3 HX	314	unsigned int len;
fbdae9f3 HX	315
e853c3cf	316	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
27d2a330 HX	317	if (type_obj)
27d2a330 HX	318	return len + type_obj->ctxsize(alg, type, mask);
e853c3cf	319
fbdae9f3 HX	320	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
	321	default:
	322	BUG();
	323
	324	case CRYPTO_ALG_TYPE_CIPHER:
f1ddcaf3	325	len += crypto_cipher_ctxsize(alg);
fbdae9f3	326	break;
6941c3a0	327
fbdae9f3	328	case CRYPTO_ALG_TYPE_COMPRESS:
f1ddcaf3	329	len += crypto_compress_ctxsize(alg);
fbdae9f3 HX	330	break;
	331	}
	332
e853c3cf	333	return len;
fbdae9f3 HX	334	}
fbdae9f3 HX	335
73669cc5	336	static void crypto_shoot_alg(struct crypto_alg *alg)
6bfd4809 HX	337	{
	338	down_write(&crypto_alg_sem);
	339	alg->cra_flags \|= CRYPTO_ALG_DYING;
	340	up_write(&crypto_alg_sem);
	341	}
6bfd4809	342
27d2a330 HX	343	struct crypto_tfm __crypto_alloc_tfm(struct crypto_alg alg, u32 type,
27d2a330 HX	344	u32 mask)
1da177e4 LT	345	{
1da177e4 LT	346	struct crypto_tfm *tfm = NULL;
fbdae9f3	347	unsigned int tfm_size;
6bfd4809	348	int err = -ENOMEM;
fbdae9f3	349
27d2a330	350	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
bbeb563f	351	tfm = kzalloc(tfm_size, GFP_KERNEL);
1da177e4	352	if (tfm == NULL)
9765d262	353	goto out_err;
1da177e4	354
1da177e4	355	tfm->__crt_alg = alg;
6bfd4809	356
27d2a330	357	err = crypto_init_ops(tfm, type, mask);
6bfd4809	358	if (err)
1da177e4	359	goto out_free_tfm;
c7fc0599	360
4a779486	361	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
c7fc0599	362	goto cra_init_failed;
1da177e4 LT	363
	364	goto out;
	365
c7fc0599 HX	366	cra_init_failed:
c7fc0599 HX	367	crypto_exit_ops(tfm);
1da177e4	368	out_free_tfm:
4a779486 HX	369	if (err == -EAGAIN)
4a779486 HX	370	crypto_shoot_alg(alg);
1da177e4	371	kfree(tfm);
9765d262	372	out_err:
6bfd4809	373	tfm = ERR_PTR(err);
1da177e4 LT	374	out:
	375	return tfm;
	376	}
6bfd4809 HX	377	EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
6bfd4809 HX	378
6d7d684d HX	379	/*
	380	* crypto_alloc_base - Locate algorithm and allocate transform
	381	* @alg_name: Name of algorithm
	382	* @type: Type of algorithm
	383	* @mask: Mask for type comparison
	384	*
7b0bac64	385	* This function should not be used by new algorithm types.
fd1a1900	386	* Please use crypto_alloc_tfm instead.
7b0bac64	387	*
6d7d684d HX	388	* crypto_alloc_base() will first attempt to locate an already loaded
	389	* algorithm. If that fails and the kernel supports dynamically loadable
	390	* modules, it will then attempt to load a module of the same name or
	391	* alias. If that fails it will send a query to any loaded crypto manager
	392	* to construct an algorithm on the fly. A refcount is grabbed on the
	393	* algorithm which is then associated with the new transform.
	394	*
	395	* The returned transform is of a non-determinate type. Most people
	396	* should use one of the more specific allocation functions such as
c65058b7	397	* crypto_alloc_skcipher().
6d7d684d HX	398	*
	399	* In case of error the return value is an error pointer.
	400	*/
	401	struct crypto_tfm crypto_alloc_base(const char alg_name, u32 type, u32 mask)
	402	{
	403	struct crypto_tfm *tfm;
	404	int err;
	405
	406	for (;;) {
	407	struct crypto_alg *alg;
	408
	409	alg = crypto_alg_mod_lookup(alg_name, type, mask);
9765d262 AM	410	if (IS_ERR(alg)) {
9765d262 AM	411	err = PTR_ERR(alg);
6d7d684d	412	goto err;
9765d262	413	}
6d7d684d	414
27d2a330	415	tfm = __crypto_alloc_tfm(alg, type, mask);
6d7d684d	416	if (!IS_ERR(tfm))
9765d262	417	return tfm;
6d7d684d HX	418
	419	crypto_mod_put(alg);
	420	err = PTR_ERR(tfm);
	421
	422	err:
	423	if (err != -EAGAIN)
	424	break;
3fc89adb	425	if (fatal_signal_pending(current)) {
6d7d684d HX	426	err = -EINTR;
	427	break;
	428	}
9765d262	429	}
6d7d684d	430
9765d262	431	return ERR_PTR(err);
6d7d684d HX	432	}
6d7d684d HX	433	EXPORT_SYMBOL_GPL(crypto_alloc_base);
7b0bac64	434
3f683d61 HX	435	void crypto_create_tfm(struct crypto_alg alg,
3f683d61 HX	436	const struct crypto_type *frontend)
7b0bac64 HX	437	{
	438	char *mem;
	439	struct crypto_tfm *tfm = NULL;
	440	unsigned int tfmsize;
	441	unsigned int total;
	442	int err = -ENOMEM;
	443
	444	tfmsize = frontend->tfmsize;
2ca33da1	445	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
7b0bac64 HX	446
	447	mem = kzalloc(total, GFP_KERNEL);
	448	if (mem == NULL)
	449	goto out_err;
	450
	451	tfm = (struct crypto_tfm *)(mem + tfmsize);
	452	tfm->__crt_alg = alg;
	453
2ca33da1	454	err = frontend->init_tfm(tfm);
7b0bac64 HX	455	if (err)
	456	goto out_free_tfm;
	457
	458	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
	459	goto cra_init_failed;
	460
	461	goto out;
	462
	463	cra_init_failed:
	464	crypto_exit_ops(tfm);
	465	out_free_tfm:
	466	if (err == -EAGAIN)
	467	crypto_shoot_alg(alg);
	468	kfree(mem);
	469	out_err:
3f683d61	470	mem = ERR_PTR(err);
7b0bac64	471	out:
3f683d61	472	return mem;
7b0bac64 HX	473	}
	474	EXPORT_SYMBOL_GPL(crypto_create_tfm);
	475
d06854f0 HX	476	struct crypto_alg crypto_find_alg(const char alg_name,
	477	const struct crypto_type *frontend,
	478	u32 type, u32 mask)
	479	{
d06854f0 HX	480	if (frontend) {
	481	type &= frontend->maskclear;
	482	mask &= frontend->maskclear;
	483	type \|= frontend->type;
	484	mask \|= frontend->maskset;
d06854f0 HX	485	}
d06854f0 HX	486
4989d4f0	487	return crypto_alg_mod_lookup(alg_name, type, mask);
d06854f0 HX	488	}
	489	EXPORT_SYMBOL_GPL(crypto_find_alg);
	490
7b0bac64 HX	491	/*
	492	* crypto_alloc_tfm - Locate algorithm and allocate transform
	493	* @alg_name: Name of algorithm
	494	* @frontend: Frontend algorithm type
	495	* @type: Type of algorithm
	496	* @mask: Mask for type comparison
	497	*
	498	* crypto_alloc_tfm() will first attempt to locate an already loaded
	499	* algorithm. If that fails and the kernel supports dynamically loadable
	500	* modules, it will then attempt to load a module of the same name or
	501	* alias. If that fails it will send a query to any loaded crypto manager
	502	* to construct an algorithm on the fly. A refcount is grabbed on the
	503	* algorithm which is then associated with the new transform.
	504	*
	505	* The returned transform is of a non-determinate type. Most people
	506	* should use one of the more specific allocation functions such as
0a940d4e	507	* crypto_alloc_skcipher().
7b0bac64 HX	508	*
	509	* In case of error the return value is an error pointer.
	510	*/
3f683d61 HX	511	void crypto_alloc_tfm(const char alg_name,
3f683d61 HX	512	const struct crypto_type *frontend, u32 type, u32 mask)
7b0bac64	513	{
3f683d61	514	void *tfm;
7b0bac64 HX	515	int err;
7b0bac64 HX	516
7b0bac64 HX	517	for (;;) {
	518	struct crypto_alg *alg;
	519
d06854f0	520	alg = crypto_find_alg(alg_name, frontend, type, mask);
7b0bac64 HX	521	if (IS_ERR(alg)) {
	522	err = PTR_ERR(alg);
	523	goto err;
	524	}
	525
	526	tfm = crypto_create_tfm(alg, frontend);
	527	if (!IS_ERR(tfm))
	528	return tfm;
	529
	530	crypto_mod_put(alg);
	531	err = PTR_ERR(tfm);
	532
	533	err:
	534	if (err != -EAGAIN)
	535	break;
3fc89adb	536	if (fatal_signal_pending(current)) {
7b0bac64 HX	537	err = -EINTR;
	538	break;
	539	}
	540	}
	541
	542	return ERR_PTR(err);
	543	}
	544	EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
7b2cd92a	545
6d7d684d	546	/*
7b2cd92a HX	547	* crypto_destroy_tfm - Free crypto transform
7b2cd92a HX	548	* @mem: Start of tfm slab
6d7d684d HX	549	* @tfm: Transform to free
6d7d684d HX	550	*
7b2cd92a	551	* This function frees up the transform and any associated resources,
6d7d684d HX	552	* then drops the refcount on the associated algorithm.
6d7d684d HX	553	*/
7b2cd92a	554	void crypto_destroy_tfm(void mem, struct crypto_tfm tfm)
1da177e4	555	{
a61cc448	556	struct crypto_alg *alg;
a61cc448	557
7b2cd92a	558	if (unlikely(!mem))
a61cc448 JJ	559	return;
	560
	561	alg = tfm->__crt_alg;
1da177e4	562
4a779486	563	if (!tfm->exit && alg->cra_exit)
c7fc0599	564	alg->cra_exit(tfm);
1da177e4	565	crypto_exit_ops(tfm);
72fa4919	566	crypto_mod_put(alg);
811d8f06	567	kzfree(mem);
1da177e4	568	}
7b2cd92a	569	EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
fce32d70 HX	570
	571	int crypto_has_alg(const char *name, u32 type, u32 mask)
	572	{
	573	int ret = 0;
	574	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
3d01a33b	575
fce32d70 HX	576	if (!IS_ERR(alg)) {
	577	crypto_mod_put(alg);
	578	ret = 1;
	579	}
3d01a33b	580
fce32d70 HX	581	return ret;
	582	}
	583	EXPORT_SYMBOL_GPL(crypto_has_alg);
c3715cb9	584
ada69a16 GBY	585	void crypto_req_done(struct crypto_async_request *req, int err)
	586	{
	587	struct crypto_wait *wait = req->data;
	588
	589	if (err == -EINPROGRESS)
	590	return;
	591
	592	wait->err = err;
	593	complete(&wait->completion);
	594	}
	595	EXPORT_SYMBOL_GPL(crypto_req_done);
	596
c3715cb9 SS	597	MODULE_DESCRIPTION("Cryptographic core API");
c3715cb9 SS	598	MODULE_LICENSE("GPL");
8ab23d54	599	MODULE_SOFTDEP("pre: cryptomgr");