[linux.git] / crypto / api.c

/*
 * Scatterlist Cryptographic API.
 *
 * Copyright (c) 2002 James Morris <[email protected]>
 * Copyright (c) 2002 David S. Miller ([email protected])
 * Copyright (c) 2005 Herbert Xu <[email protected]>
 *
 * Portions derived from Cryptoapi, by Alexander Kjeldaas <[email protected]>
 * and Nettle, by Niels Möller.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 */

#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.h>
#include <linux/slab.h>
#include <linux/string.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 inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
{
	atomic_inc(&alg->cra_refcnt);
	return 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);

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) &&
		    ((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;
}
EXPORT_SYMBOL_GPL(__crypto_alg_lookup);

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

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

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

	atomic_set(&larval->alg.cra_refcnt, 2);
	strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
	init_completion(&larval->completion);

	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);

	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;

	wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ);
	alg = larval->adult;
	if (alg) {
		if (!crypto_mod_get(alg))
			alg = ERR_PTR(-EAGAIN);
	} else
		alg = ERR_PTR(-ENOENT);
	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;

	down_read(&crypto_alg_sem);
	alg = __crypto_alg_lookup(name, type, mask);
	up_read(&crypto_alg_sem);

	return alg;
}

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

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

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

	alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
				      name);
	if (alg)
		return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;

	return crypto_larval_alloc(name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_larval_lookup);

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

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

	ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
	if (ok == NOTIFY_DONE) {
		request_module("cryptomgr");
		ok = crypto_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);

	switch (crypto_tfm_alg_type(tfm)) {
	case CRYPTO_ALG_TYPE_CIPHER:
		return crypto_init_cipher_ops(tfm);
		
	case CRYPTO_ALG_TYPE_DIGEST:
		return crypto_init_digest_ops(tfm);
		
	case CRYPTO_ALG_TYPE_COMPRESS:
		return crypto_init_compress_ops(tfm);
	
	default:
		break;
	}
	
	BUG();
	return -EINVAL;
}

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

	if (type) {
		if (type->exit)
			type->exit(tfm);
		return;
	}

	switch (crypto_tfm_alg_type(tfm)) {
	case CRYPTO_ALG_TYPE_CIPHER:
		crypto_exit_cipher_ops(tfm);
		break;
		
	case CRYPTO_ALG_TYPE_DIGEST:
		crypto_exit_digest_ops(tfm);
		break;
		
	case CRYPTO_ALG_TYPE_COMPRESS:
		crypto_exit_compress_ops(tfm);
		break;
	
	default:
		BUG();
		
	}
}

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

	return len;
}

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

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 (alg->cra_init && (err = alg->cra_init(tfm))) {
		if (err == -EAGAIN)
			crypto_shoot_alg(alg);
		goto cra_init_failed;
	}

	goto out;

cra_init_failed:
	crypto_exit_ops(tfm);
out_free_tfm:
	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
 *
 *	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_blkcipher.
 *
 *	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 (signal_pending(current)) {
			err = -EINTR;
			break;
		}
	}

	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_base);
 
/*
 *	crypto_free_tfm - Free crypto transform
 *	@tfm: Transform to free
 *
 *	crypto_free_tfm() frees up the transform and any associated resources,
 *	then drops the refcount on the associated algorithm.
 */
void crypto_free_tfm(struct crypto_tfm *tfm)
{
	struct crypto_alg *alg;
	int size;

	if (unlikely(!tfm))
		return;

	alg = tfm->__crt_alg;
	size = sizeof(*tfm) + alg->cra_ctxsize;

	if (alg->cra_exit)
		alg->cra_exit(tfm);
	crypto_exit_ops(tfm);
	crypto_mod_put(alg);
	memset(tfm, 0, size);
	kfree(tfm);
}

EXPORT_SYMBOL_GPL(crypto_free_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);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Scatterlist Cryptographic API.
	3	*
	4	* Copyright (c) 2002 James Morris <[email protected]>
	5	* Copyright (c) 2002 David S. Miller ([email protected])
5cb1454b	6	* Copyright (c) 2005 Herbert Xu <[email protected]>
1da177e4 LT	7	*
1da177e4 LT	8	* Portions derived from Cryptoapi, by Alexander Kjeldaas <[email protected]>
991d1740	9	* and Nettle, by Niels Möller.
1da177e4 LT	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	*/
a61cc448	17
6bfd4809	18	#include <linux/err.h>
1da177e4	19	#include <linux/errno.h>
5cb1454b	20	#include <linux/kernel.h>
176c3652	21	#include <linux/kmod.h>
2b8c19db	22	#include <linux/module.h>
2825982d	23	#include <linux/param.h>
6bfd4809	24	#include <linux/sched.h>
1da177e4	25	#include <linux/slab.h>
5cb1454b	26	#include <linux/string.h>
1da177e4 LT	27	#include "internal.h"
	28
	29	LIST_HEAD(crypto_alg_list);
cce9e06d	30	EXPORT_SYMBOL_GPL(crypto_alg_list);
1da177e4	31	DECLARE_RWSEM(crypto_alg_sem);
cce9e06d	32	EXPORT_SYMBOL_GPL(crypto_alg_sem);
1da177e4	33
2825982d HX	34	BLOCKING_NOTIFIER_HEAD(crypto_chain);
	35	EXPORT_SYMBOL_GPL(crypto_chain);
	36
6521f302	37	static inline struct crypto_alg crypto_alg_get(struct crypto_alg alg)
1da177e4	38	{
6521f302 HX	39	atomic_inc(&alg->cra_refcnt);
	40	return alg;
	41	}
	42
2825982d	43	struct crypto_alg crypto_mod_get(struct crypto_alg alg)
6521f302 HX	44	{
6521f302 HX	45	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
1da177e4	46	}
2825982d	47	EXPORT_SYMBOL_GPL(crypto_mod_get);
1da177e4	48
2825982d	49	void crypto_mod_put(struct crypto_alg *alg)
1da177e4	50	{
da7cd59a HX	51	struct module *module = alg->cra_module;
da7cd59a HX	52
6521f302	53	crypto_alg_put(alg);
da7cd59a	54	module_put(module);
1da177e4	55	}
2825982d	56	EXPORT_SYMBOL_GPL(crypto_mod_put);
1da177e4	57
492e2b63	58	struct crypto_alg __crypto_alg_lookup(const char name, u32 type, u32 mask)
1da177e4 LT	59	{
1da177e4 LT	60	struct crypto_alg q, alg = NULL;
2825982d	61	int best = -2;
1da177e4	62
1da177e4	63	list_for_each_entry(q, &crypto_alg_list, cra_list) {
5cb1454b HX	64	int exact, fuzzy;
5cb1454b HX	65
6bfd4809 HX	66	if (crypto_is_moribund(q))
	67	continue;
	68
492e2b63 HX	69	if ((q->cra_flags ^ type) & mask)
	70	continue;
	71
	72	if (crypto_is_larval(q) &&
	73	((struct crypto_larval *)q)->mask != mask)
	74	continue;
	75
5cb1454b HX	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
72fa4919	81	if (unlikely(!crypto_mod_get(q)))
5cb1454b HX	82	continue;
	83
	84	best = q->cra_priority;
	85	if (alg)
72fa4919	86	crypto_mod_put(alg);
5cb1454b HX	87	alg = q;
	88
	89	if (exact)
1da177e4	90	break;
1da177e4	91	}
2825982d HX	92
	93	return alg;
	94	}
	95	EXPORT_SYMBOL_GPL(__crypto_alg_lookup);
	96
	97	static void crypto_larval_destroy(struct crypto_alg *alg)
	98	{
	99	struct crypto_larval larval = (void )alg;
	100
	101	BUG_ON(!crypto_is_larval(alg));
	102	if (larval->adult)
	103	crypto_mod_put(larval->adult);
	104	kfree(larval);
	105	}
	106
492e2b63 HX	107	static struct crypto_alg crypto_larval_alloc(const char name, u32 type,
492e2b63 HX	108	u32 mask)
2825982d HX	109	{
	110	struct crypto_alg *alg;
	111	struct crypto_larval *larval;
	112
	113	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
	114	if (!larval)
6bfd4809	115	return ERR_PTR(-ENOMEM);
2825982d	116
492e2b63 HX	117	larval->mask = mask;
492e2b63 HX	118	larval->alg.cra_flags = CRYPTO_ALG_LARVAL \| type;
2825982d HX	119	larval->alg.cra_priority = -1;
	120	larval->alg.cra_destroy = crypto_larval_destroy;
	121
	122	atomic_set(&larval->alg.cra_refcnt, 2);
	123	strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
	124	init_completion(&larval->completion);
	125
	126	down_write(&crypto_alg_sem);
492e2b63	127	alg = __crypto_alg_lookup(name, type, mask);
2825982d HX	128	if (!alg) {
	129	alg = &larval->alg;
	130	list_add(&alg->cra_list, &crypto_alg_list);
	131	}
	132	up_write(&crypto_alg_sem);
	133
	134	if (alg != &larval->alg)
	135	kfree(larval);
	136
	137	return alg;
	138	}
	139
b9c55aa4	140	void crypto_larval_kill(struct crypto_alg *alg)
2825982d HX	141	{
	142	struct crypto_larval larval = (void )alg;
	143
	144	down_write(&crypto_alg_sem);
	145	list_del(&alg->cra_list);
	146	up_write(&crypto_alg_sem);
fe3c5206	147	complete_all(&larval->completion);
2825982d HX	148	crypto_alg_put(alg);
2825982d HX	149	}
b9c55aa4	150	EXPORT_SYMBOL_GPL(crypto_larval_kill);
2825982d HX	151
	152	static struct crypto_alg crypto_larval_wait(struct crypto_alg alg)
	153	{
	154	struct crypto_larval larval = (void )alg;
	155
	156	wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ);
	157	alg = larval->adult;
6bfd4809 HX	158	if (alg) {
	159	if (!crypto_mod_get(alg))
	160	alg = ERR_PTR(-EAGAIN);
	161	} else
	162	alg = ERR_PTR(-ENOENT);
2825982d HX	163	crypto_mod_put(&larval->alg);
	164
	165	return alg;
	166	}
	167
492e2b63 HX	168	static struct crypto_alg crypto_alg_lookup(const char name, u32 type,
492e2b63 HX	169	u32 mask)
2825982d HX	170	{
	171	struct crypto_alg *alg;
	172
2825982d	173	down_read(&crypto_alg_sem);
492e2b63	174	alg = __crypto_alg_lookup(name, type, mask);
1da177e4	175	up_read(&crypto_alg_sem);
2825982d	176
1da177e4 LT	177	return alg;
	178	}
	179
b9c55aa4	180	struct crypto_alg crypto_larval_lookup(const char name, u32 type, u32 mask)
176c3652	181	{
2825982d	182	struct crypto_alg *alg;
2825982d	183
6bfd4809 HX	184	if (!name)
	185	return ERR_PTR(-ENOENT);
	186
	187	mask &= ~(CRYPTO_ALG_LARVAL \| CRYPTO_ALG_DEAD);
492e2b63 HX	188	type &= mask;
	189
	190	alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
	191	name);
2825982d HX	192	if (alg)
	193	return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
	194
b9c55aa4 HX	195	return crypto_larval_alloc(name, type, mask);
	196	}
	197	EXPORT_SYMBOL_GPL(crypto_larval_lookup);
	198
	199	struct crypto_alg crypto_alg_mod_lookup(const char name, u32 type, u32 mask)
	200	{
	201	struct crypto_alg *alg;
	202	struct crypto_alg *larval;
	203	int ok;
	204
	205	larval = crypto_larval_lookup(name, type, mask);
6bfd4809	206	if (IS_ERR(larval) \|\| !crypto_is_larval(larval))
2825982d HX	207	return larval;
2825982d HX	208
2b8c19db HX	209	ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
	210	if (ok == NOTIFY_DONE) {
	211	request_module("cryptomgr");
	212	ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
	213	}
	214
	215	if (ok == NOTIFY_STOP)
2825982d HX	216	alg = crypto_larval_wait(larval);
	217	else {
	218	crypto_mod_put(larval);
6bfd4809	219	alg = ERR_PTR(-ENOENT);
2825982d HX	220	}
	221	crypto_larval_kill(larval);
	222	return alg;
176c3652	223	}
492e2b63	224	EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
176c3652	225
27d2a330	226	static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
1da177e4	227	{
27d2a330	228	const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
e853c3cf	229
27d2a330 HX	230	if (type_obj)
27d2a330 HX	231	return type_obj->init(tfm, type, mask);
e853c3cf	232
1da177e4 LT	233	switch (crypto_tfm_alg_type(tfm)) {
	234	case CRYPTO_ALG_TYPE_CIPHER:
	235	return crypto_init_cipher_ops(tfm);
	236
	237	case CRYPTO_ALG_TYPE_DIGEST:
	238	return crypto_init_digest_ops(tfm);
	239
	240	case CRYPTO_ALG_TYPE_COMPRESS:
	241	return crypto_init_compress_ops(tfm);
	242
	243	default:
	244	break;
	245	}
	246
	247	BUG();
	248	return -EINVAL;
	249	}
	250
	251	static void crypto_exit_ops(struct crypto_tfm *tfm)
	252	{
e853c3cf HX	253	const struct crypto_type *type = tfm->__crt_alg->cra_type;
	254
	255	if (type) {
	256	if (type->exit)
	257	type->exit(tfm);
	258	return;
	259	}
	260
1da177e4 LT	261	switch (crypto_tfm_alg_type(tfm)) {
	262	case CRYPTO_ALG_TYPE_CIPHER:
	263	crypto_exit_cipher_ops(tfm);
	264	break;
	265
	266	case CRYPTO_ALG_TYPE_DIGEST:
	267	crypto_exit_digest_ops(tfm);
	268	break;
	269
	270	case CRYPTO_ALG_TYPE_COMPRESS:
	271	crypto_exit_compress_ops(tfm);
	272	break;
	273
	274	default:
	275	BUG();
	276
	277	}
	278	}
	279
27d2a330	280	static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
fbdae9f3	281	{
27d2a330	282	const struct crypto_type *type_obj = alg->cra_type;
fbdae9f3 HX	283	unsigned int len;
fbdae9f3 HX	284
e853c3cf	285	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
27d2a330 HX	286	if (type_obj)
27d2a330 HX	287	return len + type_obj->ctxsize(alg, type, mask);
e853c3cf	288
fbdae9f3 HX	289	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
	290	default:
	291	BUG();
	292
	293	case CRYPTO_ALG_TYPE_CIPHER:
f1ddcaf3	294	len += crypto_cipher_ctxsize(alg);
fbdae9f3 HX	295	break;
	296
	297	case CRYPTO_ALG_TYPE_DIGEST:
f1ddcaf3	298	len += crypto_digest_ctxsize(alg);
fbdae9f3 HX	299	break;
	300
	301	case CRYPTO_ALG_TYPE_COMPRESS:
f1ddcaf3	302	len += crypto_compress_ctxsize(alg);
fbdae9f3 HX	303	break;
	304	}
	305
e853c3cf	306	return len;
fbdae9f3 HX	307	}
fbdae9f3 HX	308
6bfd4809 HX	309	void crypto_shoot_alg(struct crypto_alg *alg)
	310	{
	311	down_write(&crypto_alg_sem);
	312	alg->cra_flags \|= CRYPTO_ALG_DYING;
	313	up_write(&crypto_alg_sem);
	314	}
	315	EXPORT_SYMBOL_GPL(crypto_shoot_alg);
	316
27d2a330 HX	317	struct crypto_tfm __crypto_alloc_tfm(struct crypto_alg alg, u32 type,
27d2a330 HX	318	u32 mask)
1da177e4 LT	319	{
1da177e4 LT	320	struct crypto_tfm *tfm = NULL;
fbdae9f3	321	unsigned int tfm_size;
6bfd4809	322	int err = -ENOMEM;
fbdae9f3	323
27d2a330	324	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
bbeb563f	325	tfm = kzalloc(tfm_size, GFP_KERNEL);
1da177e4	326	if (tfm == NULL)
9765d262	327	goto out_err;
1da177e4	328
1da177e4	329	tfm->__crt_alg = alg;
6bfd4809	330
27d2a330	331	err = crypto_init_ops(tfm, type, mask);
6bfd4809	332	if (err)
1da177e4	333	goto out_free_tfm;
c7fc0599	334
6bfd4809 HX	335	if (alg->cra_init && (err = alg->cra_init(tfm))) {
	336	if (err == -EAGAIN)
	337	crypto_shoot_alg(alg);
c7fc0599	338	goto cra_init_failed;
6bfd4809	339	}
1da177e4 LT	340
	341	goto out;
	342
c7fc0599 HX	343	cra_init_failed:
c7fc0599 HX	344	crypto_exit_ops(tfm);
1da177e4 LT	345	out_free_tfm:
1da177e4 LT	346	kfree(tfm);
9765d262	347	out_err:
6bfd4809	348	tfm = ERR_PTR(err);
1da177e4 LT	349	out:
	350	return tfm;
	351	}
6bfd4809 HX	352	EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
6bfd4809 HX	353
6d7d684d HX	354	/*
	355	* crypto_alloc_base - Locate algorithm and allocate transform
	356	* @alg_name: Name of algorithm
	357	* @type: Type of algorithm
	358	* @mask: Mask for type comparison
	359	*
	360	* crypto_alloc_base() will first attempt to locate an already loaded
	361	* algorithm. If that fails and the kernel supports dynamically loadable
	362	* modules, it will then attempt to load a module of the same name or
	363	* alias. If that fails it will send a query to any loaded crypto manager
	364	* to construct an algorithm on the fly. A refcount is grabbed on the
	365	* algorithm which is then associated with the new transform.
	366	*
	367	* The returned transform is of a non-determinate type. Most people
	368	* should use one of the more specific allocation functions such as
	369	* crypto_alloc_blkcipher.
	370	*
	371	* In case of error the return value is an error pointer.
	372	*/
	373	struct crypto_tfm crypto_alloc_base(const char alg_name, u32 type, u32 mask)
	374	{
	375	struct crypto_tfm *tfm;
	376	int err;
	377
	378	for (;;) {
	379	struct crypto_alg *alg;
	380
	381	alg = crypto_alg_mod_lookup(alg_name, type, mask);
9765d262 AM	382	if (IS_ERR(alg)) {
9765d262 AM	383	err = PTR_ERR(alg);
6d7d684d	384	goto err;
9765d262	385	}
6d7d684d	386
27d2a330	387	tfm = __crypto_alloc_tfm(alg, type, mask);
6d7d684d	388	if (!IS_ERR(tfm))
9765d262	389	return tfm;
6d7d684d HX	390
	391	crypto_mod_put(alg);
	392	err = PTR_ERR(tfm);
	393
	394	err:
	395	if (err != -EAGAIN)
	396	break;
	397	if (signal_pending(current)) {
	398	err = -EINTR;
	399	break;
	400	}
9765d262	401	}
6d7d684d	402
9765d262	403	return ERR_PTR(err);
6d7d684d HX	404	}
	405	EXPORT_SYMBOL_GPL(crypto_alloc_base);
	406
	407	/*
	408	* crypto_free_tfm - Free crypto transform
	409	* @tfm: Transform to free
	410	*
	411	* crypto_free_tfm() frees up the transform and any associated resources,
	412	* then drops the refcount on the associated algorithm.
	413	*/
1da177e4 LT	414	void crypto_free_tfm(struct crypto_tfm *tfm)
1da177e4 LT	415	{
a61cc448 JJ	416	struct crypto_alg *alg;
	417	int size;
	418
	419	if (unlikely(!tfm))
	420	return;
	421
	422	alg = tfm->__crt_alg;
	423	size = sizeof(*tfm) + alg->cra_ctxsize;
1da177e4	424
c7fc0599 HX	425	if (alg->cra_exit)
c7fc0599 HX	426	alg->cra_exit(tfm);
1da177e4	427	crypto_exit_ops(tfm);
72fa4919	428	crypto_mod_put(alg);
1da177e4 LT	429	memset(tfm, 0, size);
	430	kfree(tfm);
	431	}
	432
1da177e4	433	EXPORT_SYMBOL_GPL(crypto_free_tfm);
fce32d70 HX	434
	435	int crypto_has_alg(const char *name, u32 type, u32 mask)
	436	{
	437	int ret = 0;
	438	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
	439
	440	if (!IS_ERR(alg)) {
	441	crypto_mod_put(alg);
	442	ret = 1;
	443	}
	444
	445	return ret;
	446	}
	447	EXPORT_SYMBOL_GPL(crypto_has_alg);