[mirror_ubuntu-bionic-kernel.git] / crypto / api.c

/*
 * 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.
 *
 * 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/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 (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);

	atomic_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 (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;
}

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;
}
EXPORT_SYMBOL_GPL(crypto_alg_lookup);

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 (alg)
		return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;

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

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 (!((type | mask) & CRYPTO_ALG_TESTED)) {
		type |= CRYPTO_ALG_TESTED;
		mask |= CRYPTO_ALG_TESTED;
	}

	/*
	 * 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);

	switch (crypto_tfm_alg_type(tfm)) {
	case CRYPTO_ALG_TYPE_CIPHER:
		return crypto_init_cipher_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 && 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_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 (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)
{
	struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask) =
		crypto_alg_mod_lookup;

	if (frontend) {
		type &= frontend->maskclear;
		mask &= frontend->maskclear;
		type |= frontend->type;
		mask |= frontend->maskset;

		if (frontend->lookup)
			lookup = frontend->lookup;
	}

	return 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_blkcipher.
 *
 *	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");
Commit	Line	Data
	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/signal.h>
	25	#include <linux/slab.h>
	26	#include <linux/string.h>
	27	#include <linux/completion.h>
	28	#include "internal.h"
	29
	30	LIST_HEAD(crypto_alg_list);
	31	EXPORT_SYMBOL_GPL(crypto_alg_list);
	32	DECLARE_RWSEM(crypto_alg_sem);
	33	EXPORT_SYMBOL_GPL(crypto_alg_sem);
	34
	35	BLOCKING_NOTIFIER_HEAD(crypto_chain);
	36	EXPORT_SYMBOL_GPL(crypto_chain);
	37
	38	static struct crypto_alg crypto_larval_wait(struct crypto_alg alg);
	39
	40	struct crypto_alg crypto_mod_get(struct crypto_alg alg)
	41	{
	42	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
	43	}
	44	EXPORT_SYMBOL_GPL(crypto_mod_get);
	45
	46	void crypto_mod_put(struct crypto_alg *alg)
	47	{
	48	struct module *module = alg->cra_module;
	49
	50	crypto_alg_put(alg);
	51	module_put(module);
	52	}
	53	EXPORT_SYMBOL_GPL(crypto_mod_put);
	54
	55	static inline int crypto_is_test_larval(struct crypto_larval *larval)
	56	{
	57	return larval->alg.cra_driver_name[0];
	58	}
	59
	60	static struct crypto_alg __crypto_alg_lookup(const char name, u32 type,
	61	u32 mask)
	62	{
	63	struct crypto_alg q, alg = NULL;
	64	int best = -2;
	65
	66	list_for_each_entry(q, &crypto_alg_list, cra_list) {
	67	int exact, fuzzy;
	68
	69	if (crypto_is_moribund(q))
	70	continue;
	71
	72	if ((q->cra_flags ^ type) & mask)
	73	continue;
	74
	75	if (crypto_is_larval(q) &&
	76	!crypto_is_test_larval((struct crypto_larval *)q) &&
	77	((struct crypto_larval *)q)->mask != mask)
	78	continue;
	79
	80	exact = !strcmp(q->cra_driver_name, name);
	81	fuzzy = !strcmp(q->cra_name, name);
	82	if (!exact && !(fuzzy && q->cra_priority > best))
	83	continue;
	84
	85	if (unlikely(!crypto_mod_get(q)))
	86	continue;
	87
	88	best = q->cra_priority;
	89	if (alg)
	90	crypto_mod_put(alg);
	91	alg = q;
	92
	93	if (exact)
	94	break;
	95	}
	96
	97	return alg;
	98	}
	99
	100	static void crypto_larval_destroy(struct crypto_alg *alg)
	101	{
	102	struct crypto_larval larval = (void )alg;
	103
	104	BUG_ON(!crypto_is_larval(alg));
	105	if (larval->adult)
	106	crypto_mod_put(larval->adult);
	107	kfree(larval);
	108	}
	109
	110	struct crypto_larval crypto_larval_alloc(const char name, u32 type, u32 mask)
	111	{
	112	struct crypto_larval *larval;
	113
	114	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
	115	if (!larval)
	116	return ERR_PTR(-ENOMEM);
	117
	118	larval->mask = mask;
	119	larval->alg.cra_flags = CRYPTO_ALG_LARVAL \| type;
	120	larval->alg.cra_priority = -1;
	121	larval->alg.cra_destroy = crypto_larval_destroy;
	122
	123	strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
	124	init_completion(&larval->completion);
	125
	126	return larval;
	127	}
	128	EXPORT_SYMBOL_GPL(crypto_larval_alloc);
	129
	130	static struct crypto_alg crypto_larval_add(const char name, u32 type,
	131	u32 mask)
	132	{
	133	struct crypto_alg *alg;
	134	struct crypto_larval *larval;
	135
	136	larval = crypto_larval_alloc(name, type, mask);
	137	if (IS_ERR(larval))
	138	return ERR_CAST(larval);
	139
	140	atomic_set(&larval->alg.cra_refcnt, 2);
	141
	142	down_write(&crypto_alg_sem);
	143	alg = __crypto_alg_lookup(name, type, mask);
	144	if (!alg) {
	145	alg = &larval->alg;
	146	list_add(&alg->cra_list, &crypto_alg_list);
	147	}
	148	up_write(&crypto_alg_sem);
	149
	150	if (alg != &larval->alg) {
	151	kfree(larval);
	152	if (crypto_is_larval(alg))
	153	alg = crypto_larval_wait(alg);
	154	}
	155
	156	return alg;
	157	}
	158
	159	void crypto_larval_kill(struct crypto_alg *alg)
	160	{
	161	struct crypto_larval larval = (void )alg;
	162
	163	down_write(&crypto_alg_sem);
	164	list_del(&alg->cra_list);
	165	up_write(&crypto_alg_sem);
	166	complete_all(&larval->completion);
	167	crypto_alg_put(alg);
	168	}
	169	EXPORT_SYMBOL_GPL(crypto_larval_kill);
	170
	171	static struct crypto_alg crypto_larval_wait(struct crypto_alg alg)
	172	{
	173	struct crypto_larval larval = (void )alg;
	174	long timeout;
	175
	176	timeout = wait_for_completion_killable_timeout(
	177	&larval->completion, 60 * HZ);
	178
	179	alg = larval->adult;
	180	if (timeout < 0)
	181	alg = ERR_PTR(-EINTR);
	182	else if (!timeout)
	183	alg = ERR_PTR(-ETIMEDOUT);
	184	else if (!alg)
	185	alg = ERR_PTR(-ENOENT);
	186	else if (crypto_is_test_larval(larval) &&
	187	!(alg->cra_flags & CRYPTO_ALG_TESTED))
	188	alg = ERR_PTR(-EAGAIN);
	189	else if (!crypto_mod_get(alg))
	190	alg = ERR_PTR(-EAGAIN);
	191	crypto_mod_put(&larval->alg);
	192
	193	return alg;
	194	}
	195
	196	struct crypto_alg crypto_alg_lookup(const char name, u32 type, u32 mask)
	197	{
	198	struct crypto_alg *alg;
	199
	200	down_read(&crypto_alg_sem);
	201	alg = __crypto_alg_lookup(name, type, mask);
	202	up_read(&crypto_alg_sem);
	203
	204	return alg;
	205	}
	206	EXPORT_SYMBOL_GPL(crypto_alg_lookup);
	207
	208	struct crypto_alg crypto_larval_lookup(const char name, u32 type, u32 mask)
	209	{
	210	struct crypto_alg *alg;
	211
	212	if (!name)
	213	return ERR_PTR(-ENOENT);
	214
	215	type &= ~(CRYPTO_ALG_LARVAL \| CRYPTO_ALG_DEAD);
	216	mask &= ~(CRYPTO_ALG_LARVAL \| CRYPTO_ALG_DEAD);
	217
	218	alg = crypto_alg_lookup(name, type, mask);
	219	if (!alg && !(mask & CRYPTO_NOLOAD)) {
	220	request_module("crypto-%s", name);
	221
	222	if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
	223	CRYPTO_ALG_NEED_FALLBACK))
	224	request_module("crypto-%s-all", name);
	225
	226	alg = crypto_alg_lookup(name, type, mask);
	227	}
	228
	229	if (alg)
	230	return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
	231
	232	return crypto_larval_add(name, type, mask);
	233	}
	234	EXPORT_SYMBOL_GPL(crypto_larval_lookup);
	235
	236	int crypto_probing_notify(unsigned long val, void *v)
	237	{
	238	int ok;
	239
	240	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
	241	if (ok == NOTIFY_DONE) {
	242	request_module("cryptomgr");
	243	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
	244	}
	245
	246	return ok;
	247	}
	248	EXPORT_SYMBOL_GPL(crypto_probing_notify);
	249
	250	struct crypto_alg crypto_alg_mod_lookup(const char name, u32 type, u32 mask)
	251	{
	252	struct crypto_alg *alg;
	253	struct crypto_alg *larval;
	254	int ok;
	255
	256	if (!((type \| mask) & CRYPTO_ALG_TESTED)) {
	257	type \|= CRYPTO_ALG_TESTED;
	258	mask \|= CRYPTO_ALG_TESTED;
	259	}
	260
	261	/*
	262	* If the internal flag is set for a cipher, require a caller to
	263	* to invoke the cipher with the internal flag to use that cipher.
	264	* Also, if a caller wants to allocate a cipher that may or may
	265	* not be an internal cipher, use type \| CRYPTO_ALG_INTERNAL and
	266	* !(mask & CRYPTO_ALG_INTERNAL).
	267	*/
	268	if (!((type \| mask) & CRYPTO_ALG_INTERNAL))
	269	mask \|= CRYPTO_ALG_INTERNAL;
	270
	271	larval = crypto_larval_lookup(name, type, mask);
	272	if (IS_ERR(larval) \|\| !crypto_is_larval(larval))
	273	return larval;
	274
	275	ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
	276
	277	if (ok == NOTIFY_STOP)
	278	alg = crypto_larval_wait(larval);
	279	else {
	280	crypto_mod_put(larval);
	281	alg = ERR_PTR(-ENOENT);
	282	}
	283	crypto_larval_kill(larval);
	284	return alg;
	285	}
	286	EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
	287
	288	static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
	289	{
	290	const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
	291
	292	if (type_obj)
	293	return type_obj->init(tfm, type, mask);
	294
	295	switch (crypto_tfm_alg_type(tfm)) {
	296	case CRYPTO_ALG_TYPE_CIPHER:
	297	return crypto_init_cipher_ops(tfm);
	298
	299	case CRYPTO_ALG_TYPE_COMPRESS:
	300	return crypto_init_compress_ops(tfm);
	301
	302	default:
	303	break;
	304	}
	305
	306	BUG();
	307	return -EINVAL;
	308	}
	309
	310	static void crypto_exit_ops(struct crypto_tfm *tfm)
	311	{
	312	const struct crypto_type *type = tfm->__crt_alg->cra_type;
	313
	314	if (type && tfm->exit)
	315	tfm->exit(tfm);
	316	}
	317
	318	static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
	319	{
	320	const struct crypto_type *type_obj = alg->cra_type;
	321	unsigned int len;
	322
	323	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
	324	if (type_obj)
	325	return len + type_obj->ctxsize(alg, type, mask);
	326
	327	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
	328	default:
	329	BUG();
	330
	331	case CRYPTO_ALG_TYPE_CIPHER:
	332	len += crypto_cipher_ctxsize(alg);
	333	break;
	334
	335	case CRYPTO_ALG_TYPE_COMPRESS:
	336	len += crypto_compress_ctxsize(alg);
	337	break;
	338	}
	339
	340	return len;
	341	}
	342
	343	static void crypto_shoot_alg(struct crypto_alg *alg)
	344	{
	345	down_write(&crypto_alg_sem);
	346	alg->cra_flags \|= CRYPTO_ALG_DYING;
	347	up_write(&crypto_alg_sem);
	348	}
	349
	350	struct crypto_tfm __crypto_alloc_tfm(struct crypto_alg alg, u32 type,
	351	u32 mask)
	352	{
	353	struct crypto_tfm *tfm = NULL;
	354	unsigned int tfm_size;
	355	int err = -ENOMEM;
	356
	357	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
	358	tfm = kzalloc(tfm_size, GFP_KERNEL);
	359	if (tfm == NULL)
	360	goto out_err;
	361
	362	tfm->__crt_alg = alg;
	363
	364	err = crypto_init_ops(tfm, type, mask);
	365	if (err)
	366	goto out_free_tfm;
	367
	368	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
	369	goto cra_init_failed;
	370
	371	goto out;
	372
	373	cra_init_failed:
	374	crypto_exit_ops(tfm);
	375	out_free_tfm:
	376	if (err == -EAGAIN)
	377	crypto_shoot_alg(alg);
	378	kfree(tfm);
	379	out_err:
	380	tfm = ERR_PTR(err);
	381	out:
	382	return tfm;
	383	}
	384	EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
	385
	386	/*
	387	* crypto_alloc_base - Locate algorithm and allocate transform
	388	* @alg_name: Name of algorithm
	389	* @type: Type of algorithm
	390	* @mask: Mask for type comparison
	391	*
	392	* This function should not be used by new algorithm types.
	393	* Please use crypto_alloc_tfm instead.
	394	*
	395	* crypto_alloc_base() will first attempt to locate an already loaded
	396	* algorithm. If that fails and the kernel supports dynamically loadable
	397	* modules, it will then attempt to load a module of the same name or
	398	* alias. If that fails it will send a query to any loaded crypto manager
	399	* to construct an algorithm on the fly. A refcount is grabbed on the
	400	* algorithm which is then associated with the new transform.
	401	*
	402	* The returned transform is of a non-determinate type. Most people
	403	* should use one of the more specific allocation functions such as
	404	* crypto_alloc_blkcipher.
	405	*
	406	* In case of error the return value is an error pointer.
	407	*/
	408	struct crypto_tfm crypto_alloc_base(const char alg_name, u32 type, u32 mask)
	409	{
	410	struct crypto_tfm *tfm;
	411	int err;
	412
	413	for (;;) {
	414	struct crypto_alg *alg;
	415
	416	alg = crypto_alg_mod_lookup(alg_name, type, mask);
	417	if (IS_ERR(alg)) {
	418	err = PTR_ERR(alg);
	419	goto err;
	420	}
	421
	422	tfm = __crypto_alloc_tfm(alg, type, mask);
	423	if (!IS_ERR(tfm))
	424	return tfm;
	425
	426	crypto_mod_put(alg);
	427	err = PTR_ERR(tfm);
	428
	429	err:
	430	if (err != -EAGAIN)
	431	break;
	432	if (fatal_signal_pending(current)) {
	433	err = -EINTR;
	434	break;
	435	}
	436	}
	437
	438	return ERR_PTR(err);
	439	}
	440	EXPORT_SYMBOL_GPL(crypto_alloc_base);
	441
	442	void crypto_create_tfm(struct crypto_alg alg,
	443	const struct crypto_type *frontend)
	444	{
	445	char *mem;
	446	struct crypto_tfm *tfm = NULL;
	447	unsigned int tfmsize;
	448	unsigned int total;
	449	int err = -ENOMEM;
	450
	451	tfmsize = frontend->tfmsize;
	452	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
	453
	454	mem = kzalloc(total, GFP_KERNEL);
	455	if (mem == NULL)
	456	goto out_err;
	457
	458	tfm = (struct crypto_tfm *)(mem + tfmsize);
	459	tfm->__crt_alg = alg;
	460
	461	err = frontend->init_tfm(tfm);
	462	if (err)
	463	goto out_free_tfm;
	464
	465	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
	466	goto cra_init_failed;
	467
	468	goto out;
	469
	470	cra_init_failed:
	471	crypto_exit_ops(tfm);
	472	out_free_tfm:
	473	if (err == -EAGAIN)
	474	crypto_shoot_alg(alg);
	475	kfree(mem);
	476	out_err:
	477	mem = ERR_PTR(err);
	478	out:
	479	return mem;
	480	}
	481	EXPORT_SYMBOL_GPL(crypto_create_tfm);
	482
	483	struct crypto_alg crypto_find_alg(const char alg_name,
	484	const struct crypto_type *frontend,
	485	u32 type, u32 mask)
	486	{
	487	struct crypto_alg (lookup)(const char *name, u32 type, u32 mask) =
	488	crypto_alg_mod_lookup;
	489
	490	if (frontend) {
	491	type &= frontend->maskclear;
	492	mask &= frontend->maskclear;
	493	type \|= frontend->type;
	494	mask \|= frontend->maskset;
	495
	496	if (frontend->lookup)
	497	lookup = frontend->lookup;
	498	}
	499
	500	return lookup(alg_name, type, mask);
	501	}
	502	EXPORT_SYMBOL_GPL(crypto_find_alg);
	503
	504	/*
	505	* crypto_alloc_tfm - Locate algorithm and allocate transform
	506	* @alg_name: Name of algorithm
	507	* @frontend: Frontend algorithm type
	508	* @type: Type of algorithm
	509	* @mask: Mask for type comparison
	510	*
	511	* crypto_alloc_tfm() will first attempt to locate an already loaded
	512	* algorithm. If that fails and the kernel supports dynamically loadable
	513	* modules, it will then attempt to load a module of the same name or
	514	* alias. If that fails it will send a query to any loaded crypto manager
	515	* to construct an algorithm on the fly. A refcount is grabbed on the
	516	* algorithm which is then associated with the new transform.
	517	*
	518	* The returned transform is of a non-determinate type. Most people
	519	* should use one of the more specific allocation functions such as
	520	* crypto_alloc_blkcipher.
	521	*
	522	* In case of error the return value is an error pointer.
	523	*/
	524	void crypto_alloc_tfm(const char alg_name,
	525	const struct crypto_type *frontend, u32 type, u32 mask)
	526	{
	527	void *tfm;
	528	int err;
	529
	530	for (;;) {
	531	struct crypto_alg *alg;
	532
	533	alg = crypto_find_alg(alg_name, frontend, type, mask);
	534	if (IS_ERR(alg)) {
	535	err = PTR_ERR(alg);
	536	goto err;
	537	}
	538
	539	tfm = crypto_create_tfm(alg, frontend);
	540	if (!IS_ERR(tfm))
	541	return tfm;
	542
	543	crypto_mod_put(alg);
	544	err = PTR_ERR(tfm);
	545
	546	err:
	547	if (err != -EAGAIN)
	548	break;
	549	if (fatal_signal_pending(current)) {
	550	err = -EINTR;
	551	break;
	552	}
	553	}
	554
	555	return ERR_PTR(err);
	556	}
	557	EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
	558
	559	/*
	560	* crypto_destroy_tfm - Free crypto transform
	561	* @mem: Start of tfm slab
	562	* @tfm: Transform to free
	563	*
	564	* This function frees up the transform and any associated resources,
	565	* then drops the refcount on the associated algorithm.
	566	*/
	567	void crypto_destroy_tfm(void mem, struct crypto_tfm tfm)
	568	{
	569	struct crypto_alg *alg;
	570
	571	if (unlikely(!mem))
	572	return;
	573
	574	alg = tfm->__crt_alg;
	575
	576	if (!tfm->exit && alg->cra_exit)
	577	alg->cra_exit(tfm);
	578	crypto_exit_ops(tfm);
	579	crypto_mod_put(alg);
	580	kzfree(mem);
	581	}
	582	EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
	583
	584	int crypto_has_alg(const char *name, u32 type, u32 mask)
	585	{
	586	int ret = 0;
	587	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
	588
	589	if (!IS_ERR(alg)) {
	590	crypto_mod_put(alg);
	591	ret = 1;
	592	}
	593
	594	return ret;
	595	}
	596	EXPORT_SYMBOL_GPL(crypto_has_alg);
	597
	598	void crypto_req_done(struct crypto_async_request *req, int err)
	599	{
	600	struct crypto_wait *wait = req->data;
	601
	602	if (err == -EINPROGRESS)
	603	return;
	604
	605	wait->err = err;
	606	complete(&wait->completion);
	607	}
	608	EXPORT_SYMBOL_GPL(crypto_req_done);
	609
	610	MODULE_DESCRIPTION("Cryptographic core API");
	611	MODULE_LICENSE("GPL");