[mirror_ubuntu-zesty-kernel.git] / crypto / crypto_null.c

/*
 * Cryptographic API.
 *
 * Null algorithms, aka Much Ado About Nothing.
 *
 * These are needed for IPsec, and may be useful in general for
 * testing & debugging.
 *
 * The null cipher is compliant with RFC2410.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 *
 * 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 <crypto/null.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/skcipher.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/string.h>

static DEFINE_MUTEX(crypto_default_null_skcipher_lock);
static struct crypto_blkcipher *crypto_default_null_skcipher;
static int crypto_default_null_skcipher_refcnt;

static int null_compress(struct crypto_tfm *tfm, const u8 *src,
			 unsigned int slen, u8 *dst, unsigned int *dlen)
{
	if (slen > *dlen)
		return -EINVAL;
	memcpy(dst, src, slen);
	*dlen = slen;
	return 0;
}

static int null_init(struct shash_desc *desc)
{
	return 0;
}

static int null_update(struct shash_desc *desc, const u8 *data,
		       unsigned int len)
{
	return 0;
}

static int null_final(struct shash_desc *desc, u8 *out)
{
	return 0;
}

static int null_digest(struct shash_desc *desc, const u8 *data,
		       unsigned int len, u8 *out)
{
	return 0;
}

static int null_hash_setkey(struct crypto_shash *tfm, const u8 *key,
			    unsigned int keylen)
{ return 0; }

static int null_setkey(struct crypto_tfm *tfm, const u8 *key,
		       unsigned int keylen)
{ return 0; }

static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	memcpy(dst, src, NULL_BLOCK_SIZE);
}

static int skcipher_null_crypt(struct blkcipher_desc *desc,
			       struct scatterlist *dst,
			       struct scatterlist *src, unsigned int nbytes)
{
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while (walk.nbytes) {
		if (walk.src.virt.addr != walk.dst.virt.addr)
			memcpy(walk.dst.virt.addr, walk.src.virt.addr,
			       walk.nbytes);
		err = blkcipher_walk_done(desc, &walk, 0);
	}

	return err;
}

static struct shash_alg digest_null = {
	.digestsize		=	NULL_DIGEST_SIZE,
	.setkey   		=	null_hash_setkey,
	.init   		=	null_init,
	.update 		=	null_update,
	.finup 			=	null_digest,
	.digest 		=	null_digest,
	.final  		=	null_final,
	.base			=	{
		.cra_name		=	"digest_null",
		.cra_flags		=	CRYPTO_ALG_TYPE_SHASH,
		.cra_blocksize		=	NULL_BLOCK_SIZE,
		.cra_module		=	THIS_MODULE,
	}
};

static struct crypto_alg null_algs[3] = { {
	.cra_name		=	"cipher_null",
	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		=	NULL_BLOCK_SIZE,
	.cra_ctxsize		=	0,
	.cra_module		=	THIS_MODULE,
	.cra_u			=	{ .cipher = {
	.cia_min_keysize	=	NULL_KEY_SIZE,
	.cia_max_keysize	=	NULL_KEY_SIZE,
	.cia_setkey		= 	null_setkey,
	.cia_encrypt		=	null_crypt,
	.cia_decrypt		=	null_crypt } }
}, {
	.cra_name		=	"ecb(cipher_null)",
	.cra_driver_name	=	"ecb-cipher_null",
	.cra_priority		=	100,
	.cra_flags		=	CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		=	NULL_BLOCK_SIZE,
	.cra_type		=	&crypto_blkcipher_type,
	.cra_ctxsize		=	0,
	.cra_module		=	THIS_MODULE,
	.cra_u			=	{ .blkcipher = {
	.min_keysize		=	NULL_KEY_SIZE,
	.max_keysize		=	NULL_KEY_SIZE,
	.ivsize			=	NULL_IV_SIZE,
	.setkey			= 	null_setkey,
	.encrypt		=	skcipher_null_crypt,
	.decrypt		=	skcipher_null_crypt } }
}, {
	.cra_name		=	"compress_null",
	.cra_flags		=	CRYPTO_ALG_TYPE_COMPRESS,
	.cra_blocksize		=	NULL_BLOCK_SIZE,
	.cra_ctxsize		=	0,
	.cra_module		=	THIS_MODULE,
	.cra_u			=	{ .compress = {
	.coa_compress		=	null_compress,
	.coa_decompress		=	null_compress } }
} };

MODULE_ALIAS_CRYPTO("compress_null");
MODULE_ALIAS_CRYPTO("digest_null");
MODULE_ALIAS_CRYPTO("cipher_null");

struct crypto_blkcipher *crypto_get_default_null_skcipher(void)
{
	struct crypto_blkcipher *tfm;

	mutex_lock(&crypto_default_null_skcipher_lock);
	tfm = crypto_default_null_skcipher;

	if (!tfm) {
		tfm = crypto_alloc_blkcipher("ecb(cipher_null)", 0, 0);
		if (IS_ERR(tfm))
			goto unlock;

		crypto_default_null_skcipher = tfm;
	}

	crypto_default_null_skcipher_refcnt++;

unlock:
	mutex_unlock(&crypto_default_null_skcipher_lock);

	return tfm;
}
EXPORT_SYMBOL_GPL(crypto_get_default_null_skcipher);

void crypto_put_default_null_skcipher(void)
{
	mutex_lock(&crypto_default_null_skcipher_lock);
	if (!--crypto_default_null_skcipher_refcnt) {
		crypto_free_blkcipher(crypto_default_null_skcipher);
		crypto_default_null_skcipher = NULL;
	}
	mutex_unlock(&crypto_default_null_skcipher_lock);
}
EXPORT_SYMBOL_GPL(crypto_put_default_null_skcipher);

static int __init crypto_null_mod_init(void)
{
	int ret = 0;

	ret = crypto_register_algs(null_algs, ARRAY_SIZE(null_algs));
	if (ret < 0)
		goto out;

	ret = crypto_register_shash(&digest_null);
	if (ret < 0)
		goto out_unregister_algs;

	return 0;

out_unregister_algs:
	crypto_unregister_algs(null_algs, ARRAY_SIZE(null_algs));
out:
	return ret;
}

static void __exit crypto_null_mod_fini(void)
{
	crypto_unregister_shash(&digest_null);
	crypto_unregister_algs(null_algs, ARRAY_SIZE(null_algs));
}

module_init(crypto_null_mod_init);
module_exit(crypto_null_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Null Cryptographic Algorithms");
Commit	Line	Data
c9af70fb	1	/*
1da177e4 LT	2	* Cryptographic API.
	3	*
	4	* Null algorithms, aka Much Ado About Nothing.
	5	*
	6	* These are needed for IPsec, and may be useful in general for
	7	* testing & debugging.
c9af70fb	8	*
1da177e4 LT	9	* The null cipher is compliant with RFC2410.
	10	*
	11	* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
	12	*
	13	* This program is free software; you can redistribute it and/or modify
	14	* it under the terms of the GNU General Public License as published by
	15	* the Free Software Foundation; either version 2 of the License, or
	16	* (at your option) any later version.
	17	*
	18	*/
3631c650	19
72567258	20	#include <crypto/null.h>
d35d2454	21	#include <crypto/internal/hash.h>
3631c650	22	#include <crypto/internal/skcipher.h>
1da177e4 LT	23	#include <linux/init.h>
	24	#include <linux/module.h>
	25	#include <linux/mm.h>
d0856009	26	#include <linux/string.h>
1da177e4	27
33023463 HX	28	static DEFINE_MUTEX(crypto_default_null_skcipher_lock);
	29	static struct crypto_blkcipher *crypto_default_null_skcipher;
	30	static int crypto_default_null_skcipher_refcnt;
	31
6c2bb98b HX	32	static int null_compress(struct crypto_tfm tfm, const u8 src,
6c2bb98b HX	33	unsigned int slen, u8 dst, unsigned int dlen)
d0856009 PM	34	{
	35	if (slen > *dlen)
	36	return -EINVAL;
	37	memcpy(dst, src, slen);
	38	*dlen = slen;
	39	return 0;
	40	}
1da177e4	41
d35d2454 HX	42	static int null_init(struct shash_desc *desc)
	43	{
	44	return 0;
	45	}
1da177e4	46
d35d2454 HX	47	static int null_update(struct shash_desc desc, const u8 data,
	48	unsigned int len)
	49	{
	50	return 0;
	51	}
1da177e4	52
d35d2454 HX	53	static int null_final(struct shash_desc desc, u8 out)
	54	{
	55	return 0;
	56	}
	57
	58	static int null_digest(struct shash_desc desc, const u8 data,
	59	unsigned int len, u8 *out)
	60	{
	61	return 0;
	62	}
	63
	64	static int null_hash_setkey(struct crypto_shash tfm, const u8 key,
	65	unsigned int keylen)
	66	{ return 0; }
1da177e4	67
6c2bb98b	68	static int null_setkey(struct crypto_tfm tfm, const u8 key,
560c06ae	69	unsigned int keylen)
1da177e4 LT	70	{ return 0; }
1da177e4 LT	71
6c2bb98b	72	static void null_crypt(struct crypto_tfm tfm, u8 dst, const u8 *src)
d0856009 PM	73	{
	74	memcpy(dst, src, NULL_BLOCK_SIZE);
	75	}
1da177e4	76
3631c650 HX	77	static int skcipher_null_crypt(struct blkcipher_desc *desc,
	78	struct scatterlist *dst,
	79	struct scatterlist *src, unsigned int nbytes)
	80	{
	81	struct blkcipher_walk walk;
	82	int err;
	83
	84	blkcipher_walk_init(&walk, dst, src, nbytes);
	85	err = blkcipher_walk_virt(desc, &walk);
	86
	87	while (walk.nbytes) {
	88	if (walk.src.virt.addr != walk.dst.virt.addr)
	89	memcpy(walk.dst.virt.addr, walk.src.virt.addr,
	90	walk.nbytes);
	91	err = blkcipher_walk_done(desc, &walk, 0);
	92	}
	93
	94	return err;
	95	}
	96
d35d2454 HX	97	static struct shash_alg digest_null = {
	98	.digestsize = NULL_DIGEST_SIZE,
	99	.setkey = null_hash_setkey,
	100	.init = null_init,
	101	.update = null_update,
	102	.finup = null_digest,
	103	.digest = null_digest,
	104	.final = null_final,
	105	.base = {
	106	.cra_name = "digest_null",
	107	.cra_flags = CRYPTO_ALG_TYPE_SHASH,
	108	.cra_blocksize = NULL_BLOCK_SIZE,
	109	.cra_module = THIS_MODULE,
	110	}
1da177e4 LT	111	};
1da177e4 LT	112
70a03bff	113	static struct crypto_alg null_algs[3] = { {
1da177e4 LT	114	.cra_name = "cipher_null",
	115	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
	116	.cra_blocksize = NULL_BLOCK_SIZE,
	117	.cra_ctxsize = 0,
	118	.cra_module = THIS_MODULE,
1da177e4 LT	119	.cra_u = { .cipher = {
	120	.cia_min_keysize = NULL_KEY_SIZE,
	121	.cia_max_keysize = NULL_KEY_SIZE,
	122	.cia_setkey = null_setkey,
d0856009 PM	123	.cia_encrypt = null_crypt,
d0856009 PM	124	.cia_decrypt = null_crypt } }
70a03bff	125	}, {
3631c650 HX	126	.cra_name = "ecb(cipher_null)",
	127	.cra_driver_name = "ecb-cipher_null",
	128	.cra_priority = 100,
	129	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
	130	.cra_blocksize = NULL_BLOCK_SIZE,
	131	.cra_type = &crypto_blkcipher_type,
	132	.cra_ctxsize = 0,
	133	.cra_module = THIS_MODULE,
3631c650 HX	134	.cra_u = { .blkcipher = {
	135	.min_keysize = NULL_KEY_SIZE,
	136	.max_keysize = NULL_KEY_SIZE,
	137	.ivsize = NULL_IV_SIZE,
	138	.setkey = null_setkey,
	139	.encrypt = skcipher_null_crypt,
	140	.decrypt = skcipher_null_crypt } }
70a03bff JK	141	}, {
	142	.cra_name = "compress_null",
	143	.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
	144	.cra_blocksize = NULL_BLOCK_SIZE,
	145	.cra_ctxsize = 0,
	146	.cra_module = THIS_MODULE,
	147	.cra_u = { .compress = {
	148	.coa_compress = null_compress,
	149	.coa_decompress = null_compress } }
	150	} };
3631c650	151
5d26a105 KC	152	MODULE_ALIAS_CRYPTO("compress_null");
	153	MODULE_ALIAS_CRYPTO("digest_null");
	154	MODULE_ALIAS_CRYPTO("cipher_null");
1da177e4	155
33023463 HX	156	struct crypto_blkcipher *crypto_get_default_null_skcipher(void)
	157	{
	158	struct crypto_blkcipher *tfm;
	159
	160	mutex_lock(&crypto_default_null_skcipher_lock);
	161	tfm = crypto_default_null_skcipher;
	162
	163	if (!tfm) {
	164	tfm = crypto_alloc_blkcipher("ecb(cipher_null)", 0, 0);
	165	if (IS_ERR(tfm))
	166	goto unlock;
	167
	168	crypto_default_null_skcipher = tfm;
	169	}
	170
	171	crypto_default_null_skcipher_refcnt++;
	172
	173	unlock:
	174	mutex_unlock(&crypto_default_null_skcipher_lock);
	175
	176	return tfm;
	177	}
	178	EXPORT_SYMBOL_GPL(crypto_get_default_null_skcipher);
	179
	180	void crypto_put_default_null_skcipher(void)
	181	{
	182	mutex_lock(&crypto_default_null_skcipher_lock);
	183	if (!--crypto_default_null_skcipher_refcnt) {
	184	crypto_free_blkcipher(crypto_default_null_skcipher);
	185	crypto_default_null_skcipher = NULL;
	186	}
	187	mutex_unlock(&crypto_default_null_skcipher_lock);
	188	}
	189	EXPORT_SYMBOL_GPL(crypto_put_default_null_skcipher);
	190
3af5b90b	191	static int __init crypto_null_mod_init(void)
1da177e4 LT	192	{
1da177e4 LT	193	int ret = 0;
c9af70fb	194
70a03bff	195	ret = crypto_register_algs(null_algs, ARRAY_SIZE(null_algs));
1da177e4 LT	196	if (ret < 0)
	197	goto out;
	198
d35d2454	199	ret = crypto_register_shash(&digest_null);
3631c650	200	if (ret < 0)
70a03bff	201	goto out_unregister_algs;
1da177e4	202
70a03bff	203	return 0;
1da177e4	204
70a03bff JK	205	out_unregister_algs:
70a03bff JK	206	crypto_unregister_algs(null_algs, ARRAY_SIZE(null_algs));
c9af70fb	207	out:
1da177e4 LT	208	return ret;
	209	}
	210
3af5b90b	211	static void __exit crypto_null_mod_fini(void)
1da177e4	212	{
d35d2454	213	crypto_unregister_shash(&digest_null);
70a03bff	214	crypto_unregister_algs(null_algs, ARRAY_SIZE(null_algs));
1da177e4 LT	215	}
1da177e4 LT	216
3af5b90b KB	217	module_init(crypto_null_mod_init);
3af5b90b KB	218	module_exit(crypto_null_mod_fini);
1da177e4 LT	219
	220	MODULE_LICENSE("GPL");
	221	MODULE_DESCRIPTION("Null Cryptographic Algorithms");