[thirdparty/kernel/linux.git] / crypto / crypto_null.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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>
 */

#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_sync_skcipher *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_skcipher_setkey(struct crypto_skcipher *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 null_skcipher_crypt(struct skcipher_request *req)
{
	struct skcipher_walk walk;
	int err;

	err = skcipher_walk_virt(&walk, req, false);

	while (walk.nbytes) {
		if (walk.src.virt.addr != walk.dst.virt.addr)
			memcpy(walk.dst.virt.addr, walk.src.virt.addr,
			       walk.nbytes);
		err = skcipher_walk_done(&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_blocksize		=	NULL_BLOCK_SIZE,
		.cra_module		=	THIS_MODULE,
	}
};

static struct skcipher_alg skcipher_null = {
	.base.cra_name		=	"ecb(cipher_null)",
	.base.cra_driver_name	=	"ecb-cipher_null",
	.base.cra_priority	=	100,
	.base.cra_blocksize	=	NULL_BLOCK_SIZE,
	.base.cra_ctxsize	=	0,
	.base.cra_module	=	THIS_MODULE,
	.min_keysize		=	NULL_KEY_SIZE,
	.max_keysize		=	NULL_KEY_SIZE,
	.ivsize			=	NULL_IV_SIZE,
	.setkey			=	null_skcipher_setkey,
	.encrypt		=	null_skcipher_crypt,
	.decrypt		=	null_skcipher_crypt,
};

static struct crypto_alg null_algs[] = { {
	.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		=	"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_sync_skcipher *crypto_get_default_null_skcipher(void)
{
	struct crypto_sync_skcipher *tfm;

	mutex_lock(&crypto_default_null_skcipher_lock);
	tfm = crypto_default_null_skcipher;

	if (!tfm) {
		tfm = crypto_alloc_sync_skcipher("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_sync_skcipher(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;

	ret = crypto_register_skcipher(&skcipher_null);
	if (ret < 0)
		goto out_unregister_shash;

	return 0;

out_unregister_shash:
	crypto_unregister_shash(&digest_null);
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_algs(null_algs, ARRAY_SIZE(null_algs));
	crypto_unregister_shash(&digest_null);
	crypto_unregister_skcipher(&skcipher_null);
}

subsys_initcall(crypto_null_mod_init);
module_exit(crypto_null_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Null Cryptographic Algorithms");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
c9af70fb	2	/*
1da177e4 LT	3	* Cryptographic API.
	4	*
	5	* Null algorithms, aka Much Ado About Nothing.
	6	*
	7	* These are needed for IPsec, and may be useful in general for
	8	* testing & debugging.
c9af70fb	9	*
1da177e4 LT	10	* The null cipher is compliant with RFC2410.
	11	*
	12	* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
1da177e4	13	*/
3631c650	14
72567258	15	#include <crypto/null.h>
d35d2454	16	#include <crypto/internal/hash.h>
3631c650	17	#include <crypto/internal/skcipher.h>
1da177e4 LT	18	#include <linux/init.h>
	19	#include <linux/module.h>
	20	#include <linux/mm.h>
d0856009	21	#include <linux/string.h>
1da177e4	22
33023463	23	static DEFINE_MUTEX(crypto_default_null_skcipher_lock);
8d605398	24	static struct crypto_sync_skcipher *crypto_default_null_skcipher;
33023463 HX	25	static int crypto_default_null_skcipher_refcnt;
33023463 HX	26
6c2bb98b HX	27	static int null_compress(struct crypto_tfm tfm, const u8 src,
6c2bb98b HX	28	unsigned int slen, u8 dst, unsigned int dlen)
d0856009 PM	29	{
	30	if (slen > *dlen)
	31	return -EINVAL;
	32	memcpy(dst, src, slen);
	33	*dlen = slen;
	34	return 0;
	35	}
1da177e4	36
d35d2454 HX	37	static int null_init(struct shash_desc *desc)
	38	{
	39	return 0;
	40	}
1da177e4	41
d35d2454 HX	42	static int null_update(struct shash_desc desc, const u8 data,
	43	unsigned int len)
	44	{
	45	return 0;
	46	}
1da177e4	47
d35d2454 HX	48	static int null_final(struct shash_desc desc, u8 out)
	49	{
	50	return 0;
	51	}
	52
	53	static int null_digest(struct shash_desc desc, const u8 data,
	54	unsigned int len, u8 *out)
	55	{
	56	return 0;
	57	}
	58
	59	static int null_hash_setkey(struct crypto_shash tfm, const u8 key,
	60	unsigned int keylen)
	61	{ return 0; }
1da177e4	62
31d40c20 EB	63	static int null_skcipher_setkey(struct crypto_skcipher tfm, const u8 key,
	64	unsigned int keylen)
	65	{ return 0; }
	66
6c2bb98b	67	static int null_setkey(struct crypto_tfm tfm, const u8 key,
560c06ae	68	unsigned int keylen)
1da177e4 LT	69	{ return 0; }
1da177e4 LT	70
6c2bb98b	71	static void null_crypt(struct crypto_tfm tfm, u8 dst, const u8 *src)
d0856009 PM	72	{
	73	memcpy(dst, src, NULL_BLOCK_SIZE);
	74	}
1da177e4	75
31d40c20	76	static int null_skcipher_crypt(struct skcipher_request *req)
3631c650	77	{
31d40c20	78	struct skcipher_walk walk;
3631c650 HX	79	int err;
3631c650 HX	80
31d40c20	81	err = skcipher_walk_virt(&walk, req, false);
3631c650 HX	82
	83	while (walk.nbytes) {
	84	if (walk.src.virt.addr != walk.dst.virt.addr)
	85	memcpy(walk.dst.virt.addr, walk.src.virt.addr,
	86	walk.nbytes);
31d40c20	87	err = skcipher_walk_done(&walk, 0);
3631c650 HX	88	}
	89
	90	return err;
	91	}
	92
d35d2454 HX	93	static struct shash_alg digest_null = {
	94	.digestsize = NULL_DIGEST_SIZE,
	95	.setkey = null_hash_setkey,
	96	.init = null_init,
	97	.update = null_update,
	98	.finup = null_digest,
	99	.digest = null_digest,
	100	.final = null_final,
	101	.base = {
	102	.cra_name = "digest_null",
d35d2454 HX	103	.cra_blocksize = NULL_BLOCK_SIZE,
	104	.cra_module = THIS_MODULE,
	105	}
1da177e4 LT	106	};
1da177e4 LT	107
31d40c20 EB	108	static struct skcipher_alg skcipher_null = {
	109	.base.cra_name = "ecb(cipher_null)",
	110	.base.cra_driver_name = "ecb-cipher_null",
	111	.base.cra_priority = 100,
	112	.base.cra_blocksize = NULL_BLOCK_SIZE,
	113	.base.cra_ctxsize = 0,
	114	.base.cra_module = THIS_MODULE,
	115	.min_keysize = NULL_KEY_SIZE,
	116	.max_keysize = NULL_KEY_SIZE,
	117	.ivsize = NULL_IV_SIZE,
	118	.setkey = null_skcipher_setkey,
	119	.encrypt = null_skcipher_crypt,
	120	.decrypt = null_skcipher_crypt,
	121	};
	122
	123	static struct crypto_alg null_algs[] = { {
1da177e4 LT	124	.cra_name = "cipher_null",
	125	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
	126	.cra_blocksize = NULL_BLOCK_SIZE,
	127	.cra_ctxsize = 0,
	128	.cra_module = THIS_MODULE,
1da177e4 LT	129	.cra_u = { .cipher = {
	130	.cia_min_keysize = NULL_KEY_SIZE,
	131	.cia_max_keysize = NULL_KEY_SIZE,
	132	.cia_setkey = null_setkey,
d0856009 PM	133	.cia_encrypt = null_crypt,
d0856009 PM	134	.cia_decrypt = null_crypt } }
70a03bff JK	135	}, {
	136	.cra_name = "compress_null",
	137	.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
	138	.cra_blocksize = NULL_BLOCK_SIZE,
	139	.cra_ctxsize = 0,
	140	.cra_module = THIS_MODULE,
	141	.cra_u = { .compress = {
	142	.coa_compress = null_compress,
	143	.coa_decompress = null_compress } }
	144	} };
3631c650	145
5d26a105 KC	146	MODULE_ALIAS_CRYPTO("compress_null");
	147	MODULE_ALIAS_CRYPTO("digest_null");
	148	MODULE_ALIAS_CRYPTO("cipher_null");
1da177e4	149
8d605398	150	struct crypto_sync_skcipher *crypto_get_default_null_skcipher(void)
33023463	151	{
8d605398	152	struct crypto_sync_skcipher *tfm;
33023463 HX	153
	154	mutex_lock(&crypto_default_null_skcipher_lock);
	155	tfm = crypto_default_null_skcipher;
	156
	157	if (!tfm) {
8d605398	158	tfm = crypto_alloc_sync_skcipher("ecb(cipher_null)", 0, 0);
33023463 HX	159	if (IS_ERR(tfm))
	160	goto unlock;
	161
	162	crypto_default_null_skcipher = tfm;
	163	}
	164
	165	crypto_default_null_skcipher_refcnt++;
	166
	167	unlock:
	168	mutex_unlock(&crypto_default_null_skcipher_lock);
	169
	170	return tfm;
	171	}
	172	EXPORT_SYMBOL_GPL(crypto_get_default_null_skcipher);
	173
	174	void crypto_put_default_null_skcipher(void)
	175	{
	176	mutex_lock(&crypto_default_null_skcipher_lock);
	177	if (!--crypto_default_null_skcipher_refcnt) {
8d605398	178	crypto_free_sync_skcipher(crypto_default_null_skcipher);
33023463 HX	179	crypto_default_null_skcipher = NULL;
	180	}
	181	mutex_unlock(&crypto_default_null_skcipher_lock);
	182	}
	183	EXPORT_SYMBOL_GPL(crypto_put_default_null_skcipher);
	184
3af5b90b	185	static int __init crypto_null_mod_init(void)
1da177e4 LT	186	{
1da177e4 LT	187	int ret = 0;
c9af70fb	188
70a03bff	189	ret = crypto_register_algs(null_algs, ARRAY_SIZE(null_algs));
1da177e4 LT	190	if (ret < 0)
	191	goto out;
	192
d35d2454	193	ret = crypto_register_shash(&digest_null);
3631c650	194	if (ret < 0)
70a03bff	195	goto out_unregister_algs;
1da177e4	196
31d40c20 EB	197	ret = crypto_register_skcipher(&skcipher_null);
	198	if (ret < 0)
	199	goto out_unregister_shash;
	200
70a03bff	201	return 0;
1da177e4	202
31d40c20 EB	203	out_unregister_shash:
31d40c20 EB	204	crypto_unregister_shash(&digest_null);
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	{
70a03bff	213	crypto_unregister_algs(null_algs, ARRAY_SIZE(null_algs));
31d40c20 EB	214	crypto_unregister_shash(&digest_null);
31d40c20 EB	215	crypto_unregister_skcipher(&skcipher_null);
1da177e4 LT	216	}
1da177e4 LT	217
c4741b23	218	subsys_initcall(crypto_null_mod_init);
3af5b90b	219	module_exit(crypto_null_mod_fini);
1da177e4 LT	220
	221	MODULE_LICENSE("GPL");
	222	MODULE_DESCRIPTION("Null Cryptographic Algorithms");