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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * CBC: Cipher Block Chaining mode
 *
 * Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <crypto/algapi.h>
#include <crypto/cbc.h>
#include <crypto/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/module.h>

static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,
					  const u8 *src, u8 *dst)
{
	crypto_cipher_encrypt_one(skcipher_cipher_simple(tfm), dst, src);
}

static int crypto_cbc_encrypt(struct skcipher_request *req)
{
	return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);
}

static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,
					  const u8 *src, u8 *dst)
{
	crypto_cipher_decrypt_one(skcipher_cipher_simple(tfm), dst, src);
}

static int crypto_cbc_decrypt(struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct skcipher_walk walk;
	int err;

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

	while (walk.nbytes) {
		err = crypto_cbc_decrypt_blocks(&walk, tfm,
						crypto_cbc_decrypt_one);
		err = skcipher_walk_done(&walk, err);
	}

	return err;
}

static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
{
	struct skcipher_instance *inst;
	struct crypto_alg *alg;
	int err;

	inst = skcipher_alloc_instance_simple(tmpl, tb);
	if (IS_ERR(inst))
		return PTR_ERR(inst);

	alg = skcipher_ialg_simple(inst);

	err = -EINVAL;
	if (!is_power_of_2(alg->cra_blocksize))
		goto out_free_inst;

	inst->alg.encrypt = crypto_cbc_encrypt;
	inst->alg.decrypt = crypto_cbc_decrypt;

	err = skcipher_register_instance(tmpl, inst);
	if (err) {
out_free_inst:
		inst->free(inst);
	}

	return err;
}

static struct crypto_template crypto_cbc_tmpl = {
	.name = "cbc",
	.create = crypto_cbc_create,
	.module = THIS_MODULE,
};

static int __init crypto_cbc_module_init(void)
{
	return crypto_register_template(&crypto_cbc_tmpl);
}

static void __exit crypto_cbc_module_exit(void)
{
	crypto_unregister_template(&crypto_cbc_tmpl);
}

subsys_initcall(crypto_cbc_module_init);
module_exit(crypto_cbc_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("CBC block cipher mode of operation");
MODULE_ALIAS_CRYPTO("cbc");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
db131ef9 HX	2	/*
	3	* CBC: Cipher Block Chaining mode
	4	*
cc868d82	5	* Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.au>
db131ef9 HX	6	*/
db131ef9 HX	7
e6c2e65c	8	#include <crypto/algapi.h>
cc868d82	9	#include <crypto/cbc.h>
79c65d17	10	#include <crypto/internal/skcipher.h>
db131ef9 HX	11	#include <linux/err.h>
	12	#include <linux/init.h>
	13	#include <linux/kernel.h>
50b6544e	14	#include <linux/log2.h>
db131ef9	15	#include <linux/module.h>
db131ef9	16
79c65d17 HX	17	static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,
	18	const u8 src, u8 dst)
	19	{
a5a84a9d	20	crypto_cipher_encrypt_one(skcipher_cipher_simple(tfm), dst, src);
79c65d17 HX	21	}
	22
	23	static int crypto_cbc_encrypt(struct skcipher_request *req)
db131ef9	24	{
79c65d17 HX	25	return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);
	26	}
	27
79c65d17 HX	28	static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,
	29	const u8 src, u8 dst)
	30	{
a5a84a9d	31	crypto_cipher_decrypt_one(skcipher_cipher_simple(tfm), dst, src);
79c65d17 HX	32	}
	33
	34	static int crypto_cbc_decrypt(struct skcipher_request *req)
	35	{
	36	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	37	struct skcipher_walk walk;
db131ef9 HX	38	int err;
db131ef9 HX	39
79c65d17	40	err = skcipher_walk_virt(&walk, req, false);
db131ef9	41
79c65d17 HX	42	while (walk.nbytes) {
	43	err = crypto_cbc_decrypt_blocks(&walk, tfm,
	44	crypto_cbc_decrypt_one);
	45	err = skcipher_walk_done(&walk, err);
db131ef9 HX	46	}
	47
	48	return err;
	49	}
	50
79c65d17 HX	51	static int crypto_cbc_create(struct crypto_template tmpl, struct rtattr *tb)
	52	{
	53	struct skcipher_instance *inst;
db131ef9	54	struct crypto_alg *alg;
ebc610e5 HX	55	int err;
ebc610e5 HX	56
b3c16bfc	57	inst = skcipher_alloc_instance_simple(tmpl, tb);
a5a84a9d EB	58	if (IS_ERR(inst))
a5a84a9d EB	59	return PTR_ERR(inst);
50b6544e	60
b3c16bfc HX	61	alg = skcipher_ialg_simple(inst);
b3c16bfc HX	62
79c65d17 HX	63	err = -EINVAL;
79c65d17 HX	64	if (!is_power_of_2(alg->cra_blocksize))
a5a84a9d	65	goto out_free_inst;
db131ef9	66
79c65d17 HX	67	inst->alg.encrypt = crypto_cbc_encrypt;
79c65d17 HX	68	inst->alg.decrypt = crypto_cbc_decrypt;
db131ef9	69
79c65d17	70	err = skcipher_register_instance(tmpl, inst);
b3c16bfc	71	if (err) {
a5a84a9d	72	out_free_inst:
b3c16bfc HX	73	inst->free(inst);
	74	}
	75
a5a84a9d	76	return err;
db131ef9 HX	77	}
	78
	79	static struct crypto_template crypto_cbc_tmpl = {
	80	.name = "cbc",
79c65d17	81	.create = crypto_cbc_create,
db131ef9 HX	82	.module = THIS_MODULE,
	83	};
	84
	85	static int __init crypto_cbc_module_init(void)
	86	{
	87	return crypto_register_template(&crypto_cbc_tmpl);
	88	}
	89
	90	static void __exit crypto_cbc_module_exit(void)
	91	{
	92	crypto_unregister_template(&crypto_cbc_tmpl);
	93	}
	94
c4741b23	95	subsys_initcall(crypto_cbc_module_init);
db131ef9 HX	96	module_exit(crypto_cbc_module_exit);
	97
	98	MODULE_LICENSE("GPL");
a5a84a9d	99	MODULE_DESCRIPTION("CBC block cipher mode of operation");
4943ba16	100	MODULE_ALIAS_CRYPTO("cbc");