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/*
* CBC: Cipher Block Chaining mode
*
* Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.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/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, &alg);
if (IS_ERR(inst))
return PTR_ERR(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)
goto out_free_inst;
goto out_put_alg;
out_free_inst:
inst->free(inst);
out_put_alg:
crypto_mod_put(alg);
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");
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