linux/crypto/ecb.c

110 lines
2.7 KiB
C
Raw Normal View History

/*
* ECB: Electronic CodeBook mode
*
* Copyright (c) 2006 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/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
static int crypto_ecb_crypt(struct skcipher_request *req,
struct crypto_cipher *cipher,
void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
{
const unsigned int bsize = crypto_cipher_blocksize(cipher);
struct skcipher_walk walk;
unsigned int nbytes;
int err;
err = skcipher_walk_virt(&walk, req, false);
while ((nbytes = walk.nbytes) != 0) {
const u8 *src = walk.src.virt.addr;
u8 *dst = walk.dst.virt.addr;
do {
fn(crypto_cipher_tfm(cipher), dst, src);
src += bsize;
dst += bsize;
} while ((nbytes -= bsize) >= bsize);
err = skcipher_walk_done(&walk, nbytes);
}
return err;
}
static int crypto_ecb_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
return crypto_ecb_crypt(req, cipher,
crypto_cipher_alg(cipher)->cia_encrypt);
}
static int crypto_ecb_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
return crypto_ecb_crypt(req, cipher,
crypto_cipher_alg(cipher)->cia_decrypt);
}
static int crypto_ecb_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);
inst->alg.ivsize = 0; /* ECB mode doesn't take an IV */
inst->alg.encrypt = crypto_ecb_encrypt;
inst->alg.decrypt = crypto_ecb_decrypt;
err = skcipher_register_instance(tmpl, inst);
if (err)
inst->free(inst);
crypto_mod_put(alg);
return err;
}
static struct crypto_template crypto_ecb_tmpl = {
.name = "ecb",
.create = crypto_ecb_create,
.module = THIS_MODULE,
};
static int __init crypto_ecb_module_init(void)
{
return crypto_register_template(&crypto_ecb_tmpl);
}
static void __exit crypto_ecb_module_exit(void)
{
crypto_unregister_template(&crypto_ecb_tmpl);
}
subsys_initcall(crypto_ecb_module_init);
module_exit(crypto_ecb_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ECB block cipher mode of operation");
MODULE_ALIAS_CRYPTO("ecb");