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[CRYPTO] cipher: Added block ciphers for CBC/ECB

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This patch adds two block cipher algorithms, CBC and ECB.  These
are implemented as templates on top of existing single-block cipher
algorithms.  They invoke the single-block cipher through the new
encrypt_one/decrypt_one interface.

This also optimises the in-place encryption and decryption to remove
the cost of an IV copy each round.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu
2006-09-21 11:44:08 +10:00
parent 5cde0af2a9
commit db131ef908
6 changed files with 546 additions and 1 deletions
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181
crypto/ecb.c Normal file
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/*
* 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 <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
struct crypto_ecb_ctx {
struct crypto_cipher *child;
};
static int crypto_ecb_setkey(struct crypto_tfm *parent, const u8 *key,
unsigned int keylen)
{
struct crypto_ecb_ctx *ctx = crypto_tfm_ctx(parent);
struct crypto_cipher *child = ctx->child;
int err;
crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_cipher_setkey(child, key, keylen);
crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
static int crypto_ecb_crypt(struct blkcipher_desc *desc,
struct blkcipher_walk *walk,
struct crypto_cipher *tfm,
void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
{
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes;
int err;
err = blkcipher_walk_virt(desc, walk);
while ((nbytes = walk->nbytes)) {
u8 *wsrc = walk->src.virt.addr;
u8 *wdst = walk->dst.virt.addr;
do {
fn(crypto_cipher_tfm(tfm), wdst, wsrc);
wsrc += bsize;
wdst += bsize;
} while ((nbytes -= bsize) >= bsize);
err = blkcipher_walk_done(desc, walk, nbytes);
}
return err;
}
static int crypto_ecb_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct blkcipher_walk walk;
struct crypto_blkcipher *tfm = desc->tfm;
struct crypto_ecb_ctx *ctx = crypto_blkcipher_ctx(tfm);
struct crypto_cipher *child = ctx->child;
blkcipher_walk_init(&walk, dst, src, nbytes);
return crypto_ecb_crypt(desc, &walk, child,
crypto_cipher_alg(child)->cia_encrypt);
}
static int crypto_ecb_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct blkcipher_walk walk;
struct crypto_blkcipher *tfm = desc->tfm;
struct crypto_ecb_ctx *ctx = crypto_blkcipher_ctx(tfm);
struct crypto_cipher *child = ctx->child;
blkcipher_walk_init(&walk, dst, src, nbytes);
return crypto_ecb_crypt(desc, &walk, child,
crypto_cipher_alg(child)->cia_decrypt);
}
static int crypto_ecb_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct crypto_spawn *spawn = crypto_instance_ctx(inst);
struct crypto_ecb_ctx *ctx = crypto_tfm_ctx(tfm);
tfm = crypto_spawn_tfm(spawn);
if (IS_ERR(tfm))
return PTR_ERR(tfm);
ctx->child = crypto_cipher_cast(tfm);
return 0;
}
static void crypto_ecb_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_ecb_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_cipher(ctx->child);
}
static struct crypto_instance *crypto_ecb_alloc(void *param, unsigned int len)
{
struct crypto_instance *inst;
struct crypto_alg *alg;
alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER,
CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
if (IS_ERR(alg))
return ERR_PTR(PTR_ERR(alg));
inst = crypto_alloc_instance("ecb", alg);
if (IS_ERR(inst))
goto out_put_alg;
inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
inst->alg.cra_priority = alg->cra_priority;
inst->alg.cra_blocksize = alg->cra_blocksize;
inst->alg.cra_alignmask = alg->cra_alignmask;
inst->alg.cra_type = &crypto_blkcipher_type;
inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
inst->alg.cra_ctxsize = sizeof(struct crypto_ecb_ctx);
inst->alg.cra_init = crypto_ecb_init_tfm;
inst->alg.cra_exit = crypto_ecb_exit_tfm;
inst->alg.cra_blkcipher.setkey = crypto_ecb_setkey;
inst->alg.cra_blkcipher.encrypt = crypto_ecb_encrypt;
inst->alg.cra_blkcipher.decrypt = crypto_ecb_decrypt;
out_put_alg:
crypto_mod_put(alg);
return inst;
}
static void crypto_ecb_free(struct crypto_instance *inst)
{
crypto_drop_spawn(crypto_instance_ctx(inst));
kfree(inst);
}
static struct crypto_template crypto_ecb_tmpl = {
.name = "ecb",
.alloc = crypto_ecb_alloc,
.free = crypto_ecb_free,
.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);
}
module_init(crypto_ecb_module_init);
module_exit(crypto_ecb_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ECB block cipher algorithm");