linux/crypto/arc4.c
Ard Biesheuvel dc51f25752 crypto: arc4 - refactor arc4 core code into separate library
Refactor the core rc4 handling so we can move most users to a library
interface, permitting us to drop the cipher interface entirely in a
future patch. This is part of an effort to simplify the crypto API
and improve its robustness against incorrect use.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-06-20 14:18:33 +08:00

117 lines
2.8 KiB
C

/*
* Cryptographic API
*
* ARC4 Cipher Algorithm
*
* Jon Oberheide <jon@oberheide.org>
*
* 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/arc4.h>
#include <crypto/internal/skcipher.h>
#include <linux/init.h>
#include <linux/module.h>
static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);
return arc4_setkey(ctx, in_key, key_len);
}
static int arc4_set_key_skcipher(struct crypto_skcipher *tfm, const u8 *in_key,
unsigned int key_len)
{
return arc4_set_key(&tfm->base, in_key, key_len);
}
static void arc4_crypt_one(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
arc4_crypt(crypto_tfm_ctx(tfm), out, in, 1);
}
static int ecb_arc4_crypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes > 0) {
arc4_crypt(ctx, walk.dst.virt.addr, walk.src.virt.addr,
walk.nbytes);
err = skcipher_walk_done(&walk, 0);
}
return err;
}
static struct crypto_alg arc4_cipher = {
.cra_name = "arc4",
.cra_driver_name = "arc4-generic",
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = ARC4_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct arc4_ctx),
.cra_module = THIS_MODULE,
.cra_u = {
.cipher = {
.cia_min_keysize = ARC4_MIN_KEY_SIZE,
.cia_max_keysize = ARC4_MAX_KEY_SIZE,
.cia_setkey = arc4_set_key,
.cia_encrypt = arc4_crypt_one,
.cia_decrypt = arc4_crypt_one,
},
},
};
static struct skcipher_alg arc4_skcipher = {
.base.cra_name = "ecb(arc4)",
.base.cra_driver_name = "ecb(arc4)-generic",
.base.cra_priority = 100,
.base.cra_blocksize = ARC4_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct arc4_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = ARC4_MIN_KEY_SIZE,
.max_keysize = ARC4_MAX_KEY_SIZE,
.setkey = arc4_set_key_skcipher,
.encrypt = ecb_arc4_crypt,
.decrypt = ecb_arc4_crypt,
};
static int __init arc4_init(void)
{
int err;
err = crypto_register_alg(&arc4_cipher);
if (err)
return err;
err = crypto_register_skcipher(&arc4_skcipher);
if (err)
crypto_unregister_alg(&arc4_cipher);
return err;
}
static void __exit arc4_exit(void)
{
crypto_unregister_alg(&arc4_cipher);
crypto_unregister_skcipher(&arc4_skcipher);
}
subsys_initcall(arc4_init);
module_exit(arc4_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
MODULE_ALIAS_CRYPTO("arc4");