linux/crypto/blowfish_generic.c
Herbert Xu 14386d4713 crypto: Prepare to move crypto_tfm_ctx
The helper crypto_tfm_ctx is only used by the Crypto API algorithm
code and should really be in algapi.h.  However, for historical
reasons many files relied on it to be in crypto.h.  This patch
changes those files to use algapi.h instead in prepartion for a
move.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-12-02 18:12:40 +08:00

134 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Cryptographic API.
*
* Blowfish Cipher Algorithm, by Bruce Schneier.
* http://www.counterpane.com/blowfish.html
*
* Adapted from Kerneli implementation.
*
* Copyright (c) Herbert Valerio Riedel <hvr@hvrlab.org>
* Copyright (c) Kyle McMartin <kyle@debian.org>
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
*/
#include <crypto/algapi.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <asm/unaligned.h>
#include <linux/types.h>
#include <crypto/blowfish.h>
/*
* Round loop unrolling macros, S is a pointer to a S-Box array
* organized in 4 unsigned longs at a row.
*/
#define GET32_3(x) (((x) & 0xff))
#define GET32_2(x) (((x) >> (8)) & (0xff))
#define GET32_1(x) (((x) >> (16)) & (0xff))
#define GET32_0(x) (((x) >> (24)) & (0xff))
#define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \
S[512 + GET32_2(x)]) + S[768 + GET32_3(x)])
#define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); })
static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
const u32 *P = ctx->p;
const u32 *S = ctx->s;
u32 yl = get_unaligned_be32(src);
u32 yr = get_unaligned_be32(src + 4);
ROUND(yr, yl, 0);
ROUND(yl, yr, 1);
ROUND(yr, yl, 2);
ROUND(yl, yr, 3);
ROUND(yr, yl, 4);
ROUND(yl, yr, 5);
ROUND(yr, yl, 6);
ROUND(yl, yr, 7);
ROUND(yr, yl, 8);
ROUND(yl, yr, 9);
ROUND(yr, yl, 10);
ROUND(yl, yr, 11);
ROUND(yr, yl, 12);
ROUND(yl, yr, 13);
ROUND(yr, yl, 14);
ROUND(yl, yr, 15);
yl ^= P[16];
yr ^= P[17];
put_unaligned_be32(yr, dst);
put_unaligned_be32(yl, dst + 4);
}
static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
const u32 *P = ctx->p;
const u32 *S = ctx->s;
u32 yl = get_unaligned_be32(src);
u32 yr = get_unaligned_be32(src + 4);
ROUND(yr, yl, 17);
ROUND(yl, yr, 16);
ROUND(yr, yl, 15);
ROUND(yl, yr, 14);
ROUND(yr, yl, 13);
ROUND(yl, yr, 12);
ROUND(yr, yl, 11);
ROUND(yl, yr, 10);
ROUND(yr, yl, 9);
ROUND(yl, yr, 8);
ROUND(yr, yl, 7);
ROUND(yl, yr, 6);
ROUND(yr, yl, 5);
ROUND(yl, yr, 4);
ROUND(yr, yl, 3);
ROUND(yl, yr, 2);
yl ^= P[1];
yr ^= P[0];
put_unaligned_be32(yr, dst);
put_unaligned_be32(yl, dst + 4);
}
static struct crypto_alg alg = {
.cra_name = "blowfish",
.cra_driver_name = "blowfish-generic",
.cra_priority = 100,
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = BF_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct bf_ctx),
.cra_module = THIS_MODULE,
.cra_u = { .cipher = {
.cia_min_keysize = BF_MIN_KEY_SIZE,
.cia_max_keysize = BF_MAX_KEY_SIZE,
.cia_setkey = blowfish_setkey,
.cia_encrypt = bf_encrypt,
.cia_decrypt = bf_decrypt } }
};
static int __init blowfish_mod_init(void)
{
return crypto_register_alg(&alg);
}
static void __exit blowfish_mod_fini(void)
{
crypto_unregister_alg(&alg);
}
subsys_initcall(blowfish_mod_init);
module_exit(blowfish_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Blowfish Cipher Algorithm");
MODULE_ALIAS_CRYPTO("blowfish");
MODULE_ALIAS_CRYPTO("blowfish-generic");