[linux-block.git] / crypto / blowfish_generic.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");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
0d8fb0a1	2	/*
1da177e4 LT	3	* Cryptographic API.
	4	*
	5	* Blowfish Cipher Algorithm, by Bruce Schneier.
	6	* http://www.counterpane.com/blowfish.html
	7	*
	8	* Adapted from Kerneli implementation.
	9	*
	10	* Copyright (c) Herbert Valerio Riedel <hvr@hvrlab.org>
	11	* Copyright (c) Kyle McMartin <kyle@debian.org>
	12	* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
1da177e4	13	*/
14386d47 HX	14
14386d47 HX	15	#include <crypto/algapi.h>
1da177e4 LT	16	#include <linux/init.h>
	17	#include <linux/module.h>
	18	#include <linux/mm.h>
50a3a9fa	19	#include <asm/unaligned.h>
06ace7a9	20	#include <linux/types.h>
52ba867c	21	#include <crypto/blowfish.h>
1da177e4	22
0d8fb0a1	23	/*
1da177e4 LT	24	* Round loop unrolling macros, S is a pointer to a S-Box array
	25	* organized in 4 unsigned longs at a row.
	26	*/
	27	#define GET32_3(x) (((x) & 0xff))
	28	#define GET32_2(x) (((x) >> (8)) & (0xff))
	29	#define GET32_1(x) (((x) >> (16)) & (0xff))
	30	#define GET32_0(x) (((x) >> (24)) & (0xff))
	31
	32	#define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \
3f2a5d2d	33	S[512 + GET32_2(x)]) + S[768 + GET32_3(x)])
1da177e4	34
3f2a5d2d	35	#define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); })
1da177e4	36
52ba867c	37	static void bf_encrypt(struct crypto_tfm tfm, u8 dst, const u8 *src)
1da177e4	38	{
52ba867c	39	struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
52ba867c JK	40	const u32 *P = ctx->p;
52ba867c JK	41	const u32 *S = ctx->s;
50a3a9fa AB	42	u32 yl = get_unaligned_be32(src);
50a3a9fa AB	43	u32 yr = get_unaligned_be32(src + 4);
1da177e4 LT	44
	45	ROUND(yr, yl, 0);
	46	ROUND(yl, yr, 1);
	47	ROUND(yr, yl, 2);
	48	ROUND(yl, yr, 3);
	49	ROUND(yr, yl, 4);
	50	ROUND(yl, yr, 5);
	51	ROUND(yr, yl, 6);
	52	ROUND(yl, yr, 7);
	53	ROUND(yr, yl, 8);
	54	ROUND(yl, yr, 9);
	55	ROUND(yr, yl, 10);
	56	ROUND(yl, yr, 11);
	57	ROUND(yr, yl, 12);
	58	ROUND(yl, yr, 13);
	59	ROUND(yr, yl, 14);
	60	ROUND(yl, yr, 15);
	61
	62	yl ^= P[16];
	63	yr ^= P[17];
	64
50a3a9fa AB	65	put_unaligned_be32(yr, dst);
50a3a9fa AB	66	put_unaligned_be32(yl, dst + 4);
1da177e4 LT	67	}
1da177e4 LT	68
6c2bb98b	69	static void bf_decrypt(struct crypto_tfm tfm, u8 dst, const u8 *src)
1da177e4	70	{
6c2bb98b	71	struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
6c2bb98b HX	72	const u32 *P = ctx->p;
6c2bb98b HX	73	const u32 *S = ctx->s;
50a3a9fa AB	74	u32 yl = get_unaligned_be32(src);
50a3a9fa AB	75	u32 yr = get_unaligned_be32(src + 4);
1da177e4 LT	76
	77	ROUND(yr, yl, 17);
	78	ROUND(yl, yr, 16);
	79	ROUND(yr, yl, 15);
	80	ROUND(yl, yr, 14);
	81	ROUND(yr, yl, 13);
	82	ROUND(yl, yr, 12);
	83	ROUND(yr, yl, 11);
	84	ROUND(yl, yr, 10);
	85	ROUND(yr, yl, 9);
	86	ROUND(yl, yr, 8);
	87	ROUND(yr, yl, 7);
	88	ROUND(yl, yr, 6);
	89	ROUND(yr, yl, 5);
	90	ROUND(yl, yr, 4);
	91	ROUND(yr, yl, 3);
	92	ROUND(yl, yr, 2);
	93
	94	yl ^= P[1];
	95	yr ^= P[0];
	96
50a3a9fa AB	97	put_unaligned_be32(yr, dst);
50a3a9fa AB	98	put_unaligned_be32(yl, dst + 4);
1da177e4 LT	99	}
1da177e4 LT	100
1da177e4 LT	101	static struct crypto_alg alg = {
1da177e4 LT	102	.cra_name = "blowfish",
3f2a5d2d JK	103	.cra_driver_name = "blowfish-generic",
3f2a5d2d JK	104	.cra_priority = 100,
1da177e4 LT	105	.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
	106	.cra_blocksize = BF_BLOCK_SIZE,
	107	.cra_ctxsize = sizeof(struct bf_ctx),
	108	.cra_module = THIS_MODULE,
1da177e4 LT	109	.cra_u = { .cipher = {
	110	.cia_min_keysize = BF_MIN_KEY_SIZE,
	111	.cia_max_keysize = BF_MAX_KEY_SIZE,
52ba867c	112	.cia_setkey = blowfish_setkey,
3f2a5d2d JK	113	.cia_encrypt = bf_encrypt,
3f2a5d2d JK	114	.cia_decrypt = bf_decrypt } }
1da177e4 LT	115	};
1da177e4 LT	116
3af5b90b	117	static int __init blowfish_mod_init(void)
1da177e4 LT	118	{
	119	return crypto_register_alg(&alg);
	120	}
	121
3af5b90b	122	static void __exit blowfish_mod_fini(void)
1da177e4 LT	123	{
	124	crypto_unregister_alg(&alg);
	125	}
	126
c4741b23	127	subsys_initcall(blowfish_mod_init);
3af5b90b	128	module_exit(blowfish_mod_fini);
1da177e4 LT	129
	130	MODULE_LICENSE("GPL");
	131	MODULE_DESCRIPTION("Blowfish Cipher Algorithm");
5d26a105	132	MODULE_ALIAS_CRYPTO("blowfish");
3e14dcf7	133	MODULE_ALIAS_CRYPTO("blowfish-generic");