1/*
2 * Cryptographic API.
3 *
4 * Blowfish Cipher Algorithm, by Bruce Schneier.
5 * http://www.counterpane.com/blowfish.html
6 *
7 * Adapted from Kerneli implementation.
8 *
9 * Copyright (c) Herbert Valerio Riedel <hvr@hvrlab.org>
10 * Copyright (c) Kyle McMartin <kyle@debian.org>
11 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 */
19#include <linux/init.h>
20#include <linux/module.h>
21#include <linux/mm.h>
22#include <asm/byteorder.h>
23#include <linux/crypto.h>
24#include <linux/types.h>
25#include <crypto/blowfish.h>
26
27/*
28 * Round loop unrolling macros, S is a pointer to a S-Box array
29 * organized in 4 unsigned longs at a row.
30 */
31#define GET32_3(x) (((x) & 0xff))
32#define GET32_2(x) (((x) >> (8)) & (0xff))
33#define GET32_1(x) (((x) >> (16)) & (0xff))
34#define GET32_0(x) (((x) >> (24)) & (0xff))
35
36#define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \
37		S[512 + GET32_2(x)]) + S[768 + GET32_3(x)])
38
39#define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); })
40
41static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
42{
43	struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
44	const __be32 *in_blk = (const __be32 *)src;
45	__be32 *const out_blk = (__be32 *)dst;
46	const u32 *P = ctx->p;
47	const u32 *S = ctx->s;
48	u32 yl = be32_to_cpu(in_blk[0]);
49	u32 yr = be32_to_cpu(in_blk[1]);
50
51	ROUND(yr, yl, 0);
52	ROUND(yl, yr, 1);
53	ROUND(yr, yl, 2);
54	ROUND(yl, yr, 3);
55	ROUND(yr, yl, 4);
56	ROUND(yl, yr, 5);
57	ROUND(yr, yl, 6);
58	ROUND(yl, yr, 7);
59	ROUND(yr, yl, 8);
60	ROUND(yl, yr, 9);
61	ROUND(yr, yl, 10);
62	ROUND(yl, yr, 11);
63	ROUND(yr, yl, 12);
64	ROUND(yl, yr, 13);
65	ROUND(yr, yl, 14);
66	ROUND(yl, yr, 15);
67
68	yl ^= P[16];
69	yr ^= P[17];
70
71	out_blk[0] = cpu_to_be32(yr);
72	out_blk[1] = cpu_to_be32(yl);
73}
74
75static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
76{
77	struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
78	const __be32 *in_blk = (const __be32 *)src;
79	__be32 *const out_blk = (__be32 *)dst;
80	const u32 *P = ctx->p;
81	const u32 *S = ctx->s;
82	u32 yl = be32_to_cpu(in_blk[0]);
83	u32 yr = be32_to_cpu(in_blk[1]);
84
85	ROUND(yr, yl, 17);
86	ROUND(yl, yr, 16);
87	ROUND(yr, yl, 15);
88	ROUND(yl, yr, 14);
89	ROUND(yr, yl, 13);
90	ROUND(yl, yr, 12);
91	ROUND(yr, yl, 11);
92	ROUND(yl, yr, 10);
93	ROUND(yr, yl, 9);
94	ROUND(yl, yr, 8);
95	ROUND(yr, yl, 7);
96	ROUND(yl, yr, 6);
97	ROUND(yr, yl, 5);
98	ROUND(yl, yr, 4);
99	ROUND(yr, yl, 3);
100	ROUND(yl, yr, 2);
101
102	yl ^= P[1];
103	yr ^= P[0];
104
105	out_blk[0] = cpu_to_be32(yr);
106	out_blk[1] = cpu_to_be32(yl);
107}
108
109static struct crypto_alg alg = {
110	.cra_name		=	"blowfish",
111	.cra_driver_name	=	"blowfish-generic",
112	.cra_priority		=	100,
113	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
114	.cra_blocksize		=	BF_BLOCK_SIZE,
115	.cra_ctxsize		=	sizeof(struct bf_ctx),
116	.cra_alignmask		=	3,
117	.cra_module		=	THIS_MODULE,
118	.cra_u			=	{ .cipher = {
119	.cia_min_keysize	=	BF_MIN_KEY_SIZE,
120	.cia_max_keysize	=	BF_MAX_KEY_SIZE,
121	.cia_setkey		=	blowfish_setkey,
122	.cia_encrypt		=	bf_encrypt,
123	.cia_decrypt		=	bf_decrypt } }
124};
125
126static int __init blowfish_mod_init(void)
127{
128	return crypto_register_alg(&alg);
129}
130
131static void __exit blowfish_mod_fini(void)
132{
133	crypto_unregister_alg(&alg);
134}
135
136module_init(blowfish_mod_init);
137module_exit(blowfish_mod_fini);
138
139MODULE_LICENSE("GPL");
140MODULE_DESCRIPTION("Blowfish Cipher Algorithm");
141MODULE_ALIAS_CRYPTO("blowfish");
142MODULE_ALIAS_CRYPTO("blowfish-generic");
143