Root/crypto/blowfish_generic.c

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("blowfish");
142

Archive Download this file



interactive