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
bf_encrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)41 static 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
bf_decrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)75 static 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
109 static 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
blowfish_mod_init(void)126 static int __init blowfish_mod_init(void)
127 {
128 return crypto_register_alg(&alg);
129 }
130
blowfish_mod_fini(void)131 static void __exit blowfish_mod_fini(void)
132 {
133 crypto_unregister_alg(&alg);
134 }
135
136 module_init(blowfish_mod_init);
137 module_exit(blowfish_mod_fini);
138
139 MODULE_LICENSE("GPL");
140 MODULE_DESCRIPTION("Blowfish Cipher Algorithm");
141 MODULE_ALIAS_CRYPTO("blowfish");
142 MODULE_ALIAS_CRYPTO("blowfish-generic");
143