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