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 | |
15 | #include <crypto/algapi.h> |
16 | #include <linux/init.h> |
17 | #include <linux/module.h> |
18 | #include <linux/mm.h> |
19 | #include <asm/unaligned.h> |
20 | #include <linux/types.h> |
21 | #include <crypto/blowfish.h> |
22 | |
23 | /* |
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)]) ^ \ |
33 | S[512 + GET32_2(x)]) + S[768 + GET32_3(x)]) |
34 | |
35 | #define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); }) |
36 | |
37 | static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
38 | { |
39 | struct bf_ctx *ctx = crypto_tfm_ctx(tfm); |
40 | const u32 *P = ctx->p; |
41 | const u32 *S = ctx->s; |
42 | u32 yl = get_unaligned_be32(p: src); |
43 | u32 yr = get_unaligned_be32(p: src + 4); |
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 | |
65 | put_unaligned_be32(val: yr, p: dst); |
66 | put_unaligned_be32(val: yl, p: dst + 4); |
67 | } |
68 | |
69 | static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
70 | { |
71 | struct bf_ctx *ctx = crypto_tfm_ctx(tfm); |
72 | const u32 *P = ctx->p; |
73 | const u32 *S = ctx->s; |
74 | u32 yl = get_unaligned_be32(p: src); |
75 | u32 yr = get_unaligned_be32(p: src + 4); |
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 | |
97 | put_unaligned_be32(val: yr, p: dst); |
98 | put_unaligned_be32(val: yl, p: dst + 4); |
99 | } |
100 | |
101 | static struct crypto_alg alg = { |
102 | .cra_name = "blowfish" , |
103 | .cra_driver_name = "blowfish-generic" , |
104 | .cra_priority = 100, |
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, |
109 | .cra_u = { .cipher = { |
110 | .cia_min_keysize = BF_MIN_KEY_SIZE, |
111 | .cia_max_keysize = BF_MAX_KEY_SIZE, |
112 | .cia_setkey = blowfish_setkey, |
113 | .cia_encrypt = bf_encrypt, |
114 | .cia_decrypt = bf_decrypt } } |
115 | }; |
116 | |
117 | static int __init blowfish_mod_init(void) |
118 | { |
119 | return crypto_register_alg(alg: &alg); |
120 | } |
121 | |
122 | static void __exit blowfish_mod_fini(void) |
123 | { |
124 | crypto_unregister_alg(alg: &alg); |
125 | } |
126 | |
127 | subsys_initcall(blowfish_mod_init); |
128 | module_exit(blowfish_mod_fini); |
129 | |
130 | MODULE_LICENSE("GPL" ); |
131 | MODULE_DESCRIPTION("Blowfish Cipher Algorithm" ); |
132 | MODULE_ALIAS_CRYPTO("blowfish" ); |
133 | MODULE_ALIAS_CRYPTO("blowfish-generic" ); |
134 | |