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/byteorder.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 __be32 *in_blk = (const __be32 *)src;
40 __be32 *const out_blk = (__be32 *)dst;
41 const u32 *P = ctx->p;
42 const u32 *S = ctx->s;
43 u32 yl = be32_to_cpu(in_blk[0]);
44 u32 yr = be32_to_cpu(in_blk[1]);
45
46 ROUND(yr, yl, 0);
47 ROUND(yl, yr, 1);
48 ROUND(yr, yl, 2);
49 ROUND(yl, yr, 3);
50 ROUND(yr, yl, 4);
51 ROUND(yl, yr, 5);
52 ROUND(yr, yl, 6);
53 ROUND(yl, yr, 7);
54 ROUND(yr, yl, 8);
55 ROUND(yl, yr, 9);
56 ROUND(yr, yl, 10);
57 ROUND(yl, yr, 11);
58 ROUND(yr, yl, 12);
59 ROUND(yl, yr, 13);
60 ROUND(yr, yl, 14);
61 ROUND(yl, yr, 15);
62
63 yl ^= P[16];
64 yr ^= P[17];
65
66 out_blk[0] = cpu_to_be32(yr);
67 out_blk[1] = cpu_to_be32(yl);
68 }
69
bf_decrypt(struct crypto_tfm * tfm,u8 * dst,const u8 * src)70 static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
71 {
72 struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
73 const __be32 *in_blk = (const __be32 *)src;
74 __be32 *const out_blk = (__be32 *)dst;
75 const u32 *P = ctx->p;
76 const u32 *S = ctx->s;
77 u32 yl = be32_to_cpu(in_blk[0]);
78 u32 yr = be32_to_cpu(in_blk[1]);
79
80 ROUND(yr, yl, 17);
81 ROUND(yl, yr, 16);
82 ROUND(yr, yl, 15);
83 ROUND(yl, yr, 14);
84 ROUND(yr, yl, 13);
85 ROUND(yl, yr, 12);
86 ROUND(yr, yl, 11);
87 ROUND(yl, yr, 10);
88 ROUND(yr, yl, 9);
89 ROUND(yl, yr, 8);
90 ROUND(yr, yl, 7);
91 ROUND(yl, yr, 6);
92 ROUND(yr, yl, 5);
93 ROUND(yl, yr, 4);
94 ROUND(yr, yl, 3);
95 ROUND(yl, yr, 2);
96
97 yl ^= P[1];
98 yr ^= P[0];
99
100 out_blk[0] = cpu_to_be32(yr);
101 out_blk[1] = cpu_to_be32(yl);
102 }
103
104 static struct crypto_alg alg = {
105 .cra_name = "blowfish",
106 .cra_driver_name = "blowfish-generic",
107 .cra_priority = 100,
108 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
109 .cra_blocksize = BF_BLOCK_SIZE,
110 .cra_ctxsize = sizeof(struct bf_ctx),
111 .cra_alignmask = 3,
112 .cra_module = THIS_MODULE,
113 .cra_u = { .cipher = {
114 .cia_min_keysize = BF_MIN_KEY_SIZE,
115 .cia_max_keysize = BF_MAX_KEY_SIZE,
116 .cia_setkey = blowfish_setkey,
117 .cia_encrypt = bf_encrypt,
118 .cia_decrypt = bf_decrypt } }
119 };
120
blowfish_mod_init(void)121 static int __init blowfish_mod_init(void)
122 {
123 return crypto_register_alg(&alg);
124 }
125
blowfish_mod_fini(void)126 static void __exit blowfish_mod_fini(void)
127 {
128 crypto_unregister_alg(&alg);
129 }
130
131 subsys_initcall(blowfish_mod_init);
132 module_exit(blowfish_mod_fini);
133
134 MODULE_LICENSE("GPL");
135 MODULE_DESCRIPTION("Blowfish Cipher Algorithm");
136 MODULE_ALIAS_CRYPTO("blowfish");
137 MODULE_ALIAS_CRYPTO("blowfish-generic");
138