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27#include <asm/unaligned.h>
28#include <crypto/twofish.h>
29#include <linux/module.h>
30#include <linux/init.h>
31#include <linux/types.h>
32#include <linux/errno.h>
33#include <linux/crypto.h>
34#include <linux/bitops.h>
35
36
37
38
39
40#define G1(a) \
41 (ctx->s[0][(a) & 0xFF]) ^ (ctx->s[1][((a) >> 8) & 0xFF]) \
42 ^ (ctx->s[2][((a) >> 16) & 0xFF]) ^ (ctx->s[3][(a) >> 24])
43
44#define G2(b) \
45 (ctx->s[1][(b) & 0xFF]) ^ (ctx->s[2][((b) >> 8) & 0xFF]) \
46 ^ (ctx->s[3][((b) >> 16) & 0xFF]) ^ (ctx->s[0][(b) >> 24])
47
48
49
50
51
52
53#define ENCROUND(n, a, b, c, d) \
54 x = G1 (a); y = G2 (b); \
55 x += y; y += x + ctx->k[2 * (n) + 1]; \
56 (c) ^= x + ctx->k[2 * (n)]; \
57 (c) = ror32((c), 1); \
58 (d) = rol32((d), 1) ^ y
59
60#define DECROUND(n, a, b, c, d) \
61 x = G1 (a); y = G2 (b); \
62 x += y; y += x; \
63 (d) ^= y + ctx->k[2 * (n) + 1]; \
64 (d) = ror32((d), 1); \
65 (c) = rol32((c), 1); \
66 (c) ^= (x + ctx->k[2 * (n)])
67
68
69
70
71#define ENCCYCLE(n) \
72 ENCROUND (2 * (n), a, b, c, d); \
73 ENCROUND (2 * (n) + 1, c, d, a, b)
74
75#define DECCYCLE(n) \
76 DECROUND (2 * (n) + 1, c, d, a, b); \
77 DECROUND (2 * (n), a, b, c, d)
78
79
80
81
82
83
84
85#define INPACK(n, x, m) \
86 x = get_unaligned_le32(in + (n) * 4) ^ ctx->w[m]
87
88#define OUTUNPACK(n, x, m) \
89 x ^= ctx->w[m]; \
90 put_unaligned_le32(x, out + (n) * 4)
91
92
93
94
95static void twofish_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
96{
97 struct twofish_ctx *ctx = crypto_tfm_ctx(tfm);
98
99
100 u32 a, b, c, d;
101
102
103 u32 x, y;
104
105
106 INPACK (0, a, 0);
107 INPACK (1, b, 1);
108 INPACK (2, c, 2);
109 INPACK (3, d, 3);
110
111
112 ENCCYCLE (0);
113 ENCCYCLE (1);
114 ENCCYCLE (2);
115 ENCCYCLE (3);
116 ENCCYCLE (4);
117 ENCCYCLE (5);
118 ENCCYCLE (6);
119 ENCCYCLE (7);
120
121
122 OUTUNPACK (0, c, 4);
123 OUTUNPACK (1, d, 5);
124 OUTUNPACK (2, a, 6);
125 OUTUNPACK (3, b, 7);
126
127}
128
129
130static void twofish_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
131{
132 struct twofish_ctx *ctx = crypto_tfm_ctx(tfm);
133
134
135 u32 a, b, c, d;
136
137
138 u32 x, y;
139
140
141 INPACK (0, c, 4);
142 INPACK (1, d, 5);
143 INPACK (2, a, 6);
144 INPACK (3, b, 7);
145
146
147 DECCYCLE (7);
148 DECCYCLE (6);
149 DECCYCLE (5);
150 DECCYCLE (4);
151 DECCYCLE (3);
152 DECCYCLE (2);
153 DECCYCLE (1);
154 DECCYCLE (0);
155
156
157 OUTUNPACK (0, a, 0);
158 OUTUNPACK (1, b, 1);
159 OUTUNPACK (2, c, 2);
160 OUTUNPACK (3, d, 3);
161
162}
163
164static struct crypto_alg alg = {
165 .cra_name = "twofish",
166 .cra_driver_name = "twofish-generic",
167 .cra_priority = 100,
168 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
169 .cra_blocksize = TF_BLOCK_SIZE,
170 .cra_ctxsize = sizeof(struct twofish_ctx),
171 .cra_module = THIS_MODULE,
172 .cra_u = { .cipher = {
173 .cia_min_keysize = TF_MIN_KEY_SIZE,
174 .cia_max_keysize = TF_MAX_KEY_SIZE,
175 .cia_setkey = twofish_setkey,
176 .cia_encrypt = twofish_encrypt,
177 .cia_decrypt = twofish_decrypt } }
178};
179
180static int __init twofish_mod_init(void)
181{
182 return crypto_register_alg(&alg);
183}
184
185static void __exit twofish_mod_fini(void)
186{
187 crypto_unregister_alg(&alg);
188}
189
190subsys_initcall(twofish_mod_init);
191module_exit(twofish_mod_fini);
192
193MODULE_LICENSE("GPL");
194MODULE_DESCRIPTION ("Twofish Cipher Algorithm");
195MODULE_ALIAS_CRYPTO("twofish");
196MODULE_ALIAS_CRYPTO("twofish-generic");
197