1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
/*
* SEED
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/seed.h>
#include <botan/loadstor.h>
namespace Botan {
/*
* SEED G Function
*/
u32bit SEED::G_FUNC::operator()(u32bit X) const
{
return (S0[get_byte(3, X)] ^ S1[get_byte(2, X)] ^
S2[get_byte(1, X)] ^ S3[get_byte(0, X)]);
}
/*
* SEED Encryption
*/
void SEED::encrypt_n(const byte in[], byte out[], size_t blocks) const
{
for(size_t i = 0; i != blocks; ++i)
{
u32bit B0 = load_be<u32bit>(in, 0);
u32bit B1 = load_be<u32bit>(in, 1);
u32bit B2 = load_be<u32bit>(in, 2);
u32bit B3 = load_be<u32bit>(in, 3);
G_FUNC G;
for(size_t j = 0; j != 16; j += 2)
{
u32bit T0, T1;
T0 = B2 ^ K[2*j];
T1 = G(B2 ^ B3 ^ K[2*j+1]);
T0 = G(T1 + T0);
T1 = G(T1 + T0);
B1 ^= T1;
B0 ^= T0 + T1;
T0 = B0 ^ K[2*j+2];
T1 = G(B0 ^ B1 ^ K[2*j+3]);
T0 = G(T1 + T0);
T1 = G(T1 + T0);
B3 ^= T1;
B2 ^= T0 + T1;
}
store_be(out, B2, B3, B0, B1);
in += block_size();
out += block_size();
}
}
/*
* SEED Decryption
*/
void SEED::decrypt_n(const byte in[], byte out[], size_t blocks) const
{
for(size_t i = 0; i != blocks; ++i)
{
u32bit B0 = load_be<u32bit>(in, 0);
u32bit B1 = load_be<u32bit>(in, 1);
u32bit B2 = load_be<u32bit>(in, 2);
u32bit B3 = load_be<u32bit>(in, 3);
G_FUNC G;
for(size_t j = 0; j != 16; j += 2)
{
u32bit T0, T1;
T0 = B2 ^ K[30-2*j];
T1 = G(B2 ^ B3 ^ K[31-2*j]);
T0 = G(T1 + T0);
T1 = G(T1 + T0);
B1 ^= T1;
B0 ^= T0 + T1;
T0 = B0 ^ K[28-2*j];
T1 = G(B0 ^ B1 ^ K[29-2*j]);
T0 = G(T1 + T0);
T1 = G(T1 + T0);
B3 ^= T1;
B2 ^= T0 + T1;
}
store_be(out, B2, B3, B0, B1);
in += block_size();
out += block_size();
}
}
/*
* SEED Key Schedule
*/
void SEED::key_schedule(const byte key[], size_t)
{
const u32bit RC[16] = {
0x9E3779B9, 0x3C6EF373, 0x78DDE6E6, 0xF1BBCDCC,
0xE3779B99, 0xC6EF3733, 0x8DDE6E67, 0x1BBCDCCF,
0x3779B99E, 0x6EF3733C, 0xDDE6E678, 0xBBCDCCF1,
0x779B99E3, 0xEF3733C6, 0xDE6E678D, 0xBCDCCF1B
};
SecureVector<u32bit> WK(4);
for(size_t i = 0; i != 4; ++i)
WK[i] = load_be<u32bit>(key, i);
G_FUNC G;
for(size_t i = 0; i != 16; i += 2)
{
K[2*i ] = G(WK[0] + WK[2] - RC[i]);
K[2*i+1] = G(WK[1] - WK[3] + RC[i]) ^ K[2*i];
byte T = get_byte(3, WK[0]);
WK[0] = (WK[0] >> 8) | (get_byte(3, WK[1]) << 24);
WK[1] = (WK[1] >> 8) | (T << 24);
K[2*i+2] = G(WK[0] + WK[2] - RC[i+1]);
K[2*i+3] = G(WK[1] - WK[3] + RC[i+1]) ^ K[2*i+2];
T = get_byte(0, WK[3]);
WK[3] = (WK[3] << 8) | get_byte(0, WK[2]);
WK[2] = (WK[2] << 8) | T;
}
}
}
|
