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
|
/*************************************************
* SEED Source File *
* (C) 1999-2007 Jack Lloyd *
*************************************************/
#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::enc(const byte in[], byte out[]) const
{
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(u32bit 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);
}
/*************************************************
* SEED Decryption *
*************************************************/
void SEED::dec(const byte in[], byte out[]) const
{
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(u32bit 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);
}
/*************************************************
* SEED Key Schedule *
*************************************************/
void SEED::key_schedule(const byte key[], u32bit)
{
const u32bit RC[16] = {
0x9E3779B9, 0x3C6EF373, 0x78DDE6E6, 0xF1BBCDCC,
0xE3779B99, 0xC6EF3733, 0x8DDE6E67, 0x1BBCDCCF,
0x3779B99E, 0x6EF3733C, 0xDDE6E678, 0xBBCDCCF1,
0x779B99E3, 0xEF3733C6, 0xDE6E678D, 0xBCDCCF1B
};
SecureBuffer<u32bit, 4> WK;
for(u32bit j = 0; j != 4; ++j)
WK[j] = load_be<u32bit>(key, j);
G_FUNC G;
for(u32bit j = 0; j != 16; j += 2)
{
K[2*j ] = G(WK[0] + WK[2] - RC[j]);
K[2*j+1] = G(WK[1] - WK[3] + RC[j]) ^ K[2*j];
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*j+2] = G(WK[0] + WK[2] - RC[j+1]);
K[2*j+3] = G(WK[1] - WK[3] + RC[j+1]) ^ K[2*j+2];
T = get_byte(0, WK[3]);
WK[3] = (WK[3] << 8) | get_byte(0, WK[2]);
WK[2] = (WK[2] << 8) | T;
}
}
}
|
