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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
/*
* Skipjack
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/skipjack.h>
#include <botan/loadstor.h>
namespace Botan {
/*
* Skipjack Encryption
*/
void Skipjack::enc(const byte in[], byte out[]) const
{
u16bit W1 = load_le<u16bit>(in, 3);
u16bit W2 = load_le<u16bit>(in, 2);
u16bit W3 = load_le<u16bit>(in, 1);
u16bit W4 = load_le<u16bit>(in, 0);
step_A(W1,W4, 1); step_A(W4,W3, 2); step_A(W3,W2, 3); step_A(W2,W1, 4);
step_A(W1,W4, 5); step_A(W4,W3, 6); step_A(W3,W2, 7); step_A(W2,W1, 8);
step_B(W1,W2, 9); step_B(W4,W1,10); step_B(W3,W4,11); step_B(W2,W3,12);
step_B(W1,W2,13); step_B(W4,W1,14); step_B(W3,W4,15); step_B(W2,W3,16);
step_A(W1,W4,17); step_A(W4,W3,18); step_A(W3,W2,19); step_A(W2,W1,20);
step_A(W1,W4,21); step_A(W4,W3,22); step_A(W3,W2,23); step_A(W2,W1,24);
step_B(W1,W2,25); step_B(W4,W1,26); step_B(W3,W4,27); step_B(W2,W3,28);
step_B(W1,W2,29); step_B(W4,W1,30); step_B(W3,W4,31); step_B(W2,W3,32);
store_le(out, W4, W3, W2, W1);
}
/*
* Skipjack Decryption
*/
void Skipjack::dec(const byte in[], byte out[]) const
{
u16bit W1 = load_le<u16bit>(in, 3);
u16bit W2 = load_le<u16bit>(in, 2);
u16bit W3 = load_le<u16bit>(in, 1);
u16bit W4 = load_le<u16bit>(in, 0);
step_Bi(W2,W3,32); step_Bi(W3,W4,31); step_Bi(W4,W1,30); step_Bi(W1,W2,29);
step_Bi(W2,W3,28); step_Bi(W3,W4,27); step_Bi(W4,W1,26); step_Bi(W1,W2,25);
step_Ai(W1,W2,24); step_Ai(W2,W3,23); step_Ai(W3,W4,22); step_Ai(W4,W1,21);
step_Ai(W1,W2,20); step_Ai(W2,W3,19); step_Ai(W3,W4,18); step_Ai(W4,W1,17);
step_Bi(W2,W3,16); step_Bi(W3,W4,15); step_Bi(W4,W1,14); step_Bi(W1,W2,13);
step_Bi(W2,W3,12); step_Bi(W3,W4,11); step_Bi(W4,W1,10); step_Bi(W1,W2, 9);
step_Ai(W1,W2, 8); step_Ai(W2,W3, 7); step_Ai(W3,W4, 6); step_Ai(W4,W1, 5);
step_Ai(W1,W2, 4); step_Ai(W2,W3, 3); step_Ai(W3,W4, 2); step_Ai(W4,W1, 1);
store_le(out, W4, W3, W2, W1);
}
/*
* Skipjack Stepping Rule 'A'
*/
void Skipjack::step_A(u16bit& W1, u16bit& W4, u32bit round) const
{
byte G1 = get_byte(0, W1), G2 = get_byte(1, W1), G3;
G3 = FTABLE[(4 * round - 4) % 10][G2] ^ G1;
G1 = FTABLE[(4 * round - 3) % 10][G3] ^ G2;
G2 = FTABLE[(4 * round - 2) % 10][G1] ^ G3;
G3 = FTABLE[(4 * round - 1) % 10][G2] ^ G1;
W1 = make_u16bit(G2, G3);
W4 ^= W1 ^ round;
}
/*
* Skipjack Stepping Rule 'B'
*/
void Skipjack::step_B(u16bit& W1, u16bit& W2, u32bit round) const
{
W2 ^= W1 ^ round;
byte G1 = get_byte(0, W1), G2 = get_byte(1, W1), G3;
G3 = FTABLE[(4 * round - 4) % 10][G2] ^ G1;
G1 = FTABLE[(4 * round - 3) % 10][G3] ^ G2;
G2 = FTABLE[(4 * round - 2) % 10][G1] ^ G3;
G3 = FTABLE[(4 * round - 1) % 10][G2] ^ G1;
W1 = make_u16bit(G2, G3);
}
/*
* Skipjack Invserse Stepping Rule 'A'
*/
void Skipjack::step_Ai(u16bit& W1, u16bit& W2, u32bit round) const
{
W1 ^= W2 ^ round;
byte G1 = get_byte(1, W2), G2 = get_byte(0, W2), G3;
G3 = FTABLE[(4 * round - 1) % 10][G2] ^ G1;
G1 = FTABLE[(4 * round - 2) % 10][G3] ^ G2;
G2 = FTABLE[(4 * round - 3) % 10][G1] ^ G3;
G3 = FTABLE[(4 * round - 4) % 10][G2] ^ G1;
W2 = make_u16bit(G3, G2);
}
/*
* Skipjack Invserse Stepping Rule 'B'
*/
void Skipjack::step_Bi(u16bit& W2, u16bit& W3, u32bit round) const
{
byte G1 = get_byte(1, W2), G2 = get_byte(0, W2), G3;
G3 = FTABLE[(4 * round - 1) % 10][G2] ^ G1;
G1 = FTABLE[(4 * round - 2) % 10][G3] ^ G2;
G2 = FTABLE[(4 * round - 3) % 10][G1] ^ G3;
G3 = FTABLE[(4 * round - 4) % 10][G2] ^ G1;
W2 = make_u16bit(G3, G2);
W3 ^= W2 ^ round;
}
/*
* Skipjack Key Schedule
*/
void Skipjack::key_schedule(const byte key[], u32bit)
{
static const byte F[256] = {
0xA3, 0xD7, 0x09, 0x83, 0xF8, 0x48, 0xF6, 0xF4, 0xB3, 0x21, 0x15, 0x78,
0x99, 0xB1, 0xAF, 0xF9, 0xE7, 0x2D, 0x4D, 0x8A, 0xCE, 0x4C, 0xCA, 0x2E,
0x52, 0x95, 0xD9, 0x1E, 0x4E, 0x38, 0x44, 0x28, 0x0A, 0xDF, 0x02, 0xA0,
0x17, 0xF1, 0x60, 0x68, 0x12, 0xB7, 0x7A, 0xC3, 0xE9, 0xFA, 0x3D, 0x53,
0x96, 0x84, 0x6B, 0xBA, 0xF2, 0x63, 0x9A, 0x19, 0x7C, 0xAE, 0xE5, 0xF5,
0xF7, 0x16, 0x6A, 0xA2, 0x39, 0xB6, 0x7B, 0x0F, 0xC1, 0x93, 0x81, 0x1B,
0xEE, 0xB4, 0x1A, 0xEA, 0xD0, 0x91, 0x2F, 0xB8, 0x55, 0xB9, 0xDA, 0x85,
0x3F, 0x41, 0xBF, 0xE0, 0x5A, 0x58, 0x80, 0x5F, 0x66, 0x0B, 0xD8, 0x90,
0x35, 0xD5, 0xC0, 0xA7, 0x33, 0x06, 0x65, 0x69, 0x45, 0x00, 0x94, 0x56,
0x6D, 0x98, 0x9B, 0x76, 0x97, 0xFC, 0xB2, 0xC2, 0xB0, 0xFE, 0xDB, 0x20,
0xE1, 0xEB, 0xD6, 0xE4, 0xDD, 0x47, 0x4A, 0x1D, 0x42, 0xED, 0x9E, 0x6E,
0x49, 0x3C, 0xCD, 0x43, 0x27, 0xD2, 0x07, 0xD4, 0xDE, 0xC7, 0x67, 0x18,
0x89, 0xCB, 0x30, 0x1F, 0x8D, 0xC6, 0x8F, 0xAA, 0xC8, 0x74, 0xDC, 0xC9,
0x5D, 0x5C, 0x31, 0xA4, 0x70, 0x88, 0x61, 0x2C, 0x9F, 0x0D, 0x2B, 0x87,
0x50, 0x82, 0x54, 0x64, 0x26, 0x7D, 0x03, 0x40, 0x34, 0x4B, 0x1C, 0x73,
0xD1, 0xC4, 0xFD, 0x3B, 0xCC, 0xFB, 0x7F, 0xAB, 0xE6, 0x3E, 0x5B, 0xA5,
0xAD, 0x04, 0x23, 0x9C, 0x14, 0x51, 0x22, 0xF0, 0x29, 0x79, 0x71, 0x7E,
0xFF, 0x8C, 0x0E, 0xE2, 0x0C, 0xEF, 0xBC, 0x72, 0x75, 0x6F, 0x37, 0xA1,
0xEC, 0xD3, 0x8E, 0x62, 0x8B, 0x86, 0x10, 0xE8, 0x08, 0x77, 0x11, 0xBE,
0x92, 0x4F, 0x24, 0xC5, 0x32, 0x36, 0x9D, 0xCF, 0xF3, 0xA6, 0xBB, 0xAC,
0x5E, 0x6C, 0xA9, 0x13, 0x57, 0x25, 0xB5, 0xE3, 0xBD, 0xA8, 0x3A, 0x01,
0x05, 0x59, 0x2A, 0x46 };
for(u32bit j = 0; j != 10; ++j)
for(u32bit k = 0; k != 256; ++k)
FTABLE[j][k] = F[k ^ key[9-j]];
}
/*
* Clear memory of sensitive data
*/
void Skipjack::clear() throw()
{
for(u32bit j = 0; j != 10; ++j)
FTABLE[j].clear();
}
}
|
