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
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
/*************************************************
* Square Source File *
* (C) 1999-2007 The Botan Project *
*************************************************/
#include <botan/square.h>
#include <botan/bit_ops.h>
namespace Botan {
/*************************************************
* Square Encryption *
*************************************************/
void Square::enc(const byte in[], byte out[]) const
{
u32bit T0, T1, T2, T3, B0, B1, B2, B3;
B0 = TE0[in[ 0] ^ ME[ 0]] ^ TE1[in[ 4] ^ ME[ 4]] ^
TE2[in[ 8] ^ ME[ 8]] ^ TE3[in[12] ^ ME[12]] ^ EK[0];
B1 = TE0[in[ 1] ^ ME[ 1]] ^ TE1[in[ 5] ^ ME[ 5]] ^
TE2[in[ 9] ^ ME[ 9]] ^ TE3[in[13] ^ ME[13]] ^ EK[1];
B2 = TE0[in[ 2] ^ ME[ 2]] ^ TE1[in[ 6] ^ ME[ 6]] ^
TE2[in[10] ^ ME[10]] ^ TE3[in[14] ^ ME[14]] ^ EK[2];
B3 = TE0[in[ 3] ^ ME[ 3]] ^ TE1[in[ 7] ^ ME[ 7]] ^
TE2[in[11] ^ ME[11]] ^ TE3[in[15] ^ ME[15]] ^ EK[3];
for(u32bit j = 1; j != 7; j += 2)
{
T0 = TE0[get_byte(0, B0)] ^ TE1[get_byte(0, B1)] ^
TE2[get_byte(0, B2)] ^ TE3[get_byte(0, B3)] ^ EK[4*j+0];
T1 = TE0[get_byte(1, B0)] ^ TE1[get_byte(1, B1)] ^
TE2[get_byte(1, B2)] ^ TE3[get_byte(1, B3)] ^ EK[4*j+1];
T2 = TE0[get_byte(2, B0)] ^ TE1[get_byte(2, B1)] ^
TE2[get_byte(2, B2)] ^ TE3[get_byte(2, B3)] ^ EK[4*j+2];
T3 = TE0[get_byte(3, B0)] ^ TE1[get_byte(3, B1)] ^
TE2[get_byte(3, B2)] ^ TE3[get_byte(3, B3)] ^ EK[4*j+3];
B0 = TE0[get_byte(0, T0)] ^ TE1[get_byte(0, T1)] ^
TE2[get_byte(0, T2)] ^ TE3[get_byte(0, T3)] ^ EK[4*j+4];
B1 = TE0[get_byte(1, T0)] ^ TE1[get_byte(1, T1)] ^
TE2[get_byte(1, T2)] ^ TE3[get_byte(1, T3)] ^ EK[4*j+5];
B2 = TE0[get_byte(2, T0)] ^ TE1[get_byte(2, T1)] ^
TE2[get_byte(2, T2)] ^ TE3[get_byte(2, T3)] ^ EK[4*j+6];
B3 = TE0[get_byte(3, T0)] ^ TE1[get_byte(3, T1)] ^
TE2[get_byte(3, T2)] ^ TE3[get_byte(3, T3)] ^ EK[4*j+7];
}
out[ 0] = SE[get_byte(0, B0)] ^ ME[16];
out[ 1] = SE[get_byte(0, B1)] ^ ME[17];
out[ 2] = SE[get_byte(0, B2)] ^ ME[18];
out[ 3] = SE[get_byte(0, B3)] ^ ME[19];
out[ 4] = SE[get_byte(1, B0)] ^ ME[20];
out[ 5] = SE[get_byte(1, B1)] ^ ME[21];
out[ 6] = SE[get_byte(1, B2)] ^ ME[22];
out[ 7] = SE[get_byte(1, B3)] ^ ME[23];
out[ 8] = SE[get_byte(2, B0)] ^ ME[24];
out[ 9] = SE[get_byte(2, B1)] ^ ME[25];
out[10] = SE[get_byte(2, B2)] ^ ME[26];
out[11] = SE[get_byte(2, B3)] ^ ME[27];
out[12] = SE[get_byte(3, B0)] ^ ME[28];
out[13] = SE[get_byte(3, B1)] ^ ME[29];
out[14] = SE[get_byte(3, B2)] ^ ME[30];
out[15] = SE[get_byte(3, B3)] ^ ME[31];
}
/*************************************************
* Square Decryption *
*************************************************/
void Square::dec(const byte in[], byte out[]) const
{
u32bit T0, T1, T2, T3, B0, B1, B2, B3;
B0 = TD0[in[ 0] ^ MD[ 0]] ^ TD1[in[ 4] ^ MD[ 4]] ^
TD2[in[ 8] ^ MD[ 8]] ^ TD3[in[12] ^ MD[12]] ^ DK[0];
B1 = TD0[in[ 1] ^ MD[ 1]] ^ TD1[in[ 5] ^ MD[ 5]] ^
TD2[in[ 9] ^ MD[ 9]] ^ TD3[in[13] ^ MD[13]] ^ DK[1];
B2 = TD0[in[ 2] ^ MD[ 2]] ^ TD1[in[ 6] ^ MD[ 6]] ^
TD2[in[10] ^ MD[10]] ^ TD3[in[14] ^ MD[14]] ^ DK[2];
B3 = TD0[in[ 3] ^ MD[ 3]] ^ TD1[in[ 7] ^ MD[ 7]] ^
TD2[in[11] ^ MD[11]] ^ TD3[in[15] ^ MD[15]] ^ DK[3];
for(u32bit j = 1; j != 7; j += 2)
{
T0 = TD0[get_byte(0, B0)] ^ TD1[get_byte(0, B1)] ^
TD2[get_byte(0, B2)] ^ TD3[get_byte(0, B3)] ^ DK[4*j+0];
T1 = TD0[get_byte(1, B0)] ^ TD1[get_byte(1, B1)] ^
TD2[get_byte(1, B2)] ^ TD3[get_byte(1, B3)] ^ DK[4*j+1];
T2 = TD0[get_byte(2, B0)] ^ TD1[get_byte(2, B1)] ^
TD2[get_byte(2, B2)] ^ TD3[get_byte(2, B3)] ^ DK[4*j+2];
T3 = TD0[get_byte(3, B0)] ^ TD1[get_byte(3, B1)] ^
TD2[get_byte(3, B2)] ^ TD3[get_byte(3, B3)] ^ DK[4*j+3];
B0 = TD0[get_byte(0, T0)] ^ TD1[get_byte(0, T1)] ^
TD2[get_byte(0, T2)] ^ TD3[get_byte(0, T3)] ^ DK[4*j+4];
B1 = TD0[get_byte(1, T0)] ^ TD1[get_byte(1, T1)] ^
TD2[get_byte(1, T2)] ^ TD3[get_byte(1, T3)] ^ DK[4*j+5];
B2 = TD0[get_byte(2, T0)] ^ TD1[get_byte(2, T1)] ^
TD2[get_byte(2, T2)] ^ TD3[get_byte(2, T3)] ^ DK[4*j+6];
B3 = TD0[get_byte(3, T0)] ^ TD1[get_byte(3, T1)] ^
TD2[get_byte(3, T2)] ^ TD3[get_byte(3, T3)] ^ DK[4*j+7];
}
out[ 0] = SD[get_byte(0, B0)] ^ MD[16];
out[ 1] = SD[get_byte(0, B1)] ^ MD[17];
out[ 2] = SD[get_byte(0, B2)] ^ MD[18];
out[ 3] = SD[get_byte(0, B3)] ^ MD[19];
out[ 4] = SD[get_byte(1, B0)] ^ MD[20];
out[ 5] = SD[get_byte(1, B1)] ^ MD[21];
out[ 6] = SD[get_byte(1, B2)] ^ MD[22];
out[ 7] = SD[get_byte(1, B3)] ^ MD[23];
out[ 8] = SD[get_byte(2, B0)] ^ MD[24];
out[ 9] = SD[get_byte(2, B1)] ^ MD[25];
out[10] = SD[get_byte(2, B2)] ^ MD[26];
out[11] = SD[get_byte(2, B3)] ^ MD[27];
out[12] = SD[get_byte(3, B0)] ^ MD[28];
out[13] = SD[get_byte(3, B1)] ^ MD[29];
out[14] = SD[get_byte(3, B2)] ^ MD[30];
out[15] = SD[get_byte(3, B3)] ^ MD[31];
}
/*************************************************
* Square Key Schedule *
*************************************************/
void Square::key(const byte key[], u32bit)
{
SecureBuffer<u32bit, 36> XEK, XDK;
for(u32bit j = 0; j != 4; ++j)
XEK[j] = make_u32bit(key[4*j], key[4*j+1], key[4*j+2], key[4*j+3]);
for(u32bit j = 0; j != 8; ++j)
{
XEK[4*j+4] = XEK[4*j ] ^ rotate_left(XEK[4*j+3], 8) ^ (0x01000000 << j);
XEK[4*j+5] = XEK[4*j+1] ^ XEK[4*j+4];
XEK[4*j+6] = XEK[4*j+2] ^ XEK[4*j+5];
XEK[4*j+7] = XEK[4*j+3] ^ XEK[4*j+6];
XDK.copy(28 - 4*j, XEK + 4*(j+1), 4);
transform(XEK + 4*j);
}
for(u32bit j = 0; j != 4; ++j)
for(u32bit k = 0; k != 4; ++k)
{
ME[4*j+k ] = get_byte(k, XEK[j ]);
ME[4*j+k+16] = get_byte(k, XEK[j+32]);
MD[4*j+k ] = get_byte(k, XDK[j ]);
MD[4*j+k+16] = get_byte(k, XEK[j ]);
}
EK.copy(XEK + 4, 28);
DK.copy(XDK + 4, 28);
}
/*************************************************
* Square's Inverse Linear Transformation *
*************************************************/
void Square::transform(u32bit round_key[4])
{
static const byte G[4][4] = {
{ 0x02, 0x01, 0x01, 0x03 },
{ 0x03, 0x02, 0x01, 0x01 },
{ 0x01, 0x03, 0x02, 0x01 },
{ 0x01, 0x01, 0x03, 0x02 } };
SecureBuffer<byte, 4> A[4], B[4];
for(u32bit j = 0; j != 4; ++j)
for(u32bit k = 0; k != 4; ++k)
A[j][k] = get_byte(k, round_key[j]);
for(u32bit j = 0; j != 4; ++j)
for(u32bit k = 0; k != 4; ++k)
for(u32bit l = 0; l != 4; ++l)
B[j][k] ^= mul(A[j][l], G[l][k]);
for(u32bit j = 0; j != 4; ++j)
round_key[j] = make_u32bit(B[j][0], B[j][1], B[j][2], B[j][3]);
}
/*************************************************
* Multiply in GF(2^8) *
*************************************************/
byte Square::mul(byte a, byte b)
{
if(a && b)
return ALog[(Log[a] + Log[b]) % 255];
else
return 0;
}
/*************************************************
* Clear memory of sensitive data *
*************************************************/
void Square::clear() throw()
{
EK.clear();
DK.clear();
ME.clear();
MD.clear();
}
}
|
