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
|
/*
* SAFER-SK
* (C) 1999-2009 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/safer_sk.h>
#include <botan/rotate.h>
#include <botan/parsing.h>
#include <botan/rotate.h>
namespace Botan {
/*
* SAFER-SK Encryption
*/
void SAFER_SK::encrypt_n(const byte in[], byte out[], size_t blocks) const
{
for(size_t i = 0; i != blocks; ++i)
{
byte A = in[0], B = in[1], C = in[2], D = in[3],
E = in[4], F = in[5], G = in[6], H = in[7], X, Y;
for(size_t j = 0; j != 16*ROUNDS; j += 16)
{
A = EXP[A ^ EK[j ]]; B = LOG[B + EK[j+1]];
C = LOG[C + EK[j+2]]; D = EXP[D ^ EK[j+3]];
E = EXP[E ^ EK[j+4]]; F = LOG[F + EK[j+5]];
G = LOG[G + EK[j+6]]; H = EXP[H ^ EK[j+7]];
A += EK[j+ 8]; B ^= EK[j+ 9]; C ^= EK[j+10]; D += EK[j+11];
E += EK[j+12]; F ^= EK[j+13]; G ^= EK[j+14]; H += EK[j+15];
B += A; D += C; F += E; H += G; A += B; C += D; E += F; G += H;
C += A; G += E; D += B; H += F; A += C; E += G; B += D; F += H;
H += D; Y = D + H; D = B + F; X = B + D; B = A + E;
A += B; F = C + G; E = C + F; C = X; G = Y;
}
out[0] = A ^ EK[16*ROUNDS+0]; out[1] = B + EK[16*ROUNDS+1];
out[2] = C + EK[16*ROUNDS+2]; out[3] = D ^ EK[16*ROUNDS+3];
out[4] = E ^ EK[16*ROUNDS+4]; out[5] = F + EK[16*ROUNDS+5];
out[6] = G + EK[16*ROUNDS+6]; out[7] = H ^ EK[16*ROUNDS+7];
in += BLOCK_SIZE;
out += BLOCK_SIZE;
}
}
/*
* SAFER-SK Decryption
*/
void SAFER_SK::decrypt_n(const byte in[], byte out[], size_t blocks) const
{
for(size_t i = 0; i != blocks; ++i)
{
byte A = in[0], B = in[1], C = in[2], D = in[3],
E = in[4], F = in[5], G = in[6], H = in[7];
A ^= EK[16*ROUNDS+0]; B -= EK[16*ROUNDS+1]; C -= EK[16*ROUNDS+2];
D ^= EK[16*ROUNDS+3]; E ^= EK[16*ROUNDS+4]; F -= EK[16*ROUNDS+5];
G -= EK[16*ROUNDS+6]; H ^= EK[16*ROUNDS+7];
for(s32bit j = 16*(ROUNDS-1); j >= 0; j -= 16)
{
byte T = E; E = B; B = C; C = T; T = F; F = D; D = G; G = T;
A -= E; B -= F; C -= G; D -= H; E -= A; F -= B; G -= C; H -= D;
A -= C; E -= G; B -= D; F -= H; C -= A; G -= E; D -= B; H -= F;
A -= B; C -= D; E -= F; G -= H; B -= A; D -= C; F -= E; H -= G;
A = LOG[A - EK[j+8 ] + 256]; B = EXP[B ^ EK[j+9 ]];
C = EXP[C ^ EK[j+10]]; D = LOG[D - EK[j+11] + 256];
E = LOG[E - EK[j+12] + 256]; F = EXP[F ^ EK[j+13]];
G = EXP[G ^ EK[j+14]]; H = LOG[H - EK[j+15] + 256];
A ^= EK[j+0]; B -= EK[j+1]; C -= EK[j+2]; D ^= EK[j+3];
E ^= EK[j+4]; F -= EK[j+5]; G -= EK[j+6]; H ^= EK[j+7];
}
out[0] = A; out[1] = B; out[2] = C; out[3] = D;
out[4] = E; out[5] = F; out[6] = G; out[7] = H;
in += BLOCK_SIZE;
out += BLOCK_SIZE;
}
}
/*
* SAFER-SK Key Schedule
*/
void SAFER_SK::key_schedule(const byte key[], u32bit)
{
SecureVector<byte> KB(18);
for(size_t i = 0; i != 8; ++i)
{
KB[ 8] ^= KB[i] = rotate_left(key[i], 5);
KB[17] ^= KB[i+9] = EK[i] = key[i+8];
}
for(size_t i = 0; i != ROUNDS; ++i)
{
for(size_t j = 0; j != 18; ++j)
KB[j] = rotate_left(KB[j], 6);
for(size_t j = 0; j != 16; ++j)
EK[16*i+j+8] = KB[KEY_INDEX[16*i+j]] + BIAS[16*i+j];
}
}
/*
* Return the name of this type
*/
std::string SAFER_SK::name() const
{
return "SAFER-SK(" + to_string(ROUNDS) + ")";
}
/*
* Return a clone of this object
*/
BlockCipher* SAFER_SK::clone() const
{
return new SAFER_SK(ROUNDS);
}
/*
* SAFER-SK Constructor
*/
SAFER_SK::SAFER_SK(size_t rounds) : BlockCipher(8, 16),
EK(16 * rounds + 8), ROUNDS(rounds)
{
if(ROUNDS > 13 || ROUNDS == 0)
throw Invalid_Argument(name() + ": Invalid number of rounds");
}
}
|
