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
|
// mars.cpp - originally written and placed in the public domain by Wei Dai
// includes IBM's key setup "tweak" proposed in August 1999 (http://www.research.ibm.com/security/key-setup.txt)
#include "pch.h"
#include "mars.h"
#include "misc.h"
NAMESPACE_BEGIN(CryptoPP)
void MARS::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
{
AssertValidKeyLength(length);
// Initialize T[] with the key data
FixedSizeSecBlock<word32, 15> T;
GetUserKey(LITTLE_ENDIAN_ORDER, T.begin(), 15, userKey, length);
T[length/4] = length/4;
for (unsigned int j=0; j<4; j++) // compute 10 words of K[] in each iteration
{
unsigned int i;
// Do linear transformation
for (i=0; i<15; i++)
T[i] = T[i] ^ rotlConstant<3>(T[(i + 8) % 15] ^ T[(i + 13) % 15]) ^ (4 * i + j);
// Do four rounds of stirring
for (unsigned int k=0; k<4; k++)
for (i=0; i<15; i++)
T[i] = rotlConstant<9>(T[i] + Sbox[T[(i + 14) % 15] % 512]);
// Store next 10 key words into K[]
for (i=0; i<10; i++)
m_k[10*j+i] = T[4*i%15];
}
// Modify multiplication key-words
for(unsigned int i = 5; i < 37; i += 2)
{
word32 m, w = m_k[i] | 3;
m = (~w ^ (w<<1)) & (~w ^ (w>>1)) & 0x7ffffffe;
m &= m>>1; m &= m>>2; m &= m>>4;
m |= m<<1; m |= m<<2; m |= m<<4;
m &= 0x7ffffffc;
w ^= rotlMod(Sbox[265 + (m_k[i] & 3)], m_k[i-1]) & m;
m_k[i] = w;
}
}
#define S(a) Sbox[(a)&0x1ff]
#define S0(a) Sbox[(a)&0xff]
#define S1(a) Sbox[((a)&0xff) + 256]
typedef BlockGetAndPut<word32, LittleEndian> Block;
void MARS::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
unsigned int i;
word32 a, b, c, d, l, m, r, t;
const word32 *k = m_k;
Block::Get(inBlock)(a)(b)(c)(d);
a += k[0]; b += k[1]; c += k[2]; d += k[3];
for (i=0; i<8; i++)
{
b = (b ^ S0(a)) + S1(a>>8);
c += S0(a>>16);
a = rotrConstant<24>(a);
d ^= S1(a);
a += (i%4==0) ? d : 0;
a += (i%4==1) ? b : 0;
t = a; a = b; b = c; c = d; d = t;
}
for (i=0; i<16; i++)
{
t = rotlConstant<13>(a);
r = rotlConstant<10>(t * k[2 * i + 5]);
m = a + k[2*i+4];
l = rotlMod((S(m) ^ rotrConstant<5>(r) ^ r), r);
c += rotlMod(m, rotrConstant<5>(r));
(i<8 ? b : d) += l;
(i<8 ? d : b) ^= r;
a = b; b = c; c = d; d = t;
}
for (i=0; i<8; i++)
{
a -= (i%4==2) ? d : 0;
a -= (i%4==3) ? b : 0;
b ^= S1(a);
c -= S0(a>>24);
t = rotlConstant<24>(a);
d = (d - S1(a>>16)) ^ S0(t);
a = b; b = c; c = d; d = t;
}
a -= k[36]; b -= k[37]; c -= k[38]; d -= k[39];
Block::Put(xorBlock, outBlock)(a)(b)(c)(d);
}
void MARS::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
unsigned int i;
word32 a, b, c, d, l, m, r, t;
const word32 *k = m_k;
Block::Get(inBlock)(d)(c)(b)(a);
d += k[36]; c += k[37]; b += k[38]; a += k[39];
for (i=0; i<8; i++)
{
b = (b ^ S0(a)) + S1(a>>8);
c += S0(a>>16);
a = rotrConstant<24>(a);
d ^= S1(a);
a += (i%4==0) ? d : 0;
a += (i%4==1) ? b : 0;
t = a; a = b; b = c; c = d; d = t;
}
for (i=0; i<16; i++)
{
t = rotrConstant<13>(a);
r = rotlConstant<10>(a * k[35 - 2 * i]);
m = t + k[34-2*i];
l = rotlMod((S(m) ^ rotrConstant<5>(r) ^ r), r);
c -= rotlMod(m, rotrConstant<5>(r));
(i<8 ? b : d) -= l;
(i<8 ? d : b) ^= r;
a = b; b = c; c = d; d = t;
}
for (i=0; i<8; i++)
{
a -= (i%4==2) ? d : 0;
a -= (i%4==3) ? b : 0;
b ^= S1(a);
c -= S0(a>>24);
t = rotlConstant<24>(a);
d = (d - S1(a>>16)) ^ S0(t);
a = b; b = c; c = d; d = t;
}
d -= k[0]; c -= k[1]; b -= k[2]; a -= k[3];
Block::Put(xorBlock, outBlock)(d)(c)(b)(a);
}
NAMESPACE_END
|
