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
|
/*
* RC2
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/rc2.h>
#include <botan/loadstor.h>
#include <botan/rotate.h>
namespace Botan {
/*
* RC2 Encryption
*/
void RC2::encrypt_n(const byte in[], byte out[], size_t blocks) const
{
for(size_t i = 0; i != blocks; ++i)
{
u16bit R0 = load_le<u16bit>(in, 0);
u16bit R1 = load_le<u16bit>(in, 1);
u16bit R2 = load_le<u16bit>(in, 2);
u16bit R3 = load_le<u16bit>(in, 3);
for(size_t j = 0; j != 16; ++j)
{
R0 += (R1 & ~R3) + (R2 & R3) + K[4*j];
R0 = rotate_left(R0, 1);
R1 += (R2 & ~R0) + (R3 & R0) + K[4*j + 1];
R1 = rotate_left(R1, 2);
R2 += (R3 & ~R1) + (R0 & R1) + K[4*j + 2];
R2 = rotate_left(R2, 3);
R3 += (R0 & ~R2) + (R1 & R2) + K[4*j + 3];
R3 = rotate_left(R3, 5);
if(j == 4 || j == 10)
{
R0 += K[R3 % 64];
R1 += K[R0 % 64];
R2 += K[R1 % 64];
R3 += K[R2 % 64];
}
}
store_le(out, R0, R1, R2, R3);
in += BLOCK_SIZE;
out += BLOCK_SIZE;
}
}
/*
* RC2 Decryption
*/
void RC2::decrypt_n(const byte in[], byte out[], size_t blocks) const
{
for(size_t i = 0; i != blocks; ++i)
{
u16bit R0 = load_le<u16bit>(in, 0);
u16bit R1 = load_le<u16bit>(in, 1);
u16bit R2 = load_le<u16bit>(in, 2);
u16bit R3 = load_le<u16bit>(in, 3);
for(size_t j = 0; j != 16; ++j)
{
R3 = rotate_right(R3, 5);
R3 -= (R0 & ~R2) + (R1 & R2) + K[63 - (4*j + 0)];
R2 = rotate_right(R2, 3);
R2 -= (R3 & ~R1) + (R0 & R1) + K[63 - (4*j + 1)];
R1 = rotate_right(R1, 2);
R1 -= (R2 & ~R0) + (R3 & R0) + K[63 - (4*j + 2)];
R0 = rotate_right(R0, 1);
R0 -= (R1 & ~R3) + (R2 & R3) + K[63 - (4*j + 3)];
if(j == 4 || j == 10)
{
R3 -= K[R2 % 64];
R2 -= K[R1 % 64];
R1 -= K[R0 % 64];
R0 -= K[R3 % 64];
}
}
store_le(out, R0, R1, R2, R3);
in += BLOCK_SIZE;
out += BLOCK_SIZE;
}
}
/*
* RC2 Key Schedule
*/
void RC2::key_schedule(const byte key[], size_t length)
{
static const byte TABLE[256] = {
0xD9, 0x78, 0xF9, 0xC4, 0x19, 0xDD, 0xB5, 0xED, 0x28, 0xE9, 0xFD, 0x79,
0x4A, 0xA0, 0xD8, 0x9D, 0xC6, 0x7E, 0x37, 0x83, 0x2B, 0x76, 0x53, 0x8E,
0x62, 0x4C, 0x64, 0x88, 0x44, 0x8B, 0xFB, 0xA2, 0x17, 0x9A, 0x59, 0xF5,
0x87, 0xB3, 0x4F, 0x13, 0x61, 0x45, 0x6D, 0x8D, 0x09, 0x81, 0x7D, 0x32,
0xBD, 0x8F, 0x40, 0xEB, 0x86, 0xB7, 0x7B, 0x0B, 0xF0, 0x95, 0x21, 0x22,
0x5C, 0x6B, 0x4E, 0x82, 0x54, 0xD6, 0x65, 0x93, 0xCE, 0x60, 0xB2, 0x1C,
0x73, 0x56, 0xC0, 0x14, 0xA7, 0x8C, 0xF1, 0xDC, 0x12, 0x75, 0xCA, 0x1F,
0x3B, 0xBE, 0xE4, 0xD1, 0x42, 0x3D, 0xD4, 0x30, 0xA3, 0x3C, 0xB6, 0x26,
0x6F, 0xBF, 0x0E, 0xDA, 0x46, 0x69, 0x07, 0x57, 0x27, 0xF2, 0x1D, 0x9B,
0xBC, 0x94, 0x43, 0x03, 0xF8, 0x11, 0xC7, 0xF6, 0x90, 0xEF, 0x3E, 0xE7,
0x06, 0xC3, 0xD5, 0x2F, 0xC8, 0x66, 0x1E, 0xD7, 0x08, 0xE8, 0xEA, 0xDE,
0x80, 0x52, 0xEE, 0xF7, 0x84, 0xAA, 0x72, 0xAC, 0x35, 0x4D, 0x6A, 0x2A,
0x96, 0x1A, 0xD2, 0x71, 0x5A, 0x15, 0x49, 0x74, 0x4B, 0x9F, 0xD0, 0x5E,
0x04, 0x18, 0xA4, 0xEC, 0xC2, 0xE0, 0x41, 0x6E, 0x0F, 0x51, 0xCB, 0xCC,
0x24, 0x91, 0xAF, 0x50, 0xA1, 0xF4, 0x70, 0x39, 0x99, 0x7C, 0x3A, 0x85,
0x23, 0xB8, 0xB4, 0x7A, 0xFC, 0x02, 0x36, 0x5B, 0x25, 0x55, 0x97, 0x31,
0x2D, 0x5D, 0xFA, 0x98, 0xE3, 0x8A, 0x92, 0xAE, 0x05, 0xDF, 0x29, 0x10,
0x67, 0x6C, 0xBA, 0xC9, 0xD3, 0x00, 0xE6, 0xCF, 0xE1, 0x9E, 0xA8, 0x2C,
0x63, 0x16, 0x01, 0x3F, 0x58, 0xE2, 0x89, 0xA9, 0x0D, 0x38, 0x34, 0x1B,
0xAB, 0x33, 0xFF, 0xB0, 0xBB, 0x48, 0x0C, 0x5F, 0xB9, 0xB1, 0xCD, 0x2E,
0xC5, 0xF3, 0xDB, 0x47, 0xE5, 0xA5, 0x9C, 0x77, 0x0A, 0xA6, 0x20, 0x68,
0xFE, 0x7F, 0xC1, 0xAD };
secure_vector<byte> L(128);
copy_mem(&L[0], key, length);
for(size_t i = length; i != 128; ++i)
L[i] = TABLE[(L[i-1] + L[i-length]) % 256];
L[128-length] = TABLE[L[128-length]];
for(s32bit i = 127-length; i >= 0; --i)
L[i] = TABLE[L[i+1] ^ L[i+length]];
K.resize(64);
load_le<u16bit>(&K[0], &L[0], 64);
}
/*
* Return the code of the effective key bits
*/
byte RC2::EKB_code(size_t ekb)
{
const byte EKB[256] = {
0xBD, 0x56, 0xEA, 0xF2, 0xA2, 0xF1, 0xAC, 0x2A, 0xB0, 0x93, 0xD1, 0x9C,
0x1B, 0x33, 0xFD, 0xD0, 0x30, 0x04, 0xB6, 0xDC, 0x7D, 0xDF, 0x32, 0x4B,
0xF7, 0xCB, 0x45, 0x9B, 0x31, 0xBB, 0x21, 0x5A, 0x41, 0x9F, 0xE1, 0xD9,
0x4A, 0x4D, 0x9E, 0xDA, 0xA0, 0x68, 0x2C, 0xC3, 0x27, 0x5F, 0x80, 0x36,
0x3E, 0xEE, 0xFB, 0x95, 0x1A, 0xFE, 0xCE, 0xA8, 0x34, 0xA9, 0x13, 0xF0,
0xA6, 0x3F, 0xD8, 0x0C, 0x78, 0x24, 0xAF, 0x23, 0x52, 0xC1, 0x67, 0x17,
0xF5, 0x66, 0x90, 0xE7, 0xE8, 0x07, 0xB8, 0x60, 0x48, 0xE6, 0x1E, 0x53,
0xF3, 0x92, 0xA4, 0x72, 0x8C, 0x08, 0x15, 0x6E, 0x86, 0x00, 0x84, 0xFA,
0xF4, 0x7F, 0x8A, 0x42, 0x19, 0xF6, 0xDB, 0xCD, 0x14, 0x8D, 0x50, 0x12,
0xBA, 0x3C, 0x06, 0x4E, 0xEC, 0xB3, 0x35, 0x11, 0xA1, 0x88, 0x8E, 0x2B,
0x94, 0x99, 0xB7, 0x71, 0x74, 0xD3, 0xE4, 0xBF, 0x3A, 0xDE, 0x96, 0x0E,
0xBC, 0x0A, 0xED, 0x77, 0xFC, 0x37, 0x6B, 0x03, 0x79, 0x89, 0x62, 0xC6,
0xD7, 0xC0, 0xD2, 0x7C, 0x6A, 0x8B, 0x22, 0xA3, 0x5B, 0x05, 0x5D, 0x02,
0x75, 0xD5, 0x61, 0xE3, 0x18, 0x8F, 0x55, 0x51, 0xAD, 0x1F, 0x0B, 0x5E,
0x85, 0xE5, 0xC2, 0x57, 0x63, 0xCA, 0x3D, 0x6C, 0xB4, 0xC5, 0xCC, 0x70,
0xB2, 0x91, 0x59, 0x0D, 0x47, 0x20, 0xC8, 0x4F, 0x58, 0xE0, 0x01, 0xE2,
0x16, 0x38, 0xC4, 0x6F, 0x3B, 0x0F, 0x65, 0x46, 0xBE, 0x7E, 0x2D, 0x7B,
0x82, 0xF9, 0x40, 0xB5, 0x1D, 0x73, 0xF8, 0xEB, 0x26, 0xC7, 0x87, 0x97,
0x25, 0x54, 0xB1, 0x28, 0xAA, 0x98, 0x9D, 0xA5, 0x64, 0x6D, 0x7A, 0xD4,
0x10, 0x81, 0x44, 0xEF, 0x49, 0xD6, 0xAE, 0x2E, 0xDD, 0x76, 0x5C, 0x2F,
0xA7, 0x1C, 0xC9, 0x09, 0x69, 0x9A, 0x83, 0xCF, 0x29, 0x39, 0xB9, 0xE9,
0x4C, 0xFF, 0x43, 0xAB };
if(ekb < 256)
return EKB[ekb];
else
throw Encoding_Error("RC2::EKB_code: EKB is too large");
}
}
|
