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
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
/* C implementation of RC2 encryption algorithm, as described in RFC2268 */
/* By Matthew Palmer <mjp16@uow.edu.au> */
/* $Id$ */
#include "krc2.h"
unsigned char _rc2_pitable[] = { 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 };
unsigned char _rc2_expkey[128]; /* Expanded Key */
int _rc2_counter; /* global integer variable used in mixing */
int _rc2_s[] = {1, 2, 3, 5};
Krc2::Krc2()
{
}
Krc2::~Krc2()
{
}
void Krc2::rc2_expandkey(char key[], int length, int ekl)
{
int ekl8, keymask, i;
/* Put supplied key into first length - 1 bytes of the key buffer */
for (i = 0; i < length; i++) {
_rc2_expkey[i] = key[i];
}
ekl8 = (ekl + 7) / 8;
i = _rc2_pow(2, (8 + ekl - 8 * ekl8));
keymask = 255 % i;
/* First expansion step */
for (i = length; i < 128; i++) {
_rc2_expkey[i] = _rc2_pitable[(_rc2_expkey[i - 1] + _rc2_expkey[i - length]) % 256];
}
/* Expansion intermediate step */
_rc2_expkey[128 - ekl8] = _rc2_pitable[_rc2_expkey[128 - ekl8] & keymask];
/* Third Expansion step */
for (i = 127 - ekl8; i >= 0; i--) {
_rc2_expkey[i] = _rc2_pitable[_rc2_expkey[i + 1] ^ _rc2_expkey[i + ekl8]];
}
}
void Krc2::rc2_encrypt(unsigned short input[4])
{
int i;
_rc2_counter = 0;
for (i = 0; i < 5; i++) {
_rc2_mix(input);
}
_rc2_mash(input);
for (i = 0; i < 6; i++) {
_rc2_mix(input);
}
_rc2_mash(input);
for (i = 0; i < 5; i++) {
_rc2_mix(input);
}
}
void Krc2::_rc2_mix(unsigned short input[])
{
unsigned short K, i;
for (i = 0; i < 4; i++) {
K = _rc2_expkey[_rc2_counter * 2] + 256 * _rc2_expkey[_rc2_counter * 2 + 1];
input[i] = input[i] + K + (input[(i + 3) % 4] & input[(i + 2) % 4]) + ((~input[(i + 3) % 4]) & input[(i + 1) % 4]);
_rc2_counter++;
input[i] = _rc2_rol(input[i], _rc2_s[i]);
}
}
void Krc2::_rc2_mash(unsigned short input[])
{
unsigned short K, i, x;
for (i = 0; i < 4; i++) {
x = input[(i + 3) % 4] & 63;
K = _rc2_expkey[2 * x] + 256 * _rc2_expkey[2 * x + 1];
input[i] = input[i] + K;
}
}
void Krc2::rc2_decrypt(unsigned short input[4])
{
int i;
_rc2_counter = 63;
for (i = 0; i < 5; i++) {
_rc2_rmix(input);
}
_rc2_rmash(input);
for (i = 0; i < 6; i++) {
_rc2_rmix(input);
}
_rc2_rmash(input);
for (i = 0; i < 5; i++) {
_rc2_rmix(input);
}
}
void Krc2::_rc2_rmix(unsigned short input[])
{
unsigned short K;
int i;
for (i = 3; i >= 0; i--) {
input[i] = _rc2_ror(input[i], _rc2_s[i]);
K = _rc2_expkey[_rc2_counter * 2] + 256 * _rc2_expkey[_rc2_counter * 2 + 1];
input[i] = input[i] - K - (input[(i + 3) % 4] & input[(i + 2) % 4]) - ((~input[(i + 3) % 4]) & input[(i + 1) % 4]);
_rc2_counter--;
}
}
void Krc2::_rc2_rmash(unsigned short input[])
{
unsigned short K, x;
int i;
for (i = 3; i >= 0; i--) {
x = input[(i + 3) % 4] & 63;
K = _rc2_expkey[2 * x] + 256 * _rc2_expkey[2 * x + 1];
input[i] = input[i] - K;
}
}
int Krc2::_rc2_pow(int base, int exponent)
{
int i, result;
if (exponent == 0) {
return 1;
}
result = 1;
for (i = 0; i < exponent; i++) {
result = result * base;
}
return result;
}
unsigned short Krc2::_rc2_rol(unsigned short input, int places)
{
unsigned short temp, i;
for (i = 0; i < places; i++) {
temp = input & 0x8000;
input = input << 1;
if (temp) {
input++;
}
}
return input;
}
unsigned short Krc2::_rc2_ror(unsigned short input, int places)
{
unsigned short temp, i;
for (i = 0; i < places; i++) {
temp = input & 0x1;
input = input >> 1;
if (temp) {
input = input + 0x8000;
}
}
return input;
}
|
