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
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
|
/*********************************************************************
* Filename: des.c
* Author: Brad Conte (brad AT radconte.com)
* Copyright:
* Disclaimer: This code is presented "as is" without any guarantees.
* Details: Implementation of the DES encryption algorithm.
Modes of operation (such as CBC) are not included.
The formal NIST algorithm specification can be found here:
* http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf
*********************************************************************/
/*************************** HEADER FILES ***************************/
#include <stdlib.h>
#include <memory.h>
#include "des.h"
/****************************** MACROS ******************************/
// Obtain bit "b" from the left and shift it "c" places from the right
#define BITNUM(a,b,c) (((a[(b)/8] >> (7 - (b%8))) & 0x01) << (c))
#define BITNUMINTR(a,b,c) ((((a) >> (31 - (b))) & 0x00000001) << (c))
#define BITNUMINTL(a,b,c) ((((a) << (b)) & 0x80000000) >> (c))
// This macro converts a 6 bit block with the S-Box row defined as the first and last
// bits to a 6 bit block with the row defined by the first two bits.
#define SBOXBIT(a) (((a) & 0x20) | (((a) & 0x1f) >> 1) | (((a) & 0x01) << 4))
/**************************** VARIABLES *****************************/
static const BYTE sbox1[64] = {
14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13
};
static const BYTE sbox2[64] = {
15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9
};
static const BYTE sbox3[64] = {
10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12
};
static const BYTE sbox4[64] = {
7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14
};
static const BYTE sbox5[64] = {
2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3
};
static const BYTE sbox6[64] = {
12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13
};
static const BYTE sbox7[64] = {
4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12
};
static const BYTE sbox8[64] = {
13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11
};
/*********************** FUNCTION DEFINITIONS ***********************/
// Initial (Inv)Permutation step
void IP(WORD state[], const BYTE in[])
{
state[0] = BITNUM(in,57,31) | BITNUM(in,49,30) | BITNUM(in,41,29) | BITNUM(in,33,28) |
BITNUM(in,25,27) | BITNUM(in,17,26) | BITNUM(in,9,25) | BITNUM(in,1,24) |
BITNUM(in,59,23) | BITNUM(in,51,22) | BITNUM(in,43,21) | BITNUM(in,35,20) |
BITNUM(in,27,19) | BITNUM(in,19,18) | BITNUM(in,11,17) | BITNUM(in,3,16) |
BITNUM(in,61,15) | BITNUM(in,53,14) | BITNUM(in,45,13) | BITNUM(in,37,12) |
BITNUM(in,29,11) | BITNUM(in,21,10) | BITNUM(in,13,9) | BITNUM(in,5,8) |
BITNUM(in,63,7) | BITNUM(in,55,6) | BITNUM(in,47,5) | BITNUM(in,39,4) |
BITNUM(in,31,3) | BITNUM(in,23,2) | BITNUM(in,15,1) | BITNUM(in,7,0);
state[1] = BITNUM(in,56,31) | BITNUM(in,48,30) | BITNUM(in,40,29) | BITNUM(in,32,28) |
BITNUM(in,24,27) | BITNUM(in,16,26) | BITNUM(in,8,25) | BITNUM(in,0,24) |
BITNUM(in,58,23) | BITNUM(in,50,22) | BITNUM(in,42,21) | BITNUM(in,34,20) |
BITNUM(in,26,19) | BITNUM(in,18,18) | BITNUM(in,10,17) | BITNUM(in,2,16) |
BITNUM(in,60,15) | BITNUM(in,52,14) | BITNUM(in,44,13) | BITNUM(in,36,12) |
BITNUM(in,28,11) | BITNUM(in,20,10) | BITNUM(in,12,9) | BITNUM(in,4,8) |
BITNUM(in,62,7) | BITNUM(in,54,6) | BITNUM(in,46,5) | BITNUM(in,38,4) |
BITNUM(in,30,3) | BITNUM(in,22,2) | BITNUM(in,14,1) | BITNUM(in,6,0);
}
void InvIP(WORD state[], BYTE in[])
{
in[0] = BITNUMINTR(state[1],7,7) | BITNUMINTR(state[0],7,6) | BITNUMINTR(state[1],15,5) |
BITNUMINTR(state[0],15,4) | BITNUMINTR(state[1],23,3) | BITNUMINTR(state[0],23,2) |
BITNUMINTR(state[1],31,1) | BITNUMINTR(state[0],31,0);
in[1] = BITNUMINTR(state[1],6,7) | BITNUMINTR(state[0],6,6) | BITNUMINTR(state[1],14,5) |
BITNUMINTR(state[0],14,4) | BITNUMINTR(state[1],22,3) | BITNUMINTR(state[0],22,2) |
BITNUMINTR(state[1],30,1) | BITNUMINTR(state[0],30,0);
in[2] = BITNUMINTR(state[1],5,7) | BITNUMINTR(state[0],5,6) | BITNUMINTR(state[1],13,5) |
BITNUMINTR(state[0],13,4) | BITNUMINTR(state[1],21,3) | BITNUMINTR(state[0],21,2) |
BITNUMINTR(state[1],29,1) | BITNUMINTR(state[0],29,0);
in[3] = BITNUMINTR(state[1],4,7) | BITNUMINTR(state[0],4,6) | BITNUMINTR(state[1],12,5) |
BITNUMINTR(state[0],12,4) | BITNUMINTR(state[1],20,3) | BITNUMINTR(state[0],20,2) |
BITNUMINTR(state[1],28,1) | BITNUMINTR(state[0],28,0);
in[4] = BITNUMINTR(state[1],3,7) | BITNUMINTR(state[0],3,6) | BITNUMINTR(state[1],11,5) |
BITNUMINTR(state[0],11,4) | BITNUMINTR(state[1],19,3) | BITNUMINTR(state[0],19,2) |
BITNUMINTR(state[1],27,1) | BITNUMINTR(state[0],27,0);
in[5] = BITNUMINTR(state[1],2,7) | BITNUMINTR(state[0],2,6) | BITNUMINTR(state[1],10,5) |
BITNUMINTR(state[0],10,4) | BITNUMINTR(state[1],18,3) | BITNUMINTR(state[0],18,2) |
BITNUMINTR(state[1],26,1) | BITNUMINTR(state[0],26,0);
in[6] = BITNUMINTR(state[1],1,7) | BITNUMINTR(state[0],1,6) | BITNUMINTR(state[1],9,5) |
BITNUMINTR(state[0],9,4) | BITNUMINTR(state[1],17,3) | BITNUMINTR(state[0],17,2) |
BITNUMINTR(state[1],25,1) | BITNUMINTR(state[0],25,0);
in[7] = BITNUMINTR(state[1],0,7) | BITNUMINTR(state[0],0,6) | BITNUMINTR(state[1],8,5) |
BITNUMINTR(state[0],8,4) | BITNUMINTR(state[1],16,3) | BITNUMINTR(state[0],16,2) |
BITNUMINTR(state[1],24,1) | BITNUMINTR(state[0],24,0);
}
WORD f(WORD state, const BYTE key[])
{
BYTE lrgstate[6]; //,i;
WORD t1,t2;
// Expantion Permutation
t1 = BITNUMINTL(state,31,0) | ((state & 0xf0000000) >> 1) | BITNUMINTL(state,4,5) |
BITNUMINTL(state,3,6) | ((state & 0x0f000000) >> 3) | BITNUMINTL(state,8,11) |
BITNUMINTL(state,7,12) | ((state & 0x00f00000) >> 5) | BITNUMINTL(state,12,17) |
BITNUMINTL(state,11,18) | ((state & 0x000f0000) >> 7) | BITNUMINTL(state,16,23);
t2 = BITNUMINTL(state,15,0) | ((state & 0x0000f000) << 15) | BITNUMINTL(state,20,5) |
BITNUMINTL(state,19,6) | ((state & 0x00000f00) << 13) | BITNUMINTL(state,24,11) |
BITNUMINTL(state,23,12) | ((state & 0x000000f0) << 11) | BITNUMINTL(state,28,17) |
BITNUMINTL(state,27,18) | ((state & 0x0000000f) << 9) | BITNUMINTL(state,0,23);
lrgstate[0] = (t1 >> 24) & 0x000000ff;
lrgstate[1] = (t1 >> 16) & 0x000000ff;
lrgstate[2] = (t1 >> 8) & 0x000000ff;
lrgstate[3] = (t2 >> 24) & 0x000000ff;
lrgstate[4] = (t2 >> 16) & 0x000000ff;
lrgstate[5] = (t2 >> 8) & 0x000000ff;
// Key XOR
lrgstate[0] ^= key[0];
lrgstate[1] ^= key[1];
lrgstate[2] ^= key[2];
lrgstate[3] ^= key[3];
lrgstate[4] ^= key[4];
lrgstate[5] ^= key[5];
// S-Box Permutation
state = (sbox1[SBOXBIT(lrgstate[0] >> 2)] << 28) |
(sbox2[SBOXBIT(((lrgstate[0] & 0x03) << 4) | (lrgstate[1] >> 4))] << 24) |
(sbox3[SBOXBIT(((lrgstate[1] & 0x0f) << 2) | (lrgstate[2] >> 6))] << 20) |
(sbox4[SBOXBIT(lrgstate[2] & 0x3f)] << 16) |
(sbox5[SBOXBIT(lrgstate[3] >> 2)] << 12) |
(sbox6[SBOXBIT(((lrgstate[3] & 0x03) << 4) | (lrgstate[4] >> 4))] << 8) |
(sbox7[SBOXBIT(((lrgstate[4] & 0x0f) << 2) | (lrgstate[5] >> 6))] << 4) |
sbox8[SBOXBIT(lrgstate[5] & 0x3f)];
// P-Box Permutation
state = BITNUMINTL(state,15,0) | BITNUMINTL(state,6,1) | BITNUMINTL(state,19,2) |
BITNUMINTL(state,20,3) | BITNUMINTL(state,28,4) | BITNUMINTL(state,11,5) |
BITNUMINTL(state,27,6) | BITNUMINTL(state,16,7) | BITNUMINTL(state,0,8) |
BITNUMINTL(state,14,9) | BITNUMINTL(state,22,10) | BITNUMINTL(state,25,11) |
BITNUMINTL(state,4,12) | BITNUMINTL(state,17,13) | BITNUMINTL(state,30,14) |
BITNUMINTL(state,9,15) | BITNUMINTL(state,1,16) | BITNUMINTL(state,7,17) |
BITNUMINTL(state,23,18) | BITNUMINTL(state,13,19) | BITNUMINTL(state,31,20) |
BITNUMINTL(state,26,21) | BITNUMINTL(state,2,22) | BITNUMINTL(state,8,23) |
BITNUMINTL(state,18,24) | BITNUMINTL(state,12,25) | BITNUMINTL(state,29,26) |
BITNUMINTL(state,5,27) | BITNUMINTL(state,21,28) | BITNUMINTL(state,10,29) |
BITNUMINTL(state,3,30) | BITNUMINTL(state,24,31);
// Return the final state value
return(state);
}
void des_key_setup(const BYTE key[], BYTE schedule[][6], DES_MODE mode)
{
WORD i, j, to_gen, C, D;
const WORD key_rnd_shift[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
const WORD key_perm_c[28] = {56,48,40,32,24,16,8,0,57,49,41,33,25,17,
9,1,58,50,42,34,26,18,10,2,59,51,43,35};
const WORD key_perm_d[28] = {62,54,46,38,30,22,14,6,61,53,45,37,29,21,
13,5,60,52,44,36,28,20,12,4,27,19,11,3};
const WORD key_compression[48] = {13,16,10,23,0,4,2,27,14,5,20,9,
22,18,11,3,25,7,15,6,26,19,12,1,
40,51,30,36,46,54,29,39,50,44,32,47,
43,48,38,55,33,52,45,41,49,35,28,31};
// Permutated Choice #1 (copy the key in, ignoring parity bits).
for (i = 0, j = 31, C = 0; i < 28; ++i, --j)
C |= BITNUM(key,key_perm_c[i],j);
for (i = 0, j = 31, D = 0; i < 28; ++i, --j)
D |= BITNUM(key,key_perm_d[i],j);
// Generate the 16 subkeys.
for (i = 0; i < 16; ++i) {
C = ((C << key_rnd_shift[i]) | (C >> (28-key_rnd_shift[i]))) & 0xfffffff0;
D = ((D << key_rnd_shift[i]) | (D >> (28-key_rnd_shift[i]))) & 0xfffffff0;
// Decryption subkeys are reverse order of encryption subkeys so
// generate them in reverse if the key schedule is for decryption useage.
if (mode == DES_DECRYPT)
to_gen = 15 - i;
else /*(if mode == DES_ENCRYPT)*/
to_gen = i;
// Initialize the array
for (j = 0; j < 6; ++j)
schedule[to_gen][j] = 0;
for (j = 0; j < 24; ++j)
schedule[to_gen][j/8] |= BITNUMINTR(C,key_compression[j],7 - (j%8));
for ( ; j < 48; ++j)
schedule[to_gen][j/8] |= BITNUMINTR(D,key_compression[j] - 28,7 - (j%8));
}
}
void des_crypt(const BYTE in[], BYTE out[], const BYTE key[][6])
{
WORD state[2],idx,t;
IP(state,in);
for (idx=0; idx < 15; ++idx) {
t = state[1];
state[1] = f(state[1],key[idx]) ^ state[0];
state[0] = t;
}
// Perform the final loop manually as it doesn't switch sides
state[0] = f(state[1],key[15]) ^ state[0];
InvIP(state,out);
}
void three_des_key_setup(const BYTE key[], BYTE schedule[][16][6], DES_MODE mode)
{
if (mode == DES_ENCRYPT) {
des_key_setup(&key[0],schedule[0],mode);
des_key_setup(&key[8],schedule[1],!mode);
des_key_setup(&key[16],schedule[2],mode);
}
else /*if (mode == DES_DECRYPT*/ {
des_key_setup(&key[16],schedule[0],mode);
des_key_setup(&key[8],schedule[1],!mode);
des_key_setup(&key[0],schedule[2],mode);
}
}
void three_des_crypt(const BYTE in[], BYTE out[], const BYTE key[][16][6])
{
des_crypt(in,out,key[0]);
des_crypt(out,out,key[1]);
des_crypt(out,out,key[2]);
}
|
