/* Sofware DES functions
* written 12 Dec 1986 by Phil Karn, KA9Q; large sections adapted from
* the 1977 public-domain program by Jim Gillogly
*/
#define NULL 0
#if defined(_M_I86) || defined(WIN32)
#define LITTLE_ENDIAN
#include <stdlib.h>
#endif
#ifdef WIN32
#define CONSTANT_DATA
#else
#define CONSTANT_DATA __based(__segname("_CODE"))
#endif
//#define register
//#define int short
//#define PERMUTATION
/* Tables defined in the Data Encryption Standard documents */
#ifdef PERMUTATION
/* initial permutation IP */
static char CONSTANT_DATA ip[] = {
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6,
64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7
};
/* final permutation IP^-1 */
static char CONSTANT_DATA fp[] = {
40, 8, 48, 16, 56, 24, 64, 32,
39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30,
37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28,
35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25
};
#endif
/* expansion operation matrix
* This is for reference only; it is unused in the code
* as the f() function performs it implicitly for speed
*/
#ifdef notdef
static char ei[] = {
32, 1, 2, 3, 4, 5,
4, 5, 6, 7, 8, 9,
8, 9, 10, 11, 12, 13,
12, 13, 14, 15, 16, 17,
16, 17, 18, 19, 20, 21,
20, 21, 22, 23, 24, 25,
24, 25, 26, 27, 28, 29,
28, 29, 30, 31, 32, 1
};
#endif
/* permuted choice table (key) */
static char CONSTANT_DATA pc1[] = {
57, 49, 41, 33, 25, 17, 9,
1, 58, 50, 42, 34, 26, 18,
10, 2, 59, 51, 43, 35, 27,
19, 11, 3, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15,
7, 62, 54, 46, 38, 30, 22,
14, 6, 61, 53, 45, 37, 29,
21, 13, 5, 28, 20, 12, 4
};
/* number left rotations of pc1 */
static char CONSTANT_DATA totrot[] = {
1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28
};
/* permuted choice key (table) */
static char CONSTANT_DATA pc2[] = {
14, 17, 11, 24, 1, 5,
3, 28, 15, 6, 21, 10,
23, 19, 12, 4, 26, 8,
16, 7, 27, 20, 13, 2,
41, 52, 31, 37, 47, 55,
30, 40, 51, 45, 33, 48,
44, 49, 39, 56, 34, 53,
46, 42, 50, 36, 29, 32
};
/* The (in)famous S-boxes */
static char CONSTANT_DATA si[8][64] = {
/* S1 */
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,
/* S2 */
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,
/* S3 */
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,
/* S4 */
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,
/* S5 */
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,
/* S6 */
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,
/* S7 */
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,
/* S8 */
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
};
/* 32-bit permutation function P used on the output of the S-boxes */
static char CONSTANT_DATA p32i[] = {
16, 7, 20, 21,
29, 12, 28, 17,
1, 15, 23, 26,
5, 18, 31, 10,
2, 8, 24, 14,
32, 27, 3, 9,
19, 13, 30, 6,
22, 11, 4, 25
};
/* End of DES-defined tables */
/* Lookup tables initialized once only at startup by desinit() */
static long (*sp_)[64]; /* Combined S and P boxes */
#ifdef PERMUTATION
static char CONSTANT_DATA (*iperm)[16][8]; /* Initial and final permutations */
static char (*fperm)[16][8];
#else
#define iperm 0
#define fperm 0
#endif
/* 8 6-bit subkeys for each of 16 rounds, initialized by setkey() */
static unsigned char (*kn)[8];
/* bit 0 is left-most in byte */
static int CONSTANT_DATA bytebit[] = {
0200,0100,040,020,010,04,02,01
};
static int CONSTANT_DATA nibblebit[] = {
010,04,02,01
};
static int desmode;
#ifdef LITTLE_ENDIAN
/* Byte swap a long */
static unsigned long byteswap(unsigned long x)
{
register char *cp,tmp;
cp = (char *)&x;
tmp = cp[3];
cp[3] = cp[0];
cp[0] = tmp;
tmp = cp[2];
cp[2] = cp[1];
cp[1] = tmp;
return x;
}
#endif
#ifdef PERMUTATION
/* initialize a perm array */
static void perminit(char perm[16][16][8],char p[64])
//char perm[16][16][8]; /* 64-bit, either init or final */
//char p[64];
{
register int l, j, k;
int i,m;
/* Clear the permutation array */
for (i=0; i<16; i++)
for (j=0; j<16; j++)
for (k=0; k<8; k++)
perm[i][j][k]=0;
for (i=0; i<16; i++) /* each input nibble position */
for (j = 0; j < 16; j++)/* each possible input nibble */
for (k = 0; k < 64; k++)/* each output bit position */
{ l = p[k] - 1; /* where does this bit come from*/
if ((l >> 2) != i) /* does it come from input posn?*/
continue; /* if not, bit k is 0 */
if (!(j & nibblebit[l & 3]))
continue; /* any such bit in input? */
m = k & 07; /* which bit is this in the byte*/
perm[i][j][k>>3] |= bytebit[m];
}
}
#endif
/* Initialize the lookup table for the combined S and P boxes */
static void spinit()
{
char pbox[32];
int p,i,s,j,rowcol;
long val;
/* Compute pbox, the inverse of p32i.
* This is easier to work with
*/
for(p=0;p<32;p++){
for(i=0;i<32;i++){
if(p32i[i]-1 == p){
pbox[p] = i;
break;
}
}
}
for(s = 0; s < 8; s++){ /* For each S-box */
for(i=0; i<64; i++){ /* For each possible input */
val = 0;
/* The row number is formed from the first and last
* bits; the column number is from the middle 4
*/
rowcol = (i & 32) | ((i & 1) ? 16 : 0) | ((i >> 1) & 0xf);
for(j=0;j<4;j++){ /* For each output bit */
if(si[s][rowcol] & (8 >> j)){
val |= 1L << (31 - pbox[4*s + j]);
}
}
sp_[s][i] = val;
#ifdef DEBUG
printf("sp_[%d][%2d] = %08lx\n",s,i,sp_[s][i]);
#endif
}
}
}
/* Allocate space and initialize DES lookup arrays
* mode == 0: standard Data Encryption Algorithm
* mode == 1: DEA without initial and final permutations for speed
* mode == 2: DEA without permutations and with 128-byte key (completely
* independent subkeys for each round)
*/
int desinit(int mode)
{
if(sp_ != NULL){
/* Already initialized */
return 0;
}
desmode = mode;
if((sp_