sdes.cpp

来自「各种加密算法的源代码」· C++ 代码 · 共 51 行

#include <dos.h>
#include <stdio.h>
#include <stdlib.h>
#include <graphics.h>
#include <string.h>

/* initial permutation IP */
static byte ip[] = {
       2, 6, 3, 1, 4, 8, 5,  7
};

/* final permutation IP^-1 */
static byte fp[] = {
       4,  1, 3, 5, 7, 2, 8, 6
};
/* expansion operation matrix */
static byte ei[] = {
       4,  1,  2,  3,  2,  3, 4, 1
};
/* The (in)famous S-boxes */
static byte sbox[2][16] = {
       /* S1 */
       1, 0, 3,  2,  3, 2, 1, 0,  0, 2, 1, 3, 3, 1, 3, 2,

       /* S2 */
       0, 1, 2,  3,  2, 0, 1, 3,  3, 0, 1, 0, 2, 1, 0, 3
};

/* 32-bit permutation function P used on the output of the S-boxes */
static byte p32i[] = {
       2,  4, 3, 1
};
#endif

/* permuted choice table (key) */
static const byte pc1[] = {
       3, 5,2,7,4,10,1,9,8,6
};

/* number left rotations of pc1 */
static const byte totrot[] = {
       1,2
};

/* permuted choice key (table) */
static const byte pc2[] = {
       6,3,7,4,8,5,10,9
};

/* End of DES-defined tables */