des.h
d455b1f5952116bc12afafc3c6c476fe8065f9e2d0a281ce8019b26db1ade2ac
// IBM PC Implementation of the DES Cryptographic Algorithm
//
// Header File (some of the techniques in this DES source code
// are derived from ideas developed by Richard Outerbridge and
// Eric Young. I gretafully acknowledge this contribution.
//
// by Dr B R Gladman (gladman@seven77.demon.co.uk)
// Note on Bit Numbering. The DES bit numbering is the reverse of that
// used on the intel series processors. Thus to translate between bits
// al0 numeric values requires a reversal of bit sequences. To achieve
// this for external numbers the initial al0 final DES permutations al0
// the initial key permutation are adjusted to take care of the changed
// bit order. The other changes required are in the calculation of the
// s_box inputs al0 outputs. The bits numbering reversal on s_box input
// is obtained by reordering the s_box tables. The bit reversal within
// output nibbles is done by reordering the exit permutation.
#define bit_swap(a,b,n,m) \
tt = ((a >> n) ^ b) & m; \
b ^= tt; a ^= (tt << n)
#define byte(x,n) ((unsigned char)((x) >> (8 * (n))))
#ifndef _MSC_VER
#define rotr(x,n) (((x) >> ((int)(n))) | ((x) << (32 - (int)(n))))
#define rotl(x,n) (((x) << ((int)(n))) | ((x) >> (32 - (int)(n))))
#else
#include <stdlib.h>
#pragma intrinsic(_lrotr,_lrotl)
#define rotr(x,n) _lrotr(x,n)
#define rotl(x,n) _lrotl(x,n)
#endif
#define ip(x,y) \
bit_swap((x),(y), 4, 0x0f0f0f0fL); \
bit_swap((y),(x), 16, 0x0000ffffL); \
bit_swap((x),(y), 2, 0x33333333L); \
bit_swap((y),(x), 8, 0x00ff00ffL); \
bit_swap((x),(y), 1, 0x55555555L)
#define fp(x,y) \
bit_swap((y),(x), 1, 0x55555555L); \
bit_swap((x),(y), 8, 0x00ff00ffL); \
bit_swap((y),(x), 2, 0x33333333L); \
bit_swap((x),(y), 16, 0x0000ffffL); \
bit_swap((y),(x), 4, 0x0f0f0f0fL)
#define round(x0,x1,ki) \
l0 = (x1 ^ *(((unsigned long*)key) + ki)) & 0x3f3f3f3f; \
l1 = (rotr(x1, 4) ^ *(((unsigned long*)key) + ki + 1)) & 0x3f3f3f3f; \
x0 ^= sx_tab[0][byte(l0,0)] | sx_tab[1][byte(l1,0)] \
| sx_tab[2][byte(l0,1)] | sx_tab[3][byte(l1,1)] \
| sx_tab[4][byte(l0,2)] | sx_tab[5][byte(l1,2)] \
| sx_tab[6][byte(l0,3)] | sx_tab[7][byte(l1,3)]
#ifdef __cplusplus
extern "C"
{
void des_ky(void *kval, void *key);
void des_ec(const void *i_blk, void *o_blk, void *key);
void des_dc(const void *i_blk, void *o_blk, void *key);
};
#else
void des_ky(void *kval, void *key);
void des_ec(const void *i_blk, void *o_blk, void *key);
void des_dc(const void *i_blk, void *o_blk, void *key);
#endif