DES encryption algorithm

#include <windows.h>

#include <errno.h>
#include <string.h>
#include <stdio.h>

unsigned char c[17][28],d[17][28],k[17][48];

unsigned char pc_1_c[28]={
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};
unsigned char pc_1_d[28]={
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};
unsigned char pc_2[48]={
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};

unsigned char ls_count[16]={
1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};

unsigned char ip_tab[64]={
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};
unsigned char _ip_tab[64]={
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};

unsigned char e_r[48]={
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};

unsigned char p_des[32]={
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};
unsigned char sss[16][4][16]={
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,/* Err on */
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,

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,

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,

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,/* err on */

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,/* err on */
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,

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,

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,

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};

void son (unsigned char *cc,unsigned char *dd,unsigned char *kk);
void LS (unsigned char *bits, unsigned char *buffer,unsigned char count);
void Setkeystar (unsigned char bits[64]);
void S_box (unsigned char *aa,unsigned char *bb);
void F_des (unsigned char n,unsigned char *ll,unsigned char *rr,unsigned char *ll,unsigned char *rr);
void Ip_des (unsigned char *text,unsigned char *ll,unsigned char *rr);
void _ip_des (unsigned char *text,unsigned char *ll,unsigned char *rr);
void expand0 (unsigned char *in,unsigned char *out);
void Compress0 (unsigned char *out,unsigned char *in);
void compress016 (unsigned char *out,unsigned char *in);
void Encrypt0 (unsigned char *text,unsigned char *mtext);
void Discrypt0 (unsigned char *mtext,unsigned char *text);
void DES (unsigned char *key,unsigned char *text,unsigned char *mtext);
void B_des (unsigned char *key,unsigned char *text,unsigned char *mtext);

void son (unsigned char *cc,unsigned char *dd,unsigned char *kk)
{
unsigned char i;
unsigned char buffer[56];
for (i=0;i<28;i++)
buffer[i]=*cc++;

for (i=28;i<56;i++)
buffer[i]=*dd++;

for (i=0;i<48;i++)
*KK++=BUFFER[PC_2[I]-1];
}

void LS (unsigned char *bits,unsigned char *buffer,unsigned char count)
{
unsigned char i;
for (i=0;i<28;i++)
{
buffer[i]=bits[(I+count)%28];
}
}

void Setkeystar (unsigned char bits[64])
{
unsigned char i,j;

for (i=0;i<28;i++)
C[0][I]=BITS[PC_1_C[I]-1];
for (i=0;i<28;i++)
D[0][I]=BITS[PC_1_D[I]-1];
for (j=0;j<16;j++)
{
LS (C[j],c[j+1],ls_count[j]);
LS (D[j],d[j+1],ls_count[j]);
Son (C[j+1],d[j+1],k[j+1]);
}
}

void S_box (unsigned char *aa,unsigned char *bb)
{
unsigned char i,j,k,m;
unsigned char y,z;
unsigned char ss[8];
m=0;
for (i=0;i<8;i++)
{
J=6*i;
Y=AA[J]*2+AA[J+5];
Z=AA[J+1]*8+AA[J+2]*4+AA[J+3]*2+AA[J+4];
SS[I]=SSS[I][Y][Z];
y=0x08;
for (k=0;k<4;k++)
{
bb[m++]= (ss[i]/y) &1;
y/=2;
}

}
}

void F_des (unsigned char n,unsigned char *ll,unsigned char *rr,unsigned char *ll,unsigned char *rr)
{
unsigned char i;
unsigned char buffer[64],tmp[64];
for (i=0;i<48;i++)
BUFFER[I]=RR[E_R[I]-1];
for (i=0;i<48;i++)
Buffer[i]= (Buffer[i]+k[n][i]) &1;

S_box (BUFFER,TMP);

for (i=0;i<32;i++)
BUFFER[I]=TMP[P_DES[I]-1];

for (i=0;i<32;i++)
Rr[i]= (Buffer[i]+ll[i]) &1;

for (i=0;i<32;i++)
Ll[i]=rr[i];

}

void expand0 (unsigned char *in,unsigned char *out)
{
unsigned char divide;
unsigned char i,j;

for (i=0;i<8;i++)
{
divide=0x80;
for (j=0;j<8;j++)
{
*out++= (in[i]/divide) &1;
divide/=2;
}
}
}

void Ip_des (unsigned char *text,unsigned char *ll,unsigned char *rr)
{
unsigned char i;
unsigned char buffer[64];
/*
Char tmp[64];
*/
Expand0 (Text,buffer);

for (i=0;i<32;i++)
LL[I]=BUFFER[IP_TAB[I]-1];

for (i=0;i<32;i++)
RR[I]=BUFFER[IP_TAB[I+32]-1];
}

void _ip_des (unsigned char *text,unsigned char *ll,unsigned char *rr)
{
unsigned char i;
unsigned char tmp[64];
for (i=0;i<32;i++)
Tmp[i]=ll[i];
for (i=32;i<64;i++)
TMP[I]=RR[I-32];
for (i=0;i<64;i++)
TEXT[I]=TMP[_IP_TAB[I]-1];
}

void Compress0 (unsigned char *out,unsigned char *in)
/*
unsigned char *in;
Char *out;
*/
{
unsigned char times;
unsigned char i,j;

for (i=0;i<8;i++)
{
times=0x80;
in[i]=0;
for (j=0;j<8;j++)
{
in[i]+= (*out++) *times;
times/=2;
}
}
}
void compress016 (unsigned char *out,unsigned char *in)
/*
unsigned char *in;
Char *out;
*/
{
unsigned char times;
unsigned char i,j;

for (i=0;i<16;i++)
{
times=0x8;
in[i]= ' 0 ';
for (j=0;j<4;j++)
{
in[i]+= (*out++) *times;
times/=2;
}
}
}

void Encrypt0 (unsigned char *text,unsigned char *mtext)
/*
unsigned char *text,*mtext;
*/
{
unsigned char ll[64],rr[64],ll[64],rr[64];
unsigned char tmp[64];
unsigned char i,j;
Ip_des (TEXT,LL,RR);

for (i=1;i<17;i++)
{
F_des (I,LL,RR,LL,RR);
for (j=0;j<32;j++)
{
LL[J]=LL[J];
RR[J]=RR[J];
}
}

_ip_des (TMP,RR,LL);

COMPRESS0 (Tmp,mtext);
}

void Discrypt0 (unsigned char *mtext,unsigned char *text)
/*
unsigned char *text,*mtext;
*/
{
unsigned char ll[64],rr[64],ll[64],rr[64];
unsigned char tmp[64];
unsigned char i,j;
Ip_des (MTEXT,LL,RR);

for (i=16;i>0;i--)
{
F_des (I,LL,RR,LL,RR);
for (j=0;j<32;j++)
{
LL[J]=LL[J];
RR[J]=RR[J];
}
}

_ip_des (TMP,RR,LL);

COMPRESS0 (Tmp,text);
}

void DES (unsigned char *key,unsigned char *text,unsigned char *mtext)
/*
unsigned char *text,*mtext,*key;
*/
{
unsigned char tmp[64];
Expand0 (KEY,TMP);
Setkeystar (TMP);
Encrypt0 (Text,mtext);
}
void B_des (unsigned char *key,unsigned char *text,unsigned char *mtext)
/*
unsigned char *text,*mtext,*key;
*/
{
unsigned char tmp[64];
Expand0 (KEY,TMP);
Setkeystar (TMP);
Discrypt0 (Text,mtext);
}

DES encryption algorithm