des_myself.c

DES加密和解密算法源代码

#include "stdio.h"
#include "conio.h"


void byte2bit(unsigned char *, unsigned char *);
void bit2byte(unsigned char *, unsigned char *);

void ip_permute(unsigned char *);
void ip_1_permute(unsigned char *);
void expand(unsigned char *);
void p_permute(unsigned char *);
void f(unsigned char *, unsigned char *);
void keychange(unsigned char *, unsigned char [][]);

void endes(unsigned char *, unsigned char *, unsigned char *);
void undes(unsigned char *, unsigned char *, unsigned char *);

unsigned char message[8]={"computer"} ;   /*存放明文*/
unsigned char keyword[8]={112,56,155,236,118,146,133,218} ;/*存放密钥*/
unsigned char sub_keyword[16][8];         /*存放子密钥*/
unsigned char ecryption[8];               /*存放密文*/




int ip[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
        } ;
int ip_1[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
        } ;
int e[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
        } ;
int p[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 s1[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,
                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
                } ;
unsigned char s2[4][16] = { 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
                };
unsigned char s3[4][16] = { 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
                };
unsigned char s4[4][16] = { 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
                };
unsigned char s5[4][16] = { 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,
                };
unsigned char s6[4][16] = { 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
                };
unsigned char s7[4][16] = { 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
                };
unsigned char s8[4][16] = { 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
                };



                                                    
/************byte2bit(change 64byte to 64bit-8byte)（begin）********************/
void byte2bit(unsigned char byte[64] , unsigned char bit[8])
{
    int i = 0 ;

    /*byte1*/
    for(i = 0;i < 8;i++)
    {
        if(byte[0] == 0x1) bit[0] = bit[0] | 0x80 ;
        else bit[0] = bit[0] & 0x7f ;
        if(byte[1] == 0x1) bit[0] = bit[0] | 0x40 ;
        else bit[0] = bit[0] & 0xbf ;
        if(byte[2] == 0x1) bit[0] = bit[0] | 0x20 ;
        else bit[0] = bit[0] & 0xdf ;
        if(byte[3] == 0x1) bit[0] = bit[0] | 0x10 ;
        else bit[0] = bit[0] & 0xef ;
        if(byte[4] == 0x1) bit[0] = bit[0] | 0x08 ;
        else bit[0] = bit[0] & 0xf7 ;
        if(byte[5] == 0x1) bit[0] = bit[0] | 0x04 ;
        else bit[0] = bit[0] & 0xfb ;
        if(byte[6] == 0x1) bit[0] = bit[0] | 0x02 ;
        else bit[0] = bit[0] & 0xfd ;
        if(byte[7] == 0x1) bit[0] = bit[0] | 0x01 ;
        else bit[0] = bit[0] & 0xfe ;
    }
    /*byte2*/
    for(i = 8;i < 16;i++)
    {
        if(byte[8] == 0x1) bit[1] = bit[1] | 0x80 ;
        else bit[1] = bit[1] & 0x7f ;
        if(byte[9] == 0x1) bit[1] = bit[1] | 0x40 ;
        else bit[1] = bit[1] & 0xbf ;
        if(byte[10] == 0x1) bit[1] = bit[1] | 0x20 ;
        else bit[1] = bit[1] & 0xdf ;
        if(byte[11] == 0x1) bit[1] = bit[1] | 0x10 ;
        else bit[1] = bit[1] & 0xef ;
        if(byte[12] == 0x1) bit[1] = bit[1] | 0x08 ;
        else bit[1] = bit[1] & 0xf7 ;
        if(byte[13] == 0x1) bit[1] = bit[1] | 0x04 ;
        else bit[1] = bit[1] & 0xfb ;
        if(byte[14] == 0x1) bit[1] = bit[1] | 0x02 ;
        else bit[1] = bit[1] & 0xfd ;
        if(byte[15] == 0x1) bit[1] = bit[1] | 0x01 ;
        else bit[1] = bit[1] & 0xfe ;
    }
    /*byte3*/
    for(i = 16;i < 24 ;i++)
    {
        if(byte[16] == 0x1) bit[2] = bit[2] | 0x80 ;
        else bit[2] = bit[2] & 0x7f ;
        if(byte[17] == 0x1) bit[2] = bit[2] | 0x40 ;
        else bit[2] = bit[2] & 0xbf ;
        if(byte[18] == 0x1) bit[2] = bit[2] | 0x20 ;
        else bit[2] = bit[2] & 0xdf ;
        if(byte[19] == 0x1) bit[2] = bit[2] | 0x10 ;
        else bit[2] = bit[2] & 0xef ;
        if(byte[20] == 0x1) bit[2] = bit[2] | 0x08 ;
        else bit[2] = bit[2] & 0xf7 ;
        if(byte[21] == 0x1) bit[2] = bit[2] | 0x04 ;
        else bit[2] = bit[2] & 0xfb ;
        if(byte[22] == 0x1) bit[2] = bit[2] | 0x02 ;
        else bit[2] = bit[2] & 0xfd ;
        if(byte[23] == 0x1) bit[2] = bit[2] | 0x01 ;
        else bit[2] = bit[2] & 0xfe ;
    }
    /*byte4*/
    for(i = 24;i < 32 ;i++)
    {
        if(byte[24] == 0x1) bit[3] = bit[3] | 0x80 ;
        else bit[3] = bit[3] & 0x7f ;
        if(byte[25] == 0x1) bit[3] = bit[3] | 0x40 ;
        else bit[3] = bit[3] & 0xbf ;
        if(byte[26] == 0x1) bit[3] = bit[3] | 0x20 ;
        else bit[3] = bit[3] & 0xdf ;
        if(byte[27] == 0x1) bit[3] = bit[3] | 0x10 ;
        else bit[3] = bit[3] & 0xef ;
        if(byte[28] == 0x1) bit[3] = bit[3] | 0x08 ;
        else bit[3] = bit[3] & 0xf7 ;
        if(byte[29] == 0x1) bit[3] = bit[3] | 0x04 ;
        else bit[3] = bit[3] & 0xfb ;
        if(byte[30] == 0x1) bit[3] = bit[3] | 0x02 ;
        else bit[3] = bit[3] & 0xfd ;
        if(byte[31] == 0x1) bit[3] = bit[3] | 0x01 ;
        else bit[3] = bit[3] & 0xfe ;
    }
    /*byte5*/
    for(i = 32;i < 40 ;i++)
    {
        if(byte[32] == 0x1) bit[4] = bit[4] | 0x80 ;
        else bit[4] = bit[4] & 0x7f ;
        if(byte[33] == 0x1) bit[4] = bit[4] | 0x40 ;
        else bit[4] = bit[4] & 0xbf ;
        if(byte[34] == 0x1) bit[4] = bit[4] | 0x20 ;
        else bit[4] = bit[4] & 0xdf ;
        if(byte[35] == 0x1) bit[4] = bit[4] | 0x10 ;
        else bit[4] = bit[4] & 0xef ;
        if(byte[36] == 0x1) bit[4] = bit[4] | 0x08 ;
        else bit[4] = bit[4] & 0xf7 ;
        if(byte[37] == 0x1) bit[4] = bit[4] | 0x04 ;
        else bit[4] = bit[4] & 0xfb ;
        if(byte[38] == 0x1) bit[4] = bit[4] | 0x02 ;
        else bit[4] = bit[4] & 0xfd ;
        if(byte[39] == 0x1) bit[4] = bit[4] | 0x01 ;
        else bit[4] = bit[4] & 0xfe ;
    }
    /*byte6*/
    for(i = 40;i < 48 ;i++)
    {
        if(byte[40] == 0x1) bit[5] = bit[5] | 0x80 ;
        else bit[5] = bit[5] & 0x7f ;
        if(byte[41] == 0x1) bit[5] = bit[5] | 0x40 ;
        else bit[5] = bit[5] & 0xbf ;
        if(byte[42] == 0x1) bit[5] = bit[5] | 0x20 ;
        else bit[5] = bit[5] & 0xdf ;
        if(byte[43] == 0x1) bit[5] = bit[5] | 0x10 ;
        else bit[5] = bit[5] & 0xef ;
        if(byte[44] == 0x1) bit[5] = bit[5] | 0x08 ;
        else bit[5] = bit[5] & 0xf7 ;
        if(byte[45] == 0x1) bit[5] = bit[5] | 0x04 ;
        else bit[5] = bit[5] & 0xfb ;
        if(byte[46] == 0x1) bit[5] = bit[5] | 0x02 ;
        else bit[5] = bit[5] & 0xfd ;
        if(byte[47] == 0x1) bit[5] = bit[5] | 0x01 ;
        else bit[5] = bit[5] & 0xfe ;
    }
    /*byte7*/
    for(i = 48;i < 56 ;i++)
    {
        if(byte[48] == 0x1) bit[6] = bit[6] | 0x80 ;
        else bit[6] = bit[6] & 0x7f ;
        if(byte[49] == 0x1) bit[6] = bit[6] | 0x40 ;
        else bit[6] = bit[6] & 0xbf ;
        if(byte[50] == 0x1) bit[6] = bit[6] | 0x20 ;
        else bit[6] = bit[6] & 0xdf ;
        if(byte[51] == 0x1) bit[6] = bit[6] | 0x10 ;
        else bit[6] = bit[6] & 0xef ;
        if(byte[52] == 0x1) bit[6] = bit[6] | 0x08 ;
        else bit[6] = bit[6] & 0xf7;
        if(byte[53] == 0x1) bit[6] = bit[6] | 0x04 ;
        else bit[6] = bit[6] & 0xfb ;
        if(byte[54] == 0x1) bit[6] = bit[6] | 0x02 ;
        else bit[6] = bit[6] & 0xfd ;
        if(byte[55] == 0x1) bit[6] = bit[6] | 0x01 ;
        else bit[6] = bit[6] & 0xfe ;
    }
    /*byte8*/
    for(i = 56;i < 64 ;i++)
    {
        if(byte[56] == 0x1) bit[7] = bit[7] | 0x80 ;
        else bit[7] = bit[7] & 0x7f ;
        if(byte[57] == 0x1) bit[7] = bit[7] | 0x40 ;
        else bit[7] = bit[7] & 0xbf ;
        if(byte[58] == 0x1) bit[7] = bit[7] | 0x20 ;
        else bit[7] = bit[7] & 0xdf ;
        if(byte[59] == 0x1) bit[7] = bit[7] | 0x10 ;
        else bit[7] = bit[7] & 0xef ;
        if(byte[60] == 0x1) bit[7] = bit[7] | 0x08 ;
        else bit[7] = bit[7] & 0xf7 ;
        if(byte[61] == 0x1) bit[7] = bit[7] | 0x04 ;
        else bit[7] = bit[7] & 0xfb ;
        if(byte[62] == 0x1) bit[7] = bit[7] | 0x02 ;
        else bit[7] = bit[7] & 0xfd ;
        if(byte[63] == 0x1) bit[7] = bit[7] | 0x01 ;
        else bit[7] = bit[7] & 0xfe ;
    }
}
/******************************byte2bit（end）**********************************/




/***********bit2byte(change 64bit-8byte to 64byte)（begin）*********************/
void bit2byte(unsigned char bit[8] , unsigned char byte[64])
{
    int i=0 ;

    for(i=0 ; i<=63 ; i++)
    {
        byte[i] = 0x0 ;
    }
    for(i=0 ; i<=7 ; i++)
    {
        if((bit[i] & 0x80) == 0x80) byte[i*8+0] = 0x01 ;
        if((bit[i] & 0x40) == 0x40) byte[i*8+1] = 0x01 ;
        if((bit[i] & 0x20) == 0x20) byte[i*8+2] = 0x01 ;
        if((bit[i] & 0x10) == 0x10) byte[i*8+3] = 0x01 ;
        if((bit[i] & 0x08) == 0x08) byte[i*8+4] = 0x01 ;
        if((bit[i] & 0x04) == 0x04) byte[i*8+5] = 0x01 ;
        if((bit[i] & 0x02) == 0x02) byte[i*8+6] = 0x01 ;
        if((bit[i] & 0x01) == 0x01) byte[i*8+7] = 0x01 ;
    }
}
/******************************bit2byte（end）**********************************/




/*********************************IP置换（begin）*******************************/
void ip_permute(unsigned char array[64])
{
    int i;
    unsigned char temp[64];
    for(i=0;i<64;i++) temp[i]=array[ip[i]-1];
    for(i=0;i<64;i++) array[i]=temp[i];
}
/*********************************IP置换（end）*********************************/




/*********************************IP逆置换（begin）*****************************/
void ip_1_permute(unsigned char array[64])
{
    int i;
    unsigned char temp[64];
    for(i=0;i<64;i++) temp[i]=array[ip_1[i]-1];
    for(i=0;i<64;i++) array[i]=temp[i];
}
/*********************************IP逆置换（end）*******************************/