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

/**********
*C語言中，調用函數如果在main（）函數前，就不用聲明；如果
*寫在main（）后，就必須在主函數前面做聲明。
***********************/
void des(char *source,char *dest,char * inkey, int flg);

int Main(){
int i，cnt,k;
char s[9]={0};
//unsigned char readbuf[64];
//unsigned char T[64];
char d[9]={0};//65的原因是一個存放\0
char key[256]={'\0'};
char source[1024];
char destination[1024];
char *s_ptr;
int flag[1];
Uart_Printf("Please input flag to detemine encryption or decryption:");
Uart_GetString(flag);
Uart_Printf("\n");
Uart_Printf("Please input key:");
Uart_GetString(key);
Uart_Printf("\n");
Uart_Printf("Please input source:");
Uart_GetString(source);
Uart_Printf("\n");
//讀一個byte

if(flag[0]==0){
	k=0;
	s_ptr=source;
	//printf("******up loop start****\n");
	while(*s_ptr){
		cnt=0;
		//printf("******down loop start****\n");
		while(*s_ptr&&cnt<8){
			s[cnt]=*s_ptr;
			s_ptr++;
			cnt++;
				}
		//printf("******if start****\n");
		if((7-cnt)>0){
			for(i=7-cnt;i<8;i++)
				s[i]=0;
			}
		for(i=0;i<sizeof(s);i++)
		printf("%c",s[i]);
		printf("\n");
		i=0;
		printf("*");
    		des(s,d,key,flag);//flag=0表示；加密對單個字節加密
		printf("8字節加密結束");
		printf("\n");
		printf("Have dealt 8 otc!");
		printf("\n");
	for(i=0;i<strlen(d);i++){
			destination[k++]=d[i];
			printf("%c",d[i]);
		}
	printf("\n");
	}
}
else {
	k=0;
	s_ptr=source;
	//printf("******up loop start****\n");
	while(*s_ptr){
		cnt=0;
		//printf("******down loop start****\n");
		while(*s_ptr&&cnt<8){
			s[cnt]=*s_ptr;
			s_ptr++;
			cnt++;
				}
		//printf("******if start****\n");
		if((7-cnt)>0){
			for(i=7-cnt;i<8;i++)
				s[i]=0;
			}
		for(i=0;i<sizeof(s);i++)
		printf("%c",s[i]);
		printf("\n");
		i=0;
		printf("*");
    		des(s,d,key,flag);//flag=1表示；加密對單個字節解密
		printf("8字節加密結束");
		printf("\n");
		printf("Have dealt 8 otc!");
		printf("\n");
	for(i=0;i<strlen(d);i++){
			destination[k++]=d[i];
			printf("%c",d[i]);
			}
	printf("\n");
		}
	}
printf("加密|解密成功!!!\n");
return 0;
}

/* ============================================================
des()
Description: DES algorithm,do encript or descript.
============================================================ */
void des(char *source,char *dest,char * inkey,int flg){
char bufout[64],
kwork[56], worka[48], kn[48], buffer[64], key[64],
nbrofshift, temp1, temp2;
int valindex;
register i, j, k, iter;
/* INITIALIZE THE TABLES */
/* Table - s1 */
static 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 };
/* Table - s2 */
static 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 };
/* Table - s3 */
static 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 };
/* Table - s4 */
static 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 };
/* Table - s5 */
static 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 };
/* Table - s6 */
static 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 };
/* Table - s7 */
static 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 };
/* Table - s8 */
static 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 };

/* Table - Shift 循環左移表*/
static char shift[16] = {
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 };

/* Table - Binary */
static char binary[64] = {
0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1,
0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1,
1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1,
1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1 };
/* MAIN PROCESS */
/* Convert from 64-bit key into 64-byte key */
for (i = 0; i < 8; i++) {
key[8*i] = ((j = *(inkey + i)) / 128) % 2;
key[8*i+1] = (j / 64) % 2;
key[8*i+2] = (j / 32) % 2;
key[8*i+3] = (j / 16) % 2;
key[8*i+4] = (j / 8) % 2;
key[8*i+5] = (j / 4) % 2;
key[8*i+6] = (j / 2) % 2;
key[8*i+7] = j % 2;
}
printf("#");
/* Convert from 64-bit data into 64-byte data */
for (i = 0; i < 8; i++) {
buffer[8*i] = ((j = *(source + i)) / 128) % 2;
buffer[8*i+1] = (j / 64) % 2;
buffer[8*i+2] = (j / 32) % 2;
buffer[8*i+3] = (j / 16) % 2;
buffer[8*i+4] = (j / 8) % 2;
buffer[8*i+5] = (j / 4) % 2;
buffer[8*i+6] = (j / 2) % 2;
buffer[8*i+7] = j % 2;
}
/* Initial Permutation of Data */
bufout[ 0] = buffer[57];
bufout[ 1] = buffer[49];
bufout[ 2] = buffer[41];
bufout[ 3] = buffer[33];
bufout[ 4] = buffer[25];
bufout[ 5] = buffer[17];
bufout[ 6] = buffer[ 9];
bufout[ 7] = buffer[ 1];
bufout[ 8] = buffer[59];
bufout[ 9] = buffer[51];
bufout[10] = buffer[43];
bufout[11] = buffer[35];
bufout[12] = buffer[27];
bufout[13] = buffer[19];
bufout[14] = buffer[11];
bufout[15] = buffer[ 3];
bufout[16] = buffer[61];
bufout[17] = buffer[53];
bufout[18] = buffer[45];
bufout[19] = buffer[37];
bufout[20] = buffer[29];
bufout[21] = buffer[21];
bufout[22] = buffer[13];
bufout[23] = buffer[ 5];
bufout[24] = buffer[63];
bufout[25] = buffer[55];
bufout[26] = buffer[47];
bufout[27] = buffer[39];
bufout[28] = buffer[31];
bufout[29] = buffer[23];
bufout[30] = buffer[15];
bufout[31] = buffer[ 7];
bufout[32] = buffer[56];
bufout[33] = buffer[48];
bufout[34] = buffer[40];
bufout[35] = buffer[32];
bufout[36] = buffer[24];
bufout[37] = buffer[16];
bufout[38] = buffer[ 8];
bufout[39] = buffer[ 0];
bufout[40] = buffer[58];
bufout[41] = buffer[50];
bufout[42] = buffer[42];
bufout[43] = buffer[34];
bufout[44] = buffer[26];
bufout[45] = buffer[18];
bufout[46] = buffer[10];
bufout[47] = buffer[ 2];
bufout[48] = buffer[60];
bufout[49] = buffer[52];
bufout[50] = buffer[44];
bufout[51] = buffer[36];
bufout[52] = buffer[28];
bufout[53] = buffer[20];
bufout[54] = buffer[12];
bufout[55] = buffer[ 4];
bufout[56] = buffer[62];
bufout[57] = buffer[54];
bufout[58] = buffer[46];
bufout[59] = buffer[38];
bufout[60] = buffer[30];
bufout[61] = buffer[22];
bufout[62] = buffer[14];
bufout[63] = buffer[ 6];
/* Initial Permutation of Key */
kwork[ 0] = key[56];
kwork[ 1] = key[48];
kwork[ 2] = key[40];
kwork[ 3] = key[32];
kwork[ 4] = key[24];
kwork[ 5] = key[16];
kwork[ 6] = key[ 8];
kwork[ 7] = key[ 0];
kwork[ 8] = key[57];
kwork[ 9] = key[49];
kwork[10] = key[41];
kwork[11] = key[33];
kwork[12] = key[25];
kwork[13] = key[17];
kwork[14] = key[ 9];
kwork[15] = key[ 1];
kwork[16] = key[58];
kwork[17] = key[50];
kwork[18] = key[42];
kwork[19] = key[34];
kwork[20] = key[26];
kwork[21] = key[18];
kwork[22] = key[10];
kwork[23] = key[ 2];
kwork[24] = key[59];
kwork[25] = key[51];
kwork[26] = key[43];
kwork[27] = key[35];
kwork[28] = key[62];
kwork[29] = key[54];
kwork[30] = key[46];
kwork[31] = key[38];
kwork[32] = key[30];
kwork[33] = key[22];
kwork[34] = key[14];
kwork[35] = key[ 6];
kwork[36] = key[61];
kwork[37] = key[53];
kwork[38] = key[45];
kwork[39] = key[37];
kwork[40] = key[29];
kwork[41] = key[21];
kwork[42] = key[13];
kwork[43] = key[ 5];
kwork[44] = key[60];
kwork[45] = key[52];
kwork[46] = key[44];
kwork[47] = key[36];
kwork[48] = key[28];
kwork[49] = key[20];
kwork[50] = key[12];
kwork[51] = key[ 4];
kwork[52] = key[27];
kwork[53] = key[19];
kwork[54] = key[11];
kwork[55] = key[ 3];
/* 16 Iterations 迭代*/