#include?“stdafx.h“
#include?“stdlib.h“
#include?“string.h“
#include?“memory.h“

void?show1（）?//主界面
{
	printf（“%d“?‘1‘）;
	printf（“\n\n\n\t\t***************?DES加密解密系統?******************\n\n“）;
	printf（“\t\t--------------------------------------------------\n“）;
	//printf（“\t\t--------------------------------------------------\n“）;
	printf（“\t\t**************************************************\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t**\t\t\t1.加密\t\t\t**\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t**\t\t\t2.解密\t\t\t**\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t**\t\t\t3.退出\t\t\t**\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t--------------------------------------------------\n“）;
}

void?show2（）	//加密界面
{
	printf（“\n\n\n\t\t******************?DES加密?**********************\n\n“）;
	printf（“\t\t--------------------------------------------------\n“）;
	printf（“\t\t**************************************************\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t**\t請選擇明文和密鑰的輸入方式:\t\t**\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t**\t\t1.直接輸入\t\t\t**\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t**\t\t2.從文件讀取\t\t\t**\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t**\t\t3.退出\t\t\t\t**\n“）;
	printf（“\t\t**\t\t\t\t\t\t**\n“）;
	printf（“\t\t--------------------------------------------------\n“）;
	printf（“\t\t\t選擇:“）;
}

void?reader（char?str[30]?char?s[8]）??//讀取明文和密鑰
{
	FILE?*fp;
	fp?=?fopen（str?“r“）;
	if?（fp?==?NULL）
	{
		printf（“明文讀取失敗!\n“）;
	}
	else
	{
		fscanf（fp?“%s“?s）;
	}
	fclose（fp）;
}

void?To2Bin（char?p[8]?int?b[64]）????//將字節轉換成二進制流
{
	int?i?k?=?0;

	for?（i?=?0;?i<8;?i++）
	{
		int?j?=?0x80;???//完全正確，因為在數組中就是從高到低存放的
		for?（;?j;?j?>>=?1）
		{
			if?（j&p[i]）
			{
				b[k++]?=?1;
			}
			else
			{
				b[k++]?=?0;
			}
		}
	}
}



int?IP_Table[64]?=????????????//初始置換（IP）

{
	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
	56?48?40?32?24?16?8?0
	58?50?42?34?26?18?10?2
	60?52?44?36?28?20?12?4
	62?54?46?38?30?22?14?6
};


int?E_Table[]?=?{			????	//擴展變換E（個人認為此E，IP，IP逆表優于ppt上的，從0開始便于取遍數組所有元素）
	31?0?1?2?3?4
	3?4?5?6?7?8
	7?8?9?10?11?12
	11?12?13?14?15?16
	15?16?17?18?19?20
	19?20?21?22?23?24
	23?24?25?26?27?28
	27?28?29?30?31?0
};
//S盒需要根據需要確定————————————————————————————————————————————???????????????????????????????????
int?S_Box[8][4][16]?=?{												//8個s盒
	{
		{?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?}
	}

	{
		{?15?1?8?14?6?11?3?4?9?7?2?13?12?0