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

//加解密標記
#define ENCRYPT 1
#define DECRYPT 0
static bool SubKey[16][48];

//初始置換表IP
//置換選擇1
const static char PC1_Table[56] =
{
	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,
	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
};

//逆初始置換表
const static char IPR_Table[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
};

//循環(huán)左移16次
const static char LOOP_Table[16] =
{
	1, 1, 2, 2, 2, 2, 2, 2,
	1, 2, 2, 2, 2, 2, 2, 1
};

//選擇置換2
const static char PC2_Table[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
};

// 初始置換表IP
const static char IP_Table[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
};

// Expand函數(shù)
static const char E_Table[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
};

// 壓縮替換(S盒)
const static char S_Box[8][4][16] =
{
	{
		// S1 
		{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}
	},
	{
		// S2 
		{15,  1,  8, 14,  6, 11,   3,   4,   9,   7,   2, 13,  12,   0,  5, 10},
		{ 3, 13,  4,  7, 15,  2,   8,  14,   2,   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}
	},
	{
		// S3 
		{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}
	},
	{
		// S4 
		{ 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}
	},
	{
		// S5 
		{ 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}
	},
	{
	   // S6 
		{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}
	},
	{
	   // S7 
		{ 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}
	},
	{
	   // S8 
		{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}
	}
};

//P盒置換
const static char P_Table[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
};

void TranOX_To_Byte(char *Output,char *Input);//16進制轉(zhuǎn)換為BYTE
void Des_SetKey(const char Key[8]);
void Des_Run(char Out[8], char In[8], bool Type);
static void F_func(bool In[32], const bool Ki[48]); // f 函數(shù)
static void S_func(bool Out[32], const bool In[48]); // S 盒代替
static void Transform(bool *Out, bool *In, const char *Table, int len); // 變換
static void Xor(bool *InA, const bool *InB, int len); // 異或
static void RotateL(bool *In, int len, int loop);// 循環(huán)左移
static void ByteToBit(bool *Out, const char *In, int bits);// 字節(jié)組轉(zhuǎn)換成位組
static void BitToByte(char *Out, const bool *In, int bits);// 位組轉(zhuǎn)換成字節(jié)組
static void printHex( char *cmd, int len );// 打印輸出
static void printArray( const char *In, int len );//打印輸出

//子密鑰生成函數(shù)
void Des_SetKey(const char Key[8])
{
	int i;
	static bool K[64], *KL = &K[0], *KR = &K[28];//左右各28位

	ByteToBit(K, Key, 64);

	Transform(K, K, PC1_Table, 56);

	////16輪子密鑰生成 
	for(i=0; i<16; i++)
	{	
		 RotateL(KL, 28, LOOP_Table[i]);//循環(huán)左移1或者2位
		 RotateL(KR, 28, LOOP_Table[i]);//循環(huán)左移1或者2位  		 
		 Transform(SubKey[i], K, PC2_Table, 48);//選擇置換2
	 }
}

//DES運行
void Des_Run(char Out[8], char In[8], bool Type)
{
	int i;
	static bool M[64], tmp[32], *Li = &M[0], *Ri = &M[32];

	 
	ByteToBit(M, In, 64);//字節(jié)變換為位

	 
	Transform(M, M, IP_Table, 64);//初始置換IP

	//明文分組，左右各32位
	if( Type == ENCRYPT )
	{
         //16輪加密過程 
         for(i=0; i<16; i++)
         {
             memcpy(tmp, Ri, 32);
            
             //求右半部份的Ri//求R[i]=L[i-1](+)F_func(R[i-1], K[i])
             F_func(Ri, SubKey[i]);
            
             // R[I]= L[I-1] (+) f(R[i-1], Ki);
             Xor(Ri, Li, 32);
            
             // L[i] = R[i-1]
             memcpy(Li, tmp, 32);
            
         } 
     }
     else
     {
      //解密過程
         for(i=15; i>=0; i--)
         {
             memcpy(tmp, Li, 32);
             F_func(Li, SubKey[i]);
             Xor(Li, Ri, 32);
             memcpy(Ri, tmp, 32);
         }
	 }
	 
     Transform(M, M, IPR_Table, 64);
    
     BitToByte(Out, M, 64);
}

void F_func(bool In[32], const bool Ki[48])
{
     static bool MR[48];    
    
     Transform(MR, In, E_Table, 48);   //32位輸入擴展為48位 
     Xor(MR, Ki, 48); //擴展的48位輸入和48位子密鑰進行異或運算【擴展置換(48位)】
     S_func(In, MR);  //S盒置換(48位)
     Transform(In, In, P_Table, 32);//P盒置換(32位)
}

//S盒置換(32位輸出)
void S_func(bool Out[32], const bool In[48])
{
	char j,m,n;
	//8個S盒 
     for(j=0; j<8; j++,In+=6,Out+=4)
     {
		//6比特的首末位，某個S盒中的某一行m =bit[a1][a6]
		m = (In[0]<<1) + In[5];

		// //對應(yīng)列
		n = (In[1]<<3) + (In[2]<<2) + (In[3]<<1) + In[4];

		// //字節(jié)轉(zhuǎn)換成比特位
		ByteToBit(Out, &S_Box[(int)j][(int)m][(int)n], 4);
     }
}

// -- Perform the permutation --
void Transform(bool *Out, bool *In, const char *Table, int len)
{
	int i;
	static bool tmp[256];
	for(i=0; i<len; i++)
		tmp[i] = In[ Table[i]-1 ];
	memcpy(Out, tmp, len);
}

// -- 異或 --
void Xor(bool *InA, const bool *InB, int len)
{
	int i;
	for(i=0; i<len; i++)
		InA[i] ^= InB[i];
}

// 循環(huán)移位
void RotateL(bool *In, int len, int loop)
{
     static bool tmp[256];    // Sample:
	 // loop=2
     memcpy(tmp, In, loop);    // In=12345678 tmp=12
     memcpy(In, In+loop, len-loop); // In=345678   
     memcpy(In+len-loop, tmp, loop); // In=34567812
}

void ByteToBit(bool *Out, const char *In, int bits)
{
	int i;

	for(i=0; i<bits; i++)	// In[i]的第N位右移N位并和0x01按位"與"運算(N=1~8)
		Out[i] = (In[i/8]>>(i%8)) & 1;
}

void BitToByte(char *Out, const bool *In, int bits)
{
	int i;
	memset(Out, 0, (bits+7)/8);
	for(i=0; i<bits; i++)
		Out[i/8] |= In[i]<<(i%8);
}

// 打印指定位置指定長度HEX值
static void printHex( char *cmd, int len )
{
	int i;
	for(i=0; i<len; i++)
		printf("[%02X]",(unsigned char)cmd[i]);
	printf("\n");
}

void TranOX_To_Byte(char *Output,char *Input)
{
	int i, j, sum, len,temp;
	sum = 0;
	temp = 0;
	len = strlen(Input);
	j=0;
	for (i=0;i<len;i++)
	{
		if (i%2 == 0)
		{
	
			if (Input[i] >= '0' && Input[i] <= '9')
				sum = sum + Input[i] - '0';
			else
			{
				if (Input[i] =='A' )
					sum = sum + 10;
				else
				{
					if (Input[i] =='B' )
						sum = sum + 11;
					else
					{
						if (Input[i] =='C' )
							sum = sum + 12;
						else
						{

							if (Input[i] =='D' )
								sum = sum + 13;
							else
							{
								if (Input[i] =='E' )
									sum = sum + 14;
								else
									sum = sum + 15;
							}
						}
					}
				}
			}
		}
		else
		{
			if (Input[i] >= '0' && Input[i] <= '9')
			{
				temp = temp + Input[i] - '0';
				Output[j++] = sum * 16 + temp;
				sum = 0;
				temp = 0;
			}
			else
			{
				if (Input[i] =='A' )
					sum = sum + 10;
				else
				{
					if (Input[i] =='B' )
						sum = sum + 11;
					else
					{
						if (Input[i] =='C' )
							sum = sum + 12;
						else
						{

							if (Input[i] =='D' )
								sum = sum + 13;
							else
							{
								if (Input[i] =='E' )
									sum = sum + 14;
								else
									sum = sum + 15;
							}
						}
					}
				}
				temp = temp + Input[i] - '0';
				Output[j++] = sum * 16 + temp;
				sum = 0;
				temp = 0;
			}
		}
	}
	Output[j] = '\0';
}

int main(int argc, char *argv[])
{
	char array[16];
	char key[12];
	char str[64];
	char str2[12];	
	
	printf("Input Key:\n");
	gets(array);

	TranOX_To_Byte(key,array);//輸入的16進制數(shù)轉(zhuǎn)換為byte

	printf("Input PlainText:\n");
	gets(str);

	Des_SetKey(key);
	memset(str2, 0, sizeof(str2));
	Des_Run(str2, str, ENCRYPT);

	printf("CipherText:\n");
	printHex( str2, 8 );

	memset(str, 0, sizeof(str));
	printf("Decryption:\n");
	Des_Run(str, str2, DECRYPT);
	puts(str);

	return 0;
}