des.cpp

这个程序是用vc实现的des加密解密算法

#include "stdafx.h"
//////////////////////////////////////////////////////////////////////////
/*
    Provided by 黄卫立，李谟仁，肖翠萍
    Email: [e-mail]
	在程序中用bool表示位数据
*/
//////////////////////////////////////////////////////////////////////////

#include "memory.h"
#include "des.h"

//DES的初始置换IP表
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
};
//DES的IP逆置换表 
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
};

//DES加密过程的选为表E
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
};
// 32-bit permutation function P used on the output of the S-boxes 
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
};
// 置换选择表PC-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
};
//置换选择表PC-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
};
//循环左移运算表
const static char LOOP_Table[16] = {
//1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16
	1,1,2,2,2,2,2,2,1, 2, 2, 2, 2, 2, 2,1
};

//S盒运算 
const static char S_Box[8][4][16] = {
//盒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,
//盒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, 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,
//盒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,
//盒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,
//盒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,
//盒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,
//盒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,
//盒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
};


typedef bool   (*PSubKey)[16][48]; //这里用bool来表示 一个位

static void DES(char Out[8], char In[8], const PSubKey pSubKey, bool Type);//标准DES加/解密

static void SetKey(const char* Key, int len);  // 设置密钥 key 字符组  len是key字符组的长度

static void SetSubKey(PSubKey pSubKey, const char Key[8]);// 设置子密钥

static void F_func(bool In[32], const bool Ki[48]);// f 函数

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);// 变换

static void Xor(bool *InA, const bool *InB, int len);// 异或

static void RotateL(bool *In, int len, int loop);// 循环左移

static void ByteToBit(bool *Out, const char *In, int bits);// 字节组转换成位组

static void BitToByte(char *Out, const bool *In, int bits);// 位组转换成字节组

//////////////////////////////////////////////////////////////////////////

static bool SubKey[2][16][48];// 16圈子密钥

static bool Is3DES;// 3次DES标志

static char Tmp[256], deskey[16];

/*
主体加密解密函数
*/
bool Des_Go(char *Out, char *In, long datalen, const char *Key, int keylen, bool Type)
{
    if( !( Out && In && Key && (datalen=(datalen+7)&0xfffffff8) ) ) 
		return false;
	SetKey(Key, keylen);
	if( !Is3DES ) {   // 1次DES
		for(long i=0,j=datalen>>3; i<j; ++i,Out+=8,In+=8)
			DES(Out, In, &SubKey[0], Type);
	}
	 else{   // 3次DES 加密:加(key0)-解(key1)-加(key0) 解密::解(key0)-加(key1)-解(key0)
		for(long i=0,j=datalen>>3; i<j; ++i,Out+=8,In+=8) {
			DES(Out, In,  &SubKey[0], Type);
			DES(Out, Out, &SubKey[1], !Type);
			DES(Out, Out, &SubKey[0], Type);
		}
	}
	return true;
}

/*
 SetKeyz这个函数用来设置密匙，当输入的密匙长度超过16个字节时只截取前16字节
*/
void SetKey(const char* Key, int len)
{
	//对密匙存储空间进行初始化
	memset(deskey, 0, 16);
	//当密匙的长度大于16时截取前16字节，否则去实际字符长度
	memcpy(deskey, Key, len>16?16:len);
    //设置子密匙
	SetSubKey(&SubKey[0], &deskey[0]);
	//判断加解密的数据是否大于8而要进行三次DE加解密，如果len大于8对密匙空间的后八位进行处理
	Is3DES = len>8 ? (SetSubKey(&SubKey[1], &deskey[8]), true) : false;
}

//每八位一组的DES运算
void DES(char Out[8], char In[8], const PSubKey pSubKey, bool Type)
{
    static bool M[64], tmp[32], *Li=&M[0], *Ri=&M[32];
    ByteToBit(M, In, 64);
    Transform(M, M, IP_Table, 64);
    if( Type == ENCRYPT ){
		//进行16轮迭代进行加密
        for(int i=0; i<16; ++i) {
            memcpy(tmp, Ri, 32);
            F_func(Ri, (*pSubKey)[i]);
            Xor(Ri, Li, 32);
            memcpy(Li, tmp, 32);
        }
    }else{
		//进行16轮逆迭代进行解密
        for(int i=15; i>=0; --i) {
            memcpy(tmp, Li, 32);
            F_func(Li, (*pSubKey)[i]);
            Xor(Li, Ri, 32);
            memcpy(Ri, tmp, 32);
        }
	}
    Transform(M, M, IPR_Table, 64);
    BitToByte(Out, M, 64);
}


void SetSubKey(PSubKey pSubKey, const char Key[8])
{   //
    static bool K[64], *KL=&K[0], *KR=&K[28];
    //把字节转化成位数据
	ByteToBit(K, Key, 64);
	//通过PC-1置换选择表进行置换
    Transform(K, K, PC1_Table, 56);
    //进行16轮的迭代
	for(int i=0; i<16; ++i) {
        //对左部的28位进行 左循环
        RotateL(KL, 28, LOOP_Table[i]);
        //对右部的28位进行 左循环
        RotateL(KR, 28, LOOP_Table[i]);
        //根据 PC-2置换选择表进行置换
        Transform((*pSubKey)[i], K, PC2_Table, 48);
        
    }
}

//进行F函数运算
void F_func(bool In[32], const bool Ki[48])
{
    static bool MR[48];
    Transform(MR, In, E_Table, 48);
    Xor(MR, Ki, 48);
    S_func(In, MR);
    Transform(In, In, P_Table, 32);
}

//进行S函数运算
void S_func(bool Out[32], const bool In[48])
{
    for(char i=0,j,k; i<8; ++i,In+=6,Out+=4) {
        j = (In[0]<<1) + In[5];
        k = (In[1]<<3) + (In[2]<<2) + (In[3]<<1) + In[4];
		ByteToBit(Out, &S_Box[i][j][k], 4);
    }
}


//通过指定的置换表进行数据置换
void Transform(bool *Out, bool *In, const char *Table, int len)
{
    for(int i=0; i<len; ++i)
        Tmp[i] = In[ Table[i]-1 ];
    memcpy(Out, Tmp, len);
}


//进行异或运算
void Xor(bool *InA, const bool *InB, int len)
{
    for(int i=0; i<len; ++i)
        InA[i] ^= InB[i];
}

//进行循环左移运算
void RotateL(bool *In, int len, int loop)
{
    memcpy(Tmp, In, loop);  //获取In字符组的前loop个字符
    memcpy(In, In+loop, len-loop);//把In字符数组的后len-loop移到数组的开头
    memcpy(In+len-loop, Tmp, loop);//把loop个字符补到末尾
}

//把字符转化为位
void ByteToBit(bool *Out, const char *In, int bits)
{
   
    for(int i=0; i<bits; ++i)
        Out[i] = (In[i>>3]>>(i&7)) & 1;//通过移位获取每一个字符的第一个位的值
}

//把位转化为数组
void BitToByte(char *Out, const bool *In, int bits)
{
    memset(Out, 0, bits>>3);
    for(int i=0; i<bits; ++i)  //没八个位和并为一个字符
        Out[i>>3] |= In[i]<<(i&7);
}