des.h

自己写的一个DES加密算法软件,在VC环境写的,编译后,对文档进行加密解密.使用方法从界面上一目了然.

enum {ENCRYPT,DECRYPT};// 

void Des_Run(char Out[8], char In[8], bool Type);
//设置密钥
void Des_SetKey(const char Key[8]);
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
//变换
static void Transform(bool *Out,bool *In, const char *Table, int len);
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
//字节组转换成位组
static void ByteToBit(bool *Out,const char *In,int bits);
//位组转换成字节组
static void BitToByte(char *Out,const bool *In,int bits);
//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,
};

//逆转换IP-1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,
};

//PC1选位表
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
};

//左移位数表
const static char LOOP_Table[16] = {
	1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1,
};

//PC2选位表
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
};

//E位选择表
const static 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
};

//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, 8,14,12, 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,
	// 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换位表
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
};

static bool SubKey[16][48]; //16圈子密钥

void Des_Run(char Out[8], char In[8], 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)
	{
		for(int i=0;i<16;i++)
		{
			memcpy(Tmp,Ri,32);
			F_func(Ri,SubKey[i]);
			Xor(Ri,Li,32);
			memcpy(Li,Tmp,32);
		}
	}
	else
	{
		for(int 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 Des_SetKey(const char Key[8])
{
	static bool K[64],*KL = &K[0],*KR=&K[28];
	ByteToBit(K,Key,64);
	Transform(K,K,PC1_Table,56);
	for(int i=0;i<16;i++)
	{
		RotateL(KL,28,LOOP_Table[i]);
		RotateL(KR,28,LOOP_Table[i]);
		Transform(SubKey[i],K,PC2_Table,48);
	}
}

static 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);
}

static 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);
	}
}

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

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

static void RotateL(bool *In, int len,int loop)
{
	static bool Tmp[256];
	memcpy(Tmp,In,loop);
	memcpy(In,In+loop,len-loop);
	memcpy(In+len-loop,Tmp,loop);
}

static void ByteToBit(bool *Out,const char *In,int bits)
{
	for(int i=0;i<bits;i++)
		Out[i]=(In[i/8]>>(i%8)) & 1;
}

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