kernel.h

模拟DES算法

#include <stdlib.h>
#include <string>
#define ENCRYPT 1
#define DECRYPT 0

// 16 sub keys
static bool SubKey[16][48];


// Permuted Choice 1 (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
};

// Left Shifts
const static char LOOP_Table[16] =
{
	1, 1, 2, 2, 2, 2, 2, 2,
	1, 2, 2, 2, 2, 2, 2, 1
};

// Permuted Choice 2 (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
};

// Initial Permutation (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
};

// Expansion (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
};

//S-boxes
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}
     }

};

// Permutation P
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
};

// Final Permutation (IP**-1)
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
};

// 主函数
void Des_SetKey(const char Key[8]);	// 生成Subkey
void Des_Run(char Out[8], char In[8], bool Type);	// DES算法

// 功能函数
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


// 生成Subkey
void Des_SetKey(const char Key[8])
{
	int i;
    static bool K[64], *KL = &K[0], *KR = &K[28];
    ByteToBit(K, Key, 64);
    Transform(K, K, PC1_Table, 56);
    for(i=0; i<16; i++)
	{
  
        RotateL(KL, 28, LOOP_Table[i]);
        RotateL(KR, 28, LOOP_Table[i]);
        Transform(SubKey[i], K, PC2_Table, 48);
	}
}

// DES算法
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);
    Transform(M, M, IP_Table, 64);
    if( Type == ENCRYPT )
    {
        for(i=0; i<16; i++)
        {
            memcpy(tmp, Ri, 32);
            F_func(Ri, SubKey[i]);
            Xor(Ri, Li, 32);
            memcpy(Li, tmp, 32);   
        } 
    }
    else
    {
     
        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); 
	Xor(MR, Ki, 48);
	S_func(In, MR);
	Transform(In, In, P_Table, 32);
}

void S_func(bool Out[32], const bool In[48])
{
	char j,m,n;
    for(j=0; j<8; j++,In+=6,Out+=4)
    {
		m = (In[0]<<1) + In[5];
        n = (In[1]<<3) + (In[2]<<2) + (In[3]<<1) + In[4];
        ByteToBit(Out, &S_Box[(int)j][(int)m][(int)n], 4);
    }
}

// 置换
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);
}

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

//循环左移
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); 
}

void ByteToBit(bool *Out, const char *In, int bits)
{
	int i;
    for(i=0; i<bits; i++)
    {
        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);
    }
}