[demo程序] 【转载】DES加密解密算法C语言代码实现

#include<stdio.h>

#include<string.h>

#include<stdlib.h>

/*------------------------

     定义枚举型全局变量

------------------------*/

typedef enum

  {

    false = 0,

    true  = 1

  } bool;

  

  // 十六轮子密钥

static bool SubKey[16][48]={0};

  

 /*---------------------*/

/*-------------------------------------------------------------

     各种置换表

-------------------------------------------------------------*/

// IP置换表

const 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 

};

// IP-1置换表

const 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 

};



// E扩展表

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

};

// PC1置换表

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

};



// pc2表     

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,

 41,52,31,37,47,55,30,40,51,34,33,48,

 44,49,39,56,34,53,46,42,50,36,29,32 

};

//  移位表

static char Move_Table[16]={

  1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1

};

 // S盒

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, 0, 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, 0, 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置换表

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

};

/*-------------------------------------------------------------------*/

 

/*-----------------------------自定义函数-----------------------------*/

void SetKey(char My_key[8]); //生成16轮的子密钥；

void ByteToBit(bool * Data_out,char * Data_in,int Num); //字节转换成位；

void Change_bit(bool * Data_out,int Num);//二进制的位置进行转换；

void BitToByte(char My_message[8],bool * Message_in,int Num); //位转换成字节；

void TableReplace(bool *Data_out,bool *Data_in,const char *Table,int Num);  //各种表的置换算法；

void Bitcopy(bool * Data_out,bool * Data_in,int Num);  //二进制数组的拷贝

void Loop_bit(bool * Data_out,int movstep,int len);  //左移位；

void Run_Des(char My_message[8],char HexMssage[16]);//des的轮加密算法

void Xor(bool * Message_out, bool * Message_in,int Num); //执行异或

void S_change(bool * Data_out, bool * Data_in);  // S盒变换；

void HexToBit(bool * Data_out,char * Data_in,int Num); // 十六进制转二进制

void BitToHex(char * Data_out,bool * Data_in,int Num); //二进制转换成十六进制；

void Run_desDes(char My_message[8],char HexMessage[16]);// DES轮解密算法；



/*--------------------------*/



/*--------------------------主函数----------------------------------*/

int main()

{

 int i=0,j;

 char My_key[8]={0};  //记录加密密钥；

 char You_key[8]={0}; //解密密钥

 char My_message[8]={0}; //明文

 char Message_hex[16]={0};//16进制的密文

 printf("请输入你要加密的内容(8 Byte):\n");

 gets(My_message);

 printf("请输入你的加密密钥:\n");

 gets(My_key);

 i=strlen(My_key);

 while(i!=8)

 {

  printf("请输入加密密钥(8 Byte)\n");

  gets(My_key);

  i=0;

  i=strlen(My_key);

 }

 SetKey(My_key);  //生成16轮的加密子密钥； 

 Run_Des(My_message,Message_hex); //des的轮加密过程

 printf("经过加密的密文为:\n");

 for(i=0;i<16;i++)

 {

  printf("%c ",Message_hex[i]);

 }

 printf("\n");

 printf("请输入你的解密密钥(8 Byte):\n");

 gets(You_key);

 i=strlen(You_key);

 while(i!=8)

 {

  printf("请输入解密密钥(8 Byte)\n");

  gets(You_key);

  i=0;

  i=strlen(You_key);

 }

 SetKey(You_key);  //生成16轮的解密子密钥；

 Run_desDes(My_message,Message_hex);//解密;

 printf("解密结果为:\n");

 for(i=0;i<8;i++)

 {

  printf("%c ",My_message[i]);

 }

 printf("\n");

 return 0;

}



/*--------------------具体函数定义----------------------*/

void Bitcopy(bool * Data_out, bool * Data_in,int Num) //二进制数组拷贝

{

 int i=0;

 for(i=0;i<Num;i++)

 {  

  Data_out[i]=Data_in[i];

 }

 

}

void Change_bit(bool * Data_out,int Num) //二进制的位置进行转换；

{

 int i,j;

 static bool Temp[8]={0};

 for(i=0;i<Num/8;i++)

 {

  Bitcopy(Temp,Data_out,Num/8);

  for(j=0;j<Num/8;j++)

  {

   Data_out[j]=Temp[Num/8-1-j];

  }

  Data_out+=Num/8;

 }

}

void ByteToBit( bool * Data_out,char * Data_in,int Num) //字节转位

{

 int i,j; 

 for(i=0;i<Num;i++)

 {

  Data_out[i]=(Data_in[i/8]>>(i%8))&0x01;

 }

 //Change_bit(Data_out,Num);

}

void BitToHex(char * Data_out, bool * Data_in,int Num) //二进制转十六进制

{

 int i;

 for(i=0;i<Num/4;i++)

 {

  Data_out[i]=0;

 }

 for(i=0;i<Num/4;i++)

 {

  Data_out[i]=Data_in[4*i]+Data_in[4*i+1]*2+Data_in[4*i+2]*4+Data_in[4*i+3]*8;

  if(Data_out[i]%16>9)

  {

   Data_out[i]=Data_out[i]%16+'7';

  }

  else

  Data_out[i]=Data_out[i]%16+'0';

 }

}

void HexToBit(bool * Data_out,char * Data_in,int Num) //十六进制转二进制

{

 int i;

 for(i=0;i<Num;i++)

 {

  if(Data_in[i/4]<='9')

  {

   Data_out[i]=((Data_in[i/4]-'0')>>(i%4))&0x01;

  }

  else

  {

   Data_out[i]=((Data_in[i/4]-'7')>>(i%4))&0x01;

  }

 }

}

void BitToByte(char My_message[8],bool * Message_in,int Num) //位转换成字节

{

 int i=0;

 for(i=0;i<(Num/8);i++)

 {

  My_message[i]=0;

 } 

 for(i=0;i<Num;i++)

 {

  My_message[i/8]|=Message_in[i]<<(i%8); 

 }  

}

void TableReplace( bool *Data_out, bool * Data_in,const char *Table ,int Num) // 置换算法

{

 int i=0;

 static bool Temp[256]={0};

 for(i=0;i<Num;i++)

 {

  Temp[i]=Data_in[Table[i]-1];

 }

 Bitcopy(Data_out,Temp,Num);

}

void Loop_bit(bool * Data_out,int movstep,int len)

{

 static bool Temp[256]={0};

 Bitcopy(Temp,Data_out,movstep);

 Bitcopy(Data_out,Data_out+movstep,len-movstep);

 Bitcopy(Data_out+len-movstep,Temp,movstep);

 /*Temp=Data_out;

 Temp[movstep]='\0';

 Data_out=Data_out+movstep;

 Data_out+(len-movstep)=Temp;*/

}

void Xor(bool * Message_out,bool * Message_in,int Num)//执行异或

{

 int i;

 for(i=0;i<Num;i++)

 {

  Message_out[i]=Message_out[i]^Message_in[i];

 }

}

void SetKey(char My_key[8])

{

 int i,j;

 static bool Key_bit[64]={0}; //Key的二进制缓存；

 static bool *Key_bit_L,*Key_bit_R;

 Key_bit_L=&Key_bit[0]; //key的左边28位；

 Key_bit_R=&Key_bit[28]; //key的右边28位；

 ByteToBit(Key_bit,My_key,64);

/* Change_bit(Key_bit,64) ;//二进制的位置进行转换；

 for(i=0;i<64;i++)

 {

  printf("%d ",Key_bit[i]);

 }

 printf("\n");

 printf("\n");*/

 TableReplace(Key_bit,Key_bit,PC1_Table,56);//pc-1 置换

 for(i=0;i<16;i++)

 {

  Loop_bit(Key_bit_L,Move_Table[i],28);

  Loop_bit(Key_bit_R,Move_Table[i],28);

  TableReplace(SubKey[i],Key_bit,PC2_Table,48);//pc-2置换

 }

}

void S_change(bool * Data_out, bool * Data_in) //S盒变换

{

 int i;

 int r=0,c=0;//S盒的行和列；

 for(i=0;i<8;i++,Data_in=Data_in+6,Data_out=Data_out+4)

 {

  r=Data_in[0]*2+Data_in[5]*1;

  c=Data_in[1]*8+Data_in[2]*4+Data_in[3]*2+Data_in[4]*1;

  ByteToBit(Data_out,&S_Box[i][r][c],4);

 } 

}

void F_change(bool Data_out[32],bool Data_in[48])   // f函数；

{

 int i;

 static bool Message_E[48]={0};  //存放E置换的结果；

 TableReplace(Message_E,Data_out,E_Table,48);//E表置换

 Xor(Message_E,Data_in,48);

 S_change(Data_out,Message_E);                 // S盒变换

 TableReplace(Data_out,Data_out,P_Table,32);  //P置换

}

void Run_Des(char My_message[8],char HexMssage[16])//des轮加密算法；

{

 int i; 

 static bool Message_bit[64]={0};

 static bool *Message_bit_L=&Message_bit[0],*Message_bit_R=&Message_bit[32];

 static bool Temp[32]={0};

 ByteToBit(Message_bit,My_message,64);

 /*Change_bit(Message_bit,64) ;//二进制的位置进行转换；

 for(i=0;i<64;i++)

 {

  printf("%d ",Message_bit[i]);

 }

 printf("\n");

 printf("\n");*/

 TableReplace(Message_bit,Message_bit,IP_Table,64);

 for(i=0;i<16;i++)

 {

  Bitcopy(Temp,Message_bit_R,32);

  F_change(Message_bit_R,SubKey[i]); 

  Xor(Message_bit_R,Message_bit_L,32);

  Bitcopy(Message_bit_L,Temp,32);

 }

 TableReplace(Message_bit,Message_bit,IPR_Table,64);

 BitToHex(HexMssage,Message_bit,64);//二进制转换成十六进制；

}

void Run_desDes(char My_message[8],char HexMessage[16])// DES轮解密算法；

{

 int i=0;

 static bool Message_bit[64]={0};

 static bool * Message_bit_L=&Message_bit[0], * Message_bit_R=&Message_bit[32];

 static bool Temp[32]={0};

 HexToBit(Message_bit,HexMessage,64);

 TableReplace(Message_bit,Message_bit,IP_Table,64);

 for(i=15;i>=0;i--)

 {

  Bitcopy(Temp,Message_bit_L,32);

  F_change(Message_bit_L,SubKey[i]); 

  Xor(Message_bit_L,Message_bit_R,32);

  Bitcopy(Message_bit_R,Temp,32);

 }

 TableReplace(Message_bit,Message_bit,IPR_Table,64);

 BitToByte(My_message,Message_bit,64);

}