C语言实现SDES加密算法详解

#include<stdio.h>

/*定义IP,IP_1,E/P,S0,S1,P4,P10,P8数组*/
int IP[8]   ={2,6,3,1,4,8,5,7};
int IP_1[8] ={4,1,3,5,7,2,8,6};
int E_P[8]  ={4,1,2,3,2,3,4,1};
int S0[4][4]={{1,0,3,2},{3,2,1,0},{0,2,1,3},{3,1,3,2}};
int S1[4][4]={{0,1,2,3},{2,0,1,3},{3,0,1,0},{2,1,0,3}};
int P4[4]   ={2,4,3,1};
int P10[10] ={3,5,2,7,4,10,1,9,8,6};
int P8[8]   ={6,3,7,4,8,5,10,9};

 /*以下为函数定义*/
  void Dissect   (int Miwen[],int key[], int sum[]);
  void pri       (int a[],   int n);
  void Mkey      (int key[], int key1[], int key2[]);
  void Cod       (int arr[], int key[],  int cod[],   int n);
  void Decod     (int cod[], int key[],  int n);
  void coding    (int Min[], int key[],  int sum[]);

  void ArrSwap   (int bit[], int b[],    int Swap[],  int n);
  void left      (int bit[], int left[], int n);
  void right     (int bit[], int right[],int n);
  void XOR       (int bit1[],int bit2[], int xorBit[],int n);
  void s0s1      (int bit[], int s[]);
  void AtoB      (int a[],   int b[],    int n);
  int toInt      (int bit1,  int bit2);
  void toBit     (int intnum,int s[]);
  void  LeftMove (int bit[], int n);

 /*先输入10位二进制密钥key，期中若输入的数字不是二进制，报错，退出*/
 /*然后再输入n位明文，n为自己输入的数字，若输入的数字不是二进制，同样会报错，退出*/
 /*输入完之后，回车，就会显示key1,key2子密钥，以及加密后的密文以及解密后的明文*/
int main()

{

  int i=0;
  int key[10];
  int cod[255],key1[8],key2[8],arr[255];
  int n;
  printf("input the 10bit key:\n");
  for(i=0;i<10;i++)
  {   printf("NO%d: ",i+1);
      scanf("%3d",&key[i]);
     if(key[i]!=1&&key[i]!=0)
     { printf("It isn't bit!\n");getch();return 0;}
  }

  printf("\ninput the bit num: ");
  scanf("%d",&n);
  printf("input the %d bit:\n",n);
  for(i=0;i<n;i++)
  {   printf("NO%d: ",i+1);
      scanf("%3d",&arr[i]);
     if(arr[i]!=1&&arr[i]!=0)
     { printf("It isn't bit!\n");getch();return 0;}
  }