wjcdestest.cpp

DES算法加解密全套程序

// 3-Des test

#include "WjcDes.h"
#include "stdio.h"
#include "string.h"
#include "memory.h"

 #include   <string.h>   
  #include   <stdio.h>   
#define N 100
void main()
{
/////////代码由于从txt读数据到字符串，默认的字符个数为N，但是一般输入小于N，所以出现溢出，运行后会出现
	///////报错，但是不影响程序加密，加密完将2.txt文件拷贝到解密程序文件夹，直接可解密

///////PART1：从1.txt中读取要加密的数据，数据大小为N，定义成宏，可以修改
		 FILE   *stream;   
       // char   string[]   =   "This   is   a   test";   
        char   msg[N];   
	stream   =   fopen("1.txt",   "r+");     
        /*   write   a   string   into   the   file   */   
       // fwrite(string,   strlen(string),   1,   stream);       
        /*   seek   to   the   start   of   the   file   */   
        fseek(stream,   0,   SEEK_SET);     
        /*   read   a   string   from   the   file   */   
        //fgets(msg,   strlen(string)+1,   stream); 
		fgets(msg,   N,   stream);    


//////PART2，设定key，并且将1.txt的数据读入des加密函数
	char key[]={0,2,0,0,9,3,5,1,9,8,0,0,9,1,7},buf[N];
		char str[N];
			for (int i=0;i<=N-1;i++)
	{
	
		str[i]=0;
		
	}
	for (int j=0;j<=N-1;j++)
	{
	
		str[j]=msg[j];

	}

	memset(buf, 0, sizeof(buf));
	strcpy(buf, str);
	puts("\nBefore encrypting");
	puts(buf);

	Des_Go(buf, buf, sizeof(str), key, sizeof(key), ENCRYPT);
	puts("\nAfter encrypting");
	puts(buf);

//	Des_Go(buf, buf, sizeof(str), key, sizeof(key), DECRYPT);
//	puts("\nAfter decrypting");
//	puts(buf);

//	getchar();
//////////////////////////////////////////
    
    //////PART3：完成加密，输出为2.txt
        /*   open   a   file   for   update   */   
		stream   =   fopen("2.txt",   "w+");   
	
    
        /*   write   a   string   into   the   file   */   
      fwrite(buf,   strlen(buf),   1,   stream);   
    
        /*   seek   to   the   start   of   the   file   */   
        fseek(stream,   0,   SEEK_SET);   
    
        /*   read   a   string   from   the   file   */   
        fgets(msg,   strlen(buf)+1,   stream); 
        /*   display   the   string   */   
		
       printf("%s",   msg);   
    
        fclose(stream);   

	getchar();


}