一个简单的解密程序

最新推荐文章于 2024-07-06 15:38:34 发布

原创最新推荐文章于 2024-07-06 15:38:34 发布 · 1.1k 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#解密 #ios #file #output #input #加密

C++ 专栏收录该内容

17 篇文章

订阅专栏

博客给出了文件输入输出的加密和解密过程代码。加密时从1.txt读取内容，经处理后写入2.txt；解密时从2.txt读取内容，处理后写入3.txt。若文件打开失败会输出错误信息并退出程序。

加密过程：

#include<iostream>
#include<fstream>
void main(void)
{
char strch,ch;
   int i,x;
ifstream readfile;
ofstream writefile;
readfile.open("1.txt",ios::in | ios::nocreate);
if(!readfile)
{
cerr<<"cannot open thie file for input"<<endl;
exit(0);    }
writefile.open("2.txt",ios::in | ios::nocreate);
if(!writefile)
{
cerr<<"cannot open the file for output"<<endl;
exit(0);   }
while(!readfile.eof())
{
ch=readfile.get();
x=static_cast<int>(ch);
x=(x+3)%128;
strch=static_cast<char>(x);
writefile.put(strch);
}
}

相应的解密过程：

#include<iostream>
#include<string>
#include<fstream>
void main(void){
   char strch,ch;
   int i,x;
   ifstream readfile;
   ofstream writefile;

   readfile.open("2.txt",ios::in | ios::nocreate);
   if(!readfile)
     {
    cerr<<"cannot open thie file for input"<<endl;
     exit(0);
      }

   writefile.open("3.txt",ios::in | ios::nocreate);
   if(!writefile)
      {
    cerr<<"cannot open the file for output"<<endl;
          exit(0);
         }

      while(!readfile.eof())
         {
     ch=readfile.get();
     x=static_cast<int>(ch);
     x=(x-3)%128;
      strch=static_cast<char>(x);
     writefile.put(strch);
        }
      }