C＃DEC加密算法

C＃加密算法

using System;
using System.Security.Cryptography;
using System.IO;
using System.Text;

namespace NetTrade
{
 /// <summary>
 /// Security 的摘要说明。
 /// 类中URL及帐号加密使用了不同的KEY。调用URL加密过程如下： 
 ///EIP.Framework.Security objSecurity = new EIP.Framework.Security(); 
 ///objSecurity.EncryptQueryString(''待加密的字符串''); 
 ///解密:objSecurity.DecryptQueryString(''传递过来的参数);
 /// </summary>
 public class Security
 {
  string _QueryStringKey = "yx139222"; //URL传输参数加密Key 
  string _PassWordKey = "yx139222";  //PassWord加密Key 

  public Security() 
  { 
   // 
   // TODO: 在此处添加构造函数逻辑 
   // 
  } 

  ///  
  /// 加密URL传输的字符串 
  ///  
  ///  
  ///  
  public string EncryptQueryString(string QueryString) 
  { 
   return Encrypt(QueryString,_QueryStringKey); 
  } 

  ///  
  /// 解密URL传输的字符串 
  ///  
  ///  
  ///  
  public string DecryptQueryString(string QueryString) 
  { 
   return Decrypt(QueryString,_QueryStringKey); 
  } 

  ///  
  /// 加密帐号口令 
  ///  
  ///  
  ///  
  public string EncryptPassWord(string PassWord) 
  { 
   return Encrypt(PassWord,_PassWordKey); 
  } 

  ///  
  /// 解密帐号口令 
  ///  
  ///  
  ///  
  public string DecryptPassWord(string PassWord) 
  { 
   return Decrypt(PassWord,_PassWordKey); 
  } 
   
  ///  
  /// DEC 加密过程 
  ///  
  ///  
  ///  
  ///  
  public string Encrypt(string pToEncrypt,string sKey)   
  {   
   DESCryptoServiceProvider des = new DESCryptoServiceProvider();  //把字符串放到byte数组中   
    
   byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);   
   //byte[]  inputByteArray=Encoding.Unicode.GetBytes(pToEncrypt);   
   
   des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);  //建立加密对象的密钥和偏移量 
   des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);   //原文使用ASCIIEncoding.ASCII方法的GetBytes方法  
   MemoryStream ms = new MemoryStream();     //使得输入密码必须输入英文文本 
   CryptoStream cs = new CryptoStream(ms,des.CreateEncryptor(),CryptoStreamMode.Write);   
  
   cs.Write(inputByteArray, 0, inputByteArray.Length);   
   cs.FlushFinalBlock();   

   StringBuilder ret = new  StringBuilder();   
   foreach(byte b in ms.ToArray())   
   {   
    ret.AppendFormat("{0:X2}", b);   
   }   
   ret.ToString();   
   return  ret.ToString();   
  }   

  ///  
  /// DEC 解密过程 
  ///  
  ///  
  ///  
  ///  
  public string Decrypt(string pToDecrypt, string sKey)   
  {   
   DESCryptoServiceProvider des = new DESCryptoServiceProvider();   
  
   byte[] inputByteArray = new byte[pToDecrypt.Length / 2];   
   for(int x = 0; x < pToDecrypt.Length / 2; x++)   
   {   
    int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));   
    inputByteArray[x]  =  (byte)i;   
   }   
  
   des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);  //建立加密对象的密钥和偏移量，此值重要，不能修改   
   des.IV  = ASCIIEncoding.ASCII.GetBytes(sKey);   
   MemoryStream ms = new MemoryStream();   
   CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(),CryptoStreamMode.Write);   
    
   cs.Write(inputByteArray, 0, inputByteArray.Length);   
   cs.FlushFinalBlock();   

   StringBuilder ret = new StringBuilder();  //建立StringBuild对象，CreateDecrypt使用的是流对象，必须把解密后的文本变成流对象   
              
   return System.Text.Encoding.Default.GetString(ms.ToArray());   
  }  

  ///  
  /// 检查己加密的字符串是否与原文相同 
  ///  
  ///  
  ///  
  ///  
  ///  
  public bool ValidateString(string EnString, string FoString, int Mode) 
  { 
   switch (Mode) 
   { 
    default: 
    case 1: 
     if (Decrypt(EnString,_QueryStringKey) == FoString.ToString()) 
     { 
      return true; 
     } 
     else 
     { 
      return false; 
     } 
    case 2: 
     if (Decrypt(EnString,_PassWordKey) == FoString.ToString()) 
     { 
      return true; 
     } 
     else 
     { 
      return false; 
     } 
   } 
  }

//以下为另外一种加解密方式，比较简单 

  public string DecryptStr(string rs) //顺序减1解码
  {
   byte[] by=new byte[rs.Length];
   for(int i=0;i<=rs.Length-1;i++)
   {
    by[i]=(byte)((byte)rs[i]-1);
   }
   rs="";
   for(int i=by.Length-1;i>=0;i--)
   {
    rs+=((char)by[i]).ToString();
   }
   return rs;
  }

  public string EncryptStr(string rs) //倒序加1加密
  {
   byte[] by=new byte[rs.Length];
   for(int i=0;i<=rs.Length-1;i++)
   {
    by[i]=(byte)((byte)rs[i]+1);
   }
   rs="";
   for(int i=by.Length-1;i>=0;i--)
   {
    rs+=((char)by[i]).ToString();
   }
   return rs;
  }
 } 
}