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

namespace EIP.Framework ...{ public class Security ...{ string _QueryStringKey = "abcdefgh"; //URL传输参数加密Key string _PassWordKey = "hgfedcba"; //PassWord加密Key 

public Security() ...{ } 

public string EncryptQueryString(string QueryString) ...{ return Encrypt(QueryString,_QueryStringKey); } 

public string DecryptQueryString(string QueryString) ...{ return Decrypt(QueryString,_QueryStringKey); } 

public string EncryptPassWord(string PassWord) ...{ return Encrypt(PassWord,_PassWordKey); } 

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; } } } } }