登录-密码加密解密

using System;
using System.Security.Cryptography;  
using System.Text;
namespace Common
{
	/// 

	/// DES加密/解密类。
	/// 
	public class DESEncrypt
	{
		public DESEncrypt()
		{			
		}

		#region ========加密======== 
 
        /// 

        /// 加密
        /// 
        /// 
        /// 
		public static string Encrypt(string Text) 
		{
			return Encrypt(Text,"yuying");
		}
		/// 
 
		/// 加密数据 
		/// 
 
		///  
		///  
		///  
		public static string Encrypt(string Text,string sKey) 
		{ 
			DESCryptoServiceProvider des = new DESCryptoServiceProvider(); 
			byte[] inputByteArray; 
			inputByteArray=Encoding.Default.GetBytes(Text); 
			des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8)); 
			des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8)); 
			System.IO.MemoryStream ms=new System.IO.MemoryStream(); 
			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); 
			} 
			return ret.ToString(); 
		} 

		#endregion
		
		#region ========解密======== 
   
 
        /// 

        /// 解密
        /// 
        /// 
        /// 
		public static string Decrypt(string Text) 
		{
			return Decrypt(Text,"yuying");
		}
		/// 
 
		/// 解密数据 
		/// 
 
		///  
		///  
		///  
		public static string Decrypt(string Text,string sKey) 
		{ 
			DESCryptoServiceProvider des = new DESCryptoServiceProvider(); 
			int len; 
			len=Text.Length/2; 
			byte[] inputByteArray = new byte[len]; 
			int x,i; 
			for(x=0;x