MD5加密解密帮助类

using System;
using System.Security.Cryptography;
using System.Text;
namespace Maticsoft.DBUtility
{
/// <summary>
/// DES加密/解密类。
/// </summary>
public class DESEncrypt
{
public DESEncrypt()
{
}

#region ========加密========

/// <summary>
/// 加密
/// </summary>
/// <param name="Text"></param>
/// <returns></returns>
public static string Encrypt(string Text)
{
return Encrypt(Text,"litianping");
}
/// <summary>
/// 加密数据
/// </summary>
/// <param name="Text"></param>
/// <param name="sKey"></param>
/// <returns></returns>
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========

/// <summary>
/// 解密
/// </summary>
/// <param name="Text"></param>
/// <returns></returns>
public static string Decrypt(string Text)
{
return Decrypt(Text,"litianping");
}
/// <summary>
/// 解密数据
/// </summary>
/// <param name="Text"></param>
/// <param name="sKey"></param>
/// <returns></returns>
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<len;x++)
{
i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
inputByteArray[x]=(byte)i;
}
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.CreateDecryptor(),CryptoStreamMode.Write);
cs.Write(inputByteArray,0,inputByteArray.Length);
cs.FlushFinalBlock();
return Encoding.Default.GetString(ms.ToArray());
}

#endregion

}
}