DES加密解密函数

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 





	}

}