using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Security.Cryptography;

using System.Text;

using System.IO;

namespace Common

{

    /// <summary>

    /// 加密解密类

    /// </summary>

    public class EnCode

    {

        public EnCode()

        {

            //

            // TODO: 在此处添加构造函数逻辑

            //

        }

        /// <summary>

        /// 加密。注意：sKey输入密码的时候，必须使用英文字符，区分大小写，且字符数量是8个，不能多也不能少，否则出错。

        /// </summary>

        /// <param name="pToEncrypt"></param>

        /// <param name="sKey"></param>

        /// <returns></returns>

        public static string Encrypt(string pToEncrypt, string sKey)

        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            //把字符串放到byte数组中 

            byte[] inputBytArray = Encoding.Default.GetBytes(pToEncrypt);

            //建立加密对象的密钥和偏移量 

            //原文使用ASCIIEncoding.ASCII方法的GetBytes方法 

            //使得输入密码必须输入英文文本

            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);

            cs.Write(inputBytArray, 0, inputBytArray.Length);

            cs.FlushFinalBlock();

            StringBuilder ret = new StringBuilder();

            foreach (byte b in ms.ToArray())

            {

                ret.AppendFormat("{0:X2}", b);

            }

            return ret.ToString();

        }

        /// <summary>

        /// 解密

        /// </summary>

        /// <param name="pToDecrypt"></param>

        /// <param name="sKey"></param>

        /// <returns></returns>

        public static 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;

            }

            //建立加密对象的密钥和偏移量，此值重要，不能修改 

            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

            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();

            return System.Text.Encoding.Default.GetString(ms.ToArray());

        }







    }

}