#region << 版 本 注 释 >>
/**
 * 文件名： DESDZFP
 *【功 能】
 *  
 *  
 *   版本       变更时间     部门    作者             变更内容
 * ───────────────────────────────────────────────────────────────────────────────────
 *   V1.0.0     $DATE$           	 陈嘉俊           初版
 *   
 *
 * Copyright(c)$YEAR$ Zhejiang Aisino Co.,Ltd. All Rights Reserved.
 * LICENSE INFORMATION
 */
#endregion

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

namespace SiteCore.nuonuo
{

    [Guid("88433774-746B-4B6D-B043-471EBEC31718")]
    public interface IDESDZFP
    {
        string Encrypt(string content);

        string Decrypt(string ciphertext);
    }

    [ClassInterface(ClassInterfaceType.None)]
    [Guid("2AA75AD0-92E8-421D-9B49-C192BF13A606")]
    public class DESDZFP
    {
        private const string Password = "LmMGStGtOpF4xNyvYt54EQ==";

        /// <summary>
        /// 加密报文数据
        /// </summary>
        /// <param name="content">待加密的报文</param>
        /// <returns>密文</returns>
        public static string Encrypt(string content)
        {
            if (string.IsNullOrEmpty(content))
            {
                throw new Exception("明文为空!");
            }

            byte[] BKey = new byte[8];
            byte[] BIV = new byte[8];
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            des.Mode = CipherMode.CBC;
            des.Padding = PaddingMode.PKCS7;
            byte[] bytes = Convert.FromBase64String(Password);
            Buffer.BlockCopy(bytes, 0, BKey, 0, 8);
            Buffer.BlockCopy(bytes, 8, BIV, 0, 8);



            byte[] encrypt = Encoding.UTF8.GetBytes(content);

            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
            byte[] md5Hash = md5.ComputeHash(encrypt, 0, encrypt.Length);
            byte[] totalByte = CombineBytes(md5Hash, encrypt);

            using (MemoryStream ms = new MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(BKey, BIV), CryptoStreamMode.Write))
                {
                    cs.Write(totalByte, 0, totalByte.Length);
                    cs.FlushFinalBlock();
                    return Convert.ToBase64String(ms.ToArray());
                }

            }
        }

        /// <summary>
        /// 解密报文数据
        /// </summary>
        /// <param name="ciphertext">待解密的报文</param>
        /// <returns>明文</returns>
        public static string Decrypt(string ciphertext)
        {

            if (string.IsNullOrEmpty(ciphertext))
            {
                throw new Exception("密文为空!");
            }

            ciphertext = ciphertext.Replace(" ", "+");

            byte[] BKey = new byte[8];
            byte[] BIV = new byte[8];
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            des.Mode = CipherMode.CBC;
            des.Padding = PaddingMode.PKCS7;
            byte[] bytes = Convert.FromBase64String(Password);
            Buffer.BlockCopy(bytes, 0, BKey, 0, 8);
            Buffer.BlockCopy(bytes, 8, BIV, 0, 8);

            byte[] totalByte = null;
            using (MemoryStream ms = new MemoryStream())
            {
                byte[] inData = Convert.FromBase64String(ciphertext);
                using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(BKey, BIV), CryptoStreamMode.Write))
                {
                    cs.Write(inData, 0, inData.Length);
                    cs.FlushFinalBlock();
                    totalByte = ms.ToArray();
                }
            }

            if (totalByte.Length <= 16)
            {
                throw new Exception("密文格式错误!");
            }

            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
            byte[] md5Hash = md5.ComputeHash(totalByte, 16, totalByte.Length - 16);

            for (int i = 0; i < md5Hash.Length; i++)
            {
                if (md5Hash[i] != totalByte[i])
                    throw new Exception("Md5校验失败!");
            }

            return Encoding.UTF8.GetString(totalByte, 16, totalByte.Length - 16);
        }

        private static byte[] CombineBytes(byte[] bytes1, byte[] bytes2)
        {
            int len = bytes1.Length + bytes2.Length;
            byte[] lenArr = new byte[len];
            bytes1.CopyTo(lenArr, 0);
            bytes2.CopyTo(lenArr, bytes1.Length);
            return lenArr;
        }
    }
}