【原】DES Encrypt / Decrypt

using System;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.IO;
using System.Text;

namespace WB.OBE.OES.Common
{
    public static class EncryptExtensions
    {

        private static byte[] Keys = { 0xEF, 0xAB, 0x56, 0x78, 0x90, 0x34, 0xCD, 0x12 };
        /// <summary>
        /// DES Encrypt
        /// </summary>
        /// <param name="encryptString"></param>
        /// <param name="encryptKey">encryptKey</param>
        /// <returns></returns>
        public static string EncryptDES(this string encryptString, string encryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }

        /// <summary>
        /// DES Decrypt
        /// </summary>
        /// <param name="decryptString"></param>
        /// <param name="decryptKey"></param>
        /// <returns></returns>
        public static string DecryptDES(this string decryptString, string decryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey.Substring(0, 8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Convert.FromBase64String(decryptString);
                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Encoding.UTF8.GetString(mStream.ToArray());
            }
            catch
            {
                return decryptString;
            }
        }
    }
}