C# DES加密类，16位的加密。

这个加密类是与java写的DES加密不同时，自己写的，最后与Java的加密相同了，解决了加密后不同的问题。

可以直接调用里面的加密和解密的方法。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

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

namespace EallNum.Helper
{

    public class FI_DesTools
    {
        private FI_DesTools()
        {
        } 

        private static string key = "×××××"; 

        /// <summary>
        /// 对称加密解密的密钥
        /// </summary>
        public static string Key
        {
            get
            {
                return key;
            }
            set
            {
                key = value;
            }
        } 

        /// <summary>
        /// DES加密
        /// </summary>
        /// <param name="encryptString"></param>
        /// <returns></returns>
        public static string DesEncrypt(string strEncryptString)
        {
            StringBuilder strRetValue = new StringBuilder();

            try
            {
                byte[] keyBytes = Encoding.UTF8.GetBytes(key.Substring(, ));
                byte[] keyIV = keyBytes;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(strEncryptString);
                DESCryptoServiceProvider provider = new DESCryptoServiceProvider();

                provider.Mode = CipherMode.ECB;//兼容其他语言的Des加密算法
                provider.Padding = PaddingMode.Zeros;//自动补0

                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, provider.CreateEncryptor(keyBytes, keyIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, , inputByteArray.Length);
                cStream.FlushFinalBlock(); 

                //不使用base64编码
                //return Convert.ToBase64String(mStream.ToArray()); 

                //组织成16进制字符串
                foreach (byte b in mStream.ToArray())
                {
                    strRetValue.AppendFormat("{0:X2}", b);
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
            }

            return strRetValue.ToString();
        } 

        /// <summary>
        /// DES解密
        /// </summary>
        /// <param name="decryptString"></param>
        /// <returns></returns>
        public static string DesDecrypt(string strDecryptString)
        {
            string strRetValue = "";

            try
            {
                byte[] keyBytes = Encoding.UTF8.GetBytes(key.Substring(, ));
                byte[] keyIV = keyBytes;

                //不使用base64解码
                //byte[] inputByteArray = Convert.FromBase64String(decryptString);

                //16进制转换为byte字节
                byte[] inputByteArray = new byte[strDecryptString.Length / ];
                for (int x = ; x < strDecryptString.Length / ; x++)
                {
                    int i = (Convert.ToInt32(strDecryptString.Substring(x * , ), ));
                    inputByteArray[x] = (byte)i;
                }

                DESCryptoServiceProvider provider = new DESCryptoServiceProvider();

                provider.Mode = CipherMode.ECB;//兼容其他语言的Des加密算法
                provider.Padding = PaddingMode.Zeros;//自动补0  

                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, provider.CreateDecryptor(keyBytes, keyIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, , inputByteArray.Length);
                cStream.FlushFinalBlock();

                //需要去掉结尾的null字符
                //strRetValue = Encoding.UTF8.GetString(mStream.ToArray());
                strRetValue = Encoding.UTF8.GetString(mStream.ToArray()).TrimEnd('\0');
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
            }

            return strRetValue;
        }
    }
}

参考页面：http://qingqingquege.cnblogs.com/p/5933752.html