C# DES加密

需要引用名称空间

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

具体代码：

     public class CryptoHelper
     {
         /// <summary>
         /// 使用DES加密
         /// </summary>
         /// <param name="plain">明文</param>
         /// <param name="key">加密钥匙</param>
         /// <param name="iv">向量</param>
         /// <returns>返回密文</returns>
         public static string DesEncode(string plain, string key, string iv)
         {
             //把密钥转换成字节数组
             byte[] keyBytes = Encoding.ASCII.GetBytes(key);

             //把向量转换成字节数组
             byte[] ivBytes = Encoding.ASCII.GetBytes(iv);

             //声明1个新的DES对象
             DESCryptoServiceProvider des = new DESCryptoServiceProvider();

             //开辟一块内存流
             MemoryStream msEncrypt = new MemoryStream();

             //把内存流对象包装成加密流对象
             CryptoStream csEncrypt = new CryptoStream(msEncrypt, des.CreateEncryptor(keyBytes, ivBytes), CryptoStreamMode.Write);

             //把加密流对象包装成写入流对象
             StreamWriter swEncrypt = new StreamWriter(csEncrypt);

             //写入流对象写入明文
             swEncrypt.WriteLine(plain);

             //写入流关闭
             swEncrypt.Close();

             //加密流关闭
             csEncrypt.Close();

             //把内存流转换成字节数组，内存流现在已经是密文了
             byte[] bytesCipher=msEncrypt.ToArray();

             //内存流关闭
             msEncrypt.Close();
             //将字节数组转化成Base64字符串
             return Convert.ToBase64String(bytesCipher);
         }

         public static string DesDeCode(string cipher, string key, string iv)
         {
             //将密文通过Base64位还原成字节数组
             byte[] cipherByte = Convert.FromBase64String(cipher);

             //把密钥转换成字节数组
             byte[] keyBytes = Encoding.ASCII.GetBytes(key);

             //把向量转换成字节数组
             byte[] ivBytes = Encoding.ASCII.GetBytes(iv);

             //声明1个新的DES对象
             DESCryptoServiceProvider des = new DESCryptoServiceProvider();

             //开辟一块内存流，并存放密文字节数组
             MemoryStream msDecrypt = new MemoryStream(cipherByte);

             //把内存流对象包装成解密流对象
             CryptoStream csDecrypt = new CryptoStream(msDecrypt, des.CreateDecryptor(keyBytes, ivBytes), CryptoStreamMode.Read);

             //把解密流对象包装成写入流对象
             StreamReader srDecrypt = new StreamReader(csDecrypt);

             //明文=读出流的读出内容
             string strPlainText=srDecrypt.ReadLine();

             //读出流关闭
             srDecrypt.Close();

             //解密流关闭
             csDecrypt.Close();

             //内存流关闭
             msDecrypt.Close();

             //返回明文
             return strPlainText;
         }
     }