C#自定义基于Base64的加密解密类

using System;
using System.Security.Cryptography; 
using System.Text;
namespace DotNet.Utilities
{
    /// <summary>
    /// Encrypt 的摘要说明。
    /// </summary>
    public class DEncrypt
    {
        /// <summary>
        /// 构造方法
        /// </summary>
        public DEncrypt() 
        { 
        }

    #region 使用 缺省密钥字符串 加密/解密string

    /// <summary>
    /// 使用缺省密钥字符串加密string
    /// </summary>
    /// <param name="original">明文</param>
    /// <returns>密文</returns>
    public static string Encrypt(string original)
    {
        return Encrypt(original,"sharejs.com");
    }
    /// <summary>
    /// 使用缺省密钥字符串解密string
    /// </summary>
    /// <param name="original">密文</param>
    /// <returns>明文</returns>
    public static string Decrypt(string original)
    {
        return Decrypt(original,"sharejs.com",System.Text.Encoding.Default);
    }

    #endregion

    #region 使用 给定密钥字符串 加密/解密string
    /// <summary>
    /// 使用给定密钥字符串加密string
    /// </summary>
    /// <param name="original">原始文字</param>
    /// <param name="key">密钥</param>
    /// <param name="encoding">字符编码方案</param>
    /// <returns>密文</returns>
    public static string Encrypt(string original, string key) 
    { 
        byte[] buff = System.Text.Encoding.Default.GetBytes(original); 
        byte[] kb = System.Text.Encoding.Default.GetBytes(key);
        return Convert.ToBase64String(Encrypt(buff,kb));     
    }
    /// <summary>
    /// 使用给定密钥字符串解密string
    /// </summary>
    /// <param name="original">密文</param>
    /// <param name="key">密钥</param>
    /// <returns>明文</returns>
    public static string Decrypt(string original, string key)
    {
        return Decrypt(original,key,System.Text.Encoding.Default);
    }

    /// <summary>
    /// 使用给定密钥字符串解密string,返回指定编码方式明文
    /// </summary>
    /// <param name="encrypted">密文</param>
    /// <param name="key">密钥</param>
    /// <param name="encoding">字符编码方案</param>
    /// <returns>明文</returns>
    public static string Decrypt(string encrypted, string key,Encoding encoding) 
    {      
        byte[] buff = Convert.FromBase64String(encrypted); 
        byte[] kb = System.Text.Encoding.Default.GetBytes(key);
        return encoding.GetString(Decrypt(buff,kb));     
    } 
    #endregion

    #region 使用 缺省密钥字符串 加密/解密/byte[]
    /// <summary>
    /// 使用缺省密钥字符串解密byte[]
    /// </summary>
    /// <param name="encrypted">密文</param>
    /// <param name="key">密钥</param>
    /// <returns>明文</returns>
    public static byte[] Decrypt(byte[] encrypted) 
    { 
        byte[] key = System.Text.Encoding.Default.GetBytes("sharejs.com");
        return Decrypt(encrypted,key);    
    }
    /// <summary>
    /// 使用缺省密钥字符串加密
    /// </summary>
    /// <param name="original">原始数据</param>
    /// <param name="key">密钥</param>
    /// <returns>密文</returns>
    public static byte[] Encrypt(byte[] original) 
    { 
        byte[] key = System.Text.Encoding.Default.GetBytes("sharejs.com");
        return Encrypt(original,key);    
    } 
    #endregion

    #region  使用 给定密钥 加密/解密/byte[]

    /// <summary>
    /// 生成MD5摘要
    /// </summary>
    /// <param name="original">数据源</param>
    /// <returns>摘要</returns>
    public static byte[] MakeMD5(byte[] original)
    {
        MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();  
        byte[] keyhash = hashmd5.ComputeHash(original);      
        hashmd5 = null; 
        return keyhash;
    }


    /// <summary>
    /// 使用给定密钥加密
    /// </summary>
    /// <param name="original">明文</param>
    /// <param name="key">密钥</param>
    /// <returns>密文</returns>
    public static byte[] Encrypt(byte[] original, byte[] key) 
    { 
        TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();      
        des.Key =  MakeMD5(key);
        des.Mode = CipherMode.ECB; 

        return des.CreateEncryptor().TransformFinalBlock(original, 0, original.Length);    
    } 

    /// <summary>
    /// 使用给定密钥解密数据
    /// </summary>
    /// <param name="encrypted">密文</param>
    /// <param name="key">密钥</param>
    /// <returns>明文</returns>
    public static byte[] Decrypt(byte[] encrypted, byte[] key) 
    { 
        TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider(); 
        des.Key =  MakeMD5(key);   
        des.Mode = CipherMode.ECB; 

        return des.CreateDecryptor().TransformFinalBlock(encrypted, 0, encrypted.Length);
    } 

    #endregion




}

}</pre>