C# MD5加解密

using System;
using System.Collections.Generic;
using System.Text;
using System.Security.Cryptography;
using System.IO;
 
namespace Inventory
{
    class MD5
    {
        #region 使用MD5进行数据加密。
        /// <summary>   
        /// 使用MD5进行数据加密。    
        /// </summary>   
        /// <param name="str">需要加密的数据。</param>   
        /// <param name="kind">加密类型：1-普通加密；2-密码加密</param>   
        /// <returns>返回加密的数据</returns>   
 
        public string GetMD5(string str, int kind)
        {
            string reStr = "";
            //获取要加密的字段，并转化为Byte[]数组   
            byte[] data = System.Text.Encoding.Unicode.GetBytes(str.ToCharArray());
 
            //建立加密服务   
            System.Security.Cryptography.MD5 md5 = new
            System.Security.Cryptography.MD5CryptoServiceProvider();
            //1代表加密Byte[]数组   
            if (kind == 1)
            {
                //加密Byte[]数组   
                byte[] result = md5.ComputeHash(data);
                //将加密后的数组转化为字段   
                string sResult = System.Text.Encoding.Unicode.GetString(result);
                //MD5普通加密   
                reStr = sResult.ToString();
            }
                //2代表作为密码方式加密   
            else if (kind == 2)
            {
                //作为密码方式加密   
                string EnPswdStr = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile
               (str, "MD5");
                //MD5密码加密   
                reStr = EnPswdStr;
            }
            return reStr.ToString();
        }
        #endregion
        /// <summary>   
        /// 对数据进行加密。   
        /// </summary>   
        /// <param name="strText">传入加密的数据</param>   
        /// <returns>返回加密后的字字符串</returns>   
 
        public string EncryptText(String strText)
        {
            return Encrypt(strText, "&%#@?,:*_");
        }
 
        /// <summary>   
        /// 对数据进行解密。   
        /// </summary>   
        /// <param name="strText">传入解密的数据</param>   
        /// <returns>返回解密后的字字符串</returns>    
 
        public String DecryptText(String strText)
        {
            return Decrypt(strText, "&%#@?,:*_");
        }
 
        #region 加密解密函数
        /// <summary>   
        /// 加密函数   
        /// </summary>   
        /// <param name="strText"></param>   
        /// <param name="strEncrKey"></param>   
        /// <returns></returns>   
 
        private String Encrypt(String strText, String strEncrKey)
        {
 
            Byte[] byKey = { };
            Byte[] IV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
            try
            {
                byKey = System.Text.Encoding.UTF8.GetBytes(strEncrKey.Substring(0, 8));
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                Byte[] inputByteArray = Encoding.UTF8.GetBytes(strText);
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(byKey, IV),
           CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                return Convert.ToBase64String(ms.ToArray());
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
        }
        /// <summary>   
        /// 解密函数   
        /// </summary>   
        /// <param name="strText"></param>   
        /// <param name="sDecrKey"></param>   
        /// <returns></returns>   
 
        private String Decrypt(String strText, String sDecrKey)
        {
 
            Byte[] byKey = { };
            Byte[] IV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
            Byte[] inputByteArray = new byte[strText.Length];
            try
            {
                byKey = System.Text.Encoding.UTF8.GetBytes(sDecrKey.Substring(0, 8));
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                inputByteArray = Convert.FromBase64String(strText);
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(byKey, IV),
           CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                System.Text.Encoding encoding = System.Text.Encoding.UTF8;
                return encoding.GetString(ms.ToArray());
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
        }
        #endregion
    }
}