MD5加密，解密

using System;

using System.Collections.Generic;

using System.Text;

using System.Globalization;

using System.Security.Cryptography;

using System.IO;

namespace WindowsApplication2

{

    class DES

    {

        // 创建Key

        public string GenerateKey()

        {

            DESCryptoServiceProvider desCrypto = (DESCryptoServiceProvider)DESCryptoServiceProvider.Create();

            return ASCIIEncoding.ASCII.GetString(desCrypto.Key);

        }

        ///MD5加密

        public string MD5Encrypt(string pToEncrypt, string sKey)

        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);

            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);

            cs.Write(inputByteArray, 0, inputByteArray.Length);

            cs.FlushFinalBlock();

            StringBuilder ret = new StringBuilder();

            foreach (byte b in ms.ToArray())

            {

                ret.AppendFormat("{0:X2}", b);

            }

            ret.ToString();

            return ret.ToString();

 



        }

 

        ///MD5解密

        public string MD5Decrypt(string pToDecrypt, string sKey)

        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

 

            byte[] inputByteArray = new byte[pToDecrypt.Length / 2];

            for (int x = 0; x < pToDecrypt.Length / 2; x++)

            {

                int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));

                inputByteArray[x] = (byte)i;

            }

 

            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);

            cs.Write(inputByteArray, 0, inputByteArray.Length);

            cs.FlushFinalBlock();

 

            StringBuilder ret = new StringBuilder();

 

            return System.Text.Encoding.Default.GetString(ms.ToArray());

        }

 

 

 

    }

}