internal byte[] HashPassword(string password)
 {
     var cryptoServiceProvider = new System.Security.Cryptography.MD5CryptoServiceProvider();
     byte[] dataToHash = _nonce1.Concat(Encoding.UTF8.GetBytes(password)).Concat(_nonce2).ToArray();
     var hash = cryptoServiceProvider.ComputeHash(dataToHash);
     return hash;
 }

        /// <summary>
        /// 获得字节数组MD5值
        /// </summary>
        /// <param name="data">字节数组</param>
        /// <returns>返回MD5值</returns>
        public static string GetMD5Hash(byte[] data)
        {
            string strResult = "";
                string strHashData = "";

                byte[] arrbytHashValue;

                System.Security.Cryptography.MD5CryptoServiceProvider oMD5Hasher =
                           new System.Security.Cryptography.MD5CryptoServiceProvider();

                try
                {

                    arrbytHashValue = oMD5Hasher.ComputeHash(data);

                    strHashData = System.BitConverter.ToString(arrbytHashValue);
                    strHashData = strHashData.Replace("-", "");
                    strResult = strHashData;
                }
                catch
                {
                    //System.Windows.Forms.MessageBox.Show(ex.Message, "Error!",System.Exception ex
                    //           System.Windows.Forms.MessageBoxButtons.OK,
                    //           System.Windows.Forms.MessageBoxIcon.Error,
                    //           System.Windows.Forms.MessageBoxDefaultButton.Button1);
                }

                return (strResult);
        }

        public static string GetMD5(string filePath)
        {
            string strResult = "";
            string strHashData = "";

            byte[] arrbytHashValue;
            System.IO.FileStream oFileStream = null;

            System.Security.Cryptography.MD5CryptoServiceProvider oMD5Hasher =
                       new System.Security.Cryptography.MD5CryptoServiceProvider();

            try
            {
                oFileStream = new System.IO.FileStream(filePath, System.IO.FileMode.Open,
                      System.IO.FileAccess.Read, System.IO.FileShare.ReadWrite);
                arrbytHashValue = oMD5Hasher.ComputeHash(oFileStream);//计算指定Stream 对象的哈希值
                oFileStream.Close();
                //由以连字符分隔的十六进制对构成的String，其中每一对表示value 中对应的元素；例如“F-2C-4A”
                strHashData = System.BitConverter.ToString(arrbytHashValue);
                //替换-
                strHashData = strHashData.Replace("-", "");
                strResult = strHashData;
            }
            catch (System.Exception ex)
            {

            }

            return strResult;
        }

 static void Main(string[] args)
 {
     string test = "admin";
     System.Security.Cryptography.MD5CryptoServiceProvider md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
     byte[] test_encrypt = System.Text.Encoding.ASCII.GetBytes(test);
     byte[] result = md5.ComputeHash(test_encrypt);
 }

        //MD5によるハッシュ作成
        public static string Hash(string passStr,string timestampStr)
        {
            const int range = 64;
            var pass = Encoding.ASCII.GetBytes(passStr);
            var timestamp = Encoding.ASCII.GetBytes(timestampStr);
            var h = new System.Security.Cryptography.MD5CryptoServiceProvider();
            var k = new byte[range];
            if (range < pass.Length)
                throw new InvalidOperationException("key length is too long");
            var ipad = new byte[range];
            var opad = new byte[range];
            pass.CopyTo(k,0);
            for (var i = pass.Length; i < range; i++) {
                k[i] = 0x00;
            }
            for (var i = 0; i < range; i++) {
                ipad[i] = (byte)(k[i] ^ 0x36);
                opad[i] = (byte)(k[i] ^ 0x5c);
            }
            var hi = new byte[ipad.Length + timestamp.Length];
            ipad.CopyTo(hi,0);
            timestamp.CopyTo(hi,ipad.Length);
            var hash = h.ComputeHash(hi);
            var ho = new byte[opad.Length + hash.Length];
            opad.CopyTo(ho,0);
            hash.CopyTo(ho,opad.Length);
            h.Initialize();
            var tmp = h.ComputeHash(ho);

            var sb = new StringBuilder();
            foreach (var b in tmp) {
                sb.Append(b.ToString("x2"));
            }
            return sb.ToString();
        }

        public static byte[] ToMD5Bytes(this byte[] buffer)
        {
            var x = new System.Security.Cryptography.MD5CryptoServiceProvider();


            return x.ComputeHash(buffer);
        }

 public static string GetMd5(string str)
 {
     System.Security.Cryptography.MD5CryptoServiceProvider Md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
     byte[] src = System.Text.Encoding.ASCII.GetBytes(str);
     byte[] md5out=Md5.ComputeHash(src);
     return Convert.ToBase64String(md5out);
 }

 public string MD5(string str)
 {
     var md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
     var bs = md5.ComputeHash(System.Text.Encoding.UTF8.GetBytes(str));
     md5.Clear();
     return bs.Aggregate("", (current, b) => current + (b.ToString("x2")));
 }

 public string MaHoaMatKhau(string Password)
 {
     System.Security.Cryptography.MD5CryptoServiceProvider md5Hasher = new System.Security.Cryptography.MD5CryptoServiceProvider();
     byte[] hashedDataBytes = md5Hasher.ComputeHash(System.Text.UTF8Encoding.UTF8.GetBytes(Password));
     string EncryptPass = Convert.ToBase64String(hashedDataBytes);
     return EncryptPass;
 }

      /// <summary>
      /// Gets a string which represents a unique signature of this machine based on MAC addresses of interfaces.
      /// The signature has a form of: [intf.count]-[CRC32 of all MACs]-[convoluted MD5 of all MACs]
      /// </summary>
      public static string GetMachineUniqueMACSignature()
      {
          var nics = NetworkInterface.GetAllNetworkInterfaces();
          var buf = new byte[6 * 32];
          var ibuf = 0;
          var cnt=0;
          var csum = new NFX.IO.ErrorHandling.CRC32();
          foreach(var nic in nics.Where(a => a.NetworkInterfaceType!=NetworkInterfaceType.Loopback))
          {                       
            var mac = nic.GetPhysicalAddress().GetAddressBytes();
            csum.Add( mac );
            for(var i=0; i<mac.Length; i++)
            {
              buf[ibuf] = mac[i];
              ibuf++;
              if(ibuf==buf.Length) ibuf = 0;
            }
            cnt++;
          }

          var md5s = new StringBuilder();
          using (var md5 = new System.Security.Cryptography.MD5CryptoServiceProvider())
          {
               var hash = md5.ComputeHash(buf);
               for(var i=0 ; i<hash.Length ; i+=2)
                md5s.Append( (hash[i]^hash[i+1]).ToString("X2"));
          }
          
          return "{0}-{1}-{2}".Args( cnt, csum.Value.ToString("X8"),  md5s );
      }

        internal static string EncodePassword(string password, string hash)
        {
            byte[] hash_byte = new byte[hash.Length / 2];
            for (int i = 0; i <= hash.Length - 2; i += 2)
            {
                hash_byte[i / 2] = Byte.Parse(hash.Substring(i, 2), System.Globalization.NumberStyles.HexNumber, CultureInfo.InvariantCulture);
            }
            byte[] heslo = new byte[1 + password.Length + hash_byte.Length];
            heslo[0] = 0;
            Encoding.ASCII.GetBytes(password.ToCharArray()).CopyTo(heslo, 1);
            hash_byte.CopyTo(heslo, 1 + password.Length);

            Byte[] hotovo;
            System.Security.Cryptography.MD5 md5;

            md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();

            hotovo = md5.ComputeHash(heslo);

            //Convert encoded bytes back to a 'readable' string
            string result = "";
            foreach (byte h in hotovo)
            {
                result += h.ToString("x2", CultureInfo.InvariantCulture);
            }
            return result;
        }

 public static string GetEncondeMD5(string password)
 {
     System.Security.Cryptography.MD5 md5;
     md5 = new System.Security.Cryptography.MD5CryptoServiceProvider ();
     Byte[] encodedBytes = md5.ComputeHash (ASCIIEncoding.Default.GetBytes (password));
     return System.Text.RegularExpressions.Regex.Replace (BitConverter.ToString (encodedBytes).ToLower (), @"-", "");
 }

        public static string GetMD5Hash(string pathName)
        {
            string strResult = "";
            string strHashData = "";

            byte[] arrbytHashValue;
            System.IO.FileStream oFileStream = null;

            System.Security.Cryptography.MD5CryptoServiceProvider oMD5Hasher =
                       new System.Security.Cryptography.MD5CryptoServiceProvider();

            try
            {
                oFileStream = GetFileStream(pathName);
                arrbytHashValue = oMD5Hasher.ComputeHash(oFileStream);
                oFileStream.Close();

                strHashData = System.BitConverter.ToString(arrbytHashValue);
                strHashData = strHashData.Replace("-", "");
                strResult = strHashData;
                oMD5Hasher.Clear();
            }
            catch (System.Exception)
            {
                oMD5Hasher.Clear();
            }
            return (strResult);
        }

 private static string MD5(string theEmail)
 {
     var md5Obj = new System.Security.Cryptography.MD5CryptoServiceProvider();
     var bytesToHash = Encoding.ASCII.GetBytes(theEmail);
     bytesToHash = md5Obj.ComputeHash(bytesToHash);
     return bytesToHash.Aggregate("", (current, b) => current + b.ToString("x2"));
 }

 public void ProcessRequest(HttpContext context)
 {
     context.Response.ContentType = "text/plain";
     string md5Code = "NoUpdate";
     try
     {
         string fileName = context.Request.QueryString["FileName"];
         string filePath = context.Server.MapPath("App/Update/"+fileName);
         if (File.Exists(filePath))
         {
             FileStream file = new FileStream(filePath, FileMode.Open);
             System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
             byte[] retVal = md5.ComputeHash(file);
             file.Close();
             StringBuilder sb = new StringBuilder();
             for (int i = 0; i < retVal.Length; i++)
             {
                 sb.Append(retVal[i].ToString("x2"));
             }
             md5Code = sb.ToString();
         }
     }
     catch { }
     context.Response.Write(md5Code);
 }

 /// <summary>
 /// MD5 16位加密 加密后密码为大写
 /// </summary>
 /// <param name="ConvertString"></param>
 /// <returns></returns>
 public static string GetMd5Str(string ConvertString)
 {
     System.Security.Cryptography.MD5CryptoServiceProvider md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
     string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);
     t2 = t2.Replace("-", "");
     return t2;
 }

 public static string ComputeXCode(object o, string token)
 {
     var strs = ComputeSourceKey(o, token);
     var md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
     var bys = md5.ComputeHash(Encoding.Unicode.GetBytes(strs));
     return BitConverter.ToString(bys);
 }

        public static string GetMD5Hash( string pathName )
        {
            string strResult = "";
            string strHashData = "";

            byte[] arrbytHashValue;
            System.IO.FileStream oFileStream = null;

            System.Security.Cryptography.MD5CryptoServiceProvider oMD5Hasher =
                       new System.Security.Cryptography.MD5CryptoServiceProvider( );

            try
            {
                oFileStream = GetFileStream( pathName );
                arrbytHashValue = oMD5Hasher.ComputeHash( oFileStream );
                oFileStream.Close( );

                strHashData = System.BitConverter.ToString( arrbytHashValue );
                strHashData = strHashData.Replace( "-" , "" );
                strResult = strHashData;
            }
            catch ( System.Exception ex )
            {
                System.Windows.Forms.MessageBox.Show( ex.Message , "Error!" ,
                           System.Windows.Forms.MessageBoxButtons.OK ,
                           System.Windows.Forms.MessageBoxIcon.Error ,
                           System.Windows.Forms.MessageBoxDefaultButton.Button1 );
            }

            return ( strResult );
        }

 public static string ToMd5Pass(this string value)
 {
     byte[] hash = new System.Security.Cryptography.MD5CryptoServiceProvider().ComputeHash(ToByteArray(value));
     string result = System.BitConverter.ToString(hash);
     result = result.Replace("-", "");
     return result;
 }

 public static string CreateHash(string unHashed)
 {
     System.Security.Cryptography.MD5CryptoServiceProvider x = new System.Security.Cryptography.MD5CryptoServiceProvider();
     byte[] data = System.Text.Encoding.ASCII.GetBytes(unHashed);
     data = x.ComputeHash(data);
     return System.Text.Encoding.ASCII.GetString(data);
 }