using System;

using System.Security.Cryptography;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        var password = "Gisdata123";

        var username = "uDQFeSJppLXbDOZRWlPUtA==";

        var hash = Convert.ToBase64String(MD5.ComputeHash(string.Format("{0}/{1}", password, username.ToLower())));

        Console.WriteLine(hash);

    }

    public class MD5

    {

        #region Fields

​

        public static MD5CryptoServiceProvider x = null;

​

        #endregion Fields

​

        #region Methods

​

        /// <summary>

        /// Calcs the challenge hash.

        /// </summary>

        /// <param name="b_secret">The b_secret.</param>

        /// <param name="b_random">The b_random.</param>

        public static byte[] CalcChallengeHash(byte[] b_secret, byte[] b_random)

        {

            if (b_secret == null || b_random == null)

                return null;

​

            byte[] buf = new byte[b_random.Length + b_secret.Length];

            Buffer.BlockCopy(b_random, 0, buf, 0, b_random.Length);

            Buffer.BlockCopy(b_secret, 0, buf, b_random.Length, b_secret.Length);

​

            return ComputeHash(buf);

        }

​

        /// <summary>

        /// Computes the hash.

        /// </summary>

        /// <param name="txt">The text.</param>

        public static byte[] ComputeHash(string txt)

        {

            if (txt == null)

                return null;

​

            return ComputeHash(Encoding.UTF8.GetBytes(txt));

        }

​

        /// <summary>

        /// Computes the hash.

        /// </summary>

        /// <param name="plaintext">The plaintext.</param>

        public static byte[] ComputeHash(byte[] plaintext)

        {

            if (plaintext == null)

                return null;

​

            if (x == null)

                x = new MD5CryptoServiceProvider();

​

            return x.ComputeHash(plaintext);

        }

​

        /// <summary>

        /// Determines whether the specified a is equal to b.

        /// </summary>

        /// <param name="a">The a.</param>

        /// <param name="b">The b.</param>

        /// <returns>

        ///  <c>true</c> if the specified a is equal to b; otherwise, <c>false</c>.

        /// </returns>

        public static bool IsEqual(byte[] a, byte[] b)

        {

            if (a == null || b == null)

                return false;

​

            if (a.Length != b.Length)

                return false;

​

            for (int i = 0; i < a.Length; i++) if (a[i] != b[i]) return false;

​

            return (a.Length > 0);

        }

​

        #endregion Methods

    }

}