using System;

using Org.BouncyCastle.Crypto;

using Org.BouncyCastle.Crypto.Generators;

using Org.BouncyCastle.Security;

using Org.BouncyCastle.Crypto.Parameters;

public class Program

{

    public static void Main()

    {

        string pin = "12345678";

        string hash = BCPasswordHash.CreateHash(pin);

        Console.WriteLine(hash);

        Console.WriteLine("Verified: " + BCPasswordHash.ValidatePassword(pin, hash));

    }

}

​

    /// <summary>

    /// Salted password hashing with PBKDF2-SHA1.

    /// Author: havoc AT defuse.ca

    /// www: http://crackstation.net/hashing-security.htm

    /// Compatibility: .NET 3.0 and later.

    /// </summary>

    public class BCPasswordHash

    {

        // The following constants may be changed without breaking existing hashes.

        public const int SALT_BYTE_SIZE = 32;

        public const int SALT_BASE64_LENGTH = (SALT_BYTE_SIZE / 3 + (SALT_BYTE_SIZE % 3 > 0 ? 1 : 0)) * 4;

        public const int HASH_BYTE_SIZE = 16;

        public const int PBKDF2_ITERATIONS = 1000;

​

        public const int ITERATION_INDEX = 0;

        public const int SALT_INDEX = 1;

        public const int PBKDF2_INDEX = 2;

        private static SecureRandom CryptoRandom = new SecureRandom();

        //private static Random CryptoRandom = new Random();

        /// <summary>

        /// Creates a salted PBKDF2 hash of the password.

        /// </summary>

        /// <param name="password">The password to hash.</param>

        /// <returns>The hash of the password.</returns>

        public static string CreateHash(string password)

        {

            // Generate a random salt

            byte[] salt = new byte[SALT_BYTE_SIZE];

            CryptoRandom.NextBytes(salt);

​

            // Hash the password and encode the parameters

            byte[] hash = PBKDF2(password, salt, PBKDF2_ITERATIONS, HASH_BYTE_SIZE);

            string saltString = Convert.ToBase64String(salt);

            string hashString = Convert.ToBase64String(hash);

            return saltString + hashString;

        }

​

        /// <summary>

        /// Validates a password given a hash of the correct one.

        /// </summary>

        /// <param name="password">The password to check.</param>

        /// <param name="correctHash">A hash of the correct password.</param>

        /// <returns>True if the password is correct. False otherwise.</returns>

        public static bool ValidatePassword(string password, string correctHash)

        {

            string saltString = correctHash.Substring(0, SALT_BASE64_LENGTH);

            string hashString = correctHash.Substring(SALT_BASE64_LENGTH);

            byte[] salt = Convert.FromBase64String(saltString);

            byte[] hash = Convert.FromBase64String(hashString);

​

            byte[] testHash = PBKDF2(password, salt, PBKDF2_ITERATIONS, hash.Length);

            return SlowEquals(hash, testHash);

        }

​

        /// <summary>

        /// Compares two byte arrays in length-constant time. This comparison

        /// method is used so that password hashes cannot be extracted from

        /// on-line systems using a timing attack and then attacked off-line.

        /// </summary>

        /// <param name="a">The first byte array.</param>

        /// <param name="b">The second byte array.</param>

        /// <returns>True if both byte arrays are equal. False otherwise.</returns>

        private static bool SlowEquals(byte[] a, byte[] b)

        {

            uint diff = (uint)a.Length ^ (uint)b.Length;

            for (int i = 0; i < a.Length && i < b.Length; i++)

                diff |= (uint)(a[i] ^ b[i]);

            return diff == 0;

        }

​

        /// <summary>

        /// Computes the PBKDF2-SHA1 hash of a password.

        /// </summary>

        /// <param name="password">The password to hash.</param>

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

        /// <param name="iterations">The PBKDF2 iteration count.</param>

        /// <param name="outputBytes">The length of the hash to generate, in bytes.</param>

        /// <returns>A hash of the password.</returns>

        private static byte[] PBKDF2(string password, byte[] salt, int iterations, int outputBytes)

        {

            var pdb = new Pkcs5S2ParametersGenerator();

            pdb.Init(PbeParametersGenerator.Pkcs5PasswordToBytes(password.ToCharArray()), salt,

                         iterations);

            var key = (KeyParameter)pdb.GenerateDerivedMacParameters(outputBytes * 8);

            return key.GetKey();

        }

    }

​

​