using Microsoft.AspNetCore.Cryptography.KeyDerivation;

using System;

using System.Linq;

using System.Security.Cryptography;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        string hashed = CredentialEncryptionService.GenerateHashFromUnencryptedPassword(RandomString(12));

        Console.WriteLine($"Hashed key: {hashed}");

        Console.WriteLine($"Is ASCII? {IsAsciiString(hashed)}");

        Console.WriteLine($"String length: {hashed.Length}");

        Console.WriteLine($"Bits: {GetBits(hashed).Length}");

    }

​

    private static Random random = new Random();

    public static string RandomString(int length)

    {

        const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_!@#$%^&*()";

        return new string (Enumerable.Repeat(chars, length).Select(s => s[random.Next(s.Length)]).ToArray());

    }

​

    private static bool IsAsciiString(string s)

    {

        if (s == null)

            throw new ArgumentNullException("s");

        foreach (char c in s)

        {

            if (c > '\u007F')

                return false;

        }

​

        return true;

    }

​

    public static string GetBits(string input)

    {

        StringBuilder sb = new StringBuilder();

        foreach (byte b in Encoding.ASCII.GetBytes(input))

        {

            sb.Append(Convert.ToString(b, 2));

        }

​

        return sb.ToString();

    }

​

    public static class CredentialEncryptionService

    {

        public static string GenerateHashFromUnencryptedPassword(string plainTextPassword)

        {

            // generate a 128-bit salt using a cryptographically strong random sequence of nonzero values

            byte[] salt = new byte[128 / 8];

            using (var rngCsp = new RNGCryptoServiceProvider())

            {

                rngCsp.GetNonZeroBytes(salt);

            }

​

            // derive a 256-bit subkey (use HMACSHA256 with 100,000 iterations)

            string hashed = Convert.ToBase64String(KeyDerivation.Pbkdf2(password: plainTextPassword, salt: salt, prf: KeyDerivationPrf.HMACSHA256, iterationCount: 100000, numBytesRequested: 256 / 8));

            return hashed;

        }

    }

}