PasswordHasher.cs

public string Hash(string password)
{
  using (var algorithm = new Rfc2898DeriveBytes(
    password,
    SaltSize,
    Options.Iterations,
    HashAlgorithmName.SHA256))
  {
    var key = Convert.ToBase64String(algorithm.GetBytes(KeySize));
    var salt = Convert.ToBase64String(algorithm.Salt);

    return $"{Options.Iterations}.{salt}.{key}";
  }
}