fulib

defmodule Fulib.RSA.PrivateKey do
  defstruct version: nil,
            public_exponent: nil,
            public_modulus: nil,
            private_exponent: nil,
            prime_one: nil,
            prime_two: nil,
            exponent_one: nil,
            exponent_two: nil,
            ctr_coefficient: nil,
            other_prime_infos: nil

  @type t :: %Fulib.RSA.PrivateKey{
          version: atom,
          public_exponent: integer,
          public_modulus: integer,
          private_exponent: integer,
          prime_one: integer,
          prime_two: integer,
          exponent_one: integer,
          exponent_two: integer,
          ctr_coefficient: integer,
          other_prime_infos: atom
        }

  def from_sequence(rsa_key_seq) do
    %Fulib.RSA.PrivateKey{}
    |> struct(
      version: elem(rsa_key_seq, 1),
      public_exponent: elem(rsa_key_seq, 2),
      public_modulus: elem(rsa_key_seq, 3),
      private_exponent: elem(rsa_key_seq, 4),
      prime_one: elem(rsa_key_seq, 5),
      prime_two: elem(rsa_key_seq, 6),
      exponent_one: elem(rsa_key_seq, 7),
      exponent_two: elem(rsa_key_seq, 8),
      ctr_coefficient: elem(rsa_key_seq, 9),
      other_prime_infos: elem(rsa_key_seq, 10)
    )
  end

  def as_sequence(rsa_private_key) do
    case rsa_private_key do
      %Fulib.RSA.PrivateKey{} ->
        {:ok,
         {
           :RSAPrivateKey,
           rsa_private_key.version,
           rsa_private_key.public_exponent,
           rsa_private_key.public_modulus,
           rsa_private_key.private_exponent,
           rsa_private_key.prime_one,
           rsa_private_key.prime_two,
           rsa_private_key.exponent_one,
           rsa_private_key.exponent_two,
           rsa_private_key.ctr_coefficient,
           rsa_private_key.other_prime_infos
         }}

      _ ->
        {:error, "invalid Fulib.RSA.PrivateKey: #{inspect(rsa_private_key)}"}
    end
  end
end