# Pleroma: A lightweight social networking server # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.MFA.BackupCodes do @moduledoc """ This module contains functions for generating backup codes. """ alias Pleroma.Config @config_ns [:instance, :multi_factor_authentication, :backup_codes] @doc """ Generates backup codes. """ @spec generate(Keyword.t()) :: list(String.t()) def generate(opts \\ []) do number_of_codes = Keyword.get(opts, :number_of_codes, default_backup_codes_number()) code_length = Keyword.get(opts, :length, default_backup_codes_code_length()) Enum.map(1..number_of_codes, fn _ -> :crypto.strong_rand_bytes(div(code_length, 2)) |> Base.encode16(case: :lower) end) end defp default_backup_codes_number, do: Config.get(@config_ns ++ [:number], 5) defp default_backup_codes_code_length, do: Config.get(@config_ns ++ [:length], 16) end