{
  nixos =
    {
      config,
      lib,
      pkgs,
      ...
    }:
    let
      cfg = config.features.gnupg;
    in
    {
      options.features.gnupg = {
        enable = lib.mkEnableOption "gnupg";

        yubikey.enable = lib.mkOption {
          type = lib.types.bool;
          default = false;
        };
      };

      config = lib.mkIf cfg.enable (
        lib.mkMerge [
          {
            programs.gnupg.agent = {
              enable = true;
              enableSSHSupport = true;
              enableExtraSocket = true;
            };
          }

          (lib.mkIf cfg.yubikey.enable {
            environment.systemPackages = with pkgs; [
              yubikey-personalization
              yubikey-manager
            ];

            services.pcscd.enable = true;
          })
        ]
      );
    };
}