{ config, lib, pkgs, ... }: with lib; let cfg = config.hardware.u2f; in { options = { hardware.u2f = { enable = mkOption { type = types.bool; default = false; description = '' Enable U2F hardware support. ''; }; }; }; config = mkIf cfg.enable { services.udev.packages = [ pkgs.libu2f-host ]; }; }