nix-los/nixos/modules/yubikey.nix

{ pkgs, ... }:

{
  # Create the plugdev group (required for user-space USB access to YubiKey)
  users.groups.plugdev = {};

  # Enable PC/SC daemon — required for GPG smartcard (gpg --card-status) and YubiKey
  services.pcscd.enable = true;

  # udev rules so the YubiKey gets plugdev group ownership and correct permissions
  services.udev.packages = with pkgs; [
    yubikey-personalization
    libu2f-host
    ccid
  ];

  # CCID driver for smartcard access (required for YubiKey CCID functionality)
  # Set up the PC/SC drivers directory with CCID driver bundle
  system.activationScripts.pcscdSetup = ''
    mkdir -p /var/lib/pcsc/drivers/ccid.bundle
    # Try to symlink CCID bundle files if they exist
    if [ -d "${pkgs.ccid}/lib/pcsc/drivers/ccid.bundle" ]; then
      ln -sf "${pkgs.ccid}/lib/pcsc/drivers/ccid.bundle"/* /var/lib/pcsc/drivers/ccid.bundle/ 2>/dev/null || true
    fi
  '';

  # YubiKey management tools
  environment.systemPackages = with pkgs; [
    yubikey-manager          # ykman CLI
    yubikey-personalization  # ykpers / ykchalresp
    yubico-piv-tool          # PIV applet management
  ];
}