Enable U2F on linux systems

modules/personal/u2f.nix

@@ -0,0 +1,29 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+let
+  cfg = config.personal.u2f;
+in
+{
+  options.personal.u2f = {
+    enable = mkEnableOption "Enable personal U2F login modules and stuff";
+  };
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = with pkgs; [
+      pam_u2f # for pamu2fcfg
+    ];
+    security.pam = mkIf (strings.hasSuffix "linux" pkgs.system) {
+      u2f = {
+        enable = true;
+        cue = true;
+        interactive = true;
+      };
+
+      # Services
+      services.sudo.u2fAuth = true;
+      services.login.u2fAuth = true;
+      services.swaylock.u2fAuth = mkIf (config.services.swaylock.enable) true;
+    };
+  };
+}