initial refactoring

platforms/nixos/modules/nmasur/presets/services/openssh.nix

@@ -0,0 +1,48 @@
+# SSHD service for allowing SSH access to my machines.
+
+{
+  config,
+  lib,
+  ...
+}:
+
+let
+  cfg = config.nmasur.presets.services.openssh;
+in
+{
+
+  options.nmasur.presets.services.openssh = {
+    enable = lib.mkEnableOption "OpenSSH remote access service";
+    publicKeys = lib.mkOption {
+      type = lib.types.nullOr (lib.types.listOf lib.types.str);
+      description = "Public SSH keys authorized for this system.";
+      default = null;
+    };
+    # permitRootLogin = lib.mkOption {
+    #   type = lib.types.str;
+    #   description = "Root login settings.";
+    #   default = "no";
+    # };
+  };
+
+  config = lib.mkIf cfg.enable {
+    services.openssh = {
+      enable = true;
+      ports = [ 22 ];
+      allowSFTP = true;
+      settings = {
+        GatewayPorts = "no";
+        X11Forwarding = false;
+        PasswordAuthentication = false;
+        PermitRootLogin = "no";
+      };
+    };
+
+    users.users.${config.user}.openssh.authorizedKeys.keys = lib.mkIf (
+      cfg.publicKeys != null
+    ) cfg.publicKeys;
+
+    # Add terminfo for SSH from popular terminal emulators
+    environment.enableAllTerminfo = true;
+  };
+}