1 files changed, 71 insertions, 0 deletions
diff --git a/nixos/modules/security/google_oslogin.nix b/nixos/modules/security/google_oslogin.nix
new file mode 100644
index 00000000000..cf416035ef6
--- /dev/null
+++ b/nixos/modules/security/google_oslogin.nix
@@ -0,0 +1,71 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.security.googleOsLogin;
+  package = pkgs.google-guest-oslogin;
+
+in
+
+{
+
+  options = {
+
+    security.googleOsLogin.enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to enable Google OS Login.
+
+        The OS Login package enables the following components:
+        AuthorizedKeysCommand to query valid SSH keys from the user's OS Login
+        profile during ssh authentication phase.
+        NSS Module to provide user and group information
+        PAM Module for the sshd service, providing authorization and
+        authentication support, allowing the system to use data stored in
+        Google Cloud IAM permissions to control both, the ability to log into
+        an instance, and to perform operations as root (sudo).
+      '';
+    };
+
+  };
+
+  config = mkIf cfg.enable {
+    security.pam.services.sshd = {
+      makeHomeDir = true;
+      googleOsLoginAccountVerification = true;
+      googleOsLoginAuthentication = true;
+    };
+
+    security.sudo.extraConfig = ''
+      #includedir /run/google-sudoers.d
+    '';
+    systemd.tmpfiles.rules = [
+      "d /run/google-sudoers.d 750 root root -"
+      "d /var/google-users.d 750 root root -"
+    ];
+
+    systemd.packages = [ package ];
+    systemd.timers.google-oslogin-cache.wantedBy = [ "timers.target" ];
+
+    # enable the nss module, so user lookups etc. work
+    system.nssModules = [ package ];
+    system.nssDatabases.passwd = [ "cache_oslogin" "oslogin" ];
+    system.nssDatabases.group = [ "cache_oslogin" "oslogin" ];
+
+    # Ugly: sshd refuses to start if a store path is given because /nix/store is group-writable.
+    # So indirect by a symlink.
+    environment.etc."ssh/authorized_keys_command_google_oslogin" = {
+      mode = "0755";
+      text = ''
+        #!/bin/sh
+        exec ${package}/bin/google_authorized_keys "$@"
+      '';
+    };
+    services.openssh.authorizedKeysCommand = "/etc/ssh/authorized_keys_command_google_oslogin %u";
+    services.openssh.authorizedKeysCommandUser = "nobody";
+  };
+
+}