nixos-config/modules/nixos/kanidm-client.nix

{
  config,
  pkgs,
  lib,
  ...
}:
with lib;

let
  cfg = config.custom.kanidm-client;
in
{
  options = {
    custom.kanidm-client = {
      enable = mkEnableOption "Kanidm client service";
      asSSHAuth = mkOption {
        type = types.submodule {
          options = {
            enable = mkEnableOption "Kanidm as system authentication source";
            allowedGroups = mkOption {
              type = types.listOf types.str;
              example = [ "linux_users" ];
            };
            hardening = mkOption {
              type = types.bool;
              default = false;
            };
          };
        };
      };
      sudoers = mkOption {
        type = types.listOf types.str;
        default = [ ];
      };
      uri = mkOption { type = types.str; };
    };
  };
  config = mkIf cfg.enable {
    services.kanidm = mkMerge [
      (mkIf cfg.enable {
        enableClient = true;
        clientSettings = {
          uri = cfg.uri;
        };
      })
      (mkIf cfg.asSSHAuth.enable {
        enablePam = true;
        unixSettings = {
          pam_allowed_login_groups = cfg.asSSHAuth.allowedGroups;
          default_shell = "/bin/sh";
        };
      })
    ];
    services.openssh = mkIf cfg.asSSHAuth.enable {
      enable = true;
      authorizedKeysCommand = "/etc/ssh/auth %u";
      authorizedKeysCommandUser = "kanidm-ssh-runner";
      settings = mkIf cfg.asSSHAuth.enable {
        PasswordAuthentication = false;
        KbdInteractiveAuthentication = false;
        PermitRootLogin = lib.mkForce "no";
        GSSAPIAuthentication = "no";
        KerberosAuthentication = "no";
      };
    };

    environment.etc."ssh/auth" = mkIf cfg.asSSHAuth.enable {
      mode = "0555";
      text = ''
        #!${pkgs.stdenv.shell}
        ${pkgs.kanidm}/bin/kanidm_ssh_authorizedkeys $1
      '';
    };
    users.groups.wheel.members = cfg.sudoers;
    users.groups.kanidm-ssh-runner = { };
    users.users.kanidm-ssh-runner = {
      isSystemUser = true;
      group = "kanidm-ssh-runner";
    };

  };
}