JezK

Edit File: class-rbauthenticator.php

<?php

if ( ! defined( 'WPINC' ) || ! defined( 'ABSPATH' ) ) {
	die;
}

class RBAuthenticator {
	private $session_key = '';
	private $redirect_to_after_login;
	private $unauthorized_file;

public function __construct( $session_key, $redirect_to_after_login, $unauthorized_file ) {
		$this->session_key             = $session_key;
		$this->redirect_to_after_login = $redirect_to_after_login;
		$this->unauthorized_file       = $unauthorized_file;
	}

public function run() {
		if ( isset( $_GET['signature'] ) && isset( $_GET['data'] ) ) {
			$signature = sanitize_text_field( wp_unslash( $_GET['signature'] ) );
			$data      = sanitize_text_field( wp_unslash( $_GET['data'] ) );
			$request   = wp_remote_get(
				RB_DASHBOARD_BASE_URL . '/dbauth/isvalid'
				. '?signature=' . rawurlencode( $signature )
				. '&data=' . rawurlencode( $data )
				. '&source=' . rawurlencode( RB_BOX_NAME )
			);
			$body      = wp_remote_retrieve_body( $request );

if ( $body === '1' ) {
				session_start();
				try {
                    session_regenerate_id( true );
                } catch ( \TypeError $e ) {
                    // Broken third-party session handler (e.g. wp-native-php-sessions);
                    // regenerate without destroying the old session — destroy() is then not invoked.
                    session_regenerate_id( false );
                }
				$_SESSION[ $this->session_key ] = '1';
				header( sprintf( 'Location: %s', $this->redirect_to_after_login ) );
				return;
			}
		} else {
			include $this->unauthorized_file;
			exit;
		}

session_start();
		if ( ! isset( $_SESSION[ $this->session_key ] ) ) {
			include $this->unauthorized_file;
			exit;
		}
	}
}