Session.php

<?php
/**
 * The Session class holds information about a user session, and everything attached to it.
 *
 * The session will have a duration and validity, and also cache information about the different
 * federation protocols, as Shibboleth and SAML 2.0. On the IdP side the Session class holds
 * information about all the currently logged in SPs. This is used when the user initiates a
 * Single-Log-Out.
 *
 * Bear in mind that the session object implements the Serializable interface, and as such,
 * all its contents MUST be serializable. If you need to store something in the session object
 * that is not serializable, make sure to convert it first to a representation that can be
 * serialized.
 *
 * @author Andreas Åkre Solberg, UNINETT AS. <andreas.solberg@uninett.no>
 * @author Jaime Pérez Crespo, UNINETT AS <jaime.perez@uninett.no>
 * @package SimpleSAMLphp
 */
class SimpleSAML_Session implements Serializable
{

    /**
     * This is a timeout value for setData, which indicates that the data
     * should never be deleted, i.e. lasts the whole session lifetime.
     */
    const DATA_TIMEOUT_SESSION_END = 'sessionEndTimeout';


    /**
     * The list of loaded session objects.
     *
     * This is an associative array indexed with the session id.
     *
     * @var array
     */
    private static $sessions = array();


    /**
     * This variable holds the instance of the session - Singleton approach.
     *
     * Warning: do not set the instance manually, call SimpleSAML_Session::load() instead.
     */
    private static $instance = null;


    /**
     * The session ID of this session.
     *
     * @var string|null
     */
    private $sessionId;


    /**
     * Transient session flag.
     *
     * @var boolean|false
     */
    private $transient = false;


    /**
     * The track id is a new random unique identifier that is generated for each session.
     * This is used in the debug logs and error messages to easily track more information
     * about what went wrong.
     *
     * @var string|null
     */
    private $trackid = null;