/** * Session API: WP_Session_Tokens class * * @package WordPress * @subpackage Session * @since 4.7.0 */ /** * Abstract class for managing user session tokens. * * @since 4.0.0 */ abstract class WP_Session_Tokens { /** * User ID. * * @since 4.0.0 * @access protected * @var int User ID. */ protected $user_id; /** * Protected constructor. * * @since 4.0.0 * * @param int $user_id User whose session to manage. */ protected function __construct( $user_id ) { $this->user_id = $user_id; } /** * Get a session token manager instance for a user. * * This method contains a filter that allows a plugin to swap out * the session manager for a subclass of WP_Session_Tokens. * * @since 4.0.0 * @access public * @static * * @param int $user_id User whose session to manage. */ final public static function get_instance( $user_id ) { /** * Filters the session token manager used. * * @since 4.0.0 * * @param string $session Name of class to use as the manager. * Default 'WP_User_Meta_Session_Tokens'. */ $manager = apply_filters( 'session_token_manager', 'WP_User_Meta_Session_Tokens' ); return new $manager( $user_id ); } /** * Hashes a session token for storage. * * @since 4.0.0 * @access private * * @param string $token Session token to hash. * @return string A hash of the session token (a verifier). */ final private function hash_token( $token ) { // If ext/hash is not present, use sha1() instead. if ( function_exists( 'hash' ) ) { return hash( 'sha256', $token ); } else { return sha1( $token ); } } /** * Get a user's session. * * @since 4.0.0 * @access public * * @param string $token Session token * @return array User session */ final public function get( $token ) { $verifier = $this->hash_token( $token ); return $this->get_session( $verifier ); } /** * Validate a user's session token as authentic. * * Checks that the given token is present and hasn't expired. * * @since 4.0.0 * @access public * * @param string $token Token to verify. * @return bool Whether the token is valid for the user. */ final public function verify( $token ) { $verifier = $this->hash_token( $token ); return (bool) $this->get_session( $verifier ); } /** * Generate a session token and attach session information to it. * * A session token is a long, random string. It is used in a cookie * link that cookie to an expiration time and to ensure the cookie * becomes invalidated upon logout. * * This function generates a token and stores it with the associated * expiration time (and potentially other session information via the * {@see 'attach_session_information'} filter). * * @since 4.0.0 * @access public * * @param int $expiration Session expiration timestamp. * @return string Session token. */ final public function create( $expiration ) { /** * Filters the information attached to the newly created session. * * Could be used in the future to attach information such as * IP address or user agent to a session. * * @since 4.0.0 * * @param array $session Array of extra data. * @param int $user_id User ID. */ $session = apply_filters( 'attach_session_information', array(), $this->user_id ); $session['expiration'] = $expiration; // IP address. if ( !empty( $_SERVER['REMOTE_ADDR'] ) ) { $session['ip'] = $_SERVER['REMOTE_ADDR']; } // User-agent. if ( ! empty( $_SERVER['HTTP_USER_AGENT'] ) ) { $session['ua'] = wp_unslash( $_SERVER['HTTP_USER_AGENT'] ); } // Timestamp $session['login'] = time(); $token = wp_generate_password( 43, false, false ); $this->update( $token, $session ); return $token; } /** * Update a session token. * * @since 4.0.0 * @access public * * @param string $token Session token to update. * @param array $session Session information. */ final public function update( $token, $session ) { $verifier = $this->hash_token( $token ); $this->update_session( $verifier, $session ); } /** * Destroy a session token. * * @since 4.0.0 * @access public * * @param string $token Session token to destroy. */ final public function destroy( $token ) { $verifier = $this->hash_token( $token ); $this->update_session( $verifier, null ); } /** * Destroy all session tokens for this user, * except a single token, presumably the one in use. * * @since 4.0.0 * @access public * * @param string $token_to_keep Session token to keep. */ final public function destroy_others( $token_to_keep ) { $verifier = $this->hash_token( $token_to_keep ); $session = $this->get_session( $verifier ); if ( $session ) { $this->destroy_other_sessions( $verifier ); } else { $this->destroy_all_sessions(); } } /** * Determine whether a session token is still valid, * based on expiration. * * @since 4.0.0 * @access protected * * @param array $session Session to check. * @return bool Whether session is valid. */ final protected function is_still_valid( $session ) { return $session['expiration'] >= time(); } /** * Destroy all session tokens for a user. * * @since 4.0.0 * @access public */ final public function destroy_all() { $this->destroy_all_sessions(); } /** * Destroy all session tokens for all users. * * @since 4.0.0 * @access public * @static */ final public static function destroy_all_for_all_users() { /** This filter is documented in wp-includes/class-wp-session-tokens.php */ $manager = apply_filters( 'session_token_manager', 'WP_User_Meta_Session_Tokens' ); call_user_func( array( $manager, 'drop_sessions' ) ); } /** * Retrieve all sessions of a user. * * @since 4.0.0 * @access public * * @return array Sessions of a user. */ final public function get_all() { return array_values( $this->get_sessions() ); } /** * This method should retrieve all sessions of a user, keyed by verifier. * * @since 4.0.0 * @access protected * * @return array Sessions of a user, keyed by verifier. */ abstract protected function get_sessions(); /** * This method should look up a session by its verifier (token hash). * * @since 4.0.0 * @access protected * * @param string $verifier Verifier of the session to retrieve. * @return array|null The session, or null if it does not exist. */ abstract protected function get_session( $verifier ); /** * This method should update a session by its verifier. * * Omitting the second argument should destroy the session. * * @since 4.0.0 * @access protected * * @param string $verifier Verifier of the session to update. * @param array $session Optional. Session. Omitting this argument destroys the session. */ abstract protected function update_session( $verifier, $session = null ); /** * This method should destroy all session tokens for this user, * except a single session passed. * * @since 4.0.0 * @access protected * * @param string $verifier Verifier of the session to keep. */ abstract protected function destroy_other_sessions( $verifier ); /** * This method should destroy all sessions for a user. * * @since 4.0.0 * @access protected */ abstract protected function destroy_all_sessions(); /** * This static method should destroy all session tokens for all users. * * @since 4.0.0 * @access public * @static */ public static function drop_sessions() {} }