<?php
/**
* 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
* @var int User ID.
*/
protected $user_id;
/**
* Protected constructor. Use the `get_instance()` method to get the instance.
*
* @since 4.0.0
*
* @param int $user_id User whose session to manage.
*/
protected function __construct( $user_id ) {
$this->user_id = $user_id;
}
/**
* Retrieves a session manager instance for a user.
*
* This method contains a {@see 'session_token_manager'} filter, allowing a plugin to swap out
* the session manager for a subclass of `WP_Session_Tokens`.
*
* @since 4.0.0
*
* @param int $user_id User whose session to manage.
* @return WP_Session_Tokens The session object, which is by default an instance of
* the `WP_User_Meta_Session_Tokens` class.
*/
final public static function get_instance( $user_id ) {
/**
* Filters the class name for the session token manager.
*
* @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 the given session token for storage.
*
* @since 4.0.0
*
* @param string $token Session token to hash.
* @return string A hash of the session token (a verifier).
*/
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 );
}
}
/**
* Retrieves a user's session for the given token.
*
* @since 4.0.0
*
* @param string $token Session token.
* @return array|null The session, or null if it does not exist.
*/
final public function get( $token ) {
$verifier = $this->hash_token( $token );
return $this->get_session( $verifier );
}
/**
* Validates the given session token for authenticity and validity.
*
* Checks that the given token is present and hasn't expired.
*
* @since 4.0.0
*
* @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 );
}
/**
* Generates a session token and attaches session information to it.
*
* A session token is a long, random string. It is used in a cookie
* to link that cookie to an expiration time and to ensure the cookie
* becomes invalidated when the user logs out.
*
* 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
*
* @param int $expiration Session expiration timestamp.
* @return string Session token.
*/
final public function create( $expiration ) {
/**
* Filters the information attached to the newly created session.
*
* Can be used to attach further information 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;
}
/**
* Updates the data for the session with the given token.
*
* @since 4.0.0
*
* @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 );
}
/**
* Destroys the session with the given token.
*
* @since 4.0.0
*
* @param string $token Session token to destroy.
*/
final public function destroy( $token ) {
$verifier = $this->hash_token( $token );
$this->update_session( $verifier, null );
}
/**
* Destroys all sessions for this user except the one with the given token (presumably the one in use).
*
* @since 4.0.0
*
* @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();
}
}
/**
* Determines whether a session is still valid, based on its expiration timestamp.
*
* @since 4.0.0
*
* @param array $session Session to check.
* @return bool Whether session is valid.
*/
final protected function is_still_valid( $session ) {
return $session['expiration'] >= time();
}
/**
* Destroys all sessions for a user.
*
* @since 4.0.0
*/
final public function destroy_all() {
$this->destroy_all_sessions();
}
/**
* Destroys all sessions for all users.
*
* @since 4.0.0
*/
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' ) );
}
/**
* Retrieves all sessions for a user.
*
* @since 4.0.0
*
* @return array Sessions for a user.
*/
final public function get_all() {
return array_values( $this->get_sessions() );
}
/**
* Retrieves all sessions of the user.
*
* @since 4.0.0
*
* @return array Sessions of the user.
*/
abstract protected function get_sessions();
/**
* Retrieves a session based on its verifier (token hash).
*
* @since 4.0.0
*
* @param string $verifier Verifier for the session to retrieve.
* @return array|null The session, or null if it does not exist.
*/
abstract protected function get_session( $verifier );
/**
* Updates a session based on its verifier (token hash).
*
* Omitting the second argument destroys the session.
*
* @since 4.0.0
*
* @param string $verifier Verifier for the session to update.
* @param array $session Optional. Session. Omitting this argument destroys the session.
*/
abstract protected function update_session( $verifier, $session = null );
/**
* Destroys all sessions for this user, except the single session with the given verifier.
*
* @since 4.0.0
*
* @param string $verifier Verifier of the session to keep.
*/
abstract protected function destroy_other_sessions( $verifier );
/**
* Destroys all sessions for the user.
*
* @since 4.0.0
*/
abstract protected function destroy_all_sessions();
/**
* Destroys all sessions for all users.
*
* @since 4.0.0
*/
public static function drop_sessions() {}
}