PHPSessionHandler: Implement SessionHandlerInterface

[mediawiki.git] / includes / session / Session.php

<?php
/**
 * MediaWiki session
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Session
 */

namespace MediaWiki\Session;

use User;
use WebRequest;

/**
 * Manages data for an an authenticated session
 *
 * A Session represents the fact that the current HTTP request is part of a
 * session. There are two broad types of Sessions, based on whether they
 * return true or false from self::canSetUser():
 * * When true (mutable), the Session identifies multiple requests as part of
 *   a session generically, with no tie to a particular user.
 * * When false (immutable), the Session identifies multiple requests as part
 *   of a session by identifying and authenticating the request itself as
 *   belonging to a particular user.
 *
 * The Session object also serves as a replacement for PHP's $_SESSION,
 * managing access to per-session data.
 *
 * @todo Once we drop support for PHP 5.3.3, implementing ArrayAccess would be nice.
 * @ingroup Session
 * @since 1.27
 */
final class Session implements \Countable, \Iterator {
        /** @var SessionBackend Session backend */
        private $backend;

        /** @var int Session index */
        private $index;

        /**
         * @param SessionBackend $backend
         * @param int $index
         */
        public function __construct( SessionBackend $backend, $index ) {
                $this->backend = $backend;
                $this->index = $index;
        }

        public function __destruct() {
                $this->backend->deregisterSession( $this->index );
        }

        /**
         * Returns the session ID
         * @return string
         */
        public function getId() {
                return $this->backend->getId();
        }

        /**
         * Returns the SessionId object
         * @private For internal use by WebRequest
         * @return SessionId
         */
        public function getSessionId() {
                return $this->backend->getSessionId();
        }

        /**
         * Changes the session ID
         * @return string New ID (might be the same as the old)
         */
        public function resetId() {
                return $this->backend->resetId();
        }

        /**
         * Fetch the SessionProvider for this session
         * @return SessionProviderInterface
         */
        public function getProvider() {
                return $this->backend->getProvider();
        }

        /**
         * Indicate whether this session is persisted across requests
         *
         * For example, if cookies are set.
         *
         * @return bool
         */
        public function isPersistent() {
                return $this->backend->isPersistent();
        }

        /**
         * Make this session persisted across requests
         *
         * If the session is already persistent, equivalent to calling
         * $this->renew().
         */
        public function persist() {
                $this->backend->persist();
        }

        /**
         * Indicate whether the user should be remembered independently of the
         * session ID.
         * @return bool
         */
        public function shouldRememberUser() {
                return $this->backend->shouldRememberUser();
        }

        /**
         * Set whether the user should be remembered independently of the session
         * ID.
         * @param bool $remember
         */
        public function setRememberUser( $remember ) {
                $this->backend->setRememberUser( $remember );
        }

        /**
         * Returns the request associated with this session
         * @return WebRequest
         */
        public function getRequest() {
                return $this->backend->getRequest( $this->index );
        }

        /**
         * Returns the authenticated user for this session
         * @return User
         */
        public function getUser() {
                return $this->backend->getUser();
        }

        /**
         * Fetch the rights allowed the user when this session is active.
         * @return null|string[] Allowed user rights, or null to allow all.
         */
        public function getAllowedUserRights() {
                return $this->backend->getAllowedUserRights();
        }

        /**
         * Indicate whether the session user info can be changed
         * @return bool
         */
        public function canSetUser() {
                return $this->backend->canSetUser();
        }

        /**
         * Set a new user for this session
         * @note This should only be called when the user has been authenticated
         * @param User $user User to set on the session.
         *   This may become a "UserValue" in the future, or User may be refactored
         *   into such.
         */
        public function setUser( $user ) {
                $this->backend->setUser( $user );
        }

        /**
         * Get a suggested username for the login form
         * @return string|null
         */
        public function suggestLoginUsername() {
                return $this->backend->suggestLoginUsername( $this->index );
        }

        /**
         * Whether HTTPS should be forced
         * @return bool
         */
        public function shouldForceHTTPS() {
                return $this->backend->shouldForceHTTPS();
        }

        /**
         * Set whether HTTPS should be forced
         * @param bool $force
         */
        public function setForceHTTPS( $force ) {
                $this->backend->setForceHTTPS( $force );
        }

        /**
         * Fetch the "logged out" timestamp
         * @return int
         */
        public function getLoggedOutTimestamp() {
                return $this->backend->getLoggedOutTimestamp();
        }

        /**
         * Set the "logged out" timestamp
         * @param int $ts
         */
        public function setLoggedOutTimestamp( $ts ) {
                $this->backend->setLoggedOutTimestamp( $ts );
        }

        /**
         * Fetch provider metadata
         * @protected For use by SessionProvider subclasses only
         * @return mixed
         */
        public function getProviderMetadata() {
                return $this->backend->getProviderMetadata();
        }

        /**
         * Delete all session data and clear the user (if possible)
         */
        public function clear() {
                $data = &$this->backend->getData();
                if ( $data ) {
                        $data = array();
                        $this->backend->dirty();
                }
                if ( $this->backend->canSetUser() ) {
                        $this->backend->setUser( new User );
                }
                $this->backend->save();
        }

        /**
         * Renew the session
         *
         * Resets the TTL in the backend store if the session is near expiring, and
         * re-persists the session to any active WebRequests if persistent.
         */
        public function renew() {
                $this->backend->renew();
        }

        /**
         * Fetch a copy of this session attached to an alternative WebRequest
         *
         * Actions on the copy will affect this session too, and vice versa.
         *
         * @param WebRequest $request Any existing session associated with this
         *  WebRequest object will be overwritten.
         * @return Session
         */
        public function sessionWithRequest( WebRequest $request ) {
                $request->setSessionId( $this->backend->getSessionId() );
                return $this->backend->getSession( $request );
        }

        /**
         * Fetch a value from the session
         * @param string|int $key
         * @param mixed $default
         * @return mixed
         */
        public function get( $key, $default = null ) {
                $data = &$this->backend->getData();
                return array_key_exists( $key, $data ) ? $data[$key] : $default;
        }

        /**
         * Test if a value exists in the session
         * @param string|int $key
         * @return bool
         */
        public function exists( $key ) {
                $data = &$this->backend->getData();
                return array_key_exists( $key, $data );
        }

        /**
         * Set a value in the session
         * @param string|int $key
         * @param mixed $value
         */
        public function set( $key, $value ) {
                $data = &$this->backend->getData();
                if ( !array_key_exists( $key, $data ) || $data[$key] !== $value ) {
                        $data[$key] = $value;
                        $this->backend->dirty();
                }
        }

        /**
         * Remove a value from the session
         * @param string|int $key
         */
        public function remove( $key ) {
                $data = &$this->backend->getData();
                if ( array_key_exists( $key, $data ) ) {
                        unset( $data[$key] );
                        $this->backend->dirty();
                }
        }

        /**
         * Fetch a CSRF token from the session
         *
         * Note that this does not persist the session, which you'll probably want
         * to do if you want the token to actually be useful.
         *
         * @param string|string[] $salt Token salt
         * @param string $key Token key
         * @return MediaWiki\\Session\\SessionToken
         */
        public function getToken( $salt = '', $key = 'default' ) {
                $new = false;
                $secrets = $this->get( 'wsTokenSecrets' );
                if ( !is_array( $secrets ) ) {
                        $secrets = array();
                }
                if ( isset( $secrets[$key] ) && is_string( $secrets[$key] ) ) {
                        $secret = $secrets[$key];
                } else {
                        $secret = \MWCryptRand::generateHex( 32 );
                        $secrets[$key] = $secret;
                        $this->set( 'wsTokenSecrets', $secrets );
                        $new = true;
                }
                if ( is_array( $salt ) ) {
                        $salt = join( '|', $salt );
                }
                return new Token( $secret, (string)$salt, $new );
        }

        /**
         * Remove a CSRF token from the session
         *
         * The next call to self::getToken() with $key will generate a new secret.
         *
         * @param string $key Token key
         */
        public function resetToken( $key = 'default' ) {
                $secrets = $this->get( 'wsTokenSecrets' );
                if ( is_array( $secrets ) && isset( $secrets[$key] ) ) {
                        unset( $secrets[$key] );
                        $this->set( 'wsTokenSecrets', $secrets );
                }
        }

        /**
         * Remove all CSRF tokens from the session
         */
        public function resetAllTokens() {
                $this->remove( 'wsTokenSecrets' );
        }

        /**
         * Delay automatic saving while multiple updates are being made
         *
         * Calls to save() or clear() will not be delayed.
         *
         * @return \ScopedCallback When this goes out of scope, a save will be triggered
         */
        public function delaySave() {
                return $this->backend->delaySave();
        }

        /**
         * Save the session
         */
        public function save() {
                $this->backend->save();
        }

        /**
         * @name Interface methods
         * @{
         */

        public function count() {
                $data = &$this->backend->getData();
                return count( $data );
        }

        public function current() {
                $data = &$this->backend->getData();
                return current( $data );
        }

        public function key() {
                $data = &$this->backend->getData();
                return key( $data );
        }

        public function next() {
                $data = &$this->backend->getData();
                next( $data );
        }

        public function rewind() {
                $data = &$this->backend->getData();
                reset( $data );
        }

        public function valid() {
                $data = &$this->backend->getData();
                return key( $data ) !== null;
        }

        /**@}*/

}