wikimedia/mediawiki-core

<?php
/**
 * MediaWiki session provider base class
 *
 * 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 InvalidArgumentException;
use MediaWiki\MainConfigNames;
use MediaWiki\Request\WebRequest;

/**
 * An ImmutableSessionProviderWithCookie doesn't persist the user, but
 * optionally can use a cookie to support multiple IDs per session.
 *
 * As mentioned in the documentation for SessionProvider, many methods that are
 * technically "cannot persist ID" could be turned into "can persist ID but
 * not changing User" using a session cookie. This class implements such an
 * optional session cookie.
 *
 * @stable to extend
 * @ingroup Session
 * @since 1.27
 */
abstract class ImmutableSessionProviderWithCookie extends SessionProvider {

    /** @var string|null */
    protected $sessionCookieName = null;
    /** @var mixed[] */
    protected $sessionCookieOptions = [];

    /**
     * @stable to call
     * @param array $params Keys include:
     *  - sessionCookieName: Session cookie name, if multiple sessions per
     *    client are to be supported.
     *  - sessionCookieOptions: Options to pass to WebResponse::setCookie().
     */
    public function __construct( $params = [] ) {
        parent::__construct();

        if ( isset( $params['sessionCookieName'] ) ) {
            if ( !is_string( $params['sessionCookieName'] ) ) {
                throw new InvalidArgumentException( 'sessionCookieName must be a string' );
            }
            $this->sessionCookieName = $params['sessionCookieName'];
        }
        if ( isset( $params['sessionCookieOptions'] ) ) {
            if ( !is_array( $params['sessionCookieOptions'] ) ) {
                throw new InvalidArgumentException( 'sessionCookieOptions must be an array' );
            }
            $this->sessionCookieOptions = $params['sessionCookieOptions'];
        }
    }

    /**
     * Get the session ID from the cookie, if any.
     *
     * Only call this if $this->sessionCookieName !== null. If
     * sessionCookieName is null, do some logic (probably involving a call to
     * $this->hashToSessionId()) to create the single session ID corresponding
     * to this WebRequest instead of calling this method.
     *
     * @param WebRequest $request
     * @return string|null
     */
    protected function getSessionIdFromCookie( WebRequest $request ) {
        if ( $this->sessionCookieName === null ) {
            throw new \BadMethodCallException(
                __METHOD__ . ' may not be called when $this->sessionCookieName === null'
            );
        }

        $prefix = $this->sessionCookieOptions['prefix']
            ?? $this->getConfig()->get( MainConfigNames::CookiePrefix );
        $id = $request->getCookie( $this->sessionCookieName, $prefix );
        return SessionManager::validateSessionId( $id ) ? $id : null;
    }

    /**
     * @inheritDoc
     * @stable to override
     */
    public function persistsSessionId() {
        return $this->sessionCookieName !== null;
    }

    /**
     * @inheritDoc
     * @stable to override
     */
    public function canChangeUser() {
        return false;
    }

    /**
     * @inheritDoc
     * @stable to override
     */
    public function persistSession( SessionBackend $session, WebRequest $request ) {
        if ( $this->sessionCookieName === null ) {
            return;
        }

        $response = $request->response();
        if ( $response->headersSent() ) {
            // Can't do anything now
            $this->logger->debug( __METHOD__ . ': Headers already sent' );
            return;
        }

        $options = $this->sessionCookieOptions;
        if ( $session->shouldForceHTTPS() || $session->getUser()->requiresHTTPS() ) {
            // Send a cookie unless $wgForceHTTPS is set (T256095)
            if ( !$this->getConfig()->get( MainConfigNames::ForceHTTPS ) ) {
                $response->setCookie( 'forceHTTPS', 'true', null,
                    [ 'prefix' => '', 'secure' => false ] + $options );
            }
            $options['secure'] = true;
        }

        $response->setCookie( $this->sessionCookieName, $session->getId(), null, $options );
    }

    /**
     * @inheritDoc
     * @stable to override
     */
    public function unpersistSession( WebRequest $request ) {
        if ( $this->sessionCookieName === null ) {
            return;
        }

        $response = $request->response();
        if ( $response->headersSent() ) {
            // Can't do anything now
            $this->logger->debug( __METHOD__ . ': Headers already sent' );
            return;
        }

        $response->clearCookie( $this->sessionCookieName, $this->sessionCookieOptions );
    }

    /**
     * @inheritDoc
     * @stable to override
     */
    public function getVaryCookies() {
        if ( $this->sessionCookieName === null ) {
            return [];
        }

        $prefix = $this->sessionCookieOptions['prefix'] ??
            $this->getConfig()->get( MainConfigNames::CookiePrefix );
        return [ $prefix . $this->sessionCookieName ];
    }

    public function whyNoSession() {
        return wfMessage( 'sessionprovider-nocookies' );
    }
}