CookieSessionProvider.php

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<?php
namespace MediaWiki\Session;

use Config;
use User;
use WebRequest;

class CookieSessionProvider extends SessionProvider {

    protected $params = [];

    protected $cookieOptions = [];

    public function __construct( $params = [] ) {
        parent::__construct();

        $params += [
            'cookieOptions' => [],
            // @codeCoverageIgnoreStart
        ];
        // @codeCoverageIgnoreEnd

        if ( !isset( $params['priority'] ) ) {
            throw new \InvalidArgumentException( __METHOD__ . ': priority must be specified' );
        }
        if ( $params['priority'] < SessionInfo::MIN_PRIORITY ||
            $params['priority'] > SessionInfo::MAX_PRIORITY
        ) {
            throw new \InvalidArgumentException( __METHOD__ . ': Invalid priority' );
        }

        if ( !is_array( $params['cookieOptions'] ) ) {
            throw new \InvalidArgumentException( __METHOD__ . ': cookieOptions must be an array' );
        }

        $this->priority = $params['priority'];
        $this->cookieOptions = $params['cookieOptions'];
        $this->params = $params;
        unset( $this->params['priority'] );
        unset( $this->params['cookieOptions'] );
    }

    public function setConfig( Config $config ) {
        parent::setConfig( $config );

        // @codeCoverageIgnoreStart
        $this->params += [
            // @codeCoverageIgnoreEnd
            'callUserSetCookiesHook' => false,
            'sessionName' =>
                $config->get( 'SessionName' ) ?: $config->get( 'CookiePrefix' ) . '_session',
        ];

        // @codeCoverageIgnoreStart
        $this->cookieOptions += [
            // @codeCoverageIgnoreEnd
            'prefix' => $config->get( 'CookiePrefix' ),
            'path' => $config->get( 'CookiePath' ),
            'domain' => $config->get( 'CookieDomain' ),
            'secure' => $config->get( 'CookieSecure' ),
            'httpOnly' => $config->get( 'CookieHttpOnly' ),
        ];
    }

    public function provideSessionInfo( WebRequest $request ) {
        $sessionId = $this->getCookie( $request, $this->params['sessionName'], '' );
        $info = [
            'provider' => $this,
            'forceHTTPS' => $this->getCookie( $request, 'forceHTTPS', '', false )
        ];
        if ( SessionManager::validateSessionId( $sessionId ) ) {
            $info['id'] = $sessionId;
            $info['persisted'] = true;
        }

        list( $userId, $userName, $token ) = $this->getUserInfoFromCookies( $request );
        if ( $userId !== null ) {
            try {
                $userInfo = UserInfo::newFromId( $userId );
            } catch ( \InvalidArgumentException $ex ) {
                return null;
            }

            // Sanity check
            if ( $userName !== null && $userInfo->getName() !== $userName ) {
                $this->logger->warning(
                    'Session "{session}" requested with mismatched UserID and UserName cookies.',
                    [
                        'session' => $sessionId,
                        'mismatch' => [
                            'userid' => $userId,
                            'cookie_username' => $userName,
                            'username' => $userInfo->getName(),
                        ],
                ] );
                return null;
            }

            if ( $token !== null ) {
                if ( !hash_equals( $userInfo->getToken(), $token ) ) {
                    $this->logger->warning(
                        'Session "{session}" requested with invalid Token cookie.',
                        [
                            'session' => $sessionId,
                            'userid' => $userId,
                            'username' => $userInfo->getName(),
                     ] );
                    return null;
                }
                $info['userInfo'] = $userInfo->verified();
                $info['persisted'] = true; // If we have user+token, it should be
            } elseif ( isset( $info['id'] ) ) {
                $info['userInfo'] = $userInfo;
            } else {
                // No point in returning, loadSessionInfoFromStore() will
                // reject it anyway.
                return null;
            }
        } elseif ( isset( $info['id'] ) ) {
            // No UserID cookie, so insist that the session is anonymous.
            // Note: this event occurs for several normal activities:
            // * anon visits Special:UserLogin
            // * anon browsing after seeing Special:UserLogin
            // * anon browsing after edit or preview
            $this->logger->debug(
                'Session "{session}" requested without UserID cookie',
                [
                    'session' => $info['id'],
            ] );
            $info['userInfo'] = UserInfo::newAnonymous();
        } else {
            // No session ID and no user is the same as an empty session, so
            // there's no point.
            return null;
        }

        return new SessionInfo( $this->priority, $info );
    }

    public function persistsSessionId() {
        return true;
    }

    public function canChangeUser() {
        return true;
    }

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

        $user = $session->getUser();

        $cookies = $this->cookieDataToExport( $user, $session->shouldRememberUser() );
        $sessionData = $this->sessionDataToExport( $user );

        // Legacy hook
        if ( $this->params['callUserSetCookiesHook'] && !$user->isAnon() ) {
            \Hooks::run( 'UserSetCookies', [ $user, &$sessionData, &$cookies ] );
        }

        $options = $this->cookieOptions;

        $forceHTTPS = $session->shouldForceHTTPS() || $user->requiresHTTPS();
        if ( $forceHTTPS ) {
            // Don't set the secure flag if the request came in
            // over "http", for backwards compat.
            // @todo Break that backwards compat properly.
            $options['secure'] = $this->config->get( 'CookieSecure' );
        }

        $response->setCookie( $this->params['sessionName'], $session->getId(), null,
            [ 'prefix' => '' ] + $options
        );

        foreach ( $cookies as $key => $value ) {
            if ( $value === false ) {
                $response->clearCookie( $key, $options );
            } else {
                $expirationDuration = $this->getLoginCookieExpiration( $key, $session->shouldRememberUser() );
                $expiration = $expirationDuration ? $expirationDuration + time() : null;
                $response->setCookie( $key, (string)$value, $expiration, $options );
            }
        }

        $this->setForceHTTPSCookie( $forceHTTPS, $session, $request );
        $this->setLoggedOutCookie( $session->getLoggedOutTimestamp(), $request );

        if ( $sessionData ) {
            $session->addData( $sessionData );
        }
    }

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

        $cookies = [
            'UserID' => false,
            'Token' => false,
        ];

        $response->clearCookie(
            $this->params['sessionName'], [ 'prefix' => '' ] + $this->cookieOptions
        );

        foreach ( $cookies as $key => $value ) {
            $response->clearCookie( $key, $this->cookieOptions );
        }

        $this->setForceHTTPSCookie( false, null, $request );
    }

    protected function setForceHTTPSCookie(
        $set, SessionBackend $backend = null, WebRequest $request
    ) {
        $response = $request->response();
        if ( $set ) {
            if ( $backend->shouldRememberUser() ) {
                $expirationDuration = $this->getLoginCookieExpiration(
                    'forceHTTPS',
                    true
                );
                $expiration = $expirationDuration ? $expirationDuration + time() : null;
            } else {
                $expiration = null;
            }
            $response->setCookie( 'forceHTTPS', 'true', $expiration,
                [ 'prefix' => '', 'secure' => false ] + $this->cookieOptions );
        } else {
            $response->clearCookie( 'forceHTTPS',
                [ 'prefix' => '', 'secure' => false ] + $this->cookieOptions );
        }
    }

    protected function setLoggedOutCookie( $loggedOut, WebRequest $request ) {
        if ( $loggedOut + 86400 > time() &&
            $loggedOut !== (int)$this->getCookie( $request, 'LoggedOut', $this->cookieOptions['prefix'] )
        ) {
            $request->response()->setCookie( 'LoggedOut', $loggedOut, $loggedOut + 86400,
                $this->cookieOptions );
        }
    }

    public function getVaryCookies() {
        return [
            // Vary on token and session because those are the real authn
            // determiners. UserID and UserName don't matter without those.
            $this->cookieOptions['prefix'] . 'Token',
            $this->cookieOptions['prefix'] . 'LoggedOut',
            $this->params['sessionName'],
            'forceHTTPS',
        ];
    }

    public function suggestLoginUsername( WebRequest $request ) {
         $name = $this->getCookie( $request, 'UserName', $this->cookieOptions['prefix'] );
         if ( $name !== null ) {
             $name = User::getCanonicalName( $name, 'usable' );
         }
         return $name === false ? null : $name;
    }

    protected function getUserInfoFromCookies( $request ) {
        $prefix = $this->cookieOptions['prefix'];
        return [
            $this->getCookie( $request, 'UserID', $prefix ),
            $this->getCookie( $request, 'UserName', $prefix ),
            $this->getCookie( $request, 'Token', $prefix ),
        ];
    }

    protected function getCookie( $request, $key, $prefix, $default = null ) {
        $value = $request->getCookie( $key, $prefix, $default );
        if ( $value === 'deleted' ) {
            // PHP uses this value when deleting cookies. A legitimate cookie will never have
            // this value (usernames start with uppercase, token is longer, other auth cookies
            // are booleans or integers). Seeing this means that in a previous request we told the
            // client to delete the cookie, but it has poor cookie handling. Pretend the cookie is
            // not there to avoid invalidating the session.
            return null;
        }
        return $value;
    }

    protected function cookieDataToExport( $user, $remember ) {
        if ( $user->isAnon() ) {
            return [
                'UserID' => false,
                'Token' => false,
            ];
        } else {
            return [
                'UserID' => $user->getId(),
                'UserName' => $user->getName(),
                'Token' => $remember ? (string)$user->getToken() : false,
            ];
        }
    }

    protected function sessionDataToExport( $user ) {
        // If we're calling the legacy hook, we should populate $session
        // like User::setCookies() did.
        if ( !$user->isAnon() && $this->params['callUserSetCookiesHook'] ) {
            return [
                'wsUserID' => $user->getId(),
                'wsToken' => $user->getToken(),
                'wsUserName' => $user->getName(),
            ];
        }

        return [];
    }

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

    public function getRememberUserDuration() {
        return min( $this->getLoginCookieExpiration( 'UserID', true ),
            $this->getLoginCookieExpiration( 'Token', true ) ) ?: null;
    }

    protected function getExtendedLoginCookies() {
        return [ 'UserID', 'UserName', 'Token' ];
    }

    protected function getLoginCookieExpiration( $cookieName, $shouldRememberUser ) {
        $extendedCookies = $this->getExtendedLoginCookies();
        $normalExpiration = $this->config->get( 'CookieExpiration' );

        if ( $shouldRememberUser && in_array( $cookieName, $extendedCookies, true ) ) {
            $extendedExpiration = $this->config->get( 'ExtendedLoginCookieExpiration' );

            return ( $extendedExpiration !== null ) ? (int)$extendedExpiration : (int)$normalExpiration;
        } else {
            return (int)$normalExpiration;
        }
    }
}