assertRequiredOptions( self::CONSTRUCTOR_OPTIONS ); $this->options = $options; $this->responseFactory = $responseFactory; $this->user = $user; } /** * Only allow registered users to make unsafe cross-origin requests. * * @param RequestInterface $request * @param Handler $handler * @return string|null If the request is denied, the string error code. If * the request is allowed, null. */ public function authorize( RequestInterface $request, Handler $handler ) { // Handlers that need write access are by definition a cache-miss, therefore there is no // need to vary by the origin. if ( $handler->needsWriteAccess() && $request->hasHeader( 'Origin' ) && !$this->user->isRegistered() ) { $origin = Origin::parseHeaderList( $request->getHeader( 'Origin' ) ); if ( !$this->allowOrigin( $origin ) ) { return 'rest-cross-origin-anon-write'; } } return null; } /** * @param Origin $origin * @return bool */ private function allowOrigin( Origin $origin ): bool { $allowed = array_merge( [ $this->getCanonicalDomain() ], $this->options->get( MainConfigNames::CrossSiteAJAXdomains ) ); $excluded = $this->options->get( MainConfigNames::CrossSiteAJAXdomainExceptions ); return $origin->match( $allowed, $excluded ); } /** * @return string */ private function getCanonicalDomain(): string { $res = parse_url( $this->options->get( MainConfigNames::CanonicalServer ) ); '@phan-var array $res'; $host = $res['host'] ?? ''; $port = $res['port'] ?? null; return $port ? "$host:$port" : $host; } /** * Modify response to allow for CORS. * * This method should be executed for every response from the REST API * including errors. * * @param RequestInterface $request * @param ResponseInterface $response * @return ResponseInterface */ public function modifyResponse( RequestInterface $request, ResponseInterface $response ): ResponseInterface { if ( !$this->options->get( MainConfigNames::AllowCrossOrigin ) ) { return $response; } $allowedOrigin = '*'; if ( $this->options->get( MainConfigNames::RestAllowCrossOriginCookieAuth ) ) { // @TODO Since we only Vary the response if (1) the method is OPTIONS or (2) the user is // registered, it is safe to only add the Vary: Origin when those two conditions // are met since a response to a logged-in user's request is not cachable. // Therefore, logged out users should always get `Access-Control-Allow-Origin: *` // on all non-OPTIONS request and logged-in users *may* get // `Access-Control-Allow-Origin: ` // Vary All Requests by the Origin header. $response->addHeader( 'Vary', 'Origin' ); // If the Origin header is missing, there is nothing to check against. if ( $request->hasHeader( 'Origin' ) ) { $origin = Origin::parseHeaderList( $request->getHeader( 'Origin' ) ); if ( $this->allowOrigin( $origin ) ) { // Only set the allowed origin for preflight requests, or for main requests where a registered // user is authenticated. This prevents having to Vary all requests by the Origin. // Anonymous users will always get '*', registered users *may* get the requested origin back. if ( $request->getMethod() === 'OPTIONS' || $this->user->isRegistered() ) { $allowedOrigin = $origin->getSingleOrigin(); } } } } // If the Origin was determined to be something other than *any* allow the session // cookies to be sent with the main request. If this is the main request, allow the // response to be read. // // If the client includes the credentials on a simple request (HEAD, GET, etc.), but // they do not pass this check, the browser will refuse to allow the client to read the // response. The client may resolve this by repeating the request without the // credentials. if ( $allowedOrigin !== '*' ) { $response->setHeader( 'Access-Control-Allow-Credentials', 'true' ); } $response->setHeader( 'Access-Control-Allow-Origin', $allowedOrigin ); return $response; } /** * Create a CORS preflight response. * * @param array $allowedMethods * @return Response */ public function createPreflightResponse( array $allowedMethods ): Response { $response = $this->responseFactory->createNoContent(); $response->setHeader( 'Access-Control-Allow-Methods', $allowedMethods ); $allowedHeaders = $this->options->get( MainConfigNames::AllowedCorsHeaders ); $allowedHeaders = array_merge( $allowedHeaders, array_diff( [ // Authorization header must be explicitly listed which prevent the use of '*' 'Authorization', // REST must allow Content-Type to be operational 'Content-Type', // REST relies on conditional requests for some endpoints 'If-Mach', 'If-None-Match', 'If-Modified-Since', ], $allowedHeaders ) ); $response->setHeader( 'Access-Control-Allow-Headers', $allowedHeaders ); return $response; } }