' */ class ProxyAuthTokenMiddleware { /** * @var callable */ private $httpHandler; /** * @var FetchAuthTokenInterface */ private $fetcher; /** * @var ?callable */ private $tokenCallback; /** * Creates a new ProxyAuthTokenMiddleware. * * @param FetchAuthTokenInterface $fetcher is used to fetch the auth token * @param callable $httpHandler (optional) callback which delivers psr7 request * @param callable $tokenCallback (optional) function to be called when a new token is fetched. */ public function __construct( FetchAuthTokenInterface $fetcher, callable $httpHandler = null, callable $tokenCallback = null ) { $this->fetcher = $fetcher; $this->httpHandler = $httpHandler; $this->tokenCallback = $tokenCallback; } /** * Updates the request with an Authorization header when auth is 'google_auth'. * * use Google\Auth\Middleware\ProxyAuthTokenMiddleware; * use Google\Auth\OAuth2; * use GuzzleHttp\Client; * use GuzzleHttp\HandlerStack; * * $config = [...]; * $oauth2 = new OAuth2($config) * $middleware = new ProxyAuthTokenMiddleware($oauth2); * $stack = HandlerStack::create(); * $stack->push($middleware); * * $client = new Client([ * 'handler' => $stack, * 'base_uri' => 'https://www.googleapis.com/taskqueue/v1beta2/projects/', * 'proxy_auth' => 'google_auth' // authorize all requests * ]); * * $res = $client->get('myproject/taskqueues/myqueue'); * * @param callable $handler * @return \Closure */ public function __invoke(callable $handler) { return function (RequestInterface $request, array $options) use ($handler) { // Requests using "proxy_auth"="google_auth" will be authorized. if (!isset($options['proxy_auth']) || $options['proxy_auth'] !== 'google_auth') { return $handler($request, $options); } $request = $request->withHeader('proxy-authorization', 'Bearer ' . $this->fetchToken()); if ($quotaProject = $this->getQuotaProject()) { $request = $request->withHeader( GetQuotaProjectInterface::X_GOOG_USER_PROJECT_HEADER, $quotaProject ); } return $handler($request, $options); }; } /** * Call fetcher to fetch the token. * * @return string|null */ private function fetchToken() { $auth_tokens = $this->fetcher->fetchAuthToken($this->httpHandler); if (array_key_exists('access_token', $auth_tokens)) { // notify the callback if applicable if ($this->tokenCallback) { call_user_func( $this->tokenCallback, $this->fetcher->getCacheKey(), $auth_tokens['access_token'] ); } return $auth_tokens['access_token']; } if (array_key_exists('id_token', $auth_tokens)) { return $auth_tokens['id_token']; } return null; } /** * @return string|null; */ private function getQuotaProject() { if ($this->fetcher instanceof GetQuotaProjectInterface) { return $this->fetcher->getQuotaProject(); } return null; } }