push($middleware); * * $client = new Client([ * 'handler' => $stack, * 'base_uri' => 'https://www.googleapis.com/books/v1', * 'auth' => 'google_auth' * ]); * * $res = $client->get('volumes?q=Henry+David+Thoreau&country=US'); * ``` */ class AppIdentityCredentials extends CredentialsLoader implements SignBlobInterface, ProjectIdProviderInterface { /** * Result of fetchAuthToken. * * @var array */ protected $lastReceivedToken; /** * Array of OAuth2 scopes to be requested. * * @var string[] */ private $scope; /** * @var string */ private $clientName; /** * @param string|string[] $scope One or more scopes. */ public function __construct($scope = []) { $this->scope = is_array($scope) ? $scope : explode(' ', (string) $scope); } /** * Determines if this an App Engine instance, by accessing the * SERVER_SOFTWARE environment variable (prod) or the APPENGINE_RUNTIME * environment variable (dev). * * @return bool true if this an App Engine Instance, false otherwise */ public static function onAppEngine() { $appEngineProduction = isset($_SERVER['SERVER_SOFTWARE']) && 0 === strpos($_SERVER['SERVER_SOFTWARE'], 'Google App Engine'); if ($appEngineProduction) { return true; } $appEngineDevAppServer = isset($_SERVER['APPENGINE_RUNTIME']) && $_SERVER['APPENGINE_RUNTIME'] == 'php'; if ($appEngineDevAppServer) { return true; } return false; } /** * Implements FetchAuthTokenInterface#fetchAuthToken. * * Fetches the auth tokens using the AppIdentityService if available. * As the AppIdentityService uses protobufs to fetch the access token, * the GuzzleHttp\ClientInterface instance passed in will not be used. * * @param callable $httpHandler callback which delivers psr7 request * @return array { * A set of auth related metadata, containing the following * * @type string $access_token * @type string $expiration_time * } */ public function fetchAuthToken(callable $httpHandler = null) { try { $this->checkAppEngineContext(); } catch (\Exception $e) { return []; } /** @phpstan-ignore-next-line */ $token = AppIdentityService::getAccessToken($this->scope); $this->lastReceivedToken = $token; return $token; } /** * Sign a string using AppIdentityService. * * @param string $stringToSign The string to sign. * @param bool $forceOpenSsl [optional] Does not apply to this credentials * type. * @return string The signature, base64-encoded. * @throws \Exception If AppEngine SDK or mock is not available. */ public function signBlob($stringToSign, $forceOpenSsl = false) { $this->checkAppEngineContext(); /** @phpstan-ignore-next-line */ return base64_encode(AppIdentityService::signForApp($stringToSign)['signature']); } /** * Get the project ID from AppIdentityService. * * Returns null if AppIdentityService is unavailable. * * @param callable $httpHandler Not used by this type. * @return string|null */ public function getProjectId(callable $httpHandler = null) { try { $this->checkAppEngineContext(); } catch (\Exception $e) { return null; } /** @phpstan-ignore-next-line */ return AppIdentityService::getApplicationId(); } /** * Get the client name from AppIdentityService. * * Subsequent calls to this method will return a cached value. * * @param callable $httpHandler Not used in this implementation. * @return string * @throws \Exception If AppEngine SDK or mock is not available. */ public function getClientName(callable $httpHandler = null) { $this->checkAppEngineContext(); if (!$this->clientName) { /** @phpstan-ignore-next-line */ $this->clientName = AppIdentityService::getServiceAccountName(); } return $this->clientName; } /** * @return array{access_token:string,expires_at:int}|null */ public function getLastReceivedToken() { if ($this->lastReceivedToken) { return [ 'access_token' => $this->lastReceivedToken['access_token'], 'expires_at' => $this->lastReceivedToken['expiration_time'], ]; } return null; } /** * Caching is handled by the underlying AppIdentityService, return empty string * to prevent caching. * * @return string */ public function getCacheKey() { return ''; } /** * @return void */ private function checkAppEngineContext() { if (!self::onAppEngine() || !class_exists('google\appengine\api\app_identity\AppIdentityService')) { throw new \Exception( 'This class must be run in App Engine, or you must include the AppIdentityService ' . 'mock class defined in tests/mocks/AppIdentityService.php' ); } } }