<?php
/*
* Copyright 2015 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
namespace Google\Auth\Credentials;
/*
* The AppIdentityService class is automatically defined on App Engine,
* so including this dependency is not necessary, and will result in a
* PHP fatal error in the App Engine environment.
*/
use google\appengine\api\app_identity\AppIdentityService;
use Google\Auth\CredentialsLoader;
use Google\Auth\ProjectIdProviderInterface;
use Google\Auth\SignBlobInterface;
/**
* @deprecated
*
* AppIdentityCredentials supports authorization on Google App Engine.
*
* It can be used to authorize requests using the AuthTokenMiddleware or
* AuthTokenSubscriber, but will only succeed if being run on App Engine:
*
* Example:
* ```
* use Google\Auth\Credentials\AppIdentityCredentials;
* use Google\Auth\Middleware\AuthTokenMiddleware;
* use GuzzleHttp\Client;
* use GuzzleHttp\HandlerStack;
*
* $gae = new AppIdentityCredentials('https://www.googleapis.com/auth/books');
* $middleware = new AuthTokenMiddleware($gae);
* $stack = HandlerStack::create();
* $stack->push($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<mixed>
*/
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<mixed> {
* 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'
);
}
}
}