wp-stateless / lib / Google / vendor / google / auth / src / Credentials / AppIdentityCredentials.php

AppIdentityCredentials.php in WP-Stateless – Google Cloud Storage 3.0.3, at lib/Google/vendor/google/auth/src/Credentials/AppIdentityCredentials.php

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1	<?php
2	/*
3	* Copyright 2015 Google Inc.
4	*
5	* Licensed under the Apache License, Version 2.0 (the "License");
6	* you may not use this file except in compliance with the License.
7	* You may obtain a copy of the License at
8	*
9	* http://www.apache.org/licenses/LICENSE-2.0
10	*
11	* Unless required by applicable law or agreed to in writing, software
12	* distributed under the License is distributed on an "AS IS" BASIS,
13	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14	* See the License for the specific language governing permissions and
15	* limitations under the License.
16	*/
17
18	namespace Google\Auth\Credentials;
19
20	/*
21	* The AppIdentityService class is automatically defined on App Engine,
22	* so including this dependency is not necessary, and will result in a
23	* PHP fatal error in the App Engine environment.
24	*/
25	use google\appengine\api\app_identity\AppIdentityService;
26	use Google\Auth\CredentialsLoader;
27	use Google\Auth\ProjectIdProviderInterface;
28	use Google\Auth\SignBlobInterface;
29
30	/**
31	* AppIdentityCredentials supports authorization on Google App Engine.
32	*
33	* It can be used to authorize requests using the AuthTokenMiddleware or
34	* AuthTokenSubscriber, but will only succeed if being run on App Engine:
35	*
36	* Example:
37	* ```
38	* use Google\Auth\Credentials\AppIdentityCredentials;
39	* use Google\Auth\Middleware\AuthTokenMiddleware;
40	* use GuzzleHttp\Client;
41	* use GuzzleHttp\HandlerStack;
42	*
43	* $gae = new AppIdentityCredentials('https://www.googleapis.com/auth/books');
44	* $middleware = new AuthTokenMiddleware($gae);
45	* $stack = HandlerStack::create();
46	* $stack->push($middleware);
47	*
48	* $client = new Client([
49	* 'handler' => $stack,
50	* 'base_uri' => 'https://www.googleapis.com/books/v1',
51	* 'auth' => 'google_auth'
52	* ]);
53	*
54	* $res = $client->get('volumes?q=Henry+David+Thoreau&country=US');
55	* ```
56	*/
57	class AppIdentityCredentials extends CredentialsLoader implements
58	SignBlobInterface,
59	ProjectIdProviderInterface
60	{
61	/**
62	* Result of fetchAuthToken.
63	*
64	* @var array
65	*/
66	protected $lastReceivedToken;
67
68	/**
69	* Array of OAuth2 scopes to be requested.
70	*
71	* @var array
72	*/
73	private $scope;
74
75	/**
76	* @var string
77	*/
78	private $clientName;
79
80	/**
81	* @param array $scope One or more scopes.
82	*/
83	public function __construct($scope = array())
84	{
85	$this->scope = $scope;
86	}
87
88	/**
89	* Determines if this an App Engine instance, by accessing the
90	* SERVER_SOFTWARE environment variable (prod) or the APPENGINE_RUNTIME
91	* environment variable (dev).
92	*
93	* @return bool true if this an App Engine Instance, false otherwise
94	*/
95	public static function onAppEngine()
96	{
97	$appEngineProduction = isset($_SERVER['SERVER_SOFTWARE']) &&
98	0 === strpos($_SERVER['SERVER_SOFTWARE'], 'Google App Engine');
99	if ($appEngineProduction) {
100	return true;
101	}
102	$appEngineDevAppServer = isset($_SERVER['APPENGINE_RUNTIME']) &&
103	$_SERVER['APPENGINE_RUNTIME'] == 'php';
104	if ($appEngineDevAppServer) {
105	return true;
106	}
107	return false;
108	}
109
110	/**
111	* Implements FetchAuthTokenInterface#fetchAuthToken.
112	*
113	* Fetches the auth tokens using the AppIdentityService if available.
114	* As the AppIdentityService uses protobufs to fetch the access token,
115	* the GuzzleHttp\ClientInterface instance passed in will not be used.
116	*
117	* @param callable $httpHandler callback which delivers psr7 request
118	* @return array A set of auth related metadata, containing the following
119	* keys:
120	* - access_token (string)
121	* - expiration_time (string)
122	*/
123	public function fetchAuthToken(callable $httpHandler = null)
124	{
125	try {
126	$this->checkAppEngineContext();
127	} catch (\Exception $e) {
128	return [];
129	}
130
131	// AppIdentityService expects an array when multiple scopes are supplied
132	$scope = is_array($this->scope) ? $this->scope : explode(' ', $this->scope);
133
134	$token = AppIdentityService::getAccessToken($scope);
135	$this->lastReceivedToken = $token;
136
137	return $token;
138	}
139
140	/**
141	* Sign a string using AppIdentityService.
142	*
143	* @param string $stringToSign The string to sign.
144	* @param bool $forceOpenSsl [optional] Does not apply to this credentials
145	* type.
146	* @return string The signature, base64-encoded.
147	* @throws \Exception If AppEngine SDK or mock is not available.
148	*/
149	public function signBlob($stringToSign, $forceOpenSsl = false)
150	{
151	$this->checkAppEngineContext();
152
153	return base64_encode(AppIdentityService::signForApp($stringToSign)['signature']);
154	}
155
156	/**
157	* Get the project ID from AppIdentityService.
158	*
159	* Returns null if AppIdentityService is unavailable.
160	*
161	* @param callable $httpHandler Not used by this type.
162	* @return string\|null
163	*/
164	public function getProjectId(callable $httpHander = null)
165	{
166	try {
167	$this->checkAppEngineContext();
168	} catch (\Exception $e) {
169	return null;
170	}
171
172	return AppIdentityService::getApplicationId();
173	}
174
175	/**
176	* Get the client name from AppIdentityService.
177	*
178	* Subsequent calls to this method will return a cached value.
179	*
180	* @param callable $httpHandler Not used in this implementation.
181	* @return string
182	* @throws \Exception If AppEngine SDK or mock is not available.
183	*/
184	public function getClientName(callable $httpHandler = null)
185	{
186	$this->checkAppEngineContext();
187
188	if (!$this->clientName) {
189	$this->clientName = AppIdentityService::getServiceAccountName();
190	}
191
192	return $this->clientName;
193	}
194
195	/**
196	* @return array\|null
197	*/
198	public function getLastReceivedToken()
199	{
200	if ($this->lastReceivedToken) {
201	return [
202	'access_token' => $this->lastReceivedToken['access_token'],
203	'expires_at' => $this->lastReceivedToken['expiration_time'],
204	];
205	}
206
207	return null;
208	}
209
210	/**
211	* Caching is handled by the underlying AppIdentityService, return empty string
212	* to prevent caching.
213	*
214	* @return string
215	*/
216	public function getCacheKey()
217	{
218	return '';
219	}
220
221	private function checkAppEngineContext()
222	{
223	if (!self::onAppEngine() \|\| !class_exists('google\appengine\api\app_identity\AppIdentityService')) {
224	throw new \Exception(
225	'This class must be run in App Engine, or you must include the AppIdentityService '
226	. 'mock class defined in tests/mocks/AppIdentityService.php'
227	);
228	}
229	}
230	}
231