Initial commit

vendor/google/auth/src/ApplicationDefaultCredentials.php

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+<?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;
+
+use DomainException;
+use Google\Auth\Credentials\AppIdentityCredentials;
+use Google\Auth\Credentials\GCECredentials;
+use Google\Auth\Middleware\AuthTokenMiddleware;
+use Google\Auth\Subscriber\AuthTokenSubscriber;
+use Psr\Cache\CacheItemPoolInterface;
+
+/**
+ * ApplicationDefaultCredentials obtains the default credentials for
+ * authorizing a request to a Google service.
+ *
+ * Application Default Credentials are described here:
+ * https://developers.google.com/accounts/docs/application-default-credentials
+ *
+ * This class implements the search for the application default credentials as
+ * described in the link.
+ *
+ * It provides three factory methods:
+ * - #get returns the computed credentials object
+ * - #getSubscriber returns an AuthTokenSubscriber built from the credentials object
+ * - #getMiddleware returns an AuthTokenMiddleware built from the credentials object
+ *
+ * This allows it to be used as follows with GuzzleHttp\Client:
+ *
+ *   use Google\Auth\ApplicationDefaultCredentials;
+ *   use GuzzleHttp\Client;
+ *   use GuzzleHttp\HandlerStack;
+ *
+ *   $middleware = ApplicationDefaultCredentials::getMiddleware(
+ *       'https://www.googleapis.com/auth/taskqueue'
+ *   );
+ *   $stack = HandlerStack::create();
+ *   $stack->push($middleware);
+ *
+ *   $client = new Client([
+ *       'handler' => $stack,
+ *       'base_uri' => 'https://www.googleapis.com/taskqueue/v1beta2/projects/',
+ *       'auth' => 'google_auth' // authorize all requests
+ *   ]);
+ *
+ *   $res = $client->get('myproject/taskqueues/myqueue');
+ */
+class ApplicationDefaultCredentials
+{
+    /**
+     * Obtains an AuthTokenSubscriber that uses the default FetchAuthTokenInterface
+     * implementation to use in this environment.
+     *
+     * If supplied, $scope is used to in creating the credentials instance if
+     * this does not fallback to the compute engine defaults.
+     *
+     * @param string|array scope the scope of the access request, expressed
+     *   either as an Array or as a space-delimited String.
+     * @param callable $httpHandler callback which delivers psr7 request
+     * @param array $cacheConfig configuration for the cache when it's present
+     * @param CacheItemPoolInterface $cache an implementation of CacheItemPoolInterface
+     *
+     * @return AuthTokenSubscriber
+     *
+     * @throws DomainException if no implementation can be obtained.
+     */
+    public static function getSubscriber(
+        $scope = null,
+        callable $httpHandler = null,
+        array $cacheConfig = null,
+        CacheItemPoolInterface $cache = null
+    ) {
+        $creds = self::getCredentials($scope, $httpHandler, $cacheConfig, $cache);
+
+        return new AuthTokenSubscriber($creds, $cacheConfig);
+    }
+
+    /**
+     * Obtains an AuthTokenMiddleware that uses the default FetchAuthTokenInterface
+     * implementation to use in this environment.
+     *
+     * If supplied, $scope is used to in creating the credentials instance if
+     * this does not fallback to the compute engine defaults.
+     *
+     * @param string|array scope the scope of the access request, expressed
+     *   either as an Array or as a space-delimited String.
+     * @param callable $httpHandler callback which delivers psr7 request
+     * @param array $cacheConfig configuration for the cache when it's present
+     * @param CacheItemPoolInterface $cache
+     *
+     * @return AuthTokenMiddleware
+     *
+     * @throws DomainException if no implementation can be obtained.
+     */
+    public static function getMiddleware(
+        $scope = null,
+        callable $httpHandler = null,
+        array $cacheConfig = null,
+        CacheItemPoolInterface $cache = null
+    ) {
+        $creds = self::getCredentials($scope, $httpHandler, $cacheConfig, $cache);
+
+        return new AuthTokenMiddleware($creds, $cacheConfig);
+    }
+
+    /**
+     * Obtains the default FetchAuthTokenInterface implementation to use
+     * in this environment.
+     *
+     * If supplied, $scope is used to in creating the credentials instance if
+     * this does not fallback to the Compute Engine defaults.
+     *
+     * @param string|array scope the scope of the access request, expressed
+     *   either as an Array or as a space-delimited String.
+     * @param callable $httpHandler callback which delivers psr7 request
+     * @param array $cacheConfig configuration for the cache when it's present
+     * @param CacheItemPoolInterface $cache
+     *
+     * @return CredentialsLoader
+     *
+     * @throws DomainException if no implementation can be obtained.
+     */
+    public static function getCredentials(
+        $scope = null,
+        callable $httpHandler = null,
+        array $cacheConfig = null,
+        CacheItemPoolInterface $cache = null
+    ) {
+        $creds = null;
+        $jsonKey = CredentialsLoader::fromEnv()
+            ?: CredentialsLoader::fromWellKnownFile();
+
+        if (!is_null($jsonKey)) {
+            $creds = CredentialsLoader::makeCredentials($scope, $jsonKey);
+        } elseif (AppIdentityCredentials::onAppEngine() && !GCECredentials::onAppEngineFlexible()) {
+            $creds = new AppIdentityCredentials($scope);
+        } elseif (GCECredentials::onGce($httpHandler)) {
+            $creds = new GCECredentials();
+        }
+
+        if (is_null($creds)) {
+            throw new \DomainException(self::notFound());
+        }
+        if (!is_null($cache)) {
+            $creds = new FetchAuthTokenCache($creds, $cacheConfig, $cache);
+        }
+        return $creds;
+    }
+
+    private static function notFound()
+    {
+        $msg = 'Could not load the default credentials. Browse to ';
+        $msg .= 'https://developers.google.com';
+        $msg .= '/accounts/docs/application-default-credentials';
+        $msg .= ' for more information';
+
+        return $msg;
+    }
+}