Initial commit

vendor/google/auth/src/Middleware/AuthTokenMiddleware.php

@@ -0,0 +1,126 @@
+<?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\Middleware;
+
+use Google\Auth\FetchAuthTokenInterface;
+use Psr\Http\Message\RequestInterface;
+
+/**
+ * AuthTokenMiddleware is a Guzzle Middleware that adds an Authorization header
+ * provided by an object implementing FetchAuthTokenInterface.
+ *
+ * The FetchAuthTokenInterface#fetchAuthToken is used to obtain a hash; one of
+ * the values value in that hash is added as the authorization header.
+ *
+ * Requests will be accessed with the authorization header:
+ *
+ * 'Authorization' 'Bearer <value of auth_token>'
+ */
+class AuthTokenMiddleware
+{
+    /**
+     * @var callback
+     */
+    private $httpHandler;
+
+    /**
+     * @var FetchAuthTokenInterface
+     */
+    private $fetcher;
+
+    /**
+     * @var callable
+     */
+    private $tokenCallback;
+
+    /**
+     * Creates a new AuthTokenMiddleware.
+     *
+     * @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\AuthTokenMiddleware;
+     *   use Google\Auth\OAuth2;
+     *   use GuzzleHttp\Client;
+     *   use GuzzleHttp\HandlerStack;
+     *
+     *   $config = [..<oauth config param>.];
+     *   $oauth2 = new OAuth2($config)
+     *   $middleware = new AuthTokenMiddleware($oauth2);
+     *   $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');
+     *
+     * @param callable $handler
+     *
+     * @return \Closure
+     */
+    public function __invoke(callable $handler)
+    {
+        return function (RequestInterface $request, array $options) use ($handler) {
+            // Requests using "auth"="google_auth" will be authorized.
+            if (!isset($options['auth']) || $options['auth'] !== 'google_auth') {
+                return $handler($request, $options);
+            }
+
+            $request = $request->withHeader('Authorization', 'Bearer ' . $this->fetchToken());
+
+            return $handler($request, $options);
+        };
+    }
+
+    /**
+     * Call fetcher to fetch the token.
+     *
+     * @return string
+     */
+    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'];
+        }
+    }
+}