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# Google Auth Library for PHP |
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|
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<a href="https://cloud.google.com/php/docs/reference/auth/latest">Reference Docs</a> |
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|
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## Description |
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|
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This is Google's officially supported PHP client library for using OAuth 2.0 |
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authorization and authentication with Google APIs. |
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### Installing via Composer |
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|
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The recommended way to install the google auth library is through |
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[](http://getcomposer.orgComposer](http://getcomposer.org](http://getcomposer.org). |
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|
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```bash |
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# Install Composer |
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curl -sS https://getcomposer.org/installer | php |
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``` |
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Next, run the Composer command to install the latest stable version: |
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```bash |
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composer.phar require google/auth |
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``` |
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|
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## Application Default Credentials |
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|
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This library provides an implementation of |
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[Application Default Credentials (ADC)][application default credentials] for PHP. |
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|
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Application Default Credentials provides a simple way to get authorization |
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credentials for use in calling Google APIs, and is |
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the recommended approach to authorize calls to Cloud APIs. |
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|
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**Important**: If you accept a credential configuration (credential JSON/File/Stream) from an |
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external source for authentication to Google Cloud Platform, you must validate it before providing |
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it to any Google API or library. Providing an unvalidated credential configuration to Google APIs |
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can compromise the security of your systems and data. For more information, refer to |
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[Validate credential configurations from external sources][externally-sourced-credentials]. |
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|
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[externally-sourced-credentials]: https://cloud.google.com/docs/authentication/external/externally-sourced-credentials |
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|
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### Set up ADC |
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To use ADC, you must set it up by providing credentials. |
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How you set up ADC depends on the environment where your code is running, |
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and whether you are running code in a test or production environment. |
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|
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For more information, see [Set up Application Default Credentials][set-up-adc]. |
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|
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### Enable the API you want to use |
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|
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Before making your API call, you must be sure the API you're calling has been |
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enabled. Go to **APIs & Auth** > **APIs** in the |
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[Google Developers Console][developer console] and enable the APIs you'd like to |
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call. For the example below, you must enable the `Drive API`. |
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|
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### Call the APIs |
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|
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As long as you update the environment variable below to point to *your* JSON |
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credentials file, the following code should output a list of your Drive files. |
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|
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```php |
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use Google\Auth\ApplicationDefaultCredentials; |
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use GuzzleHttp\Client; |
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use GuzzleHttp\HandlerStack; |
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|
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// specify the path to your application credentials |
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putenv('GOOGLE_APPLICATION_CREDENTIALS=/path/to/my/credentials.json'); |
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|
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// define the scopes for your API call |
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$scopes = ['https://www.googleapis.com/auth/drive.readonly']; |
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|
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// create middleware |
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$middleware = ApplicationDefaultCredentials::getMiddleware($scopes); |
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$stack = HandlerStack::create(); |
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$stack->push($middleware); |
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|
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// create the HTTP client |
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$client = new Client([ |
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'handler' => $stack, |
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'base_uri' => 'https://www.googleapis.com', |
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'auth' => 'google_auth' // authorize all requests |
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]); |
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|
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// make the request |
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$response = $client->get('drive/v2/files'); |
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// show the result! |
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print_r((string) $response->getBody()); |
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``` |
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|
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##### Guzzle 5 Compatibility |
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|
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If you are using [Guzzle 5][Guzzle 5], replace the `create middleware` and |
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`create the HTTP Client` steps with the following: |
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|
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```php |
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// create the HTTP client |
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$client = new Client([ |
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'base_url' => 'https://www.googleapis.com', |
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'auth' => 'google_auth' // authorize all requests |
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]); |
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|
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// create subscriber |
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$subscriber = ApplicationDefaultCredentials::getSubscriber($scopes); |
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$client->getEmitter()->attach($subscriber); |
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``` |
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|
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#### Call using an ID Token |
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If your application is running behind Cloud Run, or using Cloud Identity-Aware |
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Proxy (IAP), you will need to fetch an ID token to access your application. For |
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this, use the static method `getIdTokenMiddleware` on |
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`ApplicationDefaultCredentials`. |
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|
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```php |
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use Google\Auth\ApplicationDefaultCredentials; |
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use GuzzleHttp\Client; |
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use GuzzleHttp\HandlerStack; |
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|
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// specify the path to your application credentials |
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putenv('GOOGLE_APPLICATION_CREDENTIALS=/path/to/my/credentials.json'); |
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// Provide the ID token audience. This can be a Client ID associated with an IAP application, |
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// Or the URL associated with a CloudRun App |
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// $targetAudience = 'IAP_CLIENT_ID.apps.googleusercontent.com'; |
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// $targetAudience = 'https://service-1234-uc.a.run.app'; |
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$targetAudience = 'YOUR_ID_TOKEN_AUDIENCE'; |
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|
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// create middleware |
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$middleware = ApplicationDefaultCredentials::getIdTokenMiddleware($targetAudience); |
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$stack = HandlerStack::create(); |
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$stack->push($middleware); |
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|
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// create the HTTP client |
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$client = new Client([ |
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'handler' => $stack, |
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'auth' => 'google_auth', |
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// Cloud Run, IAP, or custom resource URL |
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'base_uri' => 'https://YOUR_PROTECTED_RESOURCE', |
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]); |
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|
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// make the request |
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$response = $client->get('/'); |
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|
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// show the result! |
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print_r((string) $response->getBody()); |
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``` |
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For invoking Cloud Run services, your service account will need the |
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[](https://cloud.google.com/run/docs/authenticating/service-to-service`Cloud Run Invoker`](https://cloud.google.com/run/docs/authenticating/service-to-service](https://cloud.google.com/run/docs/authenticating/service-to-service) |
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IAM permission. |
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For invoking Cloud Identity-Aware Proxy, you will need to pass the Client ID |
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used when you set up your protected resource as the target audience. See how to |
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[](https://cloud.google.com/iap/docs/signed-headers-howtosecure your IAP app with signed headers](https://cloud.google.com/iap/docs/signed-headers-howto](https://cloud.google.com/iap/docs/signed-headers-howto). |
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#### Call using a specific JSON key |
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If you want to use a specific JSON key instead of using `GOOGLE_APPLICATION_CREDENTIALS` environment variable, you can |
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do this: |
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```php |
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use Google\Auth\CredentialsLoader; |
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use Google\Auth\Middleware\AuthTokenMiddleware; |
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use GuzzleHttp\Client; |
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use GuzzleHttp\HandlerStack; |
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|
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// Define the Google Application Credentials array |
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$jsonKey = ['key' => 'value']; |
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// define the scopes for your API call |
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$scopes = ['https://www.googleapis.com/auth/drive.readonly']; |
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// Load credentials from JSON containing service account credentials. |
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$creds = new ServiceAccountCredentials($scopes, $jsonKey), |
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// For other credentials types, create those classes explicitly using the |
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// "type" field in the JSON key, for example: |
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$creds = match ($jsonKey['type']) { |
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'service_account' => new ServiceAccountCredentials($scope, $jsonKey), |
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'authorized_user' => new UserRefreshCredentials($scope, $jsonKey), |
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default => throw new InvalidArgumentException('This application only supports service account and user account credentials'), |
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}; |
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// optional caching |
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$creds = new FetchAuthTokenCache($creds, $cacheConfig, $cache); |
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// create middleware |
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$middleware = new AuthTokenMiddleware($creds); |
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$stack = HandlerStack::create(); |
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$stack->push($middleware); |
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|
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// create the HTTP client |
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$client = new Client([ |
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'handler' => $stack, |
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'base_uri' => 'https://www.googleapis.com', |
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'auth' => 'google_auth' // authorize all requests |
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]); |
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|
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// make the request |
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$response = $client->get('drive/v2/files'); |
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|
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// show the result! |
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print_r((string) $response->getBody()); |
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|
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``` |
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#### Call using Proxy-Authorization Header |
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If your application is behind a proxy such as [Google Cloud IAP][iap-proxy-header], |
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and your application occupies the `Authorization` request header, |
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you can include the ID token in a `Proxy-Authorization: Bearer` |
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header instead. If a valid ID token is found in a `Proxy-Authorization` header, |
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IAP authorizes the request with it. After authorizing the request, IAP passes |
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the Authorization header to your application without processing the content. |
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For this, use the static method `getProxyIdTokenMiddleware` on |
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`ApplicationDefaultCredentials`. |
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|
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```php |
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use Google\Auth\ApplicationDefaultCredentials; |
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use GuzzleHttp\Client; |
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use GuzzleHttp\HandlerStack; |
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|
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// specify the path to your application credentials |
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putenv('GOOGLE_APPLICATION_CREDENTIALS=/path/to/my/credentials.json'); |
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// Provide the ID token audience. This can be a Client ID associated with an IAP application |
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// $targetAudience = 'IAP_CLIENT_ID.apps.googleusercontent.com'; |
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$targetAudience = 'YOUR_ID_TOKEN_AUDIENCE'; |
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// create middleware |
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$middleware = ApplicationDefaultCredentials::getProxyIdTokenMiddleware($targetAudience); |
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$stack = HandlerStack::create(); |
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$stack->push($middleware); |
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// create the HTTP client |
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$client = new Client([ |
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'handler' => $stack, |
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'auth' => ['username', 'pass'], // auth option handled by your application |
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'proxy_auth' => 'google_auth', |
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]); |
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// make the request |
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$response = $client->get('/'); |
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// show the result! |
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print_r((string) $response->getBody()); |
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``` |
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[iap-proxy-header]: https://cloud.google.com/iap/docs/authentication-howto#authenticating_from_proxy-authorization_header |
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#### External credentials (Workload identity federation) |
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Using workload identity federation, your application can access Google Cloud resources from Amazon Web Services (AWS), |
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Microsoft Azure or any identity provider that supports OpenID Connect (OIDC). |
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Traditionally, applications running outside Google Cloud have used service account keys to access Google Cloud |
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resources. Using identity federation, you can allow your workload to impersonate a service account. This lets you access |
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Google Cloud resources directly, eliminating the maintenance and security burden associated with service account keys. |
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Follow the detailed instructions on how to |
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[](https://cloud.google.com/iam/docs/workload-identity-federation-with-other-cloudsConfigure Workload Identity Federation](https://cloud.google.com/iam/docs/workload-identity-federation-with-other-clouds](https://cloud.google.com/iam/docs/workload-identity-federation-with-other-clouds). |
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#### Verifying JWTs |
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If you are [using Google ID tokens to authenticate users][google-id-tokens], use |
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the `Google\Auth\AccessToken` class to verify the ID token: |
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```php |
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use Google\Auth\AccessToken; |
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$auth = new AccessToken(); |
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$auth->verify($idToken); |
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``` |
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If your app is running behind [Google Identity-Aware Proxy][iap-id-tokens] |
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(IAP), you can verify the ID token coming from the IAP server by pointing to the |
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appropriate certificate URL for IAP. This is because IAP signs the ID |
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tokens with a different key than the Google Identity service: |
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|
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```php |
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use Google\Auth\AccessToken; |
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$auth = new AccessToken(); |
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$auth->verify($idToken, [ |
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'certsLocation' => AccessToken::IAP_CERT_URL |
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]); |
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``` |
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[google-id-tokens]: https://developers.google.com/identity/sign-in/web/backend-auth |
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[iap-id-tokens]: https://cloud.google.com/iap/docs/signed-headers-howto |
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|
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## Caching |
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Caching is enabled by passing a PSR-6 `CacheItemPoolInterface` |
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instance to the constructor when instantiating the credentials. |
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We offer some caching classes out of the box under the `Google\Auth\Cache` namespace. |
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|
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```php |
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use Google\Auth\ApplicationDefaultCredentials; |
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use Google\Auth\Cache\MemoryCacheItemPool; |
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|
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// Cache Instance |
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$memoryCache = new MemoryCacheItemPool; |
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|
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// Get the credentials |
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// From here, the credentials will cache the access token |
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$middleware = ApplicationDefaultCredentials::getCredentials($scope, cache: $memoryCache); |
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``` |
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|
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### FileSystemCacheItemPool Cache |
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The `FileSystemCacheItemPool` class is a `PSR-6` compliant cache that stores its |
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serialized objects on disk, caching data between processes and making it possible |
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to use data between different requests. |
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|
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```php |
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use Google\Auth\Cache\FileSystemCacheItemPool; |
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use Google\Auth\ApplicationDefaultCredentials; |
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// Create a Cache pool instance |
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$cache = new FileSystemCacheItemPool(__DIR__ . '/cache'); |
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// Pass your Cache to the Auth Library |
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$credentials = ApplicationDefaultCredentials::getCredentials($scope, cache: $cache); |
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// This token will be cached and be able to be used for the next request |
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$token = $credentials->fetchAuthToken(); |
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``` |
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|
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### Integrating with a third party cache |
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You can use a third party that follows the `PSR-6` interface of your choice. |
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|
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```php |
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// run "composer require symfony/cache" |
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use Google\Auth\ApplicationDefaultCredentials; |
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use Symfony\Component\Cache\Adapter\FilesystemAdapter; |
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// Create the cache instance |
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$filesystemCache = new FilesystemAdapter(); |
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// Create Get the credentials |
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$credentials = ApplicationDefaultCredentials::getCredentials($targetAudience, cache: $filesystemCache); |
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``` |
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|
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## License |
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|
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This library is licensed under Apache 2.0. Full license text is |
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available in [COPYING][copying]. |
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|
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## Contributing |
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|
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See [CONTRIBUTING][contributing]. |
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|
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## Support |
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|
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Please |
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[](https://github.com/google/google-auth-library-php/issuesreport bugs at the project on Github](https://github.com/google/google-auth-library-php/issues](https://github.com/google/google-auth-library-php/issues). Don't |
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hesitate to |
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[](http://stackoverflow.com/questions/tagged/google-auth-library-phpask questions](http://stackoverflow.com/questions/tagged/google-auth-library-php](http://stackoverflow.com/questions/tagged/google-auth-library-php) |
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about the client or APIs on [](http://stackoverflow.comStackOverflow](http://stackoverflow.com](http://stackoverflow.com). |
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|
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[google-apis-php-client]: https://github.com/google/google-api-php-client |
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[application default credentials]: https://cloud.google.com/docs/authentication/application-default-credentials |
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[contributing]: https://github.com/google/google-auth-library-php/tree/main/.github/CONTRIBUTING.md |
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[copying]: https://github.com/google/google-auth-library-php/tree/main/COPYING |
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[Guzzle]: https://github.com/guzzle/guzzle |
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[Guzzle 5]: http://docs.guzzlephp.org/en/5.3 |
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[developer console]: https://console.developers.google.com |
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[set-up-adc]: https://cloud.google.com/docs/authentication/provide-credentials-adc |
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|
