I would like to create a webapp that use Google Drive as a storage and I'm playing with the Google API but I have a problem with the authentication. I have choose the Service account as a authentication method but when I try to run the script I got this error:
An error occurred: Error refreshing the OAuth2 token, message: '{ "error" : "invalid_grant" }'Array ( )
The code is the following:
<?php
require_once 'api/Google_Client.php';
require_once 'api/contrib/Google_DriveService.php';
require_once "api/contrib/Google_Oauth2Service.php";
session_start();
$service = buildService();
$fileList = retrieveAllFiles($service);
print_r($fileList);
/**
* Build and returns a Drive service object authorized with the service accounts.
*
* @return Google_DriveService service object.
*/
function buildService($userEmail) {
$DRIVE_SCOPE = 'https://www.googleapis.com/auth/drive';
$SERVICE_ACCOUNT_EMAIL = 'xxxapps.googleusercontent.com';
$SERVICE_ACCOUNT_PKCS12_FILE_PATH = 'xxx-privatekey.p12';
$key = file_get_contents($SERVICE_ACCOUNT_PKCS12_FILE_PATH);
$auth = new Google_AssertionCredentials(
$SERVICE_ACCOUNT_EMAIL,
array($DRIVE_SCOPE),
$key);
$auth->prn = $SERVICE_ACCOUNT_EMAIL;
$client = new Google_Client();
$client->setUseObjects(true);
$client->setAssertionCredentials($auth);
return new Google_DriveService($client);
}
/**
* Retrieve a list of File resources.
*
* @param Google_DriveService $service Drive API service instance.
* @return Array List of Google_DriveFile resources.
*/
function retrieveAllFiles($service) {
$result = array();
$pageToken = NULL;
do {
try {
$parameters = array();
if ($pageToken) {
$parameters['pageToken'] = $pageToken;
}
$files = $service->files->listFiles($parameters);
$result = array_merge($result, $files->getItems());
$pageToken = $files->getNextPageToken();
} catch (Exception $e) {
print "An error occurred: " . $e->getMessage();
$pageToken = NULL;
}
} while ($pageToken);
return $result;
}
?>