<?php
/*
* Copyright 2019 Google LLC
*
* 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 Automattic\WooCommerce\GoogleListingsAndAds\Vendor\Google\Auth;
use Automattic\WooCommerce\GoogleListingsAndAds\Vendor\Google\Auth\HttpHandler\HttpClientCache;
use Automattic\WooCommerce\GoogleListingsAndAds\Vendor\Google\Auth\HttpHandler\HttpHandlerFactory;
use Automattic\WooCommerce\GoogleListingsAndAds\Vendor\GuzzleHttp\Psr7;
use Automattic\WooCommerce\GoogleListingsAndAds\Vendor\GuzzleHttp\Psr7\Utils;
/**
* Tools for using the IAM API.
*
* @see https://cloud.google.com/iam/docs IAM Documentation
*/
class Iam
{
const IAM_API_ROOT = 'https://iamcredentials.googleapis.com/v1';
const SIGN_BLOB_PATH = '%s:signBlob?alt=json';
const SERVICE_ACCOUNT_NAME = 'projects/-/serviceAccounts/%s';
/**
* @var callable
*/
private $httpHandler;
/**
* @param callable $httpHandler [optional] The HTTP Handler to send requests.
*/
public function __construct(callable $httpHandler = null)
{
$this->httpHandler = $httpHandler
?: HttpHandlerFactory::build(HttpClientCache::getHttpClient());
}
/**
* Sign a string using the IAM signBlob API.
*
* Note that signing using IAM requires your service account to have the
* `iam.serviceAccounts.signBlob` permission, part of the "Service Account
* Token Creator" IAM role.
*
* @param string $email The service account email.
* @param string $accessToken An access token from the service account.
* @param string $stringToSign The string to be signed.
* @param array<string> $delegates [optional] A list of service account emails to
* add to the delegate chain. If omitted, the value of `$email` will
* be used.
* @return string The signed string, base64-encoded.
*/
public function signBlob($email, $accessToken, $stringToSign, array $delegates = [])
{
$httpHandler = $this->httpHandler;
$name = sprintf(self::SERVICE_ACCOUNT_NAME, $email);
$uri = self::IAM_API_ROOT . '/' . sprintf(self::SIGN_BLOB_PATH, $name);
if ($delegates) {
foreach ($delegates as &$delegate) {
$delegate = sprintf(self::SERVICE_ACCOUNT_NAME, $delegate);
}
} else {
$delegates = [$name];
}
$body = [
'delegates' => $delegates,
'payload' => base64_encode($stringToSign),
];
$headers = [
'Authorization' => 'Bearer ' . $accessToken
];
$request = new Psr7\Request(
'POST',
$uri,
$headers,
Utils::streamFor(json_encode($body))
);
$res = $httpHandler($request);
$body = json_decode((string) $res->getBody(), true);
return $body['signedBlob'];
}
}