<?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\Credentials;
use Google\Auth\CredentialsLoader;
use Google\Auth\GetQuotaProjectInterface;
use Google\Auth\OAuth2;
use Google\Auth\ProjectIdProviderInterface;
use Google\Auth\ServiceAccountSignerTrait;
use Google\Auth\SignBlobInterface;
/**
* Authenticates requests using Google's Service Account credentials via
* JWT Access.
*
* This class allows authorizing requests for service accounts directly
* from credentials from a json key file downloaded from the developer
* console (via 'Generate new Json Key'). It is not part of any OAuth2
* flow, rather it creates a JWT and sends that as a credential.
*/
class ServiceAccountJwtAccessCredentials extends CredentialsLoader implements
GetQuotaProjectInterface,
SignBlobInterface,
ProjectIdProviderInterface
{
use ServiceAccountSignerTrait;
/**
* Used in observability metric headers
*
* @var string
*/
private const CRED_TYPE = 'jwt';
/**
* The OAuth2 instance used to conduct authorization.
*
* @var OAuth2
*/
protected $auth;
/**
* The quota project associated with the JSON credentials
*
* @var string
*/
protected $quotaProject;
/**
* @var string
*/
public $projectId;
/**
* Create a new ServiceAccountJwtAccessCredentials.
*
* @param string|array<mixed> $jsonKey JSON credential file path or JSON credentials
* as an associative array
* @param string|string[] $scope the scope of the access request, expressed
* either as an Array or as a space-delimited String.
*/
public function __construct($jsonKey, $scope = null)
{
if (is_string($jsonKey)) {
if (!file_exists($jsonKey)) {
throw new \InvalidArgumentException('file does not exist');
}
$jsonKeyStream = file_get_contents($jsonKey);
if (!$jsonKey = json_decode((string) $jsonKeyStream, true)) {
throw new \LogicException('invalid json for auth config');
}
}
if (!array_key_exists('client_email', $jsonKey)) {
throw new \InvalidArgumentException(
'json key is missing the client_email field'
);
}
if (!array_key_exists('private_key', $jsonKey)) {
throw new \InvalidArgumentException(
'json key is missing the private_key field'
);
}
if (array_key_exists('quota_project_id', $jsonKey)) {
$this->quotaProject = (string) $jsonKey['quota_project_id'];
}
$this->auth = new OAuth2([
'issuer' => $jsonKey['client_email'],
'sub' => $jsonKey['client_email'],
'signingAlgorithm' => 'RS256',
'signingKey' => $jsonKey['private_key'],
'scope' => $scope,
]);
$this->projectId = $jsonKey['project_id'] ?? null;
}
/**
* Updates metadata with the authorization token.
*
* @param array<mixed> $metadata metadata hashmap
* @param string $authUri optional auth uri
* @param callable|null $httpHandler callback which delivers psr7 request
* @return array<mixed> updated metadata hashmap
*/
public function updateMetadata(
$metadata,
$authUri = null,
?callable $httpHandler = null
) {
$scope = $this->auth->getScope();
if (empty($authUri) && empty($scope)) {
return $metadata;
}
$this->auth->setAudience($authUri);
return parent::updateMetadata($metadata, $authUri, $httpHandler);
}
/**
* Implements FetchAuthTokenInterface#fetchAuthToken.
*
* @param callable|null $httpHandler
*
* @return null|array{access_token:string} A set of auth related metadata
*/
public function fetchAuthToken(?callable $httpHandler = null)
{
$audience = $this->auth->getAudience();
$scope = $this->auth->getScope();
if (empty($audience) && empty($scope)) {
return null;
}
if (!empty($audience) && !empty($scope)) {
throw new \UnexpectedValueException(
'Cannot sign both audience and scope in JwtAccess'
);
}
$access_token = $this->auth->toJwt();
// Set the self-signed access token in OAuth2 for getLastReceivedToken
$this->auth->setAccessToken($access_token);
return [
'access_token' => $access_token,
'expires_in' => $this->auth->getExpiry(),
'token_type' => 'Bearer'
];
}
/**
* Return the cache key for the credentials.
* The format for the Cache Key one of the following:
* ClientEmail.Scope
* ClientEmail.Audience
*
* @return string
*/
public function getCacheKey()
{
$scopeOrAudience = $this->auth->getScope();
if (!$scopeOrAudience) {
$scopeOrAudience = $this->auth->getAudience();
}
return $this->auth->getIssuer() . '.' . $scopeOrAudience;
}
/**
* @return array<mixed>
*/
public function getLastReceivedToken()
{
return $this->auth->getLastReceivedToken();
}
/**
* Get the project ID from the service account keyfile.
*
* Returns null if the project ID does not exist in the keyfile.
*
* @param callable|null $httpHandler Not used by this credentials type.
* @return string|null
*/
public function getProjectId(?callable $httpHandler = null)
{
return $this->projectId;
}
/**
* Get the client name from the keyfile.
*
* In this case, it returns the keyfile's client_email key.
*
* @param callable|null $httpHandler Not used by this credentials type.
* @return string
*/
public function getClientName(?callable $httpHandler = null)
{
return $this->auth->getIssuer();
}
/**
* Get the private key from the keyfile.
*
* In this case, it returns the keyfile's private_key key, needed for JWT signing.
*
* @return string
*/
public function getPrivateKey()
{
return $this->auth->getSigningKey();
}
/**
* Get the quota project used for this API request
*
* @return string|null
*/
public function getQuotaProject()
{
return $this->quotaProject;
}
protected function getCredType(): string
{
return self::CRED_TYPE;
}
}
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