| 1 |
<?php |
| 2 |
|
| 3 |
/* |
| 4 |
* Copyright 2008 Google Inc. |
| 5 |
* |
| 6 |
* Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 |
* you may not use this file except in compliance with the License. |
| 8 |
* You may obtain a copy of the License at |
| 9 |
* |
| 10 |
* http://www.apache.org/licenses/LICENSE-2.0 |
| 11 |
* |
| 12 |
* Unless required by applicable law or agreed to in writing, software |
| 13 |
* distributed under the License is distributed on an "AS IS" BASIS, |
| 14 |
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 |
* See the License for the specific language governing permissions and |
| 16 |
* limitations under the License. |
| 17 |
*/ |
| 18 |
|
| 19 |
namespace Google\AccessToken; |
| 20 |
|
| 21 |
use DateTime; |
| 22 |
use DomainException; |
| 23 |
use Exception; |
| 24 |
use ExpiredException; |
| 25 |
use Firebase\JWT\ExpiredException as ExpiredExceptionV3; |
| 26 |
use Firebase\JWT\Key; |
| 27 |
use Firebase\JWT\SignatureInvalidException; |
| 28 |
use Google\Auth\Cache\MemoryCacheItemPool; |
| 29 |
use Google\Exception as GoogleException; |
| 30 |
use GuzzleHttp\Client; |
| 31 |
use GuzzleHttp\ClientInterface; |
| 32 |
use InvalidArgumentException; |
| 33 |
use LogicException; |
| 34 |
use phpseclib3\Crypt\PublicKeyLoader; |
| 35 |
use phpseclib3\Crypt\RSA\PublicKey; // Firebase v2 |
| 36 |
use Psr\Cache\CacheItemPoolInterface; |
| 37 |
|
| 38 |
/** |
| 39 |
* Wrapper around Google Access Tokens which provides convenience functions |
| 40 |
* |
| 41 |
*/ |
| 42 |
class Verify |
| 43 |
{ |
| 44 |
const FEDERATED_SIGNON_CERT_URL = 'https://www.googleapis.com/oauth2/v3/certs'; |
| 45 |
const OAUTH2_ISSUER = 'accounts.google.com'; |
| 46 |
const OAUTH2_ISSUER_HTTPS = 'https://accounts.google.com'; |
| 47 |
|
| 48 |
/** |
| 49 |
* @var ClientInterface The http client |
| 50 |
*/ |
| 51 |
private $http; |
| 52 |
|
| 53 |
/** |
| 54 |
* @var CacheItemPoolInterface cache class |
| 55 |
*/ |
| 56 |
private $cache; |
| 57 |
|
| 58 |
/** |
| 59 |
* @var \Firebase\JWT\JWT |
| 60 |
*/ |
| 61 |
public $jwt; |
| 62 |
|
| 63 |
/** |
| 64 |
* Instantiates the class, but does not initiate the login flow, leaving it |
| 65 |
* to the discretion of the caller. |
| 66 |
*/ |
| 67 |
public function __construct( |
| 68 |
ClientInterface $http = null, |
| 69 |
CacheItemPoolInterface $cache = null, |
| 70 |
$jwt = null |
| 71 |
) { |
| 72 |
if (null === $http) { |
| 73 |
$http = new Client(); |
| 74 |
} |
| 75 |
|
| 76 |
if (null === $cache) { |
| 77 |
$cache = new MemoryCacheItemPool(); |
| 78 |
} |
| 79 |
|
| 80 |
$this->http = $http; |
| 81 |
$this->cache = $cache; |
| 82 |
$this->jwt = $jwt ?: $this->getJwtService(); |
| 83 |
} |
| 84 |
|
| 85 |
/** |
| 86 |
* Verifies an id token and returns the authenticated apiLoginTicket. |
| 87 |
* Throws an exception if the id token is not valid. |
| 88 |
* The audience parameter can be used to control which id tokens are |
| 89 |
* accepted. By default, the id token must have been issued to this OAuth2 client. |
| 90 |
* |
| 91 |
* @param string $idToken the ID token in JWT format |
| 92 |
* @param string $audience Optional. The audience to verify against JWt "aud" |
| 93 |
* @return array|false the token payload, if successful |
| 94 |
*/ |
| 95 |
public function verifyIdToken($idToken, $audience = null) |
| 96 |
{ |
| 97 |
if (empty($idToken)) { |
| 98 |
throw new LogicException('id_token cannot be null'); |
| 99 |
} |
| 100 |
|
| 101 |
// set phpseclib constants if applicable |
| 102 |
$this->setPhpsecConstants(); |
| 103 |
|
| 104 |
// Check signature |
| 105 |
$certs = $this->getFederatedSignOnCerts(); |
| 106 |
foreach ($certs as $cert) { |
| 107 |
try { |
| 108 |
$args = [$idToken]; |
| 109 |
$publicKey = $this->getPublicKey($cert); |
| 110 |
if (class_exists(Key::class)) { |
| 111 |
$args[] = new Key($publicKey, 'RS256'); |
| 112 |
} else { |
| 113 |
$args[] = $publicKey; |
| 114 |
$args[] = ['RS256']; |
| 115 |
} |
| 116 |
$payload = \call_user_func_array([$this->jwt, 'decode'], $args); |
| 117 |
|
| 118 |
if (property_exists($payload, 'aud')) { |
| 119 |
if ($audience && $payload->aud != $audience) { |
| 120 |
return false; |
| 121 |
} |
| 122 |
} |
| 123 |
|
| 124 |
// support HTTP and HTTPS issuers |
| 125 |
// @see https://developers.google.com/identity/sign-in/web/backend-auth |
| 126 |
$issuers = [self::OAUTH2_ISSUER, self::OAUTH2_ISSUER_HTTPS]; |
| 127 |
if (!isset($payload->iss) || !in_array($payload->iss, $issuers)) { |
| 128 |
return false; |
| 129 |
} |
| 130 |
|
| 131 |
return (array) $payload; |
| 132 |
} catch (ExpiredException $e) { // @phpstan-ignore-line |
| 133 |
return false; |
| 134 |
} catch (ExpiredExceptionV3 $e) { |
| 135 |
return false; |
| 136 |
} catch (SignatureInvalidException $e) { |
| 137 |
// continue |
| 138 |
} catch (DomainException $e) { |
| 139 |
// continue |
| 140 |
} |
| 141 |
} |
| 142 |
|
| 143 |
return false; |
| 144 |
} |
| 145 |
|
| 146 |
private function getCache() |
| 147 |
{ |
| 148 |
return $this->cache; |
| 149 |
} |
| 150 |
|
| 151 |
/** |
| 152 |
* Retrieve and cache a certificates file. |
| 153 |
* |
| 154 |
* @param string $url location |
| 155 |
* @throws \Google\Exception |
| 156 |
* @return array certificates |
| 157 |
*/ |
| 158 |
private function retrieveCertsFromLocation($url) |
| 159 |
{ |
| 160 |
// If we're retrieving a local file, just grab it. |
| 161 |
if (0 !== strpos($url, 'http')) { |
| 162 |
if (!$file = file_get_contents($url)) { |
| 163 |
throw new GoogleException( |
| 164 |
"Failed to retrieve verification certificates: '" . |
| 165 |
$url . "'." |
| 166 |
); |
| 167 |
} |
| 168 |
|
| 169 |
return json_decode($file, true); |
| 170 |
} |
| 171 |
|
| 172 |
// @phpstan-ignore-next-line |
| 173 |
$response = $this->http->get($url); |
| 174 |
|
| 175 |
if ($response->getStatusCode() == 200) { |
| 176 |
return json_decode((string) $response->getBody(), true); |
| 177 |
} |
| 178 |
throw new GoogleException( |
| 179 |
sprintf( |
| 180 |
'Failed to retrieve verification certificates: "%s".', |
| 181 |
$response->getBody()->getContents() |
| 182 |
), |
| 183 |
$response->getStatusCode() |
| 184 |
); |
| 185 |
} |
| 186 |
|
| 187 |
// Gets federated sign-on certificates to use for verifying identity tokens. |
| 188 |
// Returns certs as array structure, where keys are key ids, and values |
| 189 |
// are PEM encoded certificates. |
| 190 |
private function getFederatedSignOnCerts() |
| 191 |
{ |
| 192 |
$certs = null; |
| 193 |
if ($cache = $this->getCache()) { |
| 194 |
$cacheItem = $cache->getItem('federated_signon_certs_v3'); |
| 195 |
$certs = $cacheItem->get(); |
| 196 |
} |
| 197 |
|
| 198 |
|
| 199 |
if (!$certs) { |
| 200 |
$certs = $this->retrieveCertsFromLocation( |
| 201 |
self::FEDERATED_SIGNON_CERT_URL |
| 202 |
); |
| 203 |
|
| 204 |
if ($cache) { |
| 205 |
$cacheItem->expiresAt(new DateTime('+1 hour')); |
| 206 |
$cacheItem->set($certs); |
| 207 |
$cache->save($cacheItem); |
| 208 |
} |
| 209 |
} |
| 210 |
|
| 211 |
if (!isset($certs['keys'])) { |
| 212 |
throw new InvalidArgumentException( |
| 213 |
'federated sign-on certs expects "keys" to be set' |
| 214 |
); |
| 215 |
} |
| 216 |
|
| 217 |
return $certs['keys']; |
| 218 |
} |
| 219 |
|
| 220 |
private function getJwtService() |
| 221 |
{ |
| 222 |
$jwtClass = 'JWT'; |
| 223 |
if (class_exists('\Firebase\JWT\JWT')) { |
| 224 |
$jwtClass = 'Firebase\JWT\JWT'; |
| 225 |
} |
| 226 |
|
| 227 |
if (property_exists($jwtClass, 'leeway') && $jwtClass::$leeway < 1) { |
| 228 |
// Ensures JWT leeway is at least 1 |
| 229 |
// @see https://github.com/google/google-api-php-client/issues/827 |
| 230 |
$jwtClass::$leeway = 1; |
| 231 |
} |
| 232 |
|
| 233 |
// @phpstan-ignore-next-line |
| 234 |
return new $jwtClass(); |
| 235 |
} |
| 236 |
|
| 237 |
private function getPublicKey($cert) |
| 238 |
{ |
| 239 |
$bigIntClass = $this->getBigIntClass(); |
| 240 |
$modulus = new $bigIntClass($this->jwt->urlsafeB64Decode($cert['n']), 256); |
| 241 |
$exponent = new $bigIntClass($this->jwt->urlsafeB64Decode($cert['e']), 256); |
| 242 |
$component = ['n' => $modulus, 'e' => $exponent]; |
| 243 |
|
| 244 |
if (class_exists('phpseclib3\Crypt\RSA\PublicKey')) { |
| 245 |
/** @var PublicKey $loader */ |
| 246 |
$loader = PublicKeyLoader::load($component); |
| 247 |
|
| 248 |
return $loader->toString('PKCS8'); |
| 249 |
} |
| 250 |
|
| 251 |
$rsaClass = $this->getRsaClass(); |
| 252 |
$rsa = new $rsaClass(); |
| 253 |
$rsa->loadKey($component); |
| 254 |
|
| 255 |
return $rsa->getPublicKey(); |
| 256 |
} |
| 257 |
|
| 258 |
private function getRsaClass() |
| 259 |
{ |
| 260 |
if (class_exists('phpseclib3\Crypt\RSA')) { |
| 261 |
return 'phpseclib3\Crypt\RSA'; |
| 262 |
} |
| 263 |
|
| 264 |
if (class_exists('phpseclib\Crypt\RSA')) { |
| 265 |
return 'phpseclib\Crypt\RSA'; |
| 266 |
} |
| 267 |
|
| 268 |
return 'Crypt_RSA'; |
| 269 |
} |
| 270 |
|
| 271 |
private function getBigIntClass() |
| 272 |
{ |
| 273 |
if (class_exists('phpseclib3\Math\BigInteger')) { |
| 274 |
return 'phpseclib3\Math\BigInteger'; |
| 275 |
} |
| 276 |
|
| 277 |
if (class_exists('phpseclib\Math\BigInteger')) { |
| 278 |
return 'phpseclib\Math\BigInteger'; |
| 279 |
} |
| 280 |
|
| 281 |
return 'Math_BigInteger'; |
| 282 |
} |
| 283 |
|
| 284 |
private function getOpenSslConstant() |
| 285 |
{ |
| 286 |
if (class_exists('phpseclib3\Crypt\AES')) { |
| 287 |
return 'phpseclib3\Crypt\AES::ENGINE_OPENSSL'; |
| 288 |
} |
| 289 |
|
| 290 |
if (class_exists('phpseclib\Crypt\RSA')) { |
| 291 |
return 'phpseclib\Crypt\RSA::MODE_OPENSSL'; |
| 292 |
} |
| 293 |
|
| 294 |
if (class_exists('Crypt_RSA')) { |
| 295 |
return 'CRYPT_RSA_MODE_OPENSSL'; |
| 296 |
} |
| 297 |
|
| 298 |
throw new Exception('Cannot find RSA class'); |
| 299 |
} |
| 300 |
|
| 301 |
/** |
| 302 |
* phpseclib calls "phpinfo" by default, which requires special |
| 303 |
* whitelisting in the AppEngine VM environment. This function |
| 304 |
* sets constants to bypass the need for phpseclib to check phpinfo |
| 305 |
* |
| 306 |
* @see phpseclib/Math/BigInteger |
| 307 |
* @see https://github.com/GoogleCloudPlatform/getting-started-php/issues/85 |
| 308 |
*/ |
| 309 |
private function setPhpsecConstants() |
| 310 |
{ |
| 311 |
if (filter_var(getenv('GAE_VM'), FILTER_VALIDATE_BOOLEAN)) { |
| 312 |
if (!defined('MATH_BIGINTEGER_OPENSSL_ENABLED')) { |
| 313 |
define('MATH_BIGINTEGER_OPENSSL_ENABLED', true); |
| 314 |
} |
| 315 |
if (!defined('CRYPT_RSA_MODE')) { |
| 316 |
define('CRYPT_RSA_MODE', constant($this->getOpenSslConstant())); |
| 317 |
} |
| 318 |
} |
| 319 |
} |
| 320 |
} |
| 321 |
|
