Verify.php
265 lines
| 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 AmeliaVendor\Google\AccessToken; |
| 20 | |
| 21 | use DateTime; |
| 22 | use DomainException; |
| 23 | use Exception; |
| 24 | use ExpiredException; |
| 25 | use AmeliaVendor\Firebase\JWT\ExpiredException as ExpiredExceptionV3; |
| 26 | use AmeliaVendor\Firebase\JWT\JWT; |
| 27 | use AmeliaVendor\Firebase\JWT\Key; |
| 28 | use AmeliaVendor\Firebase\JWT\SignatureInvalidException; |
| 29 | use AmeliaVendor\Google\Auth\Cache\MemoryCacheItemPool; |
| 30 | use AmeliaVendor\Google\Exception as GoogleException; |
| 31 | use AmeliaVendor\GuzzleHttp\Client; |
| 32 | use AmeliaVendor\GuzzleHttp\ClientInterface; |
| 33 | use InvalidArgumentException; |
| 34 | use LogicException; |
| 35 | use AmeliaVendor\phpseclib3\Crypt\AES; |
| 36 | use AmeliaVendor\phpseclib3\Crypt\PublicKeyLoader; |
| 37 | use AmeliaVendor\phpseclib3\Math\BigInteger; |
| 38 | use AmeliaVendor\Psr\Cache\CacheItemPoolInterface; |
| 39 | |
| 40 | /** |
| 41 | * Wrapper around Google Access Tokens which provides convenience functions |
| 42 | * |
| 43 | */ |
| 44 | class Verify |
| 45 | { |
| 46 | const FEDERATED_SIGNON_CERT_URL = 'https://www.googleapis.com/oauth2/v3/certs'; |
| 47 | const OAUTH2_ISSUER = 'accounts.google.com'; |
| 48 | const OAUTH2_ISSUER_HTTPS = 'https://accounts.google.com'; |
| 49 | |
| 50 | /** |
| 51 | * @var ClientInterface The http client |
| 52 | */ |
| 53 | private $http; |
| 54 | |
| 55 | /** |
| 56 | * @var CacheItemPoolInterface cache class |
| 57 | */ |
| 58 | private $cache; |
| 59 | |
| 60 | /** |
| 61 | * @var \AmeliaVendor\Firebase\JWT\JWT |
| 62 | */ |
| 63 | public $jwt; |
| 64 | |
| 65 | /** |
| 66 | * Instantiates the class, but does not initiate the login flow, leaving it |
| 67 | * to the discretion of the caller. |
| 68 | */ |
| 69 | public function __construct( |
| 70 | ?ClientInterface $http = null, |
| 71 | ?CacheItemPoolInterface $cache = null, |
| 72 | $jwt = null |
| 73 | ) { |
| 74 | if (null === $http) { |
| 75 | $http = new Client(); |
| 76 | } |
| 77 | |
| 78 | if (null === $cache) { |
| 79 | $cache = new MemoryCacheItemPool(); |
| 80 | } |
| 81 | |
| 82 | $this->http = $http; |
| 83 | $this->cache = $cache; |
| 84 | $this->jwt = $jwt ?: $this->getJwtService(); |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * Verifies an id token and returns the authenticated apiLoginTicket. |
| 89 | * Throws an exception if the id token is not valid. |
| 90 | * The audience parameter can be used to control which id tokens are |
| 91 | * accepted. By default, the id token must have been issued to this OAuth2 client. |
| 92 | * |
| 93 | * @param string $idToken the ID token in JWT format |
| 94 | * @param string $audience Optional. The audience to verify against JWt "aud" |
| 95 | * @return array|false the token payload, if successful |
| 96 | */ |
| 97 | public function verifyIdToken($idToken, $audience = null) |
| 98 | { |
| 99 | if (empty($idToken)) { |
| 100 | throw new LogicException('id_token cannot be null'); |
| 101 | } |
| 102 | |
| 103 | // set phpseclib constants if applicable |
| 104 | $this->setPhpsecConstants(); |
| 105 | |
| 106 | // Check signature |
| 107 | $certs = $this->getFederatedSignOnCerts(); |
| 108 | foreach ($certs as $cert) { |
| 109 | try { |
| 110 | $args = [$idToken]; |
| 111 | $publicKey = $this->getPublicKey($cert); |
| 112 | if (class_exists(Key::class)) { |
| 113 | $args[] = new Key($publicKey, 'RS256'); |
| 114 | } else { |
| 115 | $args[] = $publicKey; |
| 116 | $args[] = ['RS256']; |
| 117 | } |
| 118 | $payload = \call_user_func_array([$this->jwt, 'decode'], $args); |
| 119 | |
| 120 | if (property_exists($payload, 'aud')) { |
| 121 | if ($audience && $payload->aud != $audience) { |
| 122 | return false; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | // support HTTP and HTTPS issuers |
| 127 | // @see https://developers.google.com/identity/sign-in/web/backend-auth |
| 128 | $issuers = [self::OAUTH2_ISSUER, self::OAUTH2_ISSUER_HTTPS]; |
| 129 | if (!isset($payload->iss) || !in_array($payload->iss, $issuers)) { |
| 130 | return false; |
| 131 | } |
| 132 | |
| 133 | return (array) $payload; |
| 134 | } catch (ExpiredException $e) { // @phpstan-ignore-line |
| 135 | return false; |
| 136 | } catch (ExpiredExceptionV3 $e) { |
| 137 | return false; |
| 138 | } catch (SignatureInvalidException $e) { |
| 139 | // continue |
| 140 | } catch (DomainException $e) { |
| 141 | // continue |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | return false; |
| 146 | } |
| 147 | |
| 148 | private function getCache() |
| 149 | { |
| 150 | return $this->cache; |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * Retrieve and cache a certificates file. |
| 155 | * |
| 156 | * @param string $url location |
| 157 | * @throws \AmeliaVendor\Google\Exception |
| 158 | * @return array certificates |
| 159 | */ |
| 160 | private function retrieveCertsFromLocation($url) |
| 161 | { |
| 162 | // If we're retrieving a local file, just grab it. |
| 163 | if (0 !== strpos($url, 'http')) { |
| 164 | if (!$file = file_get_contents($url)) { |
| 165 | throw new GoogleException( |
| 166 | "Failed to retrieve verification certificates: '" . |
| 167 | $url . "'." |
| 168 | ); |
| 169 | } |
| 170 | |
| 171 | return json_decode($file, true); |
| 172 | } |
| 173 | |
| 174 | // @phpstan-ignore-next-line |
| 175 | $response = $this->http->get($url); |
| 176 | |
| 177 | if ($response->getStatusCode() == 200) { |
| 178 | return json_decode((string) $response->getBody(), true); |
| 179 | } |
| 180 | throw new GoogleException( |
| 181 | sprintf( |
| 182 | 'Failed to retrieve verification certificates: "%s".', |
| 183 | $response->getBody()->getContents() |
| 184 | ), |
| 185 | $response->getStatusCode() |
| 186 | ); |
| 187 | } |
| 188 | |
| 189 | // Gets federated sign-on certificates to use for verifying identity tokens. |
| 190 | // Returns certs as array structure, where keys are key ids, and values |
| 191 | // are PEM encoded certificates. |
| 192 | private function getFederatedSignOnCerts() |
| 193 | { |
| 194 | $certs = null; |
| 195 | if ($cache = $this->getCache()) { |
| 196 | $cacheItem = $cache->getItem('federated_signon_certs_v3'); |
| 197 | $certs = $cacheItem->get(); |
| 198 | } |
| 199 | |
| 200 | |
| 201 | if (!$certs) { |
| 202 | $certs = $this->retrieveCertsFromLocation( |
| 203 | self::FEDERATED_SIGNON_CERT_URL |
| 204 | ); |
| 205 | |
| 206 | if ($cache) { |
| 207 | $cacheItem->expiresAt(new DateTime('+1 hour')); |
| 208 | $cacheItem->set($certs); |
| 209 | $cache->save($cacheItem); |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | if (!isset($certs['keys'])) { |
| 214 | throw new InvalidArgumentException( |
| 215 | 'federated sign-on certs expects "keys" to be set' |
| 216 | ); |
| 217 | } |
| 218 | |
| 219 | return $certs['keys']; |
| 220 | } |
| 221 | |
| 222 | private function getJwtService() |
| 223 | { |
| 224 | $jwt = new JWT(); |
| 225 | if ($jwt::$leeway < 1) { |
| 226 | // Ensures JWT leeway is at least 1 |
| 227 | // @see https://github.com/google/google-api-php-client/issues/827 |
| 228 | $jwt::$leeway = 1; |
| 229 | } |
| 230 | |
| 231 | return $jwt; |
| 232 | } |
| 233 | |
| 234 | private function getPublicKey($cert) |
| 235 | { |
| 236 | $modulus = new BigInteger($this->jwt->urlsafeB64Decode($cert['n']), 256); |
| 237 | $exponent = new BigInteger($this->jwt->urlsafeB64Decode($cert['e']), 256); |
| 238 | $component = ['n' => $modulus, 'e' => $exponent]; |
| 239 | |
| 240 | $loader = PublicKeyLoader::load($component); |
| 241 | |
| 242 | return $loader->toString('PKCS8'); |
| 243 | } |
| 244 | |
| 245 | /** |
| 246 | * phpseclib calls "phpinfo" by default, which requires special |
| 247 | * whitelisting in the AppEngine VM environment. This function |
| 248 | * sets constants to bypass the need for phpseclib to check phpinfo |
| 249 | * |
| 250 | * @see phpseclib/Math/BigInteger |
| 251 | * @see https://github.com/GoogleCloudPlatform/getting-started-php/issues/85 |
| 252 | */ |
| 253 | private function setPhpsecConstants() |
| 254 | { |
| 255 | if (filter_var(getenv('GAE_VM'), FILTER_VALIDATE_BOOLEAN)) { |
| 256 | if (!defined('MATH_BIGINTEGER_OPENSSL_ENABLED')) { |
| 257 | define('MATH_BIGINTEGER_OPENSSL_ENABLED', true); |
| 258 | } |
| 259 | if (!defined('CRYPT_RSA_MODE')) { |
| 260 | define('CRYPT_RSA_MODE', AES::ENGINE_OPENSSL); |
| 261 | } |
| 262 | } |
| 263 | } |
| 264 | } |
| 265 |