-
Notifications
You must be signed in to change notification settings - Fork 304
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge pull request #1 from Minishlink/payload
Payload support with Firefox 46+ and Chrome 50+
- Loading branch information
Showing
9 changed files
with
519 additions
and
109 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,172 @@ | ||
| <?php | ||
|
|
||
| /* | ||
| * This file is part of the WebPush library. | ||
| * | ||
| * (c) Louis Lagrange <[email protected]> | ||
| * | ||
| * For the full copyright and license information, please view the LICENSE | ||
| * file that was distributed with this source code. | ||
| */ | ||
|
|
||
| namespace Minishlink\WebPush; | ||
|
|
||
| use Base64Url\Base64Url; | ||
| use Mdanter\Ecc\EccFactory; | ||
| use Mdanter\Ecc\Serializer\Point\UncompressedPointSerializer; | ||
|
|
||
| final class Encryption | ||
| { | ||
| const MAX_PAYLOAD_LENGTH = 4078; | ||
|
|
||
| /** | ||
| * @param string $payload | ||
| * @param bool $automatic | ||
| * @return string padded payload (plaintext) | ||
| */ | ||
| public static function padPayload($payload, $automatic) | ||
| { | ||
| $payloadLen = strlen($payload); | ||
| $padLen = $automatic ? self::MAX_PAYLOAD_LENGTH - $payloadLen : 0; | ||
| return pack('n*', $padLen).str_pad($payload, $padLen + $payloadLen, chr(0), STR_PAD_LEFT); | ||
| } | ||
|
|
||
| /** | ||
| * @param string $payload With padding | ||
| * @param string $userPublicKey MIME base 64 encoded | ||
| * @param string $userAuthToken MIME base 64 encoded | ||
| * @param bool $nativeEncryption Use OpenSSL (>PHP7.1) | ||
| * | ||
| * @return array | ||
| */ | ||
| public static function encrypt($payload, $userPublicKey, $userAuthToken, $nativeEncryption) | ||
| { | ||
| $userPublicKey = base64_decode($userPublicKey); | ||
| $userAuthToken = base64_decode($userAuthToken); | ||
|
|
||
| // initialize utilities | ||
| $math = EccFactory::getAdapter(); | ||
| $pointSerializer = new UncompressedPointSerializer($math); | ||
| $generator = EccFactory::getNistCurves()->generator256(); | ||
| $curve = EccFactory::getNistCurves()->curve256(); | ||
|
|
||
| // get local key pair | ||
| $localPrivateKeyObject = $generator->createPrivateKey(); | ||
| $localPublicKeyObject = $localPrivateKeyObject->getPublicKey(); | ||
| $localPublicKey = hex2bin($pointSerializer->serialize($localPublicKeyObject->getPoint())); | ||
|
|
||
| // get user public key object | ||
| $pointUserPublicKey = $pointSerializer->unserialize($curve, bin2hex($userPublicKey)); | ||
| $userPublicKeyObject = $generator->getPublicKeyFrom($pointUserPublicKey->getX(), $pointUserPublicKey->getY(), $generator->getOrder()); | ||
|
|
||
| // get shared secret from user public key and local private key | ||
| $sharedSecret = hex2bin($math->decHex($userPublicKeyObject->getPoint()->mul($localPrivateKeyObject->getSecret())->getX())); | ||
|
|
||
| // generate salt | ||
| $salt = openssl_random_pseudo_bytes(16); | ||
|
|
||
| // section 4.3 | ||
| $ikm = !empty($userAuthToken) ? | ||
| self::hkdf($userAuthToken, $sharedSecret, 'Content-Encoding: auth'.chr(0), 32) : | ||
| $sharedSecret; | ||
|
|
||
| // section 4.2 | ||
| $context = self::createContext($userPublicKey, $localPublicKey); | ||
|
|
||
| // derive the Content Encryption Key | ||
| $contentEncryptionKeyInfo = self::createInfo('aesgcm', $context); | ||
| $contentEncryptionKey = self::hkdf($salt, $ikm, $contentEncryptionKeyInfo, 16); | ||
|
|
||
| // section 3.3, derive the nonce | ||
| $nonceInfo = self::createInfo('nonce', $context); | ||
| $nonce = self::hkdf($salt, $ikm, $nonceInfo, 12); | ||
|
|
||
| // encrypt | ||
| // "The additional data passed to each invocation of AEAD_AES_128_GCM is a zero-length octet sequence." | ||
| if (!$nativeEncryption) { | ||
| list($encryptedText, $tag) = \AESGCM\AESGCM::encrypt($contentEncryptionKey, $nonce, $payload, ""); | ||
| } else { | ||
| $encryptedText = openssl_encrypt($payload, 'aes-128-gcm', $contentEncryptionKey, OPENSSL_RAW_DATA, $nonce, $tag); // base 64 encoded | ||
| } | ||
|
|
||
| // return values in url safe base64 | ||
| return array( | ||
| 'localPublicKey' => Base64Url::encode($localPublicKey), | ||
| 'salt' => Base64Url::encode($salt), | ||
| 'cipherText' => $encryptedText.$tag, | ||
| ); | ||
| } | ||
|
|
||
| /** | ||
| * HMAC-based Extract-and-Expand Key Derivation Function (HKDF) | ||
| * | ||
| * This is used to derive a secure encryption key from a mostly-secure shared | ||
| * secret. | ||
| * | ||
| * This is a partial implementation of HKDF tailored to our specific purposes. | ||
| * In particular, for us the value of N will always be 1, and thus T always | ||
| * equals HMAC-Hash(PRK, info | 0x01). | ||
| * | ||
| * See {@link https://www.rfc-editor.org/rfc/rfc5869.txt} | ||
| * From {@link https://github.com/GoogleChrome/push-encryption-node/blob/master/src/encrypt.js} | ||
| * | ||
| * @param $salt string A non-secret random value | ||
| * @param $ikm string Input keying material | ||
| * @param $info string Application-specific context | ||
| * @param $length int The length (in bytes) of the required output key | ||
| * @return string | ||
| */ | ||
| private static function hkdf($salt, $ikm, $info, $length) | ||
| { | ||
| // extract | ||
| $prk = hash_hmac('sha256', $ikm, $salt, true); | ||
|
|
||
| // expand | ||
| return substr(hash_hmac('sha256', $info.chr(1), $prk, true), 0, $length); | ||
| } | ||
|
|
||
| /** | ||
| * Creates a context for deriving encyption parameters. | ||
| * See section 4.2 of | ||
| * {@link https://tools.ietf.org/html/draft-ietf-httpbis-encryption-encoding-00} | ||
| * From {@link https://github.com/GoogleChrome/push-encryption-node/blob/master/src/encrypt.js} | ||
| * | ||
| * @param $clientPublicKey string The client's public key | ||
| * @param $serverPublicKey string Our public key | ||
| * @return string | ||
| * @throws \ErrorException | ||
| */ | ||
| private static function createContext($clientPublicKey, $serverPublicKey) | ||
| { | ||
| if (strlen($clientPublicKey) !== 65) { | ||
| throw new \ErrorException('Invalid client public key length'); | ||
| } | ||
|
|
||
| // This one should never happen, because it's our code that generates the key | ||
| if (strlen($serverPublicKey) !== 65) { | ||
| throw new \ErrorException('Invalid server public key length'); | ||
| } | ||
|
|
||
| $len = chr(0).'A'; // 65 as Uint16BE | ||
|
|
||
| return chr(0).$len.$clientPublicKey.$len.$serverPublicKey; | ||
| } | ||
|
|
||
| /** | ||
| * Returns an info record. See sections 3.2 and 3.3 of | ||
| * {@link https://tools.ietf.org/html/draft-ietf-httpbis-encryption-encoding-00} | ||
| * From {@link https://github.com/GoogleChrome/push-encryption-node/blob/master/src/encrypt.js} | ||
| * | ||
| * @param $type string The type of the info record | ||
| * @param $context string The context for the record | ||
| * @return string | ||
| * @throws \ErrorException | ||
| */ | ||
| private static function createInfo($type, $context) { | ||
| if (strlen($context) !== 135) { | ||
| throw new \ErrorException('Context argument has invalid size'); | ||
| } | ||
|
|
||
| return 'Content-Encoding: '.$type.chr(0).'P-256'.$context; | ||
| } | ||
| } |
Oops, something went wrong.