<?php
declare(strict_types=1);
/*
* This file is part of the WebPush library.
*
* (c) Louis Lagrange <lagrange.louis@gmail.com>
*
* 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 GuzzleHttp\Client;
use GuzzleHttp\Exception\RequestException;
use GuzzleHttp\Psr7\Request;
use Psr\Http\Message\ResponseInterface;
class WebPush
{
public const GCM_URL = 'https://android.googleapis.com/gcm/send';
public const FCM_BASE_URL = 'https://fcm.googleapis.com';
/**
* @var Client
*/
private $client;
/**
* @var array
*/
private $auth;
/**
* @var null|array Array of array of Notifications
*/
private $notifications;
/**
* @var array Default options : TTL, urgency, topic, batchSize
*/
private $defaultOptions;
/**
* @var int Automatic padding of payloads, if disabled, trade security for bandwidth
*/
private $automaticPadding = Encryption::MAX_COMPATIBILITY_PAYLOAD_LENGTH;
/**
* @var bool Reuse VAPID headers in the same flush session to improve performance
*/
private $reuseVAPIDHeaders = false;
/**
* @var array Dictionary for VAPID headers cache
*/
private $vapidHeaders = [];
/**
* WebPush constructor.
*
* @param array $auth Some servers needs authentication
* @param array $defaultOptions TTL, urgency, topic, batchSize
* @param int|null $timeout Timeout of POST request
* @param array $clientOptions
*
* @throws \ErrorException
*/
public function __construct(array $auth = [], array $defaultOptions = [], ?int $timeout = 30, array $clientOptions = [])
{
$extensions = [
'curl' => '[WebPush] curl extension is not loaded but is required. You can fix this in your php.ini.',
'gmp' => '[WebPush] gmp extension is not loaded but is required for sending push notifications with payload or for VAPID authentication. You can fix this in your php.ini.',
'mbstring' => '[WebPush] mbstring extension is not loaded but is required for sending push notifications with payload or for VAPID authentication. You can fix this in your php.ini.',
'openssl' => '[WebPush] openssl extension is not loaded but is required for sending push notifications with payload or for VAPID authentication. You can fix this in your php.ini.',
];
foreach ($extensions as $extension => $message) {
if (!extension_loaded($extension)) {
trigger_error($message, E_USER_WARNING);
}
}
if (ini_get('mbstring.func_overload') >= 2) {
trigger_error("[WebPush] mbstring.func_overload is enabled for str* functions. You must disable it if you want to send push notifications with payload or use VAPID. You can fix this in your php.ini.", E_USER_NOTICE);
}
if (isset($auth['VAPID'])) {
$auth['VAPID'] = VAPID::validate($auth['VAPID']);
}
$this->auth = $auth;
$this->setDefaultOptions($defaultOptions);
if (!array_key_exists('timeout', $clientOptions) && isset($timeout)) {
$clientOptions['timeout'] = $timeout;
}
$this->client = new Client($clientOptions);
}
/**
* Send a notification.
*
* @param SubscriptionInterface $subscription
* @param string|null $payload If you want to send an array, json_encode it
* @param bool $flush If you want to flush directly (usually when you send only one notification)
* @param array $options Array with several options tied to this notification. If not set, will use the default options that you can set in the WebPush object
* @param array $auth Use this auth details instead of what you provided when creating WebPush
*
* @return \Generator|MessageSentReport[]|true Return an array of information if $flush is set to true and the queued requests has failed.
* Else return true
*
* @throws \ErrorException
*/
public function sendNotification(SubscriptionInterface $subscription, ?string $payload = null, bool $flush = false, array $options = [], array $auth = [])
{
if (isset($payload)) {
if (Utils::safeStrlen($payload) > Encryption::MAX_PAYLOAD_LENGTH) {
throw new \ErrorException('Size of payload must not be greater than '.Encryption::MAX_PAYLOAD_LENGTH.' octets.');
}
$contentEncoding = $subscription->getContentEncoding();
if (!$contentEncoding) {
throw new \ErrorException('Subscription should have a content encoding');
}
$payload = Encryption::padPayload($payload, $this->automaticPadding, $contentEncoding);
}
if (array_key_exists('VAPID', $auth)) {
$auth['VAPID'] = VAPID::validate($auth['VAPID']);
}
$this->notifications[] = new Notification($subscription, $payload, $options, $auth);
return false !== $flush ? $this->flush() : true;
}
/**
* Flush notifications. Triggers the requests.
*
* @param null|int $batchSize Defaults the value defined in defaultOptions during instantiation (which defaults to 1000).
*
* @return \Generator|MessageSentReport[]
* @throws \ErrorException
*/
public function flush(?int $batchSize = null): \Generator
{
if (null === $this->notifications || empty($this->notifications)) {
yield from [];
return;
}
if (null === $batchSize) {
$batchSize = $this->defaultOptions['batchSize'];
}
$batches = array_chunk($this->notifications, $batchSize);
// reset queue
$this->notifications = [];
foreach ($batches as $batch) {
// for each endpoint server type
$requests = $this->prepare($batch);
$promises = [];
foreach ($requests as $request) {
$promises[] = $this->client->sendAsync($request)
->then(function ($response) use ($request) {
/** @var ResponseInterface $response * */
return new MessageSentReport($request, $response);
})
->otherwise(function ($reason) {
/** @var RequestException $reason **/
return new MessageSentReport($reason->getRequest(), $reason->getResponse(), false, $reason->getMessage());
});
}
foreach ($promises as $promise) {
yield $promise->wait();
}
}
if ($this->reuseVAPIDHeaders) {
$this->vapidHeaders = [];
}
}
/**
* @param array $notifications
*
* @return array
*
* @throws \ErrorException
*/
private function prepare(array $notifications): array
{
$requests = [];
/** @var Notification $notification */
foreach ($notifications as $notification) {
$subscription = $notification->getSubscription();
$endpoint = $subscription->getEndpoint();
$userPublicKey = $subscription->getPublicKey();
$userAuthToken = $subscription->getAuthToken();
$contentEncoding = $subscription->getContentEncoding();
$payload = $notification->getPayload();
$options = $notification->getOptions($this->getDefaultOptions());
$auth = $notification->getAuth($this->auth);
if (!empty($payload) && !empty($userPublicKey) && !empty($userAuthToken)) {
if (!$contentEncoding) {
throw new \ErrorException('Subscription should have a content encoding');
}
$encrypted = Encryption::encrypt($payload, $userPublicKey, $userAuthToken, $contentEncoding);
$cipherText = $encrypted['cipherText'];
$salt = $encrypted['salt'];
$localPublicKey = $encrypted['localPublicKey'];
$headers = [
'Content-Type' => 'application/octet-stream',
'Content-Encoding' => $contentEncoding,
];
if ($contentEncoding === "aesgcm") {
$headers['Encryption'] = 'salt='.Base64Url::encode($salt);
$headers['Crypto-Key'] = 'dh='.Base64Url::encode($localPublicKey);
}
$encryptionContentCodingHeader = Encryption::getContentCodingHeader($salt, $localPublicKey, $contentEncoding);
$content = $encryptionContentCodingHeader.$cipherText;
$headers['Content-Length'] = Utils::safeStrlen($content);
} else {
$headers = [
'Content-Length' => 0,
];
$content = '';
}
$headers['TTL'] = $options['TTL'];
if (isset($options['urgency'])) {
$headers['Urgency'] = $options['urgency'];
}
if (isset($options['topic'])) {
$headers['Topic'] = $options['topic'];
}
// if GCM
if (substr($endpoint, 0, strlen(self::GCM_URL)) === self::GCM_URL) {
if (array_key_exists('GCM', $auth)) {
$headers['Authorization'] = 'key='.$auth['GCM'];
} else {
throw new \ErrorException('No GCM API Key specified.');
}
}
// if VAPID (GCM doesn't support it but FCM does)
elseif (array_key_exists('VAPID', $auth) && $contentEncoding) {
$audience = parse_url($endpoint, PHP_URL_SCHEME).'://'.parse_url($endpoint, PHP_URL_HOST);
if (!parse_url($audience)) {
throw new \ErrorException('Audience "'.$audience.'"" could not be generated.');
}
$vapidHeaders = $this->getVAPIDHeaders($audience, $contentEncoding, $auth['VAPID']);
$headers['Authorization'] = $vapidHeaders['Authorization'];
if ($contentEncoding === 'aesgcm') {
if (array_key_exists('Crypto-Key', $headers)) {
$headers['Crypto-Key'] .= ';'.$vapidHeaders['Crypto-Key'];
} else {
$headers['Crypto-Key'] = $vapidHeaders['Crypto-Key'];
}
}
}
$requests[] = new Request('POST', $endpoint, $headers, $content);
}
return $requests;
}
/**
* @return bool
*/
public function isAutomaticPadding(): bool
{
return $this->automaticPadding !== 0;
}
/**
* @return int
*/
public function getAutomaticPadding()
{
return $this->automaticPadding;
}
/**
* @param int|bool $automaticPadding Max padding length
*
* @return WebPush
*
* @throws \Exception
*/
public function setAutomaticPadding($automaticPadding): WebPush
{
if ($automaticPadding > Encryption::MAX_PAYLOAD_LENGTH) {
throw new \Exception('Automatic padding is too large. Max is '.Encryption::MAX_PAYLOAD_LENGTH.'. Recommended max is '.Encryption::MAX_COMPATIBILITY_PAYLOAD_LENGTH.' for compatibility reasons (see README).');
} elseif ($automaticPadding < 0) {
throw new \Exception('Padding length should be positive or zero.');
} elseif ($automaticPadding === true) {
$this->automaticPadding = Encryption::MAX_COMPATIBILITY_PAYLOAD_LENGTH;
} elseif ($automaticPadding === false) {
$this->automaticPadding = 0;
} else {
$this->automaticPadding = $automaticPadding;
}
return $this;
}
/**
* @return bool
*/
public function getReuseVAPIDHeaders()
{
return $this->reuseVAPIDHeaders;
}
/**
* Reuse VAPID headers in the same flush session to improve performance
* @param bool $enabled
*
* @return WebPush
*/
public function setReuseVAPIDHeaders(bool $enabled)
{
$this->reuseVAPIDHeaders = $enabled;
return $this;
}
/**
* @return array
*/
public function getDefaultOptions(): array
{
return $this->defaultOptions;
}
/**
* @param array $defaultOptions Keys 'TTL' (Time To Live, defaults 4 weeks), 'urgency', 'topic', 'batchSize'
*
* @return WebPush
*/
public function setDefaultOptions(array $defaultOptions)
{
$this->defaultOptions['TTL'] = isset($defaultOptions['TTL']) ? $defaultOptions['TTL'] : 2419200;
$this->defaultOptions['urgency'] = isset($defaultOptions['urgency']) ? $defaultOptions['urgency'] : null;
$this->defaultOptions['topic'] = isset($defaultOptions['topic']) ? $defaultOptions['topic'] : null;
$this->defaultOptions['batchSize'] = isset($defaultOptions['batchSize']) ? $defaultOptions['batchSize'] : 1000;
return $this;
}
/**
* @return int
*/
public function countPendingNotifications(): int
{
return null !== $this->notifications ? count($this->notifications) : 0;
}
/**
* @param string $audience
* @param string $contentEncoding
* @param array $vapid
* @return array
* @throws \ErrorException
*/
private function getVAPIDHeaders(string $audience, string $contentEncoding, array $vapid)
{
$vapidHeaders = null;
$cache_key = null;
if ($this->reuseVAPIDHeaders) {
$cache_key = implode('#', [$audience, $contentEncoding, crc32(serialize($vapid))]);
if (array_key_exists($cache_key, $this->vapidHeaders)) {
$vapidHeaders = $this->vapidHeaders[$cache_key];
}
}
if (!$vapidHeaders) {
$vapidHeaders = VAPID::getVapidHeaders($audience, $vapid['subject'], $vapid['publicKey'], $vapid['privateKey'], $contentEncoding);
}
if ($this->reuseVAPIDHeaders) {
$this->vapidHeaders[$cache_key] = $vapidHeaders;
}
return $vapidHeaders;
}
}
