CasperSecurity
<?php
namespace Ratchet\RFC6455\Handshake;
use Psr\Http\Message\MessageInterface;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;
final class PermessageDeflateOptions
{
const MAX_WINDOW_BITS = 15;
/* this is a private instead of const for 5.4 compatibility */
private static $VALID_BITS = ['8', '9', '10', '11', '12', '13', '14', '15'];
private $deflateEnabled = false;
private $server_no_context_takeover;
private $client_no_context_takeover;
private $server_max_window_bits;
private $client_max_window_bits;
private function __construct() { }
public static function createEnabled() {
$new = new static();
$new->deflateEnabled = true;
$new->client_max_window_bits = self::MAX_WINDOW_BITS;
$new->client_no_context_takeover = false;
$new->server_max_window_bits = self::MAX_WINDOW_BITS;
$new->server_no_context_takeover = false;
return $new;
}
public static function createDisabled() {
return new static();
}
public function withClientNoContextTakeover() {
$new = clone $this;
$new->client_no_context_takeover = true;
return $new;
}
public function withoutClientNoContextTakeover() {
$new = clone $this;
$new->client_no_context_takeover = false;
return $new;
}
public function withServerNoContextTakeover() {
$new = clone $this;
$new->server_no_context_takeover = true;
return $new;
}
public function withoutServerNoContextTakeover() {
$new = clone $this;
$new->server_no_context_takeover = false;
return $new;
}
public function withServerMaxWindowBits($bits = self::MAX_WINDOW_BITS) {
if (!in_array($bits, self::$VALID_BITS)) {
throw new \Exception('server_max_window_bits must have a value between 8 and 15.');
}
$new = clone $this;
$new->server_max_window_bits = $bits;
return $new;
}
public function withClientMaxWindowBits($bits = self::MAX_WINDOW_BITS) {
if (!in_array($bits, self::$VALID_BITS)) {
throw new \Exception('client_max_window_bits must have a value between 8 and 15.');
}
$new = clone $this;
$new->client_max_window_bits = $bits;
return $new;
}
/**
* https://tools.ietf.org/html/rfc6455#section-9.1
* https://tools.ietf.org/html/rfc7692#section-7
*
* @param MessageInterface $requestOrResponse
* @return PermessageDeflateOptions[]
* @throws \Exception
*/
public static function fromRequestOrResponse(MessageInterface $requestOrResponse) {
$optionSets = [];
$extHeader = preg_replace('/\s+/', '', join(', ', $requestOrResponse->getHeader('Sec-Websocket-Extensions')));
$configurationRequests = explode(',', $extHeader);
foreach ($configurationRequests as $configurationRequest) {
$parts = explode(';', $configurationRequest);
if (count($parts) == 0) {
continue;
}
if ($parts[0] !== 'permessage-deflate') {
continue;
}
array_shift($parts);
$options = new static();
$options->deflateEnabled = true;
foreach ($parts as $part) {
$kv = explode('=', $part);
$key = $kv[0];
$value = count($kv) > 1 ? $kv[1] : null;
switch ($key) {
case "server_no_context_takeover":
case "client_no_context_takeover":
if ($value !== null) {
throw new InvalidPermessageDeflateOptionsException($key . ' must not have a value.');
}
$value = true;
break;
case "server_max_window_bits":
if (!in_array($value, self::$VALID_BITS)) {
throw new InvalidPermessageDeflateOptionsException($key . ' must have a value between 8 and 15.');
}
break;
case "client_max_window_bits":
if ($value === null) {
$value = '15';
}
if (!in_array($value, self::$VALID_BITS)) {
throw new InvalidPermessageDeflateOptionsException($key . ' must have no value or a value between 8 and 15.');
}
break;
default:
throw new InvalidPermessageDeflateOptionsException('Option "' . $key . '"is not valid for permessage deflate');
}
if ($options->$key !== null) {
throw new InvalidPermessageDeflateOptionsException($key . ' specified more than once. Connection must be declined.');
}
$options->$key = $value;
}
if ($options->getClientMaxWindowBits() === null) {
$options->client_max_window_bits = 15;
}
if ($options->getServerMaxWindowBits() === null) {
$options->server_max_window_bits = 15;
}
$optionSets[] = $options;
}
// always put a disabled on the end
$optionSets[] = new static();
return $optionSets;
}
/**
* @return mixed
*/
public function getServerNoContextTakeover()
{
return $this->server_no_context_takeover;
}
/**
* @return mixed
*/
public function getClientNoContextTakeover()
{
return $this->client_no_context_takeover;
}
/**
* @return mixed
*/
public function getServerMaxWindowBits()
{
return $this->server_max_window_bits;
}
/**
* @return mixed
*/
public function getClientMaxWindowBits()
{
return $this->client_max_window_bits;
}
/**
* @return bool
*/
public function isEnabled()
{
return $this->deflateEnabled;
}
/**
* @param ResponseInterface $response
* @return ResponseInterface
*/
public function addHeaderToResponse(ResponseInterface $response)
{
if (!$this->deflateEnabled) {
return $response;
}
$header = 'permessage-deflate';
if ($this->client_max_window_bits != 15) {
$header .= '; client_max_window_bits='. $this->client_max_window_bits;
}
if ($this->client_no_context_takeover) {
$header .= '; client_no_context_takeover';
}
if ($this->server_max_window_bits != 15) {
$header .= '; server_max_window_bits=' . $this->server_max_window_bits;
}
if ($this->server_no_context_takeover) {
$header .= '; server_no_context_takeover';
}
return $response->withAddedHeader('Sec-Websocket-Extensions', $header);
}
public function addHeaderToRequest(RequestInterface $request) {
if (!$this->deflateEnabled) {
return $request;
}
$header = 'permessage-deflate';
if ($this->server_no_context_takeover) {
$header .= '; server_no_context_takeover';
}
if ($this->client_no_context_takeover) {
$header .= '; client_no_context_takeover';
}
if ($this->server_max_window_bits != 15) {
$header .= '; server_max_window_bits=' . $this->server_max_window_bits;
}
$header .= '; client_max_window_bits';
if ($this->client_max_window_bits != 15) {
$header .= '='. $this->client_max_window_bits;
}
return $request->withAddedHeader('Sec-Websocket-Extensions', $header);
}
public static function permessageDeflateSupported($version = PHP_VERSION) {
if (!function_exists('deflate_init')) {
return false;
}
if (version_compare($version, '7.1.3', '>')) {
return true;
}
if (version_compare($version, '7.0.18', '>=')
&& version_compare($version, '7.1.0', '<')) {
return true;
}
return false;
}
}