PHP WebSocket Server can not access Origin and Referrer headers - php

Question

I have a simple PHP websocket server
Here is the full code : https://gist.github.com/hack4mer/e40094001d16c75fe5ae8347ebffccb7
while (true) {
$changed = $clients;
socket_select($changed, $null, $null, 0, 10);
//check for new socket
if (in_array($socket, $changed)) {
$socket_new = socket_accept($socket); //accpet new socket
$clients[] = $socket_new; //add socket to client array
//THIS DOES NOT WORK
print_r($_SERVER);
die();
}
In the browser's network tab, I can confirm the following request:
Request URL: ws://localhost:12345/
Provisional headers are shown
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9,hi;q=0.8,ms;q=0.7
Cache-Control: no-cache
Connection: Upgrade
Host: localhost:12345
Origin: http://localhost
However am not able to access these request headers in my script.
My aim is to restrict access of the WebSocket to only few hosts

Answer 1

You will have to buffer the data, at least until the headers are done (CRLF).
Have a look at react/socket.
It is very easy to use non-blocking sockets with that.
To implement the websocket protocol, have a look at ratchetphp/RFC6455.

Answer 2

I solved this issue by doing the header checking before the handshaking.
Full code : https://gist.github.com/hack4mer/e40094001d16c75fe5ae8347ebffccb7
function perform_handshaking($receved_header,$client_conn, $host, $port)
{
$headers = array();
$lines = preg_split("/\r\n/", $receved_header);
foreach($lines as $line)
{
$line = chop($line);
if(preg_match('/\A(\S+): (.*)\z/', $line, $matches))
{
$headers[$matches[1]] = $matches[2];
}
}
//HEADERS AVAILABLE HERE -> $headers
$secKey = $headers['Sec-WebSocket-Key'];
$secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));
//hand shaking header
$upgrade = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" .
"Upgrade: websocket\r\n" .
"Connection: Upgrade\r\n" .
"WebSocket-Origin: $host\r\n" .
"WebSocket-Location: ws://$host:$port/demo/shout.php\r\n".
"Sec-WebSocket-Accept:$secAccept\r\n\r\n";
socket_write($client_conn,$upgrade,strlen($upgrade));
}