Since you didn't provide a handpoint link, here is some notes, following own tests!
I guess the issue comes from the wss
part, php needs to retrieve the certificate first, so it can encrypt the data.
Your code should work just fine on a ws://
stream.
To connect to a regular ws://
stream, one can simply use fsockopen().
<?php
$fp = fsockopen("udp://echo.websocket.org", 13, $errno, $errstr);
if (!$fp) {
echo "ERROR: $errno - $errstr<br />
";
} else {
fwrite($fp, "
");
echo "Connected!";
echo fread($fp, 26);
fclose($fp);
}
But to connect to a wss://
secure websocket stream, using php, without libraries, we need to create a tunnel first, by querying the public key with stream_socket_client.
This is a handshake mechanism. This can be done as follow.
Notice the first ssl://
call. This is the TLS 1.0 protocol.
<?php
$sock = stream_socket_client("ssl://echo.websocket.org:443",$e,$n,30,STREAM_CLIENT_CONNECT,stream_context_create(null));
if(!$sock){
echo"[$n]$e".PHP_EOL;
} else {
fwrite($sock,"GET / HTTP/1.1
Host: echo.websocket.org
Accept: */*
Connection: Upgrade
Upgrade: websocket
Sec-WebSocket-Version: 13
Sec-WebSocket-Key: ".rand(0,999)."
");
while(!feof($sock)){
var_dump(fgets($sock,2048));
}
}
The output should looks like:
string(44) "HTTP/1.1 101 Web Socket Protocol Handshake"
string(21) "Connection: Upgrade"
string(37) "Date: Thu, 12 Dec 2019 04:06:27 GMT"
string(52) "Sec-WebSocket-Accept: fTYwcEa6D9kJBtghptkz1e9CtBI="
string(25) "Server: Kaazing Gateway"
string(20) "Upgrade: websocket"
Same base code, another example, pulling data from Binance wss://
stream.
We can also use TLS 1.2, with a tls://
handshake instead. Works on most servers.
<?php
$sock = stream_socket_client("tls://stream.binance.com:9443",$error,$errnum,30,STREAM_CLIENT_CONNECT,stream_context_create(null));
if (!$sock) {
echo "[$errnum] $error" . PHP_EOL;
} else {
echo "Connected - Do NOT get rekt!" . PHP_EOL;
fwrite($sock, "GET /stream?streams=btcusdt@kline_1m HTTP/1.1
Host: stream.binance.com:9443
Accept: */*
Connection: Upgrade
Upgrade: websocket
Sec-WebSocket-Version: 13
Sec-WebSocket-Key: ".rand(0,999)."
");
while (!feof($sock)) {
var_dump(explode(",",fgets($sock, 512)));
}
}
Here is a way to retrieve only the ssl RSA public key of a remote handpoint, from php. Can be used to speed up later connections.
<?php
$opt = [
"capture_peer_cert" => true,
"capture_peer_cert_chain" => true
];
$a = stream_context_create(["ssl"=>$opt]);
$b = stream_socket_client("ssl://stream.binance.com:9443", $errno, $errstr, 30, STREAM_CLIENT_CONNECT, $a);
$cont = stream_context_get_params($b);
$key = openssl_pkey_get_public($cont["options"]["ssl"]["peer_certificate"]);
$c = openssl_pkey_get_details($key);
var_dump($c["key"]);
Output something like:
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhki(...)7aEsFtUNkwM5R5b1mpqzAwqHyvdamJx20bT6SS6
PYXSr/dv8ak1d4e2Q0nIa1O7l3w0bZZ4wnp5B8Z+tjPd1W8uaZoRO2iVkPMh2yPl
j0mmtUw1YlfDyutH/t4FlRCDiD4JjdREQGs381/+jbkdjl2SIb1IyNiCdAXA6zsq
xwIDAQAB
-----END PUBLIC KEY-----
There is possibly other quircks, to be sure, we need the main handpoint^. Would be glad to test that. Otherwise good luck, there is a big lack of documentation on the subject.
This is still a new born protocol (2011!). Best details are in the RFC specification:
The WebSocket protocol was standardized by the IETF as RFC 6455 in
2011
About the handshake, it must be initiated by a GET request.
The client will send a pretty standard HTTP request with headers that
looks like this (the HTTP version must be 1.1 or greater, and the
method must be GET)
Writing_WebSocket_servers#Client_handshake_request
In short:
If unencrypted WebSocket traffic flows through an explicit or a
transparent proxy server without WebSockets support, the connection
will likely fail.
WebSocket#Proxy_traversal
Transport_Layer_Security#Digital_certificates