Connecting to websocket with PHP client

Question

I'm trying to connect a PHP-based client to a websocket server.

Here's the code I have been using which has been widely published on different forums. But for some reason I just cannot get it to work.

Any help would be appreciated.

$host = 'host';  //where is the websocket server
$port = 443; //ssl
$local = "http://www.example.com/";  //url where this script run
$data = '{"id": 2,"command": "server_info"}';  //data to be send

$head =        "GET / HTTP/1.1"."\r\n".
               "Upgrade: WebSocket"."\r\n".
               "Connection: Upgrade"."\r\n".
               "Origin: $local"."\r\n".
               "Host: $host"."\r\n".
               "Content-Length: ".strlen($data)."\r\n"."\r\n";
////WebSocket handshake
$sock = fsockopen($host, $port, $errno, $errstr, 2);
fwrite($sock, $head ) or die('error:'.$errno.':'.$errstr);
$headers = fread($sock, 2000);
fwrite($sock, "\x00$data\xff" ) or die('error:'.$errno.':'.$errstr);
$wsdata = fread($sock, 2000);  //receives the data included in the websocket package "\x00DATA\xff"
$retdata = trim($wsdata,"\x00\xff"); //extracts data
////WebSocket handshake
fclose($sock);

echo $retdata;

Answer 1

I would probably prefer to use an existing websocket client library (maybe https://github.com/gabrielbull/php-websocket-client or https://github.com/Devristo/phpws/tree/master/src/Devristo/Phpws/Client ?) rather than roll your own, but I got it to at least connect by using:

$head = "GET / HTTP/1.1"."\r\n".
    "Host: $host"."\r\n".
    "Upgrade: websocket"."\r\n".
    "Connection: Upgrade"."\r\n".
    "Sec-WebSocket-Key: asdasdaas76da7sd6asd6as7d"."\r\n".
    "Sec-WebSocket-Version: 13"."\r\n".
    "Content-Length: ".strlen($data)."\r\n"."\r\n";

My server is using TLS/SSL, so I also needed:

$sock = fsockopen('tls://'.$host, $port, $errno, $errstr, 2);

The full protocol spec is: https://tools.ietf.org/rfc/rfc6455.txt

Answer 2

UPDATE 2019: many servers requires the key to be more unique that the original example, resulting in failure to establish upgrade connection. The key generation is now changed accordingly.

Your header must contain:

Sec-WebSocket-Key: (some value) 
Sec-WebSocket-Version: 13

to connect successfully.
When you have made the connection, you also need to use the hybi10 frame encoding.
See: https://tools.ietf.org/rfc/rfc6455.txt - Its a bit dry though.

I have made this working example:

<?php
$sp=websocket_open('127.0.0.1/ws_request.php?param=php_test',$errstr);
websocket_write($sp,"Websocket request message");
echo websocket_read($sp,true);

$sp=websocket_open('127.0.0.1:8080/ws_request.php?param=php_test',$errstr);
websocket_write($sp,"Websocket request message");
echo websocket_read($sp,true);

function websocket_open($url){
  $key=base64_encode(openssl_random_pseudo_bytes(16));
  $query=parse_url($url);
  $header="GET / HTTP/1.1\r\n"
    ."pragma: no-cache\r\n"
    ."cache-control: no-cache\r\n"
    ."Upgrade: WebSocket\r\n"
    ."Connection: Upgrade\r\n"
    ."Sec-WebSocket-Key: $key\r\n"
    ."Sec-WebSocket-Version: 13\r\n"
    ."\r\n";
  $sp=fsockopen($query['host'],$query['port'], $errno, $errstr,1); 
  if(!$sp) die("Unable to connect to server ".$url);
  // Ask for connection upgrade to websocket
  fwrite($sp,$header);
  stream_set_timeout($sp,5);
  $reaponse_header=fread($sp, 1024);
  if(!strpos($reaponse_header," 101 ") 
      || !strpos($reaponse_header,'Sec-WebSocket-Accept: ')){
    die("Server did not accept to upgrade connection to websocket"
        .$reaponse_header);
  }    
  return $sp;
}

function websocket_write($sp, $data,$final=true){
  // Assamble header: FINal 0x80 | Opcode 0x02
  $header=chr(($final?0x80:0) | 0x02); // 0x02 binary

  // Mask 0x80 | payload length (0-125) 
  if(strlen($data)<126) $header.=chr(0x80 | strlen($data));  
  elseif (strlen($data)<0xFFFF) $header.=chr(0x80 | 126) . pack("n",strlen($data));
  elseif(PHP_INT_SIZE>4) // 64 bit 
    $header.=chr(0x80 | 127) . pack("Q",strlen($data));
  else  // 32 bit (pack Q dosen't work)
    $header.=chr(0x80 | 127) . pack("N",0) . pack("N",strlen($data));

  // Add mask
  $mask=pack("N",rand(1,0x7FFFFFFF));       
  $header.=$mask;

  // Mask application data. 
  for($i = 0; $i < strlen($data); $i++)
    $data[$i]=chr(ord($data[$i]) ^ ord($mask[$i % 4]));

  return fwrite($sp,$header.$data);    
}

function websocket_read($sp,$wait_for_end=true,&$err=''){
  $out_buffer="";
  do{
    // Read header
    $header=fread($sp,2);
    if(!$header) die("Reading header from websocket failed");
    $opcode = ord($header[0]) & 0x0F;
    $final = ord($header[0]) & 0x80;
    $masked = ord($header[1]) & 0x80;
    $payload_len = ord($header[1]) & 0x7F;

    // Get payload length extensions
    $ext_len = 0;
    if($payload_len >= 0x7E){
      $ext_len = 2;
      if($payload_len == 0x7F) $ext_len = 8;
      $ext=fread($sp,$ext_len);
      if(!$ext) die("Reading header extension from websocket failed");

      // Set extented paylod length
      $payload_len= 0;
      for($i=0;$i<$ext_len;$i++) 
        $payload_len += ord($header[$i]) << ($ext_len-$i-1)*8;
    }

    // Get Mask key
    if($masked){
      $mask=fread($sp,4);
      if(!$mask) die("Reading header mask from websocket failed");
    }

    // Get payload
    $frame_data='';
    do{
      $frame= fread($sp,$payload_len);
      if(!$frame) die("Reading from websocket failed.");
      $payload_len -= strlen($frame);
      $frame_data.=$frame;
    }while($payload_len>0);    

    // if opcode ping, reuse headers to send a pong and continue to read
    if($opcode==9){
      // Assamble header: FINal 0x80 | Opcode 0x02
      $header[0]=chr(($final?0x80:0) | 0x0A); // 0x0A Pong
      fwrite($sp,$header.$ext.$mask.$frame_data);

    // Recieve and unmask data
    }elseif($opcode<3){
      $data="";
      if($masked)
        for ($i = 0; $i < $data_len; $i++) 
          $data.= $frame_data[$i] ^ $mask[$i % 4];
      else    
        $data.= $frame_data;
      $out_buffer.=$data;
    }

    // wait for Final 
  }while($wait_for_end && !$final);

  return $out_buffer;
}

You can get the full version here: https://github.com/paragi/PHP-websocket-client

Answer 3

Connecting to a WSS stream with purely php:

Example with the public binance wss api.

<?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\r\nHost: stream.binance.com:9443\r\nAccept: */*\r\nConnection: Upgrade\r\nUpgrade: websocket\r\nSec-WebSocket-Version: 13\r\nSec-WebSocket-Key: ".rand(0,999)."\r\n\r\n");
  while (!feof($sock)) {
    var_dump(explode(",",fgets($sock, 512)));
  }
}

More details: WebSockets - send json data via php

Answer 4

https://github.com/ratchetphp/Pawl

I tried around 10 different solutions from various stackoverflow threads but nothing worked, after spending about 6 hours trying different solution this worked for me. scenario: Ratchet as server I was able to connect via reactjs I wasn't able to connect via php, Expected Result: To send message from php-client to all connected react clients. the git repo i provided was a lucky break i was looking for.

Answer 5

I tried the solution presented here and it works fine for me.

here are the details:

step1: Install the library from here with non-root user as follows:

php8.0 composer require textalk/websocket

then use the code below for sending some message to a socket which is located on localhost and has port number 8080:

<?php

require('vendor/autoload.php');

use WebSocket\Client;

$client = new Client("ws://127.0.0.1:8080");
$client->send($argv[1]);
?>

Since I had php7.1 webserver and the socket was installed with php8.0, I put the above code in a PHP file (testphp.php) and call it using shell_exec('php8.0 testphp.php hello');

Answer 6

The 400 error is because you're missing Host and Origin in the header.

$key=base64_encode(openssl_random_pseudo_bytes(16));
$query=parse_url($url);
$local = "http://".$query['host'];
if (isset($_SERVER['REMOTE_ADDR'])) $local = "http://".$_SERVER['REMOTE_ADDR'];  
$header="GET / HTTP/1.1\r\n"
    ."Host: ".$query['host']."\r\n"
    ."Origin: ".$local."\r\n"
    ."Pragma: no-cache\r\n"
    ."Cache-Control: no-cache\r\n"
    ."Upgrade: websocket\r\n"
    ."Connection: Upgrade\r\n"
    ."Sec-WebSocket-Key: $key\r\n"
    ."Sec-WebSocket-Version: 13\r\n"
    ."\r\n";