PHP implementation of WebSockets

You read the WebSocket protocol incorrectly.

Speaking specifically about your question, you do not take into account the fact that the frame data contains not only the data you have transmitted, but also additional information. For example, data by almost all browsers is masked (i.e. encrypted) using a mask.

The frame format looks like this:

In any case, you incorrectly implemented the protocol and I recommend reading the description of websocket to javascript.ru .

try instead

$buffer = substr($buffer,strpos($buffer,"Sec-WebSocket-Key: ")+19); 

to write

 mb_substr($buffer,strpos($buffer,"Sec-WebSocket-Key: ")+19,'utf-8'); 

I did not look closely at the code, but this should help in this situation.

To send the text you need to decode it according to the rules specified above. Here is a turnkey solution:

 function encode($payload, $type = 'text', $masked = true) { $frameHead = array(); $frame = ''; $payloadLength = strlen($payload); switch ($type) { case 'text': // first byte indicates FIN, Text-Frame (10000001): $frameHead[0] = 129; break; case 'close': // first byte indicates FIN, Close Frame(10001000): $frameHead[0] = 136; break; case 'ping': // first byte indicates FIN, Ping frame (10001001): $frameHead[0] = 137; break; case 'pong': // first byte indicates FIN, Pong frame (10001010): $frameHead[0] = 138; break; } // set mask and payload length (using 1, 3 or 9 bytes) if ($payloadLength > 65535) { $payloadLengthBin = str_split(sprintf('%064b', $payloadLength), 8); $frameHead[1] = ($masked === true) ? 255 : 127; for ($i = 0; $i < 8; $i++) { $frameHead[$i + 2] = bindec($payloadLengthBin[$i]); } // most significant bit MUST be 0 (close connection if frame too big) if ($frameHead[2] > 127) { $this->close(1004); return false; } } elseif ($payloadLength > 125) { $payloadLengthBin = str_split(sprintf('%016b', $payloadLength), 8); $frameHead[1] = ($masked === true) ? 254 : 126; $frameHead[2] = bindec($payloadLengthBin[0]); $frameHead[3] = bindec($payloadLengthBin[1]); } else { $frameHead[1] = ($masked === true) ? $payloadLength + 128 : $payloadLength; } // convert frame-head to string: foreach (array_keys($frameHead) as $i) { $frameHead[$i] = chr($frameHead[$i]); } if ($masked === true) { // generate a random mask: $mask = array(); for ($i = 0; $i < 4; $i++) { $mask[$i] = chr(rand(0, 255)); } $frameHead = array_merge($frameHead, $mask); } $frame = implode('', $frameHead); // append payload to frame: for ($i = 0; $i < $payloadLength; $i++) { $frame .= ($masked === true) ? $payload[$i] ^ $mask[$i % 4] : $payload[$i]; } return $frame; } function decode($data) { $unmaskedPayload = ''; $decodedData = array(); // estimate frame type: $firstByteBinary = sprintf('%08b', ord($data[0])); $secondByteBinary = sprintf('%08b', ord($data[1])); $opcode = bindec(substr($firstByteBinary, 4, 4)); $isMasked = ($secondByteBinary[0] == '1') ? true : false; $payloadLength = ord($data[1]) & 127; // unmasked frame is received: if (!$isMasked) { return array('type' => '', 'payload' => '', 'error' => 'protocol error (1002)'); } switch ($opcode) { // text frame: case 1: $decodedData['type'] = 'text'; break; case 2: $decodedData['type'] = 'binary'; break; // connection close frame: case 8: $decodedData['type'] = 'close'; break; // ping frame: case 9: $decodedData['type'] = 'ping'; break; // pong frame: case 10: $decodedData['type'] = 'pong'; break; default: return array('type' => '', 'payload' => '', 'error' => 'unknown opcode (1003)'); } if ($payloadLength === 126) { $mask = substr($data, 4, 4); $payloadOffset = 8; $dataLength = bindec(sprintf('%08b', ord($data[2])) . sprintf('%08b', ord($data[3]))) + $payloadOffset; } elseif ($payloadLength === 127) { $mask = substr($data, 10, 4); $payloadOffset = 14; $tmp = ''; for ($i = 0; $i < 8; $i++) { $tmp .= sprintf('%08b', ord($data[$i + 2])); } $dataLength = bindec($tmp) + $payloadOffset; unset($tmp); } else { $mask = substr($data, 2, 4); $payloadOffset = 6; $dataLength = $payloadLength + $payloadOffset; } /** * We have to check for large frames here. socket_recv cuts at 1024 bytes * so if websocket-frame is > 1024 bytes we have to wait until whole * data is transferd. */ if (strlen($data) < $dataLength) { return false; } if ($isMasked) { for ($i = $payloadOffset; $i < $dataLength; $i++) { $j = $i - $payloadOffset; if (isset($data[$i])) { $unmaskedPayload .= $data[$i] ^ $mask[$j % 4]; } } $decodedData['payload'] = $unmaskedPayload; } else { $payloadOffset = $payloadOffset - 4; $decodedData['payload'] = substr($data, $payloadOffset); } return $decodedData; } 

To send data to the socket, do this: fwrite($connect, encode('hello')); . Well, reading, respectively.