phpseclib\Net\SSH2::_send_binary_packet PHP Method

    function _send_binary_packet($data, $logged = null)
    {
        if (!is_resource($this->fsock) || feof($this->fsock)) {
            $this->bitmap = 0;
            throw new \RuntimeException('Connection closed prematurely');
        }
        //if ($this->compress) {
        //    // the -4 removes the checksum:
        //    // http://php.net/function.gzcompress#57710
        //    $data = substr(gzcompress($data), 0, -4);
        //}
        // 4 (packet length) + 1 (padding length) + 4 (minimal padding amount) == 9
        $packet_length = strlen($data) + 9;
        // round up to the nearest $this->encrypt_block_size
        $packet_length += ($this->encrypt_block_size - 1) * $packet_length % $this->encrypt_block_size;
        // subtracting strlen($data) is obvious - subtracting 5 is necessary because of packet_length and padding_length
        $padding_length = $packet_length - strlen($data) - 5;
        $padding = Random::string($padding_length);
        // we subtract 4 from packet_length because the packet_length field isn't supposed to include itself
        $packet = pack('NCa*', $packet_length - 4, $padding_length, $data . $padding);
        $hmac = $this->hmac_create !== false ? $this->hmac_create->hash(pack('Na*', $this->send_seq_no, $packet)) : '';
        $this->send_seq_no++;
        if ($this->encrypt !== false) {
            $packet = $this->encrypt->encrypt($packet);
        }
        $packet .= $hmac;
        $start = microtime(true);
        $result = strlen($packet) == fputs($this->fsock, $packet);
        $stop = microtime(true);
        if (defined('NET_SSH2_LOGGING')) {
            $current = microtime(true);
            $message_number = isset($this->message_numbers[ord($data[0])]) ? $this->message_numbers[ord($data[0])] : 'UNKNOWN (' . ord($data[0]) . ')';
            $message_number = '-> ' . $message_number . ' (since last: ' . round($current - $this->last_packet, 4) . ', network: ' . round($stop - $start, 4) . 's)';
            $this->_append_log($message_number, isset($logged) ? $logged : $data);
            $this->last_packet = $current;
        }
        return $result;
    }