Net_SSH2::_connect PHP Method

    function _connect()
    {
        if ($this->bitmap & NET_SSH2_MASK_CONSTRUCTOR) {
            return false;
        }
        $this->bitmap |= NET_SSH2_MASK_CONSTRUCTOR;
        $this->curTimeout = $this->timeout;
        $this->last_packet = strtok(microtime(), ' ') + strtok('');
        // == microtime(true) in PHP5
        if (!is_resource($this->fsock)) {
            $start = strtok(microtime(), ' ') + strtok('');
            // http://php.net/microtime#61838
            $this->fsock = @fsockopen($this->host, $this->port, $errno, $errstr, $this->curTimeout);
            if (!$this->fsock) {
                $host = $this->host . ':' . $this->port;
                user_error(rtrim("Cannot connect to {$host}. Error {$errno}. {$errstr}"));
                return false;
            }
            $elapsed = strtok(microtime(), ' ') + strtok('') - $start;
            $this->curTimeout -= $elapsed;
            if ($this->curTimeout <= 0) {
                $this->is_timeout = true;
                return false;
            }
        }
        /* According to the SSH2 specs,
        
                  "The server MAY send other lines of data before sending the version
                   string.  Each line SHOULD be terminated by a Carriage Return and Line
                   Feed.  Such lines MUST NOT begin with "SSH-", and SHOULD be encoded
                   in ISO-10646 UTF-8 [RFC3629] (language is not specified).  Clients
                   MUST be able to process such lines." */
        $temp = '';
        $extra = '';
        while (!feof($this->fsock) && !preg_match('#^SSH-(\\d\\.\\d+)#', $temp, $matches)) {
            if (substr($temp, -2) == "\r\n") {
                $extra .= $temp;
                $temp = '';
            }
            if ($this->curTimeout) {
                if ($this->curTimeout < 0) {
                    $this->is_timeout = true;
                    return false;
                }
                $read = array($this->fsock);
                $write = $except = null;
                $start = strtok(microtime(), ' ') + strtok('');
                $sec = floor($this->curTimeout);
                $usec = 1000000 * ($this->curTimeout - $sec);
                // on windows this returns a "Warning: Invalid CRT parameters detected" error
                // the !count() is done as a workaround for <https://bugs.php.net/42682>
                if (!@stream_select($read, $write, $except, $sec, $usec) && !count($read)) {
                    $this->is_timeout = true;
                    return false;
                }
                $elapsed = strtok(microtime(), ' ') + strtok('') - $start;
                $this->curTimeout -= $elapsed;
            }
            $temp .= fgets($this->fsock, 255);
        }
        if (feof($this->fsock)) {
            user_error('Connection closed by server');
            return false;
        }
        $this->identifier = $this->_generate_identifier();
        if (defined('NET_SSH2_LOGGING')) {
            $this->_append_log('<-', $extra . $temp);
            $this->_append_log('->', $this->identifier . "\r\n");
        }
        $this->server_identifier = trim($temp, "\r\n");
        if (strlen($extra)) {
            $this->errors[] = utf8_decode($extra);
        }
        if ($matches[1] != '1.99' && $matches[1] != '2.0') {
            user_error("Cannot connect to SSH {$matches['1']} servers");
            return false;
        }
        fputs($this->fsock, $this->identifier . "\r\n");
        $response = $this->_get_binary_packet();
        if ($response === false) {
            user_error('Connection closed by server');
            return false;
        }
        if (ord($response[0]) != NET_SSH2_MSG_KEXINIT) {
            user_error('Expected SSH_MSG_KEXINIT');
            return false;
        }
        if (!$this->_key_exchange($response)) {
            return false;
        }
        $this->bitmap |= NET_SSH2_MASK_CONNECTED;
        return true;
    }