Net_SSH2::_privatekey_login PHP Method

    function _privatekey_login($username, $privatekey)
    {
        // see http://tools.ietf.org/html/rfc4253#page-15
        $publickey = $privatekey->getPublicKey(CRYPT_RSA_PUBLIC_FORMAT_RAW);
        if ($publickey === false) {
            return false;
        }
        $publickey = array('e' => $publickey['e']->toBytes(true), 'n' => $publickey['n']->toBytes(true));
        $publickey = pack('Na*Na*Na*', strlen('ssh-rsa'), 'ssh-rsa', strlen($publickey['e']), $publickey['e'], strlen($publickey['n']), $publickey['n']);
        $part1 = pack('CNa*Na*Na*', NET_SSH2_MSG_USERAUTH_REQUEST, strlen($username), $username, strlen('ssh-connection'), 'ssh-connection', strlen('publickey'), 'publickey');
        $part2 = pack('Na*Na*', strlen('ssh-rsa'), 'ssh-rsa', strlen($publickey), $publickey);
        $packet = $part1 . chr(0) . $part2;
        if (!$this->_send_binary_packet($packet)) {
            return false;
        }
        $response = $this->_get_binary_packet();
        if ($response === false) {
            user_error('Connection closed by server');
            return false;
        }
        extract(unpack('Ctype', $this->_string_shift($response, 1)));
        switch ($type) {
            case NET_SSH2_MSG_USERAUTH_FAILURE:
                extract(unpack('Nlength', $this->_string_shift($response, 4)));
                $this->errors[] = 'SSH_MSG_USERAUTH_FAILURE: ' . $this->_string_shift($response, $length);
                return false;
            case NET_SSH2_MSG_USERAUTH_PK_OK:
                // we'll just take it on faith that the public key blob and the public key algorithm name are as
                // they should be
                if (defined('NET_SSH2_LOGGING') && NET_SSH2_LOGGING == NET_SSH2_LOG_COMPLEX) {
                    $this->message_number_log[count($this->message_number_log) - 1] = str_replace('UNKNOWN', 'NET_SSH2_MSG_USERAUTH_PK_OK', $this->message_number_log[count($this->message_number_log) - 1]);
                }
        }
        $packet = $part1 . chr(1) . $part2;
        $privatekey->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
        $signature = $privatekey->sign(pack('Na*a*', strlen($this->session_id), $this->session_id, $packet));
        $signature = pack('Na*Na*', strlen('ssh-rsa'), 'ssh-rsa', strlen($signature), $signature);
        $packet .= pack('Na*', strlen($signature), $signature);
        if (!$this->_send_binary_packet($packet)) {
            return false;
        }
        $response = $this->_get_binary_packet();
        if ($response === false) {
            user_error('Connection closed by server');
            return false;
        }
        extract(unpack('Ctype', $this->_string_shift($response, 1)));
        switch ($type) {
            case NET_SSH2_MSG_USERAUTH_FAILURE:
                // either the login is bad or the server employs multi-factor authentication
                return false;
            case NET_SSH2_MSG_USERAUTH_SUCCESS:
                $this->bitmap |= NET_SSH2_MASK_LOGIN;
                return true;
        }
        return false;
    }