예제 #1
0
 def handle_event(self, sock, fd, event):
     if sock == self._server_socket:
         if event & eventloop.POLL_ERR:
             logging.error('UDP server_socket err')
         try:
             self._handle_server()
         except Exception as e:
             shell.print_exception(e)
             if self._config['verbose']:
                 traceback.print_exc()
     elif sock and (fd in self._sockets):
         if event & eventloop.POLL_ERR:
             logging.error('UDP client_socket err')
         try:
             self._handle_client(sock)
         except Exception as e:
             shell.print_exception(e)
             if self._config['verbose']:
                 traceback.print_exc()
     else:
         if sock:
             handler = self._fd_to_handlers.get(fd, None)
             if handler:
                 handler.handle_event(sock, event)
         else:
             logging.warn('poll removed fd')
예제 #2
0
    def run(self):
        events = []
        while not self._stopping:
            asap = False
            try:
                events = self.poll(TIMEOUT_PRECISION)
            except (OSError, IOError) as e:
                if errno_from_exception(e) in (errno.EPIPE, errno.EINTR):
                    # EPIPE: Happens when the client closes the connection
                    # EINTR: Happens when received a signal
                    # handles them as soon as possible
                    asap = True
                    logging.debug('poll:%s', e)
                else:
                    logging.error('poll:%s', e)
                    import traceback
                    traceback.print_exc()
                    continue

            handle = False
            for sock, fd, event in events:
                handler = self._fdmap.get(fd, None)
                if handler is not None:
                    handler = handler[1]
                    try:
                        handle = handler.handle_event(sock, fd, event) or handle
                    except (OSError, IOError) as e:
                        shell.print_exception(e)
            now = time.time()
            if asap or now - self._last_time >= TIMEOUT_PRECISION:
                for callback in self._periodic_callbacks:
                    callback()
                self._last_time = now
            if events and not handle:
                time.sleep(0.001)
예제 #3
0
def check_config(config, is_local):
    if config.get('daemon', None) == 'stop':
        # no need to specify configuration for daemon stop
        return

    if is_local and not config.get('password', None):
        logging.error('password not specified')
        print_help(is_local)
        sys.exit(2)

    if not is_local and not config.get('password', None) \
            and not config.get('port_password', None):
        logging.error('password or port_password not specified')
        print_help(is_local)
        sys.exit(2)

    if 'local_port' in config:
        config['local_port'] = int(config['local_port'])

    if 'server_port' in config and type(config['server_port']) != list:
        config['server_port'] = int(config['server_port'])

    if config.get('local_address', '') in [b'0.0.0.0']:
        logging.warning('warning: local set to listen on 0.0.0.0, it\'s not safe')
    if config.get('server', '') in ['127.0.0.1', 'localhost']:
        logging.warning('warning: server set to listen on %s:%s, are you sure?' %
                        (to_str(config['server']), config['server_port']))
    if config.get('timeout', 300) < 100:
        logging.warning('warning: your timeout %d seems too short' %
                        int(config.get('timeout')))
    if config.get('timeout', 300) > 600:
        logging.warning('warning: your timeout %d seems too long' %
                        int(config.get('timeout')))
    if config.get('password') in [b'mypassword']:
        logging.error('DON\'T USE DEFAULT PASSWORD! Please change it in your '
                      'config.json!')
        sys.exit(1)
    if config.get('user', None) is not None:
        if os.name != 'posix':
            logging.error('user can be used only on Unix')
            sys.exit(1)

    encrypt.try_cipher(config['password'], config['method'])
예제 #4
0
def print_exception(e):
    global verbose
    logging.error(e)
    if verbose > 0:
        import traceback
        traceback.print_exc()
예제 #5
0
def get_config(is_local):
    global verbose
    config = {}
    config_path = None
    logging.basicConfig(level=logging.INFO,
                        format='%(levelname)-s: %(message)s')
    if is_local:
        shortopts = 'hd:s:b:p:k:l:m:O:o:G:g:c:t:vq'
        longopts = ['help', 'fast-open', 'pid-file=', 'log-file=', 'user='******'version']
    else:
        shortopts = 'hd:s:p:k:m:O:o:G:g:c:t:vq'
        longopts = ['help', 'fast-open', 'pid-file=', 'log-file=', 'workers=',
                    'forbidden-ip=', 'user='******'manager-address=', 'version']
    try:
        optlist, args = getopt.getopt(sys.argv[1:], shortopts, longopts)
        for key, value in optlist:
            if key == '-c':
                config_path = value
            elif key in ('-h', '--help'):
                print_help(is_local)
                sys.exit(0)
            elif key == '--version':
                print_shadowsocks()
                sys.exit(0)
            else:
                continue

        if config_path is None:
            config_path = find_config()

        if config_path:
            logging.debug('loading config from %s' % config_path)
            with open(config_path, 'rb') as f:
                try:
                    config = parse_json_in_str(remove_comment(f.read().decode('utf8')))
                except ValueError as e:
                    logging.error('found an error in config.json: %s', str(e))
                    sys.exit(1)

        v_count = 0
        for key, value in optlist:
            if key == '-p':
                config['server_port'] = int(value)
            elif key == '-k':
                config['password'] = to_bytes(value)
            elif key == '-l':
                config['local_port'] = int(value)
            elif key == '-s':
                config['server'] = to_str(value)
            elif key == '-m':
                config['method'] = to_str(value)
            elif key == '-O':
                config['protocol'] = to_str(value)
            elif key == '-o':
                config['obfs'] = to_str(value)
            elif key == '-G':
                config['protocol_param'] = to_str(value)
            elif key == '-g':
                config['obfs_param'] = to_str(value)
            elif key == '-b':
                config['local_address'] = to_str(value)
            elif key == '-v':
                v_count += 1
                # '-vv' turns on more verbose mode
                config['verbose'] = v_count
            elif key == '-t':
                config['timeout'] = int(value)
            elif key == '--fast-open':
                config['fast_open'] = True
            elif key == '--workers':
                config['workers'] = int(value)
            elif key == '--manager-address':
                config['manager_address'] = value
            elif key == '--user':
                config['user'] = to_str(value)
            elif key == '--forbidden-ip':
                config['forbidden_ip'] = to_str(value)

            elif key == '-d':
                config['daemon'] = to_str(value)
            elif key == '--pid-file':
                config['pid-file'] = to_str(value)
            elif key == '--log-file':
                config['log-file'] = to_str(value)
            elif key == '-q':
                v_count -= 1
                config['verbose'] = v_count
            else:
                continue
    except getopt.GetoptError as e:
        print(e, file=sys.stderr)
        print_help(is_local)
        sys.exit(2)

    if not config:
        logging.error('config not specified')
        print_help(is_local)
        sys.exit(2)

    config['password'] = to_bytes(config.get('password', b''))
    config['method'] = to_str(config.get('method', 'aes-256-cfb'))
    config['protocol'] = to_str(config.get('protocol', 'origin'))
    config['protocol_param'] = to_str(config.get('protocol_param', ''))
    config['obfs'] = to_str(config.get('obfs', 'plain'))
    config['obfs_param'] = to_str(config.get('obfs_param', ''))
    config['port_password'] = config.get('port_password', None)
    config['additional_ports'] = config.get('additional_ports', {})
    config['additional_ports_only'] = config.get('additional_ports_only', False)
    config['timeout'] = int(config.get('timeout', 300))
    config['udp_timeout'] = int(config.get('udp_timeout', 120))
    config['udp_cache'] = int(config.get('udp_cache', 64))
    config['fast_open'] = config.get('fast_open', False)
    config['workers'] = config.get('workers', 1)
    config['pid-file'] = config.get('pid-file', '/var/run/shadowsocksr.pid')
    config['log-file'] = config.get('log-file', '/var/log/shadowsocksr.log')
    config['verbose'] = config.get('verbose', False)
    config['connect_verbose_info'] = config.get('connect_verbose_info', 0)
    config['local_address'] = to_str(config.get('local_address', '127.0.0.1'))
    config['local_port'] = config.get('local_port', 1080)
    if is_local:
        if config.get('server', None) is None:
            logging.error('server addr not specified')
            print_local_help()
            sys.exit(2)
        else:
            config['server'] = to_str(config['server'])
    else:
        config['server'] = to_str(config.get('server', '0.0.0.0'))
        config['black_hostname_list'] = to_str(config.get('black_hostname_list', '')).split(',')
        if len(config['black_hostname_list']) == 1 and config['black_hostname_list'][0] == '':
            config['black_hostname_list'] = []
        try:
            config['forbidden_ip'] = \
                IPNetwork(config.get('forbidden_ip', '127.0.0.0/8,::1/128'))
        except Exception as e:
            logging.error(e)
            sys.exit(2)
        try:
            config['forbidden_port'] = PortRange(config.get('forbidden_port', ''))
        except Exception as e:
            logging.error(e)
            sys.exit(2)
        try:
            config['ignore_bind'] = \
                IPNetwork(config.get('ignore_bind', '127.0.0.0/8,::1/128,10.0.0.0/8,192.168.0.0/16'))
        except Exception as e:
            logging.error(e)
            sys.exit(2)
    config['server_port'] = config.get('server_port', 8388)

    logging.getLogger('').handlers = []
    logging.addLevelName(VERBOSE_LEVEL, 'VERBOSE')
    if config['verbose'] >= 2:
        level = VERBOSE_LEVEL
    elif config['verbose'] == 1:
        level = logging.DEBUG
    elif config['verbose'] == -1:
        level = logging.WARN
    elif config['verbose'] <= -2:
        level = logging.ERROR
    else:
        level = logging.INFO
    verbose = config['verbose']
    logging.basicConfig(level=level,
                        format='%(asctime)s %(levelname)-8s %(filename)s:%(lineno)s %(message)s',
                        datefmt='%Y-%m-%d %H:%M:%S')

    check_config(config, is_local)

    return config
예제 #6
0
    def server_post_decrypt(self, buf):
        if self.raw_trans:
            return (buf, False)
        self.recv_buf += buf
        out_buf = b''
        sendback = False

        if not self.has_recv_header:
            if len(self.recv_buf) >= 12 or len(self.recv_buf) in [7, 8]:
                recv_len = min(len(self.recv_buf), 12)
                mac_key = self.server_info.recv_iv + self.server_info.key
                md5data = hmac.new(mac_key, self.recv_buf[:4], self.hashfunc).digest()
                if md5data[:recv_len - 4] != self.recv_buf[4:recv_len]:
                    return self.not_match_return(self.recv_buf)

            if len(self.recv_buf) < 12 + 24:
                return (b'', False)

            self.last_client_hash = md5data
            uid = struct.unpack('<I', self.recv_buf[12:16])[0] ^ struct.unpack('<I', md5data[8:12])[0]
            self.user_id_num = uid
            uid = struct.pack('<I', uid)
            if uid in self.server_info.users:
                self.user_id = uid
                self.user_key = self.server_info.users[uid]
                self.server_info.update_user_func(uid)
            else:
                self.user_id_num = 0
                if not self.server_info.users:
                    self.user_key = self.server_info.key
                else:
                    self.user_key = self.server_info.recv_iv

            md5data = hmac.new(self.user_key, self.recv_buf[12: 12 + 20], self.hashfunc).digest()
            if md5data[:4] != self.recv_buf[32:36]:
                logging.error('%s data uncorrect auth HMAC-MD5 from %s:%d, data %s' % (
                    self.no_compatible_method, self.server_info.client, self.server_info.client_port,
                    binascii.hexlify(self.recv_buf)
                ))
                if len(self.recv_buf) < 36:
                    return (b'', False)
                return self.not_match_return(self.recv_buf)

            self.last_server_hash = md5data
            encryptor = encrypt.Encryptor(to_bytes(base64.b64encode(self.user_key)) + self.salt, 'aes-128-cbc')
            head = encryptor.decrypt(b'\x00' * 16 + self.recv_buf[16:32] + b'\x00')  # need an extra byte or recv empty
            self.client_over_head = struct.unpack('<H', head[12:14])[0]

            utc_time = struct.unpack('<I', head[:4])[0]
            client_id = struct.unpack('<I', head[4:8])[0]
            connection_id = struct.unpack('<I', head[8:12])[0]
            time_dif = common.int32(utc_time - (int(time.time()) & 0xffffffff))
            if time_dif < -self.max_time_dif or time_dif > self.max_time_dif:
                logging.info('%s: wrong timestamp, time_dif %d, data %s' % (
                    self.no_compatible_method, time_dif, binascii.hexlify(head)
                ))
                return self.not_match_return(self.recv_buf)
            elif self.server_info.data.insert(self.user_id, client_id, connection_id):
                self.has_recv_header = True
                self.client_id = client_id
                self.connection_id = connection_id
            else:
                logging.info('%s: auth fail, data %s' % (self.no_compatible_method, binascii.hexlify(out_buf)))
                return self.not_match_return(self.recv_buf)

            self.on_recv_auth_data(utc_time)
            self.encryptor = encrypt.Encryptor(
                to_bytes(base64.b64encode(self.user_key)) + to_bytes(base64.b64encode(self.last_client_hash)), 'rc4')
            self.recv_buf = self.recv_buf[36:]
            self.has_recv_header = True
            sendback = True

        while len(self.recv_buf) > 4:
            mac_key = self.user_key + struct.pack('<I', self.recv_id)
            data_len = struct.unpack('<H', self.recv_buf[:2])[0] ^ struct.unpack('<H', self.last_client_hash[14:16])[0]
            rand_len = self.rnd_data_len(data_len, self.last_client_hash, self.random_client)
            length = data_len + rand_len
            if length >= 4096:
                self.raw_trans = True
                self.recv_buf = b''
                if self.recv_id == 1:
                    logging.info(self.no_compatible_method + ': over size')
                    return (b'E' * 2048, False)
                else:
                    raise Exception('server_post_decrype data error')

            if length + 4 > len(self.recv_buf):
                break

            client_hash = hmac.new(mac_key, self.recv_buf[:length + 2], self.hashfunc).digest()
            if client_hash[:2] != self.recv_buf[length + 2: length + 4]:
                logging.info('%s: checksum error, data %s' % (
                    self.no_compatible_method, binascii.hexlify(self.recv_buf[:length])
                ))
                self.raw_trans = True
                self.recv_buf = b''
                if self.recv_id == 1:
                    return (b'E' * 2048, False)
                else:
                    raise Exception('server_post_decrype data uncorrect checksum')

            self.recv_id = (self.recv_id + 1) & 0xFFFFFFFF
            pos = 2
            if data_len > 0 and rand_len > 0:
                pos = 2 + self.rnd_start_pos(rand_len, self.random_client)
            out_buf += self.encryptor.decrypt(self.recv_buf[pos: data_len + pos])
            self.last_client_hash = client_hash
            self.recv_buf = self.recv_buf[length + 4:]
            if data_len == 0:
                sendback = True

        if out_buf:
            self.server_info.data.update(self.user_id, self.client_id, self.connection_id)
        return (out_buf, sendback)
예제 #7
0
    def _handle_server_dns_resolved(self, error, remote_addr, server_addr,
                                    params):
        if error:
            return
        data, r_addr, uid, header_length = params
        user_id = self._listen_port
        try:
            server_port = remote_addr[1]
            addrs = socket.getaddrinfo(server_addr, server_port, 0,
                                       socket.SOCK_DGRAM, socket.SOL_UDP)
            if not addrs:  # drop
                return
            af, socktype, proto, canonname, sa = addrs[0]
            server_addr = sa[0]
            key = client_key(r_addr, af)
            client_pair = self._cache.get(key, None)
            if client_pair is None:
                client_pair = self._cache_dns_client.get(key, None)
            if client_pair is None:
                if self._forbidden_iplist:
                    if common.to_str(sa[0]) in self._forbidden_iplist:
                        logging.debug('IP %s is in forbidden list, drop' %
                                      common.to_str(sa[0]))
                        # drop
                        return
                if self._forbidden_portset:
                    if sa[1] in self._forbidden_portset:
                        logging.debug('Port %d is in forbidden list, reject' %
                                      sa[1])
                        # drop
                        return
                client = socket.socket(af, socktype, proto)
                client_uid = uid
                client.setblocking(False)
                self._socket_bind_addr(client, af)
                is_dns = False
                if len(data) > header_length + 13 and data[
                        header_length + 4:header_length +
                        12] == b"\x00\x01\x00\x00\x00\x00\x00\x00":
                    is_dns = True
                else:
                    pass
                if sa[1] == 53 and is_dns:  #DNS
                    logging.debug("DNS query %s from %s:%d" %
                                  (common.to_str(sa[0]), r_addr[0], r_addr[1]))
                    self._cache_dns_client[key] = (client, uid)
                else:
                    self._cache[key] = (client, uid)
                self._client_fd_to_server_addr[client.fileno()] = (r_addr, af)

                self._sockets.add(client.fileno())
                self._eventloop.add(client, eventloop.POLL_IN, self)

                logging.debug('UDP port %5d sockets %d' %
                              (self._listen_port, len(self._sockets)))

                if uid is not None:
                    user_id = struct.unpack('<I', client_uid)[0]
            else:
                client, client_uid = client_pair
            self._cache.clear(self._udp_cache_size)
            self._cache_dns_client.clear(16)

            if self._is_local:
                ref_iv = [encrypt.encrypt_new_iv(self._method)]
                self._protocol.obfs.server_info.iv = ref_iv[0]
                data = self._protocol.client_udp_pre_encrypt(data)
                #logging.debug("%s" % (binascii.hexlify(data),))
                data = encrypt.encrypt_all_iv(
                    self._protocol.obfs.server_info.key, self._method, 1, data,
                    ref_iv)
                if not data:
                    return
            else:
                data = data[header_length:]
            if not data:
                return
        except Exception as e:
            shell.print_exception(e)
            logging.error("exception from user %d" % (user_id, ))

        try:
            client.sendto(data, (server_addr, server_port))
            self.add_transfer_u(client_uid, len(data))
            if client_pair is None:  # new request
                addr, port = client.getsockname()[:2]
                common.connect_log(
                    'UDP data to %s(%s):%d from %s:%d by user %d' %
                    (common.to_str(remote_addr[0]), common.to_str(server_addr),
                     server_port, addr, port, user_id))
        except IOError as e:
            err = eventloop.errno_from_exception(e)
            logging.warning('IOError sendto %s:%d by user %d' %
                            (server_addr, server_port, user_id))
            if err in (errno.EINPROGRESS, errno.EAGAIN):
                pass
            else:
                shell.print_exception(e)
예제 #8
0
    def server_post_decrypt(self, buf):
        if self.raw_trans:
            return (buf, False)
        self.recv_buf += buf
        out_buf = b''
        sendback = False

        if not self.has_recv_header:
            if len(self.recv_buf) >= 7 or len(self.recv_buf) in [2, 3]:
                recv_len = min(len(self.recv_buf), 7)
                mac_key = self.server_info.recv_iv + self.server_info.key
                sha1data = hmac.new(mac_key, self.recv_buf[:1],
                                    self.hashfunc).digest()[:recv_len - 1]
                if sha1data != self.recv_buf[1:recv_len]:
                    return self.not_match_return(self.recv_buf)

            if len(self.recv_buf) < 31:
                return (b'', False)
            sha1data = hmac.new(mac_key, self.recv_buf[7:27],
                                self.hashfunc).digest()[:4]
            if sha1data != self.recv_buf[27:31]:
                logging.error(
                    '%s data uncorrect auth HMAC-SHA1 from %s:%d, data %s' %
                    (self.no_compatible_method, self.server_info.client,
                     self.server_info.client_port,
                     binascii.hexlify(self.recv_buf)))
                if len(self.recv_buf) < 31 + self.extra_wait_size:
                    return (b'', False)
                return self.not_match_return(self.recv_buf)

            uid = self.recv_buf[7:11]
            if uid in self.server_info.users:
                self.user_id = uid
                self.user_key = self.hashfunc(
                    self.server_info.users[uid]).digest()
                self.server_info.update_user_func(uid)
            else:
                if not self.server_info.users:
                    self.user_key = self.server_info.key
                else:
                    self.user_key = self.server_info.recv_iv
            encryptor = encrypt.Encryptor(
                to_bytes(base64.b64encode(self.user_key)) + self.salt,
                'aes-128-cbc')
            head = encryptor.decrypt(
                b'\x00' * 16 + self.recv_buf[11:27] +
                b'\x00')  # need an extra byte or recv empty
            length = struct.unpack('<H', head[12:14])[0]
            if len(self.recv_buf) < length:
                return (b'', False)

            utc_time = struct.unpack('<I', head[:4])[0]
            client_id = struct.unpack('<I', head[4:8])[0]
            connection_id = struct.unpack('<I', head[8:12])[0]
            rnd_len = struct.unpack('<H', head[14:16])[0]
            if hmac.new(self.user_key, self.recv_buf[:length - 4],
                        self.hashfunc).digest()[:4] != self.recv_buf[length -
                                                                     4:length]:
                logging.info('%s: checksum error, data %s' %
                             (self.no_compatible_method,
                              binascii.hexlify(self.recv_buf[:length])))
                return self.not_match_return(self.recv_buf)
            time_dif = common.int32(utc_time - (int(time.time()) & 0xffffffff))
            if time_dif < -self.max_time_dif or time_dif > self.max_time_dif:
                logging.info('%s: wrong timestamp, time_dif %d, data %s' %
                             (self.no_compatible_method, time_dif,
                              binascii.hexlify(head)))
                return self.not_match_return(self.recv_buf)
            elif self.server_info.data.insert(self.user_id, client_id,
                                              connection_id):
                self.has_recv_header = True
                out_buf = self.recv_buf[31 + rnd_len:length - 4]
                self.client_id = client_id
                self.connection_id = connection_id
            else:
                logging.info(
                    '%s: auth fail, data %s' %
                    (self.no_compatible_method, binascii.hexlify(out_buf)))
                return self.not_match_return(self.recv_buf)
            self.recv_buf = self.recv_buf[length:]
            self.has_recv_header = True
            sendback = True

        while len(self.recv_buf) > 4:
            mac_key = self.user_key + struct.pack('<I', self.recv_id)
            mac = hmac.new(mac_key, self.recv_buf[:2],
                           self.hashfunc).digest()[:2]
            if mac != self.recv_buf[2:4]:
                self.raw_trans = True
                logging.info(self.no_compatible_method + ': wrong crc')
                if self.recv_id == 0:
                    logging.info(self.no_compatible_method + ': wrong crc')
                    return (b'E' * 2048, False)
                else:
                    raise Exception('server_post_decrype data error')
            length = struct.unpack('<H', self.recv_buf[:2])[0]
            if length >= 8192 or length < 7:
                self.raw_trans = True
                self.recv_buf = b''
                if self.recv_id == 0:
                    logging.info(self.no_compatible_method + ': over size')
                    return (b'E' * 2048, False)
                else:
                    raise Exception('server_post_decrype data error')
            if length > len(self.recv_buf):
                break

            if hmac.new(mac_key, self.recv_buf[:length - 4],
                        self.hashfunc).digest()[:4] != self.recv_buf[length -
                                                                     4:length]:
                logging.info('%s: checksum error, data %s' %
                             (self.no_compatible_method,
                              binascii.hexlify(self.recv_buf[:length])))
                self.raw_trans = True
                self.recv_buf = b''
                if self.recv_id == 0:
                    return (b'E' * 2048, False)
                else:
                    raise Exception(
                        'server_post_decrype data uncorrect checksum')

            self.recv_id = (self.recv_id + 1) & 0xFFFFFFFF
            pos = common.ord(self.recv_buf[4])
            if pos < 255:
                pos += 4
            else:
                pos = struct.unpack('<H', self.recv_buf[5:7])[0] + 4
            out_buf += self.recv_buf[pos:length - 4]
            self.recv_buf = self.recv_buf[length:]
            if pos == length - 4:
                sendback = True

        if out_buf:
            self.server_info.data.update(self.user_id, self.client_id,
                                         self.connection_id)
        return (out_buf, sendback)
예제 #9
0
    def server_post_decrypt(self, buf):
        if self.raw_trans:
            return (buf, False)
        self.recv_buf += buf
        out_buf = b''
        sendback = False

        if not self.has_recv_header:
            if len(self.recv_buf) <= 6:
                return (b'', False)
            crc = struct.pack(
                '<I',
                binascii.crc32(self.recv_buf[:2] + self.salt +
                               self.server_info.key) & 0xFFFFFFFF)
            if crc != self.recv_buf[2:6]:
                return self.not_match_return(self.recv_buf)
            length = struct.unpack('>H', self.recv_buf[:2])[0]
            if length > len(self.recv_buf):
                return (b'', False)
            sha1data = hmac.new(
                self.server_info.recv_iv + self.server_info.key,
                self.recv_buf[:length - 10], hashlib.sha1).digest()[:10]
            if sha1data != self.recv_buf[length - 10:length]:
                logging.error('auth_sha1_v4 data uncorrect auth HMAC-SHA1')
                return self.not_match_return(self.recv_buf)
            pos = common.ord(self.recv_buf[6])
            if pos < 255:
                pos += 6
            else:
                pos = struct.unpack('>H', self.recv_buf[7:9])[0] + 6
            out_buf = self.recv_buf[pos:length - 10]
            if len(out_buf) < 12:
                logging.info('auth_sha1_v4: too short, data %s' %
                             (binascii.hexlify(self.recv_buf), ))
                return self.not_match_return(self.recv_buf)
            utc_time = struct.unpack('<I', out_buf[:4])[0]
            client_id = struct.unpack('<I', out_buf[4:8])[0]
            connection_id = struct.unpack('<I', out_buf[8:12])[0]
            time_dif = common.int32(utc_time - (int(time.time()) & 0xffffffff))
            if time_dif < -self.max_time_dif or time_dif > self.max_time_dif:
                logging.info(
                    'auth_sha1_v4: wrong timestamp, time_dif %d, data %s' % (
                        time_dif,
                        binascii.hexlify(out_buf),
                    ))
                return self.not_match_return(self.recv_buf)
            elif self.server_info.data.insert(client_id, connection_id):
                self.has_recv_header = True
                out_buf = out_buf[12:]
                self.client_id = client_id
                self.connection_id = connection_id
            else:
                logging.info('auth_sha1_v4: auth fail, data %s' %
                             (binascii.hexlify(out_buf), ))
                return self.not_match_return(self.recv_buf)
            self.recv_buf = self.recv_buf[length:]
            self.has_recv_header = True
            sendback = True

        while len(self.recv_buf) > 4:
            crc = struct.pack('<H', binascii.crc32(self.recv_buf[:2]) & 0xFFFF)
            if crc != self.recv_buf[2:4]:
                self.raw_trans = True
                logging.info('auth_sha1_v4: wrong crc')
                if self.decrypt_packet_num == 0:
                    logging.info('auth_sha1_v4: wrong crc')
                    return (b'E' * 2048, False)
                else:
                    raise Exception('server_post_decrype data error')
            length = struct.unpack('>H', self.recv_buf[:2])[0]
            if length >= 8192 or length < 7:
                self.raw_trans = True
                self.recv_buf = b''
                if self.decrypt_packet_num == 0:
                    logging.info('auth_sha1_v4: over size')
                    return (b'E' * 2048, False)
                else:
                    raise Exception('server_post_decrype data error')
            if length > len(self.recv_buf):
                break

            if struct.pack(
                    '<I',
                    zlib.adler32(self.recv_buf[:length - 4])
                    & 0xFFFFFFFF) != self.recv_buf[length - 4:length]:
                logging.info('auth_sha1_v4: checksum error, data %s' %
                             (binascii.hexlify(self.recv_buf[:length]), ))
                self.raw_trans = True
                self.recv_buf = b''
                if self.decrypt_packet_num == 0:
                    return (b'E' * 2048, False)
                else:
                    raise Exception(
                        'server_post_decrype data uncorrect checksum')

            pos = common.ord(self.recv_buf[4])
            if pos < 255:
                pos += 4
            else:
                pos = struct.unpack('>H', self.recv_buf[5:7])[0] + 4
            out_buf += self.recv_buf[pos:length - 4]
            self.recv_buf = self.recv_buf[length:]
            if pos == length - 4:
                sendback = True

        if out_buf:
            self.server_info.data.update(self.client_id, self.connection_id)
            self.decrypt_packet_num += 1
        return (out_buf, sendback)