Exemplo n.º 1
0
    def __init__(self, peerid, host, port, serverinit=True, clientinit=True, printer=None):
        "Initialize communication layer."

        # Initialize Communications security core
        self.comsec_core = ComSecCore()

        # peer client attributes
        self.peerid = peerid
        self.host = host
        self.port = port

        # Get device service link
        self._device = None

        # peer key
        self.peerkey = self.comsec_core.get_public_key()

        # TLS variables
        if constants.ENABLE_TLS:
            # SSL cert, key path
            self.sslcrt = "{}/certs/{}.crt".format(constants.PROJECT_PATH, self.peerid)
            self.sslkey = "{}/certs/{}.key".format(constants.PROJECT_PATH, self.peerid)
            self.ssca = "{}/certs/demoCA/cacert.pem".format(constants.PROJECT_PATH)

        # Initialize peer manager
        self.swarm_manager = SwarmManager(peerid, self.peerkey)
        # Initialize stream manager
        self.stream_manager = StreamManager(peerid, self.peerkey, host)

        # Alias print method
        self._printer = printer

        # Auth request token dictionary, stores all auth request tokens
        # such that all acks can be validated.
        self.valid_auth_req_tokens = {}

        # Start the listener
        if serverinit:
            self.listener = self._start_listener()

        # Start peer connections
        if clientinit:
            self._start_connections()
Exemplo n.º 2
0
class CommService(object):

    """
    Twisted communications service.
    Contains both server and client code.
    """

    def __init__(self, peerid, host, port, serverinit=True, clientinit=True, printer=None):
        "Initialize communication layer."

        # Initialize Communications security core
        self.comsec_core = ComSecCore()

        # peer client attributes
        self.peerid = peerid
        self.host = host
        self.port = port

        # Get device service link
        self._device = None

        # peer key
        self.peerkey = self.comsec_core.get_public_key()

        # TLS variables
        if constants.ENABLE_TLS:
            # SSL cert, key path
            self.sslcrt = "{}/certs/{}.crt".format(constants.PROJECT_PATH, self.peerid)
            self.sslkey = "{}/certs/{}.key".format(constants.PROJECT_PATH, self.peerid)
            self.ssca = "{}/certs/demoCA/cacert.pem".format(constants.PROJECT_PATH)

        # Initialize peer manager
        self.swarm_manager = SwarmManager(peerid, self.peerkey)
        # Initialize stream manager
        self.stream_manager = StreamManager(peerid, self.peerkey, host)

        # Alias print method
        self._printer = printer

        # Auth request token dictionary, stores all auth request tokens
        # such that all acks can be validated.
        self.valid_auth_req_tokens = {}

        # Start the listener
        if serverinit:
            self.listener = self._start_listener()

        # Start peer connections
        if clientinit:
            self._start_connections()

    def __del__(self):

        # Close swarm handler
        self.swarm_manager.__del__()
        # Close stream manager
        self.stream_manager.__del__()
        # Close twisted listener
        self._stop_listener()

    def register_device_service(self, device):
        "Must be called after init."

        # Register device service, cannot rebind
        if not self._device:
            self._device = device

    def _start_listener(self):
        "Start twisted server listener."

        if constants.ENABLE_TLS:
            return reactor.listenSSL(
                self.port,
                CommCoreServerFactory(self),
                TLSCtxFactory(self.sslcrt, self.sslkey, self.ssca, self.on_ssl_verification),
            )
        else:
            return reactor.listenTCP(self.port, CommCoreServerFactory(self))

    def _stop_listener(self):
        "Stop twisted server listener"

        self.listener.stopListening()
        Logger.info("COMM: Ended twisted communications!")

    def _start_connections(self):
        "Start peer connections on start."

        # Connect to all peers
        for (pid, _, host, port, cstatus) in self.swarm_manager.list_peers():

            # Check conn status
            if not cstatus:
                self.start_connection(pid, host, port)
            else:
                pass

    def _update_peer_connection_status(self, peer_ip, peer_port, status, conn):
        "Change peer conn status based on connection/disconnection."

        # Assuming Peer ID <-> Peer IP one to one relation
        pid = self.swarm_manager.get_peerid_from_ip(peer_ip, peer_port)

        # Add the peer connection if it doesnt exist
        if status:
            self.swarm_manager.add_peer_connection(pid, conn)

        if pid:
            return self.swarm_manager.update_peer_connection_status(pid, status)
        else:
            return None

    def _sendLine(self, conn, line):
        "Implementing sendLine method locally."

        # If stream packing fails line=None
        if not line:
            Logger.error("COMM: No stream to send.")
            return None

        try:
            conn.sendLine(line)
        except:
            conn.write("{}{}".format(line, constants.STREAM_LINE_DELIMITER))
        finally:
            return True

    def _write_into_connection(self, conn, stream):
        "Write into twisted connection transport."

        try:
            if not self._sendLine(conn, stream):
                return False
        except:
            Logger.error("COMM: Connection to peer failed. Please try later.")
            print traceback.format_exc()
            return False
        else:
            return True

    def _router(self, pid):
        "Router decides best route to peer."

        return pid

    def _pack_auth_content(self, peer_id, request_id):
        "Pack peer ID and request token in to string"

        return peer_id + request_id

    def _unpack_auth_content(self, content):
        "Split peer ID and request token from string"

        INDX = constants.PEER_ID_LEN
        return (content[:INDX], content[INDX:])

    def _transfer_data(self, pid, data_class, data_content, desthost=None):
        "Transfer data to client with peer id."

        # Get peer route.
        peer_route = self._router(pid)

        # Get peer connection
        conn = self.swarm_manager.connect_to_peer(peer_route)

        # Set destination host IP
        if not desthost:
            desthost = self.swarm_manager.peer_host(pid)

        # Get peer key
        shared_key = self.swarm_manager.get_peer_key(pid)

        if not shared_key:
            raise Exception("No valid peer key could be found.")

        # Content length enforcement.
        try:
            # Pack data into stream
            stream = self.stream_manager.pack_stream(
                stream_type=data_class, stream_content=data_content, stream_host=desthost, shared_key=shared_key
            )

        except StreamOverflowError as SOError:
            self._printer(SOError.info, self.peerid)
            Logger.warn("COMM: " + SOError.info)
            return False

        else:
            # Send data over connection
            return self._write_into_connection(conn, stream)

    def _get_source_from_connection(self, connection):
        "Return the sender peer's key"

        # Get the sender peer's information from connection
        # Get host
        host = connection.getPeer().host
        # Get port
        port = constants.PEER_PORT

        # Test mode check if current service is handling
        # response or received data, maybe a peer client or
        # test server
        if constants.ENABLE_TEST_MODE and self.peerid == constants.PEER_ID:
            port = constants.LOCAL_TEST_PORT

        # Get peer ID of stream source
        pid = self.swarm_manager.get_peerid_from_ip(host, port)

        Logger.debug("COMM: IP: {} Port: {} ".format(host, port))

        # Get the stream source's key
        shared_key = None
        if pid:
            shared_key = self.swarm_manager.get_peer_key(pid)

        return (pid, shared_key, host, port)

    def _print(self, msg, dip=constants.PEER_HOST, port=constants.PEER_PORT, notify=False):
        "Print message on console with peer id."

        # Get peer ID
        peer_id = self.swarm_manager.get_peerid_from_ip(dip, port)

        # Print with local peer id
        if not peer_id:
            peer_id = self.peerid
        else:
            notify = constants.ENABLE_NOTIFICATIONS

        # Print the message
        if self._printer:
            self._printer(msg, peer_id)
        # Display device notifications
        if self._device:
            if notify:
                self._device.vibrate_cb()
                self._device.notify_cb(title="ID: {}".format(peer_id), message=msg, timeout=1)
        else:
            Logger.warn("COMM: No device service registered.")

        # Log message
        Logger.info("COMM: {} : {}".format(peer_id, msg))

    def _print_test(self, ctype, content):
        "Print test message."

        self._print(
            "<TEST TYPE:{}>{}<TEST>".format(ctype, content),
            dip=constants.LOCAL_TEST_HOST,
            port=constants.LOCAL_TEST_PORT,
        )

    def display_peer_host(self, peer_id):
        "Gets the peer IP address."

        peer_ip = self.swarm_manager.peer_host(peer_id)

        if peer_ip:
            self._print("Peer {}--{}".format(peer_id, peer_ip))
        else:
            self._print("Peer not present in swarm.")

    def start_connection(self, pid, host="localhost", port=constants.PEER_PORT):
        "Start connection with server."

        Logger.debug("COMM: Connecting to pid: {}".format(pid))

        # Check if TLS is enable
        if constants.ENABLE_TLS and reactor.connectSSL(
            host,
            port,
            CommCoreClientFactory(self),
            TLSCtxFactory(self.sslcrt, self.sslkey, self.ssca, self.on_ssl_verification),
        ):
            return True

        # Use normal TCP connection
        elif not constants.ENABLE_TLS and reactor.connectTCP(host, port, CommCoreClientFactory(self)):
            return True

        # Could not establish connection
        else:
            return False

    def start_authentication(self, pid, host="localhost", port=constants.LOCAL_TEST_PORT):
        "Start connection with specified host server."

        Logger.debug("COMM: Initiating authenticated connection with pid: {}.".format(pid))

        # Save authentication request to map with authentication ack
        self.valid_auth_req_tokens[host] = generate_auth_token()

        # Check if TLS is enabled
        if constants.ENABLE_TLS and reactor.connectSSL(
            host,
            port,
            CommCoreAuthFactory(self),
            TLSCtxFactory(self.sslcrt, self.sslkey, self.ssca, self.on_ssl_verification),
        ):
            return True

        # Use normal TCP connection
        elif not constants.ENABLE_TLS and reactor.connectTCP(host, port, CommCoreAuthFactory(self)):
            return True

        # Could not establish connection
        else:
            return False

    def on_server_connection(self, connection):
        "Executed on successful server connection."

        peer_ip = connection.getPeer().host
        peer_port = connection.getPeer().port
        peer_id = self.swarm_manager.get_peerid_from_ip(peer_ip, peer_port)

        if peer_id:
            # Announce successful server connection
            self._print(
                constants.GUI_PEER_REPR.format(peer_id, peer_ip, peer_port) + " has entered the swarm.",
                peer_ip,
                peer_port,
            )

            # Update peer connection status to CONNECTED
            self._update_peer_connection_status(peer_ip, peer_port, True, connection)

    def on_server_disconnection(self, connection):
        "Executed on successful server disconnection."

        peer_ip = connection.getPeer().host
        peer_port = connection.getPeer().port
        peer_id = self.swarm_manager.get_peerid_from_ip(peer_ip, peer_port)

        # If peer id is valid
        if peer_id:
            # Announce successful server disconnection
            self._print(
                constants.GUI_PEER_REPR.format(peer_id, peer_ip, peer_port) + " has left the swarm.", peer_ip, peer_port
            )

            # Update peer connection status to DISCONNECTED
            self._update_peer_connection_status(peer_ip, peer_port, False, None)

            # Delete peer from swarm store
            self.swarm_manager.delete_peer(peer_id)

    def on_server_auth_open(self, connection):
        "Used to handle server auth requests."

        peer_ip = connection.getPeer().host
        peer_port = connection.getPeer().port

        # Authenticate server connection
        self._print("Authenticating connection to {}:{}".format(peer_ip, peer_port), peer_ip, peer_port)

        # Get request ID
        request_id = self.valid_auth_req_tokens[peer_ip]

        # Pack auth content
        content = self._pack_auth_content(self.peerid, request_id)

        # Pack authentication data into stream
        stream = self.stream_manager.pack_stream(
            stream_type=constants.PROTO_AUTH_TYPE,
            stream_content=content,
            stream_flag=STREAM_TYPES.UNAUTH,
            stream_host=peer_ip,
        )

        return self._write_into_connection(connection, stream)

    def on_server_auth_close(self, connection):
        "Executed on successful closure of authentication connection."

        peer_ip = connection.getPeer().host
        peer_port = connection.getPeer().port

        # delete auth request id
        del self.valid_auth_req_tokens[peer_ip]

        self._print("Authentication successful to {}:{}".format(peer_ip, peer_port))

    def on_client_connection(self, connection):
        "Executed on successful client connection."

        peer_ip = connection.getPeer().host
        peer_port = connection.getPeer().port

        self._print("Client {}:{} connected.".format(peer_ip, peer_port))

    def on_client_disconnection(self, connection):
        "Executed on successful client disconnection."

        peer_ip = connection.getPeer().host
        peer_port = connection.getPeer().port

        self._print("Client {}:{} disconnected.".format(peer_ip, peer_port))

    if constants.ENABLE_TLS:

        def on_ssl_verification(self, connection, x509):
            "post ssl verification hook"

            # TODO
            # Add post TLS verification func here
            Logger.info("COMM: TLS Verification is SUCCESSFUL!")

    def handle_response_stream(self, response, connection):
        "Handle response from server."

        # Default value of response at server side is None
        # hence we add a check for this at the client side.
        if not response:
            self._print("Error processing response. Got None!")
            return None

        # Get the sender peer's information from connection
        (_, shared_key, src_ip, _) = self._get_source_from_connection(connection)

        # Response handling architecture should be placed here.
        # Unpack received stream
        try:
            (c_rsp_type, content, _) = self.stream_manager.unpack_stream(stream=response, shared_key=shared_key)
        except:
            raise
            return None
        else:
            # Check if stream ID is valid
            if not c_rsp_type:
                return None

        # Currently the test case is inbuilt into the pod.
        # MSG TEST BEGIN #
        if c_rsp_type == constants.LOCAL_TEST_STREAM_TYPE:

            if content == constants.LOCAL_TEST_STR and src_ip == constants.LOCAL_TEST_HOST:
                Logger.debug("COMM: Simple Message Transfer Test Passed.")
                self._print("Simple Message Transfer Test Passed.", src_ip, constants.LOCAL_TEST_PORT)
            else:
                Logger.debug(
                    """COMM:
                Sending Message Test Fail.
                For test to pass,
                1. Test server must be running.
                2. Add test server using 'addtest' command.
                3. Begin test with 'sendtest' command.
                """
                )
                self._print("Simple Message Transfer Test Failed.", src_ip)

        elif c_rsp_type == constants.PROTO_MACK_TYPE:
            Logger.debug("COMM: Message ACK received from {}".format(src_ip))

    def handle_auth_response_stream(self, response, connection):
        "Handle authentication response to add peer."

        # Get the sender peer's information from connection
        (_, _, src_ip, src_port) = self._get_source_from_connection(connection)

        # Response handling architecture should be placed here.
        (header, content, pkey) = self.stream_manager.unpack_stream(stream=response)

        if header == constants.PROTO_AACK_TYPE:
            # Extract peer ID, request ID
            (pid, request_id) = self._unpack_auth_content(content)

            # Check if request ACK ID is valid
            try:
                if self.valid_auth_req_tokens[src_ip] != request_id:
                    Logger.debug("COMM: Received Invalid Request ACK ID [{}].".format(request_id))
                    return None

            except KeyError:
                Logger.debug("COMM: Received Invalid host '{}' request ACK.".format(src_ip))
                return None

            else:
                Logger.debug("COMM: Received valid request ACK.")

            # Generate shared key
            shared_key = self.comsec_core.generate_shared_key(pkey)
            Logger.debug("COMM: Shared Key: {}".format(b64encode(shared_key)))

            # Add peer
            self.swarm_manager.add_peer(pid, shared_key, src_ip, src_port)

            # Add peer connection
            self._update_peer_connection_status(src_ip, src_port, False, None)

            # Connect to peer using normal connection this should refresh
            # the connection in db to normal client conn from auth conn
            self.start_connection(pid, src_ip, src_port)

            # pack auth content
            content = self._pack_auth_content(self.peerid, request_id)

            # Send disconnect response for AUTH channel
            dcon_rsp = self.stream_manager.pack_stream(
                stream_type=constants.PROTO_DCON_TYPE,
                stream_content=content,
                stream_flag=STREAM_TYPES.UNAUTH,
                stream_host=src_ip,
            )

            return dcon_rsp

        return None

    # ------------------------------------------------
    # Client Protocol Method defined here
    # ------------------------------------------------
    def pass_message(self, pid, msg):
        "Pass message to client. Stream Type: BULK"

        # Check if peer is valid
        if not self.swarm_manager.is_peer(pid):
            Logger.warn("COMM: Peer {} is not in swarm. Add peer using addpeer cmd.".format(pid))
            self._print("COMM: Peer {} is not in swarm. Add peer using addpeer cmd.".format(pid))
            return False

        # Check to see peer connection status
        if not self.swarm_manager.get_peer_connection_status(pid):
            Logger.warn("COMM: Peer {} is offline.".format(pid))
            self._print("Peer {} is offline.".format(pid))
            return False

        # Assumed Bulk message transfer
        dtype = constants.PROTO_BULK_TYPE

        if msg == constants.LOCAL_TEST_STR:
            dtype = constants.LOCAL_TEST_STREAM_TYPE

        # Send message using send data API
        return self._transfer_data(pid, dtype, msg)

    def add_peer_to_swarm(self, pid, host):
        "Adds a new user through auth request chain."

        port = constants.PEER_PORT
        # Assign port based on pid
        if pid == constants.LOCAL_TEST_PEER_ID:
            port = constants.LOCAL_TEST_PORT

        # Check if peer is present
        if self.swarm_manager.get_peer(pid):
            self._print("Peer already in swarm.")
            return False

        # Start a connection with peer
        return self.start_authentication(pid, host, port)

    # ------------------------------------------------

    # ------------------------------------------------
    # Server Protocol Method defined here
    # ------------------------------------------------
    def handle_request_stream(self, stream, connection):

        # Get the sender peer's information from connection
        (src_pid, shared_key, src_ip, _) = self._get_source_from_connection(connection)

        # Response (default = None)
        rsp = None

        # Unpack stream
        (header, content, pkey) = self.stream_manager.unpack_stream(stream=stream, shared_key=shared_key)

        # Check if stream type is valid
        if not header:
            Logger.error("COMM: Invalid Stream checksum received.")
            return rsp

        # Print test message if test server
        if self.peerid == constants.LOCAL_TEST_PEER_ID and header in (constants.LOCAL_TEST_STREAM_TYPE):
            self._print_test(header, content)

        # ------------------------------------------------------------
        # Check if the request is an AUTH request and
        # handle it accordingly, this requires no stream challenge
        # ------------------------------------------------------------
        if header == constants.PROTO_AUTH_TYPE:
            # Extract peer id
            (pid, request_id) = self._unpack_auth_content(content)

            Logger.debug("COMM: Received auth request from Peer: {}".format(pid))

            # Add check for repeat additions
            if self.swarm_manager.is_peer(pid):
                Logger.debug("COMM: Received REPEAT auth request from Peer: {}, Ignoring Request.".format(pid))
                # Close twisted connection
                connection.loseConnection()
                return None

            # Add peer
            # Generate shared key
            shared_key = self.comsec_core.generate_shared_key(pkey)
            Logger.debug("COMM: Shared Key: {}".format(b64encode(shared_key)))

            # A GUI hook could be placed here to check for
            # user approval before addition of the peer.
            self.swarm_manager.add_peer(pid=pid, key=shared_key, host=src_ip, port=constants.PEER_PORT)

            # Add peer connection and change status
            self._update_peer_connection_status(
                peer_ip=src_ip, peer_port=constants.PEER_PORT, status=True, conn=connection
            )

            # Get content
            content = self._pack_auth_content(self.peerid, request_id)

            # Send current peer info
            rsp = self.stream_manager.pack_stream(
                stream_type=constants.PROTO_AACK_TYPE,
                stream_content=content,
                stream_flag=STREAM_TYPES.UNAUTH,
                stream_host=src_ip,
            )

            Logger.debug("COMM: Auth Response: {} Stream Length: {}".format(b64encode(rsp), len(rsp)))

            # Send Auth response
            return rsp

        # Check if stream type is valid
        if not header:
            Logger.error("COMM: Invalid stream ID received from unpacking stream.")
            return rsp

        # Check if connection is recognized
        if not self.swarm_manager.get_peer(src_pid):
            Logger.warn("COMM: Unknown pid @{} attempting contact.".format(src_ip))

        Logger.debug("COMM: Received: {}".format(b64encode(stream)))

        if header == constants.PROTO_DCON_TYPE:
            Logger.debug("COMM: Received Disconnect ACK, AUTH Success!")

            # Extract peer id
            (pid, _) = self._unpack_auth_content(content)

            if self.swarm_manager.is_peer(pid) and self.comsec_core.generate_shared_key(
                pkey
            ) == self.swarm_manager.get_peer_key(pid):

                Logger.debug("COMM: Peer {} AUTH Done!".format(pid))
                # Close connection
                connection.loseConnection()

            rsp = None

        elif header == constants.LOCAL_TEST_STREAM_TYPE:

            # Message receipt successful
            self._print(content, src_ip)

            # Repack stream maintaining the same content
            rsp = self.stream_manager.pack_stream(
                stream_type=header, stream_content=content, stream_host=src_ip, shared_key=shared_key
            )

        elif header == constants.PROTO_BULK_TYPE:

            # Message receipt successful
            self._print(content, src_ip)

            # Generate response
            rsp = self.stream_manager.pack_stream(
                stream_type=constants.PROTO_MACK_TYPE, stream_content="", stream_host=src_ip, shared_key=shared_key
            )

        return rsp

    def send_pending_streams(self, peer_id):
        "Send unsent streams."

        # Check stream buffer for pending streams
        streambuffer = self.swarm_manager.get_stream_buffer(peer_id)

        if streambuffer:
            for sid in streambuffer:
                # Get stream
                stream = self.stream_manager.get_stream(sid)
                # Get connection
                connection = self.swarm_manager.get_peer_connection(peer_id)
                # Send stream
                self._write_into_connection(connection, stream)