Exemplo n.º 1
0
    def POST(self, options=[], payload=[]):

        link_layer_keyset = [self.networkKeyIndex, u.buf2str(self.networkKey)]

        configuration = {}

        configuration[
            cojpDefines.COJP_PARAMETERS_LABELS_LLKEYSET] = link_layer_keyset
        configuration_serialized = cbor.dumps(configuration)

        respPayload = [ord(b) for b in configuration_serialized]

        objectSecurity = oscoap.objectSecurityOptionLookUp(options)

        if objectSecurity:
            # we need to add the pledge to a list of joined nodes, if not present already
            eui64 = u.buf2str(objectSecurity.kid[:-1])
            found = False
            for node in self.joinedNodes:
                if node['eui64'] == eui64:
                    found = True
                    break

            if not found:
                self.joinedNodes += [{
                    'eui64': eui64,  # remove last prepended byte
                    'context': objectSecurity.context
                }]

            # return the Join Response regardless of whether it is a first or Nth join attempt
            return (d.COAP_RC_2_04_CHANGED, [], respPayload)
        else:
            return (d.COAP_RC_4_01_UNAUTHORIZED, [], [])
Exemplo n.º 2
0
    def _transmit(self, uri, confirmable, code, options=[], payload=[]):
        assert code in d.METHOD_ALL
        if code in [d.METHOD_GET, d.METHOD_DELETE]:
            assert payload == []
        assert type(uri) == str

        (host, destPort, uriOptions) = coapUri.uri2options(uri)
        destIp = socket.getaddrinfo(host, destPort)[0][4][0]
        (securityContext, sequenceNumber) = oscoap.getRequestSecurityParams(
            oscoap.objectSecurityOptionLookUp(options))

        with self.transmittersLock:
            self._cleanupTransmitter()
            messageId = self._getMessageID(destIp, destPort)
            token = self._getToken(destIp, destPort)
            newTransmitter = coapTransmitter.coapTransmitter(
                sendFunc=self.socketUdp.sendUdp,
                srcIp=self.ipAddress,
                srcPort=self.udpPort,
                destIp=destIp,
                destPort=destPort,
                confirmable=confirmable,
                messageId=messageId,
                code=code,
                token=token,
                options=uriOptions + options,
                payload=payload,
                securityContext=securityContext,
                requestSeq=sequenceNumber,
                ackTimeout=self.ackTimeout,
                respTimeout=self.respTimeout,
                maxRetransmit=self.maxRetransmit)
            key = (destIp, destPort, token, messageId)
            assert key not in self.transmitters.keys()
            self.transmitters[key] = newTransmitter

        response = newTransmitter.transmit()

        if securityContext:
            try:
                (innerOptions, plaintext) = oscoap.unprotectMessage(
                    securityContext,
                    version=response['version'],
                    code=response['code'],
                    options=response['options'],
                    ciphertext=response['ciphertext'],
                    partialIV=sequenceNumber,
                )
                response['options'] = response['options'] + innerOptions
                response['payload'] = plaintext
            except e.oscoapError:
                raise

        return response
Exemplo n.º 3
0
def parseMessage(message):

    returnVal = {}

    # header
    if len(message) < 4:
        raise e.messageFormatError(
            'message too short, {0} bytes: no space for header'.format(
                len(message)))
    returnVal['version'] = (message[0] >> 6) & 0x03
    if returnVal['version'] != d.COAP_VERSION:
        raise e.messageFormatError('invalid CoAP version {0}'.format(
            returnVal['version']))
    returnVal['type'] = (message[0] >> 4) & 0x03
    if returnVal['type'] not in d.TYPE_ALL:
        raise e.messageFormatError('invalid message type {0}'.format(
            returnVal['type']))
    TKL = message[0] & 0x0f
    if TKL > 8:
        raise e.messageFormatError('TKL too large {0}'.format(TKL))
    returnVal['code'] = message[1]
    returnVal['messageId'] = u.buf2int(message[2:4])
    message = message[4:]

    # token
    if len(message) < TKL:
        raise e.messageFormatError(
            'message too short, {0} bytes: no space for token'.format(
                len(message)))
    if TKL:
        returnVal['token'] = u.buf2int(message[:TKL])
        message = message[TKL:]
    else:
        returnVal['token'] = None

    # outer options and payload/ciphertext
    (returnVal['options'], payload) = decodeOptionsAndPayload(message)

    # if object security option is present decode the value in order to be able to decrypt the message
    objectSecurity = oscoap.objectSecurityOptionLookUp(returnVal['options'])
    if objectSecurity:
        oscoapDict = oscoap.parseObjectSecurity(
            objectSecurity.getPayloadBytes(), payload)
        objectSecurity.setKid(oscoapDict['kid'])
        returnVal.update(oscoapDict)
    else:
        returnVal['payload'] = payload

    log.debug('parsed message: {0}'.format(returnVal))

    return returnVal
Exemplo n.º 4
0
    def GET(self, options=[]):
        respCode = d.COAP_RC_2_05_CONTENT
        respOptions = []

        k1 = {}
        k1[coseDefines.KEY_LABEL_KTY] = coseDefines.KEY_VALUE_SYMMETRIC
        k1[coseDefines.KEY_LABEL_KID] = u.buf2str(self.networkKeyIndex)
        k1[coseDefines.KEY_LABEL_K] = u.buf2str(self.networkKey)

        join_response = [[k1]]
        join_response_serialized = cbor.dumps(join_response)

        respPayload = [ord(b) for b in join_response_serialized]

        objectSecurity = oscoap.objectSecurityOptionLookUp(options)
        assert objectSecurity

        self.joinedNodes += [{
            'eui64':
            u.buf2str(objectSecurity.kid[:8]),  # remove last prepended byte
            'context': objectSecurity.context
        }]

        return (respCode, respOptions, respPayload)
Exemplo n.º 5
0
    def _receive(self, timestamp, sender, rawbytes):
        # all UDP packets are received here

        output = []
        output += ['\n{0} _receive message:'.format(self.name)]
        output += ['- timestamp: {0}'.format(timestamp)]
        output += ['- sender:    {0}'.format(sender)]
        output += ['- bytes:     {0}'.format(u.formatBuf(rawbytes))]
        output = '\n'.join(output)
        log.debug(output)

        srcIp = sender[0]
        srcIp = u.trimAddress(srcIp)

        srcPort = sender[1]

        # parse messages
        try:
            message = m.parseMessage(rawbytes)
            options = message['options']
        except e.messageFormatError as err:
            log.warning('malformed message {0}: {1}'.format(
                u.formatBuf(rawbytes), str(err)))
            return

        # dispatch message
        try:
            if message['code'] in d.METHOD_ALL:
                # this is meant for a resource (request)

                #==== decrypt message if encrypted
                innerOptions = []
                foundContext = None
                requestPartialIV = None
                if 'ciphertext' in message.keys():
                    # retrieve security context
                    # before decrypting we don't know what resource this request is meant for
                    # so we take the first binding with the correct context (recipientID)
                    blindContext = self._securityContextLookup(
                        u.buf2str(message['kid']))

                    if not blindContext:
                        if self.secContextHandler:
                            appContext = self.secContextHandler(
                                u.buf2str(message['kid']))
                            if not appContext:
                                raise e.coapRcUnauthorized(
                                    'Security context not found.')
                        else:
                            raise e.coapRcUnauthorized(
                                'Security context not found.')

                    foundContext = blindContext if blindContext != None else appContext

                    requestPartialIV = u.zeroPadString(
                        u.buf2str(message['partialIV']),
                        foundContext.getIVLength())

                    # decrypt the message
                    try:
                        (innerOptions, plaintext) = oscoap.unprotectMessage(
                            foundContext,
                            version=message['version'],
                            code=message['code'],
                            options=message['options'],
                            ciphertext=message['ciphertext'],
                            partialIV=requestPartialIV)
                    except e.oscoapError as err:
                        raise e.coapRcBadRequest(
                            'OSCOAP unprotect failed: {0}'.format(str(err)))

                    payload = plaintext
                else:  # message not encrypted
                    payload = message['payload']

                options += innerOptions

                #==== find right resource

                # retrieve path
                path = coapUri.options2path(options)
                log.debug('path="{0}"'.format(path))

                # find resource that matches this path
                resource = None
                with self.resourceLock:
                    for r in self.resources:
                        if r.matchesPath(path):
                            resource = r
                            break
                log.debug('resource={0}'.format(resource))

                if not resource:
                    raise e.coapRcNotFound()

                #==== check if appropriate security context was used for the resource
                (context, authorizedMethods) = resource.getSecurityBinding()

                if context is not None:
                    if context != foundContext:
                        raise e.coapRcUnauthorized(
                            'Unauthorized security context for the given resource'
                        )

                objectSecurity = oscoap.objectSecurityOptionLookUp(options)
                if objectSecurity:
                    objectSecurity.setContext(foundContext)
                #==== get a response

                # call the right resource's method
                try:
                    if message[
                            'code'] == d.METHOD_GET and d.METHOD_GET in authorizedMethods:
                        (respCode, respOptions,
                         respPayload) = resource.GET(options=options)
                    elif message[
                            'code'] == d.METHOD_POST and d.METHOD_POST in authorizedMethods:
                        (respCode, respOptions,
                         respPayload) = resource.POST(options=options,
                                                      payload=payload)
                    elif message[
                            'code'] == d.METHOD_PUT and d.METHOD_PUT in authorizedMethods:
                        (respCode, respOptions,
                         respPayload) = resource.PUT(options=options,
                                                     payload=payload)
                    elif message[
                            'code'] == d.METHOD_DELETE and d.METHOD_DELETE in authorizedMethods:
                        (respCode, respOptions,
                         respPayload) = resource.DELETE(options=options)
                    elif message['code'] not in d.METHOD_ALL:
                        raise SystemError('unexpected code {0}'.format(
                            message['code']))
                    else:
                        raise e.coapRcUnauthorized(
                            'Unauthorized method for the given resource')
                except Exception as err:
                    if isinstance(err, e.coapRc):
                        raise
                    else:
                        raise e.coapRcInternalServerError()

                #==== send back response

                # determine type of response packet
                if message['type'] == d.TYPE_CON:
                    responseType = d.TYPE_ACK
                elif message['type'] == d.TYPE_NON:
                    responseType = d.TYPE_NON
                else:
                    raise SystemError('unexpected type {0}'.format(
                        message['type']))

                # if resource is protected with a security context, add Object-Security option
                if foundContext:
                    # verify that the Object-Security option was not set by the resource handler
                    assert not any(
                        isinstance(option, o.ObjectSecurity)
                        for option in respOptions)
                    objectSecurity = o.ObjectSecurity(context=foundContext)
                    respOptions += [objectSecurity]

                # if Stateless-Proxy option was present in the request echo it
                for option in options:
                    if isinstance(option, o.StatelessProxy):
                        respOptions += [option]
                        break

                # build response packets and pass partialIV from the request for OSCOAP's processing
                response = m.buildMessage(msgtype=responseType,
                                          token=message['token'],
                                          code=respCode,
                                          messageId=message['messageId'],
                                          options=respOptions,
                                          payload=respPayload,
                                          securityContext=foundContext,
                                          partialIV=requestPartialIV)

                # send
                self.socketUdp.sendUdp(
                    destIp=srcIp,
                    destPort=srcPort,
                    msg=response,
                )

            elif message['code'] in d.COAP_RC_ALL:
                # this is meant for a transmitter (response)

                # find transmitter
                msgkey = (srcIp, srcPort, message['token'],
                          message['messageId'])

                found = False
                with self.transmittersLock:
                    self._cleanupTransmitter()
                    for (k, v) in self.transmitters.items():
                        # try matching
                        if (msgkey[0] == k[0] and msgkey[1] == k[1]
                                and (msgkey[2] == k[2] or msgkey[3] == k[3])):
                            found = True
                            v.receiveMessage(timestamp, srcIp, srcPort,
                                             message)
                            break
                if found == False:
                    raise e.coapRcBadRequest(
                        'could not find transmitter corresponding to {0}, transmitters are {1}'
                        .format(
                            msgkey, ','.join(
                                [str(k) for k in self.transmitters.keys()])))

            else:
                raise NotImplementedError()

        except e.coapRc as err:

            # log
            log.warning(err)

            # determine type of response packet
            if message['type'] == d.TYPE_CON:
                responseType = d.TYPE_ACK
            elif message['type'] == d.TYPE_NON:
                responseType = d.TYPE_NON
            else:
                raise SystemError('unexpected type {0}'.format(
                    message['type']))

            # if Stateless-Proxy option was present in the request echo it
            errorOptions = []
            for option in options:
                if isinstance(option, o.StatelessProxy):
                    errorOptions += [option]
                    break

            # build response packets
            response = m.buildMessage(
                msgtype=responseType,
                token=message['token'],
                code=err.rc,
                messageId=message['messageId'],
                options=errorOptions,
            )

            # send
            self.socketUdp.sendUdp(
                destIp=srcIp,
                destPort=srcPort,
                msg=response,
            )

        except Exception as err:
            log.critical(traceback.format_exc())