def parse(self, decryptionKey=None):
if decryptionKey is not None:
self.decrypt(decryptionKey)
reader = BufferReader(self._data)
reader.skip(2)
if self.opCode == 7:
try:
self.payload = parseOpcode7(reader.getRemainingBytes())
except CrownstoneException:
self.payload = AdvUnknownData()
self.payload.data = self._data
raise CrownstoneException(
CrownstoneError.INVALID_SERVICE_DATA,
"Protocol not supported. Unknown data type. Could be because decryption failed."
)
elif self.opCode == 6:
self.payload = parseOpCode6(reader.getRemainingBytes())
else:
self.payload = AdvUnknownData()
self.payload.data = self._data
raise CrownstoneException(
CrownstoneError.INVALID_SERVICE_DATA,
"Protocol not supported. Unknown opcode.")
def parseHubData(reader: BufferReader):
packet = AdvHubState()
packet.crownstoneId = reader.getUInt8()
packet.flags = AdvHubFlags(reader.getUInt8())
packet.hubData = reader.getBytes(9)
partialTimestamp = reader.getUInt16()
reader.skip()
packet.validation = reader.getUInt8()
packet.uniqueIdentifier = partialTimestamp
if packet.flags.timeIsSet:
packet.timestamp = reconstructTimestamp(time.time(), partialTimestamp)
else:
packet.timestamp = partialTimestamp # this is now a counter
return packet
def parseAlternativeState(reader: BufferReader):
packet = AdvAlternativeState()
packet.crownstoneId = reader.getUInt8()
packet.switchState = SwitchState(reader.getUInt8())
packet.flags = AdvFlags(reader.getUInt8())
packet.behaviourMasterHash = reader.getUInt16()
packet.assetFilterMasterVersion = reader.getUInt16()
packet.assetFilterMasterCRC = reader.getUInt32()
partialTimestamp = reader.getUInt16()
reader.skip()
packet.validation = reader.getUInt8()
packet.uniqueIdentifier = partialTimestamp
if packet.flags.timeIsSet:
packet.timestamp = reconstructTimestamp(time.time(), partialTimestamp)
else:
packet.timestamp = partialTimestamp # this is now a counter
return packet
def load(self, data): """ Parses data buffer to set member variables. data : list of bytes Raises exception when parsing fails. """ streamBuf = BufferReader(data) samplesTypeVal = streamBuf.getUInt8() self.samplesType = PowerSamplesType(samplesTypeVal) # Throws exception of value is not in enum self.index = streamBuf.getUInt8() self.count = streamBuf.getUInt16() self.timestamp = streamBuf.getUInt32() self.delayUs = streamBuf.getUInt16() self.sampleIntervalUs = streamBuf.getUInt16() streamBuf.skip(2) self.offset = streamBuf.getInt16() self.multiplier = streamBuf.getFloat() self.samples = [] for i in range(0, self.count): self.samples.append(streamBuf.getInt16())
def decrypt(self, keyHexString):
if len(keyHexString) >= 16 and len(self._data) == 18:
if self.operationMode == CrownstoneOperationMode.NORMAL:
reader = BufferReader(self._data)
encryptedData = reader.skip(2).getRemainingBytes()
result = EncryptionHandler.decryptECB(encryptedData,
keyHexString)
for i in range(0, len(encryptedData)):
# the first 2 bytes are opcode and device type
self._data[i + 2] = result[i]
self.decrypted = True
else:
raise CrownstoneException(
CrownstoneError.COULD_NOT_DECRYPT,
"ServiceData decryption failed. Invalid key or invalid data.")
