def from_bytes(cls, _bytes: bytes):
# There is weird decoding here since it is mixed X-ADS and BER....
data = bytearray(_bytes)
apdu_tag = data.pop(0)
if apdu_tag != 0x01:
raise ValueError(
f"Data is not a InitiateReques APDU, got apdu tag {apdu_tag}")
decoder = a_xdr.AXdrDecoder(cls.ENCODING_CONF)
object_dict = decoder.decode(data)
# Since the initiate request mixes a-xdr and ber encoding we make some pragmatic
# one-off handling of that case.
rest = bytearray(object_dict.pop("rest").value)
# rest contains ber endoced propesed conformance and max reciec pdu
conformance_tag = rest[:2]
if conformance_tag != b"\x5f\x1f":
raise ValueError(
f"Didnt receive conformance tag correcly, got {conformance_tag!r}"
)
conformance = xdlms.Conformance.from_bytes(data[-5:-2])
max_pdu_size = int.from_bytes(data[-2:], "big")
dedicated_key_obj = object_dict.pop("dedicated_key")
if dedicated_key_obj:
dedicated_key = bytes(dedicated_key_obj.value)
else:
dedicated_key = None
return cls(
**object_dict,
dedicated_key=dedicated_key,
proposed_conformance=conformance,
client_max_receive_pdu_size=max_pdu_size,
)
def parse_bytes(profile_bytes: bytes):
"""
Profile generic are sent as a sequence of A-XDR encoded DlmsData.
"""
data_decoder = a_xdr.AXdrDecoder(encoding_conf=a_xdr.EncodingConf(
attributes=[a_xdr.Sequence(attribute_name="data")]))
entries: List[List[Any]] = data_decoder.decode(profile_bytes)["data"]
return AssociationObjectListParser.parse_entries(entries)
def from_bytes(cls, source_bytes: bytes):
data = bytearray(source_bytes)
tag = data.pop(0)
if tag != cls.TAG:
raise ValueError(
f"Tag not as expected. Expected: {cls.TAG} but got {tag}")
decoder = a_xdr.AXdrDecoder(encoding_conf=cls.ENCODING_CONF)
in_dict = decoder.decode(data)
system_title = in_dict["system_title"].value
ciphered_content = in_dict["ciphered_content"].value
security_control = SecurityControlField.from_bytes(
ciphered_content.pop(0).to_bytes(1, "big"))
invocation_counter = int.from_bytes(ciphered_content[:4], "big")
ciphered_text = bytes(ciphered_content[4:])
return cls(system_title, security_control, invocation_counter,
ciphered_text)
encryption_key=encryption_key,
authentication_key=authentication_key,
)
with public_client(host=host, port=port).session() as client:
response_data = client.get(
cosem.CosemAttribute(
interface=enumerations.CosemInterface.DATA,
instance=cosem.Obis(0, 0, 0x2B, 1, 0),
attribute=2,
)
)
data_decoder = a_xdr.AXdrDecoder(
encoding_conf=a_xdr.EncodingConf(
attributes=[a_xdr.Sequence(attribute_name="data")]
)
)
invocation_counter = data_decoder.decode(response_data)["data"]
print(f"meter_initial_invocation_counter = {invocation_counter}")
# we are not reusing the socket as of now. We just need to give the meter some time to
# close the connection on its side
sleep(1)
with management_client(
host=host, port=port, client_initial_invocation_counter=invocation_counter + 1
).session() as client:
profile = client.get(
cosem.CosemAttribute(
def parse_as_dlms_data(data: bytes):
data_decoder = a_xdr.AXdrDecoder(encoding_conf=a_xdr.EncodingConf(
attributes=[a_xdr.Sequence(attribute_name="data")]))
return data_decoder.decode(data)["data"]
