def test_can_send_action_request_in_ready(action_request: xdlms.ActionRequestNormal):
c = DlmsConnection(
state=state.DlmsConnectionState(current_state=state.READY),
client_system_title=b"12345678",
)
c.send(action_request)
assert c.state.current_state == state.AWAITING_ACTION_RESPONSE
def test_can_release_in_ready_state(rlrq: acse.ReleaseRequest):
c = DlmsConnection(
state=state.DlmsConnectionState(current_state=state.READY),
client_system_title=b"12345678",
)
c.send(rlrq)
assert c.state.current_state == state.AWAITING_RELEASE_RESPONSE
def test_cannot_re_associate(aarq: acse.ApplicationAssociationRequest):
c = DlmsConnection(
state=state.DlmsConnectionState(current_state=state.READY),
client_system_title=b"12345678",
)
with pytest.raises(LocalDlmsProtocolError):
c.send(aarq)
def test_can_send_get_when_ready(get_request: xdlms.GetRequestNormal):
c = DlmsConnection(
state=state.DlmsConnectionState(current_state=state.READY),
client_system_title=b"12345678",
)
c.send(get_request)
assert c.state.current_state == state.AWAITING_GET_RESPONSE
def test_rejection_resets_connection_state(
connection_with_hls: DlmsConnection,
ciphered_hls_aare: acse.ApplicationAssociationResponse,
):
connection_with_hls.state.current_state = state.AWAITING_ASSOCIATION_RESPONSE
ciphered_hls_aare.result = enumerations.AssociationResult.REJECTED_PERMANENT
connection_with_hls.receive_data(ciphered_hls_aare.to_bytes())
connection_with_hls.next_event()
assert connection_with_hls.state.current_state == state.NO_ASSOCIATION
def test_set_request_sets_state_in_waiting_for_set_response(
set_request: xdlms.SetRequestNormal, ):
c = DlmsConnection(
state=state.DlmsConnectionState(current_state=state.READY),
client_system_title=b"12345678",
)
c.send(set_request)
assert c.state.current_state == state.AWAITING_SET_RESPONSE
def test_hls_is_started_automatically(
connection_with_hls: DlmsConnection,
ciphered_hls_aare: acse.ApplicationAssociationResponseApdu,
):
# Force state into awaiting response
connection_with_hls.state.current_state = state.AWAITING_ASSOCIATION_RESPONSE
connection_with_hls.receive_data(ciphered_hls_aare.to_bytes())
connection_with_hls.next_event()
assert (connection_with_hls.state.current_state ==
state.SHOULD_SEND_HLS_SEVER_CHALLENGE_RESULT)
def test_not_able_to_send_aarq(
self, aarq: acse.ApplicationAssociationRequestApdu):
c = DlmsConnection.with_pre_established_association(
conformance=Conformance())
with pytest.raises(LocalDlmsProtocolError):
c.send(aarq)
def connection_with_hls(system_title, global_encryption_key,
global_authentication_key) -> DlmsConnection:
return DlmsConnection(
client_system_title=system_title,
authentication_method=enumerations.AuthenticationMechanism.HLS_GMAC,
global_encryption_key=global_encryption_key,
global_authentication_key=global_authentication_key,
security_suite=0,
)
def test_hls_fails(connection_with_hls: DlmsConnection):
# Force state into awaiting response
connection_with_hls.state.current_state = state.AWAITING_HLS_CLIENT_CHALLENGE_RESULT
connection_with_hls.meter_system_title = b"12345678"
connection_with_hls.meter_invocation_counter = 1
failing_action_response = xdlms.ActionResponseNormal(
status=enumerations.ActionResultStatus.OTHER_REASON
)
ciphered = security.encrypt(
security_control=connection_with_hls.security_control,
system_title=connection_with_hls.meter_system_title,
auth_key=connection_with_hls.global_authentication_key,
key=connection_with_hls.global_encryption_key,
invocation_counter=2,
plain_text=failing_action_response.to_bytes(),
)
ciphered_action_response = xdlms.GeneralGlobalCipher(
security_control=connection_with_hls.security_control,
system_title=connection_with_hls.meter_system_title,
invocation_counter=2,
ciphered_text=ciphered,
)
connection_with_hls.receive_data(ciphered_action_response.to_bytes())
connection_with_hls.next_event()
assert connection_with_hls.state.current_state == state.NO_ASSOCIATION
def test_receive_get_response_sets_state_to_ready():
c = DlmsConnection(
state=state.DlmsConnectionState(current_state=state.AWAITING_GET_RESPONSE),
client_system_title=b"12345678",
)
c.receive_data(b"\xc4\x01\xc1\x00\x06\x00\x00\x13\x91")
c.next_event()
assert c.state.current_state == state.READY
def test_receive_rlre_terminates_association(rlre: acse.ReleaseResponse):
c = DlmsConnection(
state=state.DlmsConnectionState(current_state=state.AWAITING_RELEASE_RESPONSE),
client_system_title=b"12345678",
)
c.receive_data(rlre.to_bytes())
c.next_event()
assert c.state.current_state == state.NO_ASSOCIATION
def test_set_response_sets_state_in_ready(set_response: xdlms.SetResponseNormal):
c = DlmsConnection(
state=state.DlmsConnectionState(current_state=state.AWAITING_SET_RESPONSE),
client_system_title=b"12345678",
)
c.receive_data(set_response.to_bytes())
c.next_event()
assert c.state.current_state == state.READY
def test_negotiated_conformance_is_updated():
c = DlmsConnection(client_system_title=b"12345678")
c.send(c.get_aarq())
c.receive_data(
acse.ApplicationAssociationResponseApdu(
result=enumerations.AssociationResult.ACCEPTED,
result_source_diagnostics=enumerations.AcseServiceUserDiagnostics.
NULL,
user_information=acse.UserInformation(
content=xdlms.InitiateResponseApdu(
negotiated_conformance=Conformance(
general_protection=True, general_block_transfer=True),
server_max_receive_pdu_size=500,
)),
).to_bytes())
c.next_event()
assert c.conformance.general_protection
assert c.conformance.general_block_transfer
assert c.max_pdu_size == 500
assert c.state.current_state == state.READY
def test_receive_exception_response_sets_state_to_ready(
exception_response: xdlms.ExceptionResponse,
):
c = DlmsConnection(
state=state.DlmsConnectionState(current_state=state.AWAITING_GET_RESPONSE),
client_system_title=b"12345678",
)
c.receive_data(exception_response.to_bytes())
c.next_event()
assert c.state.current_state == state.READY
def test_state_is_ready_in_init(self):
c = DlmsConnection.with_pre_established_association(
conformance=Conformance(
priority_management_supported=True,
attribute_0_supported_with_get=True,
block_transfer_with_action=True,
block_transfer_with_get_or_read=True,
block_transfer_with_set_or_write=True,
multiple_references=True,
get=True,
set=True,
selective_access=True,
event_notification=True,
action=True,
))
assert c.state.current_state == state.READY
def test_action_response_normal_sets_ready_when_awaiting_action_resoponse():
c = DlmsConnection(
state=state.DlmsConnectionState(
current_state=state.AWAITING_ACTION_RESPONSE),
client_system_title=b"12345678",
)
c.receive_data(
xdlms.ActionResponseNormal(
status=enumerations.ActionResultStatus.SUCCESS,
invoke_id_and_priority=xdlms.InvokeIdAndPriority(
invoke_id=1, confirmed=True, high_priority=True),
).to_bytes())
c.next_event()
assert c.state.current_state == state.READY
def test_not_able_to_send_rlrq(self, rlrq: acse.ReleaseRequest):
c = DlmsConnection.with_pre_established_association(conformance=Conformance())
with pytest.raises(exceptions.PreEstablishedAssociationError):
c.send(rlrq)
def test_conformance_exists_on_simple_init():
c = DlmsConnection(client_system_title=b"12345678")
assert c.conformance is not None
assert not c.conformance.general_protection
assert c.state.current_state == state.NO_ASSOCIATION
class DlmsClient:
client_logical_address: int
server_logical_address: int
io_interface: DlmsIOInterface
authentication_method: Optional[enumerations.AuthenticationMechanism] = attr.ib(
default=None
)
password: Optional[bytes] = attr.ib(default=None)
encryption_key: Optional[bytes] = attr.ib(default=None)
authentication_key: Optional[bytes] = attr.ib(default=None)
security_suite: Optional[int] = attr.ib(default=0)
dedicated_ciphering: bool = attr.ib(default=False)
block_transfer: bool = attr.ib(default=False)
max_pdu_size: int = attr.ib(default=65535)
client_system_title: Optional[bytes] = attr.ib(default=None)
client_initial_invocation_counter: int = attr.ib(default=0)
meter_initial_invocation_counter: int = attr.ib(default=0)
dlms_connection: DlmsConnection = attr.ib(
default=attr.Factory(
lambda self: DlmsConnection(
client_system_title=self.client_system_title,
authentication_method=self.authentication_method,
password=self.password,
global_encryption_key=self.encryption_key,
global_authentication_key=self.authentication_key,
use_dedicated_ciphering=self.dedicated_ciphering,
use_block_transfer=self.block_transfer,
security_suite=self.security_suite,
max_pdu_size=self.max_pdu_size,
client_invocation_counter=self.client_initial_invocation_counter,
meter_invocation_counter=self.meter_initial_invocation_counter,
),
takes_self=True,
)
)
@classmethod
def with_serial_hdlc_transport(
cls,
serial_port: str,
client_logical_address: int,
server_logical_address: int,
server_physical_address: Optional[int],
client_physical_address: Optional[int] = None,
baud_rate: int = 9600,
authentication_method: Optional[enumerations.AuthenticationMechanism] = None,
password: Optional[bytes] = None,
encryption_key: Optional[bytes] = None,
authentication_key: Optional[bytes] = None,
security_suite: Optional[int] = 0,
dedicated_ciphering: bool = False,
block_transfer: bool = False,
max_pdu_size: int = 65535,
client_system_title: Optional[bytes] = None,
client_initial_invocation_counter: int = 0,
meter_initial_invocation_counter: int = 0,
):
serial_client = SerialHdlcTransport(
client_logical_address=client_logical_address,
client_physical_address=client_physical_address,
server_logical_address=server_logical_address,
server_physical_address=server_physical_address,
serial_port=serial_port,
serial_baud_rate=baud_rate,
)
return cls(
client_logical_address=client_logical_address,
server_logical_address=server_logical_address,
authentication_method=authentication_method,
password=password,
encryption_key=encryption_key,
authentication_key=authentication_key,
security_suite=security_suite,
dedicated_ciphering=dedicated_ciphering,
block_transfer=block_transfer,
max_pdu_size=max_pdu_size,
client_system_title=client_system_title,
client_initial_invocation_counter=client_initial_invocation_counter,
meter_initial_invocation_counter=meter_initial_invocation_counter,
io_interface=serial_client,
)
@classmethod
def with_tcp_transport(
cls,
host: str,
port: int,
client_logical_address: int,
server_logical_address: int,
authentication_method: Optional[enumerations.AuthenticationMechanism] = None,
password: Optional[bytes] = None,
encryption_key: Optional[bytes] = None,
authentication_key: Optional[bytes] = None,
security_suite: Optional[int] = 0,
dedicated_ciphering: bool = False,
block_transfer: bool = False,
max_pdu_size: int = 65535,
client_system_title: Optional[bytes] = None,
client_initial_invocation_counter: int = 0,
meter_initial_invocation_counter: int = 0,
):
tcp_transport = BlockingTcpTransport(
host=host,
port=port,
client_logical_address=client_logical_address,
server_logical_address=server_logical_address,
)
return cls(
client_logical_address=client_logical_address,
server_logical_address=server_logical_address,
authentication_method=authentication_method,
password=password,
encryption_key=encryption_key,
authentication_key=authentication_key,
security_suite=security_suite,
dedicated_ciphering=dedicated_ciphering,
block_transfer=block_transfer,
max_pdu_size=max_pdu_size,
client_system_title=client_system_title,
client_initial_invocation_counter=client_initial_invocation_counter,
meter_initial_invocation_counter=meter_initial_invocation_counter,
io_interface=tcp_transport,
)
@contextlib.contextmanager
def session(self) -> "DlmsClient":
self.connect()
self.associate()
yield self
self.release_association()
self.disconnect()
def get(
self,
cosem_attribute: cosem.CosemAttribute,
access_descriptor: Optional[RangeDescriptor] = None,
) -> bytes:
self.send(
xdlms.GetRequestNormal(
cosem_attribute=cosem_attribute, access_selection=access_descriptor
)
)
all_data_received = False
data = bytearray()
while not all_data_received:
get_response = self.next_event()
if isinstance(get_response, xdlms.GetResponseNormal):
data.extend(get_response.data)
all_data_received = True
continue
if isinstance(get_response, xdlms.GetResponseWithBlock):
data.extend(get_response.data)
self.send(
xdlms.GetRequestNext(
invoke_id_and_priority=get_response.invoke_id_and_priority,
block_number=get_response.block_number,
)
)
continue
if isinstance(get_response, xdlms.GetResponseLastBlock):
data.extend(get_response.data)
all_data_received = True
continue
if isinstance(get_response, xdlms.GetResponseLastBlockWithError):
raise DataResultError(
f"Error in blocktransfer of GET response: {get_response.error!r}"
)
if isinstance(get_response, xdlms.GetResponseNormalWithError):
raise DataResultError(
f"Could not perform GET request: {get_response.error!r}"
)
return bytes(data)
def set(self, cosem_attribute: cosem.CosemAttribute, data: bytes):
self.send(xdlms.SetRequestNormal(cosem_attribute=cosem_attribute, data=data))
return self.next_event()
def action(self, method: cosem.CosemMethod, data: bytes):
self.send(xdlms.ActionRequestNormal(cosem_method=method, data=data))
response = self.next_event()
if isinstance(response, xdlms.ActionResponseNormalWithError):
raise ActionError(response.error.name)
elif isinstance(response, xdlms.ActionResponseNormalWithData):
if response.status != enumerations.ActionResultStatus.SUCCESS:
raise ActionError(f"Unsuccessful ActionRequest: {response.status.name}")
return response.data
else:
if response.status != enumerations.ActionResultStatus.SUCCESS:
raise ActionError(f"Unsuccessful ActionRequest: {response.status.name}")
return
def associate(
self,
association_request: Optional[acse.ApplicationAssociationRequest] = None,
) -> acse.ApplicationAssociationResponse:
# the aarq can be overridden or the standard one from the connection is used.
aarq = association_request or self.dlms_connection.get_aarq()
self.send(aarq)
response = self.next_event()
# we could have received an exception from the meter.
if isinstance(response, xdlms.ExceptionResponse):
raise exceptions.DlmsClientException(
f"DLMS Exception: {response.state_error!r}:{response.service_error!r}"
)
# the association might not be accepted by the meter
if isinstance(response, acse.ApplicationAssociationResponse):
if response.result is not enumerations.AssociationResult.ACCEPTED:
# there could be an error suppled with the reject.
extra_error = None
if response.user_information:
if isinstance(
response.user_information.content, ConfirmedServiceError
):
extra_error = response.user_information.content.error
raise exceptions.DlmsClientException(
f"Unable to perform Association: {response.result!r} and "
f"{response.result_source_diagnostics!r}, extra info: {extra_error}"
)
else:
raise exceptions.LocalDlmsProtocolError(
"Did not receive an AARE after sending AARQ"
)
if self.should_send_hls_reply():
try:
hls_response = self.send_hls_reply()
except ActionError as e:
raise HLSError from e
hls_data = utils.parse_as_dlms_data(hls_response)
if not hls_response:
raise HLSError("Did not receive any HLS response data")
if not self.dlms_connection.hls_response_valid(hls_data):
raise HLSError(
f"Meter did not respond with correct challenge calculation"
)
return response
def should_send_hls_reply(self) -> bool:
return (
self.dlms_connection.state.current_state
== state.SHOULD_SEND_HLS_SEVER_CHALLENGE_RESULT
)
def send_hls_reply(self) -> Optional[bytes]:
return self.action(
method=cosem.CosemMethod(
enumerations.CosemInterface.ASSOCIATION_LN,
cosem.Obis(0, 0, 40, 0, 0),
1,
),
data=dlms_data.OctetStringData(
self.dlms_connection.get_hls_reply()
).to_bytes(),
)
def release_association(self) -> acse.ReleaseResponse:
rlrq = self.dlms_connection.get_rlrq()
self.send(rlrq)
rlre = self.next_event()
return rlre
def connect(self):
self.io_interface.connect()
def disconnect(self):
self.io_interface.disconnect()
def send(self, *events):
for event in events:
data = self.dlms_connection.send(event)
response_bytes = self.io_interface.send(data)
self.dlms_connection.receive_data(response_bytes)
def next_event(self):
event = self.dlms_connection.next_event()
LOG.info(f"Received {event}")
return event
def test_conformance_protection_is_set_when_passing_encryption_key():
c = DlmsConnection(global_encryption_key=b"1234", client_system_title=b"12345678")
assert c.conformance.general_protection
assert c.state.current_state == state.NO_ASSOCIATION
