def send_message_to_middleman_and_receive_response(
message: AbstractFrame,
config: configparser.ConfigParser,
concent_private_key: bytes,
concent_public_key: bytes,
) -> GolemMessageFrame:
""" Sends message to MiddleMan using MiddleMan protocol and retrieves response. """
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, True)
try:
client_socket.connect((
config.get(Components.MIDDLEMAN.value, 'host'),
int(config.get(Components.MIDDLEMAN.value, 'port')),
))
send_over_stream(
connection=client_socket,
raw_message=message,
private_key=concent_private_key,
)
receive_frame_generator = unescape_stream(connection=client_socket)
raw_response = next(receive_frame_generator)
return GolemMessageFrame.deserialize(
raw_message=raw_response,
public_key=concent_public_key,
)
finally:
client_socket.close()
def deserialize_response_and_handle_errors(
raw_response: bytes, request_id: int) -> SignedTransaction:
"""
Deserialize received Frame and its payload and handle related errors.
Returns SignedTransaction message.
"""
assert isinstance(raw_response, bytes)
assert isinstance(request_id, int)
try:
deserialized_message = GolemMessageFrame.deserialize(
raw_message=raw_response,
public_key=settings.CONCENT_PUBLIC_KEY,
)
# Received data frame is invalid or the signature does not match its content.
except MiddlemanProtocolError as exception:
raise SCICallbackFrameError() from exception
# If the received Golem message is malformed.
except MessageError as exception:
raise SCICallbackPayloadError() from exception
if deserialized_message.request_id != request_id:
raise SCICallbackRequestIdError(
'MiddleMan response request_id does not match requested.')
if isinstance(deserialized_message, ErrorFrame):
raise SCICallbackPayloadError('Received frame is ErrorFrame.')
if isinstance(deserialized_message.payload, TransactionRejected):
raise SCICallbackPayloadError(
'Received frame is contains Golem message TransactionRejected.')
if not isinstance(deserialized_message.payload, SignedTransaction):
raise SCICallbackPayloadError(
'Received frame payload is not Golem message SignedTransaction instance.'
)
# If the received Golem message is not signed by the Signing Service.
try:
deserialized_message.payload.verify_signature(
settings.SIGNING_SERVICE_PUBLIC_KEY)
except InvalidSignature as exception:
raise SCICallbackPayloadSignatureError() from exception
return deserialized_message.payload