def create_circuit_hop1(self) -> int:
"""
The function to setup circuit with the first hop in the circuit. Creates the CREATE/CREATE2 cell and sends it
down the socket. It assumes that the open_connection was called on the first node and the socket is connected
to the first node
:return: Returns a status code. 0 --> Success DH Handshake and -1 --> Means error in processing the cell or the DH Handshake.
On error it closes the socket to node 1
"""
# First create a CREATE2 Cell.
x, x_bytes, gx, gx_bytes = CoreCryptoDH.generate_dh_priv_key()
create_cell = Builder.build_create_cell(
'TAP', x_bytes, gx_bytes, self.circ_id,
self.node_container[1].onion_key_pub)
# Sending a JSON String down the socket
self.skt.client_send_data(ComplexStructEncoder.encode(create_cell))
# self.skt.client_send_data(Serialize.obj_to_json(create_cell).encode('utf-8'))
# Get the created cell in response and convert it to python Cell Object
cell_bytes = self.skt.client_recv_data()
created_cell = Parser.parse_encoded_created_cell(cell_bytes)
self.session_key01 = Processor.process_created_cell(
created_cell, self.circ_id, x_bytes)
if self.session_key01 is None:
self.skt.close()
return -1
return 0
def create_circuit_hop2(self) -> int:
"""
The function to setup circuit with the second hop in the circuit. Creates the EXTEND/EXTEND2 cell and sends it
down the socket. It assumes that the open_connection was called on the first node and the socket is connected
to the first node, and that to the second node
:return: Returns a status code. 0 --> Success DH Handshake and -1 --> Means error in processing the cell or the DH Handshake.
On error it closes the socket to node 2.
"""
# First create a EXTEND2 Cell.
x, x_bytes, gx, gx_bytes = CoreCryptoDH.generate_dh_priv_key()
# For hop2 we get its IP:port for LSPEC ==> Link specifier
hop2_ip = self.node_container[2].host
hop2_port = self.node_container[2].port
extend_cell = Builder.build_extend_cell(
'TAP', x_bytes, gx_bytes, self.circ_id,
self.node_container[2].onion_key_pub, hop2_ip, hop2_port)
print(extend_cell)
# Sending a JSON String down the socket
self.skt.client_send_data(ComplexStructEncoder.encode(extend_cell))
# Get the extended cell in response and convert it to python Cell Object
cell_bytes = self.skt.client_recv_data()
extended_cell = Parser.parse_encoded_extended_cell(cell_bytes)
self.session_key02 = Processor.process_extended_cell(
extended_cell, self.circ_id, x_bytes)
if self.session_key02 is None:
self.skt.close()
return -1
return 0
def handle_create_cell(self, cell_bytes, direction):
# Call the Parser for create cell
create_cell = Parser.parse_encoded_create_cell(cell_bytes)
# Process the create cell
y, y_bytes, gy, gy_bytes = CoreCryptoDH.generate_dh_priv_key()
gx_bytes, kdf_dict = Processor.process_create_cell(create_cell, self.node.onion_key_pri, y_bytes)
# After processing the create cell, we make a created cell
# and send it down the socket
created_cell = Builder.build_created_cell(y_bytes, gy_bytes, self.circ_id, gx_bytes)
print(created_cell)
self.conn.sendall(ComplexStructEncoder.encode(created_cell))
print("Created cell sent")
self.session_key = kdf_dict
return 0
