def stage_three(self, stage_three_msg_main):
"""
Gets the public_key_main_dh, calculates the shared key and saves it.
sends a random ACK message that will be encrypted and signed with the shared key.
:param stage_three_msg_main (Bytes): public_key_main_dh
:return Ack message (Bytes): A random ack message
:return shared_key (Str): The shared_key
"""
self.public_key_main_dh = int(stage_three_msg_main.decode())
self.shared_key = DH.gen_shared_key(self.private_key_edge_dh, self.public_key_main_dh)
ack = ''.join(random.choice(string.printable) for i in range(128)).encode()
signature = zRSA.sign_data(ack, self.private_rsa_edge)
return ack, signature, self.shared_key
def stage_two(self, stage_two_msg_edge):
"""
Gets the public_key_edge_dh and saves it.
Creates a DH key set for main and sends the public_key_main_dh.
Calculates the shared key and returns it.
:param stage_two_msg_edge (Bytes): public_key_edge_dh
:return stage_two_msg_main (Bytes): public_key_main_dh
:return shared_key: the final shared key
"""
self.public_key_edge_dh = int(stage_two_msg_edge.decode())
self.private_key_main_dh, self.public_key_main_dh = DH.gen_key_set()
self.shared_key = DH.gen_shared_key(self.private_key_main_dh,
self.public_key_edge_dh)
stage_two_msg_main = str(self.public_key_main_dh).encode()
return stage_two_msg_main, self.shared_key
