def packet_callback(self, _packet):
tcp_packet = TCP(_packet.get_payload())
# check if this is a packet which we can modify
if self.send_count % Rate.ERR == self.random_modulo_spoil and len(
tcp_packet.load) > 1400:
self.random_modulo_spoil = random.randint(0, Rate.ERR - 1)
load_array = bytearray(tcp_packet.load)
load_array[random.randint(0,
len(tcp_packet.load) -
1)] = random.randint(0, 255)
tcp_packet.load = bytes(load_array)
_packet.set_payload(bytes(tcp_packet))
self.send_count += 1
_packet.accept()
def packet_callback(self, _packet):
ip_packet = IP(_packet.get_payload())
tcp_packet = TCP(_packet.get_payload())
# check if this is a packet which we can modify
if self.send_count % self.send_mod_packet == self.random_modulo:
self.random_modulo = random.randint(0, self.send_mod_packet - 1)
print("Trying to send stegano packet...")
# check state
if self.state == ServerState.READY:
load_array = bytearray(tcp_packet.load)
load_array = self.generate_packet(load_array,
self.send_queue.popleft())
self.state = ServerState.KEY_SENT
self.server_ip = ip_packet.src
self.client_ip = ip_packet.dst
tcp_packet.load = bytes(load_array)
_packet.set_payload(bytes(tcp_packet))
print("Stegano packet sent.")
elif self.state == ServerState.DATA_SENDING:
load_array = bytearray(tcp_packet.load)
load_array = self.generate_packet(load_array,
self.send_queue.popleft())
tcp_packet.load = bytes(load_array)
_packet.set_payload(bytes(tcp_packet))
print("Stegano packet sent.")
# If it was last send packet in the next sending send FIN KEY
if len(self.send_queue) == 0:
self.state = ServerState.FIN_SENT
elif self.send_count % Rate.ERR.value == self.random_modulo_spoil and len(
tcp_packet.load) > 1400:
self.random_modulo_spoil = random.randint(0, Rate.ERR.value - 1)
load_array = bytearray(tcp_packet.load)
load_array[random.randint(0,
len(tcp_packet.load) -
1)] = random.randint(0, 255)
tcp_packet.load = bytes(load_array)
_packet.set_payload(bytes(tcp_packet))
elif ip_packet.src == self.client_ip and len(tcp_packet.load) > 50:
if self.is_hash_valid(tcp_packet.load):
data_packet = tcp_packet.load
if self.state != ServerState.KEY_SENT:
data_packet = self.decrypt_data(tcp_packet.load)
session_id, sequence_id, flag, data_size, data = self.get_packet_data(
data_packet)
if session_id == self.session_id:
if flag == Flag.KEY.value:
self.client_public_key = RSA.importKey(data)
self.state = ServerState.DATA_SENDING
self.send_file_to_queue()
elif flag == Flag.FIN.value and self.state == ServerState.FIN_SENT:
tmp_header = self.generate_header(
self.session_id, 4294967295, Flag.FIN_ACK.value,
os.urandom(10))
encrypted_data = self.encrypt(tmp_header)
self.send_queue.append(encrypted_data)
self.state = ServerState.CLOSING
self.send_count += 1
_packet.accept()
