mirror of https://github.com/Kkevsterrr/geneva
99 lines
3.3 KiB
Python
99 lines
3.3 KiB
Python
"""
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Censor 3 ----> CENSOR 2
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Designed to be run by the evaluator.
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TCP Censor that synchronizes on first SYN only, works 100% of the time, sends 5 RSTs to
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server AND client.
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"""
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import logging
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import netifaces
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import layers.packet
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# Disable scapy ::1 warnings
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logging.getLogger("scapy.runtime").setLevel(logging.ERROR)
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from scapy.all import IP, TCP, wrpcap
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from censors.censor import Censor
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class Censor3(Censor):
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"""
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TCP Censor that synchronizes on first SYN only, works 100% of the time, sends 5 RSTs to
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server AND client.
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"""
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def __init__(self, environment_id, forbidden, log_dir, log_level, port, queue_num):
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Censor.__init__(self, environment_id, log_dir, log_level, port, queue_num)
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self.forbidden = forbidden
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self.enabled = True
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self.tcb = 0
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self.drop_all_from = None
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self.num = 0
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self.censor_interfaces = netifaces.interfaces()
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if(len(self.censor_interfaces) > 1) and 'eth0' in self.censor_interfaces:
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self.censor_ip = netifaces.ifaddresses('eth0')[netifaces.AF_INET][0]['addr']
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def check_censor(self, packet):
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"""
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Check if the censor should run against this packet. Returns true or false.
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"""
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try:
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self.num += 1
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# Only censor TCP packets for now
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self.logger.debug("Inbound packet to censor: " + layers.packet.Packet._str_packet(packet))
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if "TCP" not in packet:
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return False
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if packet["TCP"].sprintf('%TCP.flags%') == "S":
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self.tcb = packet["TCP"].seq + 1
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self.logger.debug("Synchronizing TCB on packet " + layers.packet.Packet._str_packet(packet))
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return False
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if packet["TCP"].seq == self.tcb:
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self.tcb += len(self.get_payload(packet))
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else:
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self.logger.debug("Ignoring packet: " + layers.packet.Packet._str_packet(packet))
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return False
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for keyword in self.forbidden:
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if keyword in self.get_payload(packet):
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self.logger.debug("Packet triggered censor: " + layers.packet.Packet._str_packet(packet))
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return True
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return False
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except Exception:
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self.logger.exception("Censor 3 Error caught.")
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return False
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def censor(self, scapy_packet):
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"""
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Send 5 resets to the client and the server.
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"""
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client_ip_rst = IP(src=scapy_packet[IP].dst, dst=scapy_packet[IP].src)
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client_tcp_rst = TCP(
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dport=scapy_packet[TCP].sport,
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sport=scapy_packet[TCP].dport,
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ack=scapy_packet[TCP].seq+len(str(scapy_packet[TCP].payload)),
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seq=scapy_packet[TCP].ack,
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flags="R"
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)
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client_rst = client_ip_rst / client_tcp_rst
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server_ip_rst = IP(src=self.censor_ip, dst=scapy_packet[IP].dst)
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server_tcp_rst = TCP(
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dport=scapy_packet[TCP].dport,
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sport=scapy_packet[TCP].sport,
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ack=scapy_packet[TCP].ack,
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seq=scapy_packet[TCP].seq,
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flags="R"
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)
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server_tcp_rst.show()
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server_rst = server_ip_rst / server_tcp_rst
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for _ in range(0, 5):
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self.mysend(client_rst)
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self.mysend(server_rst)
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