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Intercepting Communication: src and dst checks #7

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Intercepting Communication: src and dst checks #7

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fb489fa
src, dst mac check for Ether layer level
f4-u57 Oct 18, 2023
e0a4d23
src and dst mac, src ip check for IP layer level
f4-u57 Oct 18, 2023
5ec0264
src and dst mac, src ip check for TCP handshake level
f4-u57 Oct 18, 2023
9585077
user_host var
f4-u57 Oct 18, 2023
8e775ec
user_host var here for consistency
f4-u57 Oct 18, 2023
a664149
Merge branch 'pwncollege:main' into main
f4-u57 Jan 7, 2024
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38 changes: 27 additions & 11 deletions intercepting-communication/run
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Original file line number Diff line number Diff line change
Expand Up @@ -472,25 +472,37 @@ class RawPacketHost(UnmanagedHost):

class EtherPacketHost(RawPacketHost):
def check_packet(self, packet):
user_host = self.network.hosts[0]
return (
"Ether" in packet and
packet["Ether"].src == user_host.mac and
packet["Ether"].dst == self.mac and
packet["Ether"].type == 0xFFFF
)


class IPPacketHost(RawPacketHost):
def check_packet(self, packet):
user_host = self.network.hosts[0]
return (
"IP" in packet and
"Ether" in packet and "IP" in packet and
packet["Ether"].src == user_host.mac and
packet["Ether"].dst == self.mac and
packet["IP"].src == user_host.ip and
packet["IP"].dst == self.ip and
packet["IP"].proto == 0xFF
)


class TCPPacketHost(RawPacketHost):
def check_packet(self, packet):
user_host = self.network.hosts[0]
return (
"TCP" in packet and
"Ether" in packet and "IP" in packet and "TCP" in packet and
packet["Ether"].src == user_host.mac and
packet["Ether"].dst == self.mac and
packet["IP"].src == user_host.ip and
packet["IP"].dst == self.ip and
packet["TCP"].sport == 31337 and
packet["TCP"].dport == 31337 and
packet["TCP"].seq == 31337 and
Expand All @@ -505,7 +517,11 @@ class TCPHandshakeHost(RawPacketHost):
self.seq = None

def check_packet(self, packet):
if ("IP" in packet and "TCP" in packet["IP"] and len(packet["IP"].layers()) == 2 and
user_host = self.network.hosts[0]
if ("Ether" in packet and "IP" in packet and "TCP" in packet and len(packet["IP"].layers()) == 2 and
packet["Ether"].src == user_host.mac and
packet["Ether"].dst == self.mac and
packet["IP"].src == user_host.ip and
packet["IP"].dst == self.ip and
packet["TCP"].sport == 31337 and
packet["TCP"].dport == 31337 and
Expand Down Expand Up @@ -536,7 +552,10 @@ class TCPHandshakeHost(RawPacketHost):

self.seq = (self.seq + 1) & (2**32 - 1)

if ("IP" in packet and "TCP" in packet["IP"] and len(packet["IP"].layers()) == 2 and
if ("Ether" in packet and "IP" in packet and "TCP" in packet and len(packet["IP"].layers()) == 2 and
packet["Ether"].src == user_host.mac and
packet["Ether"].dst == self.mac and
packet["IP"].src == user_host.ip and
packet["IP"].dst == self.ip and
packet["TCP"].sport == 31337 and
packet["TCP"].dport == 31337 and
Expand All @@ -548,19 +567,16 @@ class TCPHandshakeHost(RawPacketHost):


class ARPHost(RawPacketHost):
@property
def check_host(self):
return self.network.hosts[0]

def check_packet(self, packet):
user_host = self.network.hosts[0]
WHO_HAS = 1
IS_AT = 2
return (
"Ether" in packet and "ARP" in packet["Ether"] and len(packet["Ether"].layers()) == 2 and
packet["Ether"].src == self.check_host.mac and
packet["Ether"].src == user_host.mac and
packet["ARP"].op == IS_AT and
packet["ARP"].hwsrc == self.check_host.mac and
packet["ARP"].psrc == self.check_host.ip
packet["ARP"].hwsrc == user_host.mac and
packet["ARP"].psrc == user_host.ip
)


Expand Down