mirror of
https://github.com/sonertari/SSLproxy
synced 2024-11-02 15:40:19 +00:00
210 lines
8.5 KiB
Python
210 lines
8.5 KiB
Python
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#!/usr/bin/env python
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# vim: set list et ts=8 sts=4 sw=4 ft=python:
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# SSLsplit contributed code: Converts sslsplit -L log to PCAP.
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# This script reads the log from standard input and converts it to a
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# corresponding PCAP file. Information which is not contained in the
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# log, such as TCP sequence numbers, IP ID etc are emulated and do not
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# correspond to the values in the original traffic. Note that the
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# algorithms used do not scale well for large volumes of traffic.
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# Copyright (C) 2015, Maciej Kotowicz <mak@lokalhost.pl>
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# Copyright (C) 2015, Daniel Roethlisberger <daniel@roe.ch>
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions
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# are met:
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# 1. Redistributions of source code must retain the above copyright
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# notice, this list of conditions, and the following disclaimer.
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# 2. Redistributions in binary form must reproduce the above copyright
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# notice, this list of conditions and the following disclaimer in the
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# documentation and/or other materials provided with the distribution.
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#
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# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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import sys
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import datetime
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import random
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from scapy.utils import PcapWriter
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from scapy.all import *
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import logreader
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def parse_timestamp(s):
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return datetime.datetime.strptime(s, '%Y-%m-%d %H:%M:%S %Z')
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def chunks(s, sz):
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return (s[0+i:sz+i] for i in range(0, len(s), sz))
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class NetworkStack():
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"""Emulated network stack, processing log entries into network packets"""
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class ConnState():
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"""State for a single TCP connection"""
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def __init__(self, logentry, tm, ctx):
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self.src_addr = logentry['src_addr']
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self.src_port = logentry['src_port']
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self.dst_addr = logentry['dst_addr']
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self.dst_port = logentry['dst_port']
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self.tm = tm
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self._ctx = ctx
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def touch(self, tm):
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if self.tm < tm:
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self.tm = tm
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def _write_packet(self, pkt):
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pkt.time = (self.tm - datetime.datetime(1970, 1, 1)).total_seconds()
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self._ctx.pcap.write(pkt)
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self._ctx.last_packet_tm = self.tm
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def _seq(self, addr, port, inc):
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if self.src_addr == addr and self.src_port == port:
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seq = self.src_seq
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ack = self.dst_seq
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self.src_seq += inc
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else:
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seq = self.dst_seq
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ack = self.src_seq
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self.dst_seq += inc
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return (seq, ack)
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def syn(self):
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"""Send a TCP SYN handshake, opeining the connection"""
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self.src_seq = random.randint(1024, (2**32)-1)
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self.dst_seq = random.randint(1024, (2**32)-1)
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self._write_packet(
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Ether()/
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IP(src=self.src_addr, dst=self.dst_addr)/
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TCP(flags='S',
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sport=self.src_port, dport=self.dst_port,
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seq=self.src_seq)
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)
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self.src_seq += 1
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self._write_packet(
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Ether()/
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IP(src=self.dst_addr, dst=self.src_addr)/
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TCP(flags='SA',
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sport=self.dst_port, dport=self.src_port,
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seq=self.dst_seq, ack=self.src_seq)
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)
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self.dst_seq += 1
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self._write_packet(
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Ether()/
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IP(src=self.src_addr, dst=self.dst_addr)/
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TCP(flags='A',
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sport=self.src_port, dport=self.dst_port,
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seq=self.src_seq, ack=self.dst_seq)
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)
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def fin(self):
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"""Send a TCP FIN handshake, closing current connection"""
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self._write_packet(
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Ether()/
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IP(src=self.src_addr, dst=self.dst_addr)/
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TCP(flags="FA",
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sport=self.src_port, dport=self.dst_port,
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seq=self.src_seq, ack=self.dst_seq)
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)
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self.src_seq += 1
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self._write_packet(
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Ether()/
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IP(src=self.dst_addr, dst=self.src_addr)/
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TCP(flags='A',
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sport=self.dst_port, dport=self.src_port,
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seq=self.dst_seq, ack=self.src_seq)
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)
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def data(self, logentry):
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"""Send a TCP data segment within the connection"""
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for segment in chunks(logentry['data'], self._ctx.mss):
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seq, ack = self._seq(logentry['src_addr'],
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logentry['src_port'], len(segment))
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self._write_packet(
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Ether()/
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IP(src=logentry['src_addr'], dst=logentry['dst_addr'])/
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TCP(flags='PA',
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sport=logentry['src_port'],
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dport=logentry['dst_port'],
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seq=seq, ack=ack)/
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segment
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)
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def __init__(self, outfile, mtu=1500):
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self.pcap = PcapWriter(filename=outfile, linktype=1)
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self.mss = mtu - 40
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self.connstate = {}
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self.last_packet_tm = datetime.datetime(1970, 1, 1, 0, 0, 0)
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self.last_timeout_tm = datetime.datetime(1970, 1, 1, 0, 0, 0)
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def _make5tuple(self, logentry):
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"""Construct a canonical per-connection 5-tuple"""
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if (logentry['src_addr'] < logentry['dst_addr']) or \
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(logentry['src_addr'] == logentry['dst_addr'] and \
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logentry['src_port'] < logentry['dst_port']):
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return "tcp|%s|%d|%s|%d" % (logentry['src_addr'],
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logentry['src_port'],
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logentry['dst_addr'],
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logentry['dst_port'])
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else:
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return "tcp|%s|%d|%s|%d" % (logentry['dst_addr'],
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logentry['dst_port'],
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logentry['src_addr'],
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logentry['src_port'])
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# Note that the chosen data structure for the internal state scales badly
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# for large numbers of connections: O(n) search every minute. This needs
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# to be rewritten using better data structures for scalability.
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def add(self, logentry):
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"""Process a log entry, keeping internal state"""
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tm = parse_timestamp(logentry['timestamp'])
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conn5tuple = self._make5tuple(logentry)
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if not conn5tuple in self.connstate:
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self.connstate[conn5tuple] = NetworkStack.ConnState(logentry, tm,
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self)
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self.connstate[conn5tuple].syn()
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else:
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self.connstate[conn5tuple].touch(tm)
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self.connstate[conn5tuple].data(logentry)
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# at most very 60 seconds, time out old connections (doesn't scale!)
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if tm > self.last_timeout_tm + datetime.timedelta(0, 1, 0):
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for conn in self.connstate:
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if self.last_timeout_tm > self.connstate[conn5tuple].tm + \
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datetime.timedelta(0, 1, 0):
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self.connstate[conn5tuple].fin()
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del self.connstate[conn5tuple]
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self.last_timeout_tm = tm
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def done(self):
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"""We are done, all active connections can be closed"""
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for conn in self.connstate:
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self.connstate[conn].touch(self.last_packet_tm)
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self.connstate[conn].fin()
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self.pcap.close()
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if __name__ == '__main__':
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if len(sys.argv) < 2:
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sys.stderr.write('Usage: %s example.pcap <example.log\n' % sys.argv[0])
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sys.exit(-1)
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netemu = NetworkStack(sys.argv[1])
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for logentry in logreader.parse_log(sys.stdin):
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netemu.add(logentry)
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netemu.done()
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