view test/parent_dropbear_map.py @ 1861:2b3a8026a6ce

Add re-exec for server This allows ASLR to re-randomize the address space for every connection, preventing some vulnerabilities from being exploitable by repeated probing. Overhead (memory and time) is yet to be confirmed. At present this is only enabled on Linux. Other BSD platforms with fexecve() would probably also work though have not been tested.
author Matt Johnston <matt@ucc.asn.au>
date Sun, 30 Jan 2022 10:14:56 +0800
parents
children 1c9215154d4a
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#!/usr/bin/env python3

import os
import sys
import time
import psutil

from pathlib import Path


want_name = "dropbear"
# Walks up the parent process tree, prints the first line of /proc/pid/maps when
# it finds the wanted name

def main():

	try:
		for p in psutil.Process().parents():
			print(p.pid, file=sys.stderr)
			print(p.name(), file=sys.stderr)
			print(p.cmdline(), file=sys.stderr)

			if want_name in p.name():
				with (Path('/proc') / str(p.pid) / "maps").open() as f:
					map0 = f.readline().rstrip()
				print(map0)
				return

		raise RuntimeError(f"Couldn't find parent {want_name} process")
	except Exception as e:
		print(psutil.Process().parents())
		for p in psutil.Process().parents():
			print(p.name())
		print(e)
		# time.sleep(100)
		raise

if __name__ == "__main__":
	main()