py-str0patch/str0.py

#!/usr/bin/python3


"""
Finds the location of strings and patches the first character to the null terminator,
preventing the messages from being displayed in the server console.

This can be executed while the server is running (on Linux, may not be successful on Windows).
"""

# to automatically patch after game updates use the following incron:
# /path/to/binary IN_CLOSE_WRITE,loopable=true python3 /path/to/str0.py $@/$# -c /path/to/config.txt

import argparse
import ast
import configparser
import mmap
import os

def patch_to_null(mbin, target):
	offset = mbin.find(target.encode('ascii'))
	if offset == -1:
		return False
	mbin.seek(offset)
	mbin.write_byte(0)
	mbin.flush()
	return True

if __name__ == '__main__':
	parser = argparse.ArgumentParser(
			description = "Patches various strings out of the given binary")
	
	parser.add_argument('binary', help = "Binary file to patch", type = argparse.FileType(mode = 'rb+'))
	
	args = parser.parse_args()
	
	mbin = mmap.mmap(args.binary.fileno(), length = 0, access = mmap.ACCESS_WRITE)
	
	config = configparser.ConfigParser(converters = {
		# return multiline value as an evaluated Python literal
		'pyliteral': ast.literal_eval,
	}, interpolation = None)
	config.read("str0.ini", encoding = "utf8")
	
	for target in config.getpyliteral(os.path.basename(args.binary.name), "strings"):
		if not patch_to_null(mbin, target):
			print(f'{args.binary.name}: Failed to locate string "{target}"')