Implemented compressor

This commit is contained in:
Emily 2020-03-30 01:41:07 +02:00
parent a30b9f1a62
commit cb2d31e033
2 changed files with 54 additions and 2 deletions

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@ -2,8 +2,10 @@ import socket
import asyncio import asyncio
from select import select # This is straight up magic from select import select # This is straight up magic
from .struct.server import ServerConfig from ..struct.server import ServerConfig
from .client import Client from ..client import Client
from .compression import Compressor
import logging import logging
logger = logging.getLogger(__name__) logger = logging.getLogger(__name__)
@ -14,6 +16,8 @@ class Server:
self.clients = {} self.clients = {}
self.rcon_clients = {} self.rcon_clients = {}
self.compressor = Compressor(self.config)
async def create_socket(self): async def create_socket(self):
self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP) self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

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@ -0,0 +1,48 @@
from ..shared import glob
from ..struct.server import ServerConfig
import logging
logger = logging.getLogger(__name__)
# Found @ addr 0x004C88E0
LOOKUP_TABLE = b"\xb4b\x07\xe5\x9d\xafc\xdd\xe3\xd0\xcc\xfe\xdc\xdbk.j@\xabG\xc9\xd1S\xd5 \x91\xa5\x0eJ\xdf\x18\x89\xfdo%\x12\xb7\x13w\x00e6mI\xecW*\xa9\x11_\xfax\x95\xa4\xbd\x1e\xd9yD\xcd\xde\x81\xeb\t>\xf6\xee\xda\x7f\xa3\x1a\xa7-\xa6\xad\xc1F\x93\xd2\x1b\x9c\xaa\xd7NKML\xf3\xb84\xc0\xca\x88\xf4\x94\xcb\x0490\x82\xd6s\xb0\xbf\"\x01AnH,\xa8u\xb1\n\xae\x9f\'\x80\x10\xce\xf0)(\x85\r\x05\xf75\xbb\xbc\x15\x06\xf5`q\x03\x1f\xeaZ3\x92\x8d\xe7\x90[\xe9\xcf\x9e\xd3]\xed1\x1c\x0bR\x16Q\x0f\x86\xc5h\x9b!\x0c\x8bB\x87\xffO\xbe\xc8\xe8\xc7\xd4z\xe0U/\x8a\x8e\xba\x987\xe4\xb28\xa1\xb62\x83:{\x84<a\xfb\x8c\x14=C;\x1d\xc3\xa2\x96\xb3\xf8\xc4\xf2&+\xd8|\xfc#$f\xefidPTY\xf1\xa0t\xac\xc6}\xb5\xe6\xe2\xc2~g\x17^\xe1\xb9?lp\x08\x99EVv\xf9\x9a\x97\x19r\\\x02\x8fX"
class Compressor:
def __init__(self, config: ServerConfig):
self.config = config
def decompress(self, bytestream: bytes) -> bytes:
"""Decompress client packet.
This is actually a deobfuscation as there is no compression involved anymore
as zlib was removed and just swapped with this implementation after the leak.
Arguments:
bytestream {bytes} -- Bytes sent by client
"""
checksum, data = bytestream[0], bytestream[1:]
data = self.xor_every_other_byte(self.get_port_xor_key(), data)
data = self.run_though_lookup_table(data)
if checksum != self.calc_checksum(data):
logger.error("Checksum failed!")
raise Exception("Checksum fail")
return data
def xor_every_other_byte(self, xor: int, bytestream: bytes) -> bytes:
for i in range(1, len(bytestream), 2):
bytestream[i] ^= xor
return bytestream
def run_though_lookup_table(self, bytestream: bytes) -> bytes:
return bytes(LOOKUP_TABLE[b] for b in bytestream)
def calc_checksum(self, bytestream: bytes) -> int:
checksum = 0
for byte in bytestream:
checksum ^= byte & 0xAA
return checksum
def get_port_xor_key(self) -> int:
return (self.config.port ^ 0xCCCC) & 0xFF