157 lines
5.6 KiB
Python
157 lines
5.6 KiB
Python
from .Challenge import Challenge
|
|
|
|
import subprocess
|
|
import time
|
|
import re
|
|
import os
|
|
|
|
class Carbeat(Challenge):
|
|
flag_location = 'flags/carbeat.txt'
|
|
history_location = 'history/carbeat.txt'
|
|
|
|
_CONTAINER = "carbeat_container"
|
|
_SERVICE_CMD = ["docker", "exec", "-i", _CONTAINER, "/home/ctf/chall/mybini"]
|
|
_HEX_RE = re.compile(r'^[0-9a-fA-F]+$')
|
|
|
|
def _read_container_flag(self) -> str:
|
|
out = subprocess.run(["docker", "exec", self._CONTAINER, "cat", "/flag.txt"],
|
|
capture_output=True, text=True)
|
|
if out.returncode != 0 or not out.stdout.strip():
|
|
raise FileNotFoundError("Flag not found in container (/flag.txt)")
|
|
return out.stdout.strip()
|
|
|
|
def _spawn(self):
|
|
return subprocess.Popen(
|
|
self._SERVICE_CMD,
|
|
stdin=subprocess.PIPE,
|
|
stdout=subprocess.PIPE,
|
|
stderr=subprocess.STDOUT,
|
|
text=True,
|
|
bufsize=0,
|
|
)
|
|
|
|
def _read_until(self, proc, token, timeout=5.0, max_bytes=1_000_000):
|
|
start = time.time()
|
|
buf = []
|
|
r = proc.stdout.read
|
|
while True:
|
|
if time.time() - start > timeout:
|
|
tail = ''.join(buf)[-500:]
|
|
raise TimeoutError(f"Timeout waiting for '{token}'. Got so far:\n{tail}")
|
|
ch = r(1)
|
|
if ch == "" and proc.poll() is not None:
|
|
raise RuntimeError(f"Process ended while waiting for '{token}'. Output:\n{''.join(buf)}")
|
|
buf.append(ch)
|
|
if len(buf) > max_bytes:
|
|
raise RuntimeError("Exceeded max read size")
|
|
if token in "".join(buf):
|
|
return "".join(buf)
|
|
|
|
def _send_line(self, proc, s: str):
|
|
proc.stdin.write(s + "\n")
|
|
proc.stdin.flush()
|
|
|
|
def _expect_hex_field(self, text: str, label: str) -> str:
|
|
m = re.search(rf"{re.escape(label)}\s*:\s*([0-9a-fA-F]+)", text)
|
|
assert m, f"Missing '{label}' in output. Tail:\n{text[-400:]}"
|
|
hx = m.group(1)
|
|
assert self._HEX_RE.match(hx), f"{label} is not hex"
|
|
return hx
|
|
|
|
def distribute(self, flag):
|
|
try:
|
|
os.makedirs(os.path.dirname(self.flag_location), exist_ok=True)
|
|
with open(self.flag_location, 'w') as f:
|
|
f.write(flag)
|
|
|
|
os.makedirs(os.path.dirname(self.history_location), exist_ok=True)
|
|
with open(self.history_location, 'a') as f:
|
|
f.write(flag + '\n')
|
|
|
|
self.logger.info(f'Flag {flag} written to {self.flag_location}')
|
|
return True
|
|
except Exception as e:
|
|
self.logger.error(f'Could not write flag to {self.flag_location}: {e}')
|
|
return False
|
|
|
|
|
|
def register(self, proc, name, level, timeout=1.):
|
|
self._read_until(proc, "> ", timeout=timeout)
|
|
self._send_line(proc, "1")
|
|
self._read_until(proc, ": ", timeout=timeout)
|
|
self._send_line(proc, name)
|
|
self._read_until(proc, ": ", timeout=timeout)
|
|
self._send_line(proc, str(level))
|
|
|
|
def login(self, proc, name, timeout=1.):
|
|
self._read_until(proc, "> ", timeout=timeout)
|
|
self._send_line(proc, "2")
|
|
self._read_until(proc, ": ", timeout=timeout)
|
|
self._send_line(proc, name)
|
|
|
|
def list_user(self, proc, timeout=1.):
|
|
self._read_until(proc, "> ", timeout=timeout)
|
|
self._send_line(proc, "3")
|
|
return self._read_until(proc, "\n1. register")
|
|
|
|
def bini(self, proc, id, data, timeout=1.0):
|
|
self._read_until(proc, "> ", timeout=timeout)
|
|
self._send_line(proc, str(id))
|
|
self._read_until(proc, ": ", timeout=timeout)
|
|
self._send_line(proc, data)
|
|
|
|
def logout(self, proc, timeout=1.):
|
|
self._read_until(proc, "> ", timeout=timeout)
|
|
self._send_line(proc, "4")
|
|
|
|
def exit(self, proc, timeout=1.):
|
|
self._read_until(proc, "> ", timeout=timeout)
|
|
self._send_line(proc, "3")
|
|
|
|
def check(self):
|
|
try:
|
|
with open(self.flag_location, 'r') as f:
|
|
host_flag = f.read().strip()
|
|
container_flag = self._read_container_flag()
|
|
assert host_flag == container_flag, 'Flag mismatch between host and container'
|
|
self.logger.info('[ok] flag parity (carbeat)')
|
|
|
|
proc = self._spawn()
|
|
|
|
self.register(proc, "karbit", 1337)
|
|
|
|
name = self.list_user(proc)
|
|
assert "karbit" in name
|
|
|
|
self.login(proc, "karbit")
|
|
self.bini(proc, 1, "waguri")
|
|
self.bini(proc, 2, "0")
|
|
waguri = self._read_until(proc, "0. edit", timeout=1.)
|
|
assert "waguri" in waguri
|
|
|
|
self.bini(proc, 3, "0")
|
|
self.logout(proc)
|
|
self.exit(proc)
|
|
|
|
try:
|
|
proc.wait(timeout=2.0)
|
|
except subprocess.TimeoutExpired:
|
|
proc.kill()
|
|
raise AssertionError("Program did not exit after option 3")
|
|
self.logger.info("[ok] service exit on 3")
|
|
|
|
proc_alarm = self._spawn()
|
|
self._read_until(proc_alarm, "zzz", timeout=190.0) # 180s + slack
|
|
try:
|
|
proc_alarm.wait(timeout=5.0)
|
|
except subprocess.TimeoutExpired:
|
|
proc_alarm.kill()
|
|
raise AssertionError("Alarm fired but process did not exit")
|
|
self.logger.info("[ok] alarm fired ('zzz') and process self-terminated")
|
|
|
|
self.logger.info('Check passed for carbeat')
|
|
return True
|
|
|
|
except Exception as e:
|
|
self.logger.error(f'Could not check carbeat: {e}')
|
|
return False |