picoctf-guessing-game-2-guesser-local.py

#!/usr/bin/python3

from pwn import *
import sys

if len(sys.argv) != 2:
	warn("Usage: {} binary_filename".format(sys.argv[0]))
	exit(0)

filename = sys.argv[1]

elf = ELF(filename)

class Guesser:
	def __init__(self):		
		self.found = None
		self.proc = elf.process()
		
	def start(self):
		self.proc.recvlines(3)
		for guess in range(-4097,4097):
			self.proc.recvline()
			info("Guessing {}...".format(guess))
			self.proc.sendline(str(guess))
			resp = self.proc.recvline().decode().strip()
			self.proc.recvline()
			if "Congrats" in resp:
				self.found = guess
				break			
		return self.found



# DRIVER
guesser = Guesser()
guess = guesser.start()
info("CORRECTLY GUESSED VALUE -> {}".format(guess))