HITCON2014 Finger

finger.py

import hashlib
import re
import pexpect
import sys

FILLER = '11111111111'

def fillme(text):
    x = 16 - len(text)
    return text + '1'*x

def _md5(text):
    return int(hashlib.md5( fillme(text) ).hexdigest().lower(), 16)


# p = pexpect.spawn('ruby finger-9312e72601ff37116dd1e201e9508dbb.rb')
p = pexpect.spawn('tsocks nc 210.71.253.236 7171')
p.setecho(True)
p.logfile = sys.stdout

while True:
    idx = p.expect(['hands', 'how many', 'the magic', 'here is mine', 'show me the'])
    if idx == 0:
        x = p.readline()
        hands = re.findall(r"\"[0-9a-z]+\"", x)
        hands = [s.strip('"') for s in hands]
        hands_md5 = map(_md5, hands)
        #print "I GOT HANDS", hands
        #print "I GOT THERE MD5", hands_md5
    elif idx == 1:
        p.sendline('1')
    elif idx == 2:
        magicNumber = hands_md5[2]
        p.sendline(str(magicNumber))
    elif idx == 3:
        boss_hand = p.readline().split(':')[1].strip()
        bh = hands.index(boss_hand)
        #print "I GOT BOSS HAND = ", boss_hand
    elif idx == 4:
        if bh == 0:
            p.sendline("I cheat")
        else:
            p.sendline(fillme(hands[2]))