ructf 2014 reversing 500

from struct import *
import sys

key1 = "86DE9AF8DFF585E9DD85EF".decode('hex')

def encode(data,n):
        global key1
        zero_to_100 = []
        i =0
        while i<0x100:
                zero_to_100.append(i)
                i+=1
        temp_key1 = list(key1)
        temp_key = [chr(ord(i) ^ n) for i in key1]
        calc_key1 = "".join(temp_key)

        i = 0
        v4 = 0
        v8 = 0
        v3 = 0
        while i<0x100:
                v3 += (zero_to_100[i] + ord(calc_key1[i % 0xB]))
                v3 = v3 & 0xFF
                v8 = zero_to_100[i]
                zero_to_100[i] = zero_to_100[v3]
                zero_to_100[v3] = v8
                i+=1

        i=0
        v9 = 0
        v10 = 0
        answer = ""
        while i < 0x20:
                v12 = v10+1
                v17 = v12
                v9 += zero_to_100[v12]
                v9 = v9 & 0xFF
                v13 = zero_to_100[v12]
                v15 = zero_to_100[v9]
                zero_to_100[v12] = v15
                zero_to_100[v9] = v13
                k = zero_to_100[(v13 + v15) & 0xFF]
                answer += chr(ord(data[i]) ^ k)
                v10 = v17
                i+=1

        return answer

def check(data):
        data = list(data)
        for i in data:
                if ord(i) < 0x20 or ord(i) >= 0x80:
                        return False

        return True

compare = ""
compare += pack('<L', 0x03C7C8CA)
compare += pack('<L', 0x1F2810FC)
compare += pack('<L', 0x948C7F7A)
compare += pack('<L', 0x2469F92E)
compare += pack('<L', 0xC1277D9F)
compare += pack('<L', 0x7F4509C4)
compare += pack('<L', 0x9745EE75)
compare += pack('<L', 0x1F79AF8D)

for n in range(0,0x100):
        xored = encode("1"*32,n)

        key = ""
        for i in xored:
                key += chr(ord(i) ^ ord('1'))

        i=0
        answer = ""
        while i< 32:
                answer += chr(ord(key[i]) ^ ord(compare[i]))
                i+=1

        if check(answer):
                print answer
                sys.exit()