#!/usr/bin/python
from Crypto.Cipher import AES
from Crypto import Random
import sys, time

def split_len(seq, length):
    return [seq[i:i+length] for i in range(0, len(seq), length)]

def ByteToHex( byteStr ):
    xxd = ''
    for i in range(len(byteStr)):
        xxd = xxd + "%02X " % ord (byteStr[i])
        if i % 16 == 15:
            xxd = xxd + "\n"
        #if i % 16 == 7:
        #    xxd += "- "
        if i % 64 == 63:
            xxd += "\n"

    return xxd.strip()

key = 'Sixteen byte key'
iv = Random.new().read(AES.block_size)

secret = 'jangan sembarangan ini sangat rahasia sekali'

def challengePhase1(text):
	global iv

	cipher = AES.new(key, AES.MODE_CBC, iv)
	plaintext = text + secret	
	padlen = (((len(plaintext) / AES.block_size) + 1) * AES.block_size) - len(plaintext)
	plaintext += chr(padlen)*padlen

	ciphertext = cipher.encrypt(plaintext)

	cblocks = split_len(ciphertext, AES.block_size)
	origiv = iv
	iv = cblocks[len(cblocks)-1] # New IV is last cipher block
	
	return origiv+ciphertext


def challengePhase2(text):
	global iv

	cipher = AES.new(key, AES.MODE_CBC, iv)
	plaintext = text
	ciphertext = cipher.encrypt(plaintext)

	cblocks = split_len(ciphertext, AES.block_size)
	iv = cblocks[len(cblocks)-1] # New IV is last cipher block
	
	return ciphertext

cracked = ''
factor = 4
for j in range(0,factor*AES.block_size):
	r = "\x00" * ((AES.block_size*factor) - j - 1)
	ciphertext = challengePhase1(r)

	cblocks = split_len(ciphertext, AES.block_size)
	ci = cblocks[factor-1]

	for guess in range(32,127):
		sys.stdout.write("\b"+chr(guess))
		sys.stdout.flush()
		time.sleep(0.002)
		guessblock = r + cracked + chr(guess)
		guessblock = guessblock[AES.block_size*(factor-1):]
		
		challengeblock = ""
		if len(guessblock) == AES.block_size:
			for i in range(0,len(ci)):
				challengeblock += chr(ord(ci[i]) ^ ord(iv[i]) ^ ord(guessblock[i]))

			ciphertext2 = challengePhase2(challengeblock)
			if ciphertext2 == cblocks[factor]:
				sys.stdout.write("\b"+chr(guess)+" ")				
				cracked += chr(guess)
				break
		else:
			break


print