from Crypto.Cipher import AES

class Cryptor(object):

	def __init__(self, key, iv):
		#self.aes = AES.new(key, mode=AES.MODE_CBC, IV=iv) # This resembles stuff from shairtunes
		self.aes = AES.new(key, mode=AES.MODE_ECB, IV=iv) # I found this in airtunesd
		self.inbuf = ""
		self.outbuf = ""
		self.lastLen = 0

	def decrypt(self, data):
		self.inbuf += data
		blocksEnd = len(self.inbuf)
		blocksEnd -= blocksEnd % AES.block_size
		self.outbuf += self.aes.decrypt(self.inbuf[:blocksEnd])
		self.inbuf = self.inbuf[blocksEnd:]

		res = self.outbuf[:self.lastLen]
		self.outbuf = self.outbuf[self.lastLen:]

		self.lastLen = len(data)
		return res


class EchoCryptor(object):

	def decrypt(self, data):
		return data

from Crypto.Cipher import AES
import Crypto.Util.Counter

class Cryptor(AES.AESCipher):

	def __init__(self, key, iv):
		self.counter = Crypto.Util.Counter.new(128, initial_value=long(iv.encode("hex"), 16))
		AES.AESCipher.__init__(self, key, mode=AES.MODE_CTR, counter=self.counter)

class EchoCryptor(object):

	def decrypt(self, data):
		return data

Use CTR as encrypton mode. Works with iOS6.