aes.py

import base64
from Crypto.Cipher import AES


class AESCipher:
    def __init__(self, key, iv, block_size=16):
        self.block_size = block_size
        self._cipher = AES.new(key, AES.MODE_CBC, iv)

    def _get_padding(self, s):
        length = self.block_size - (len(s) % self.block_size)
        return s + chr(length)*length

    def encrypt(self, raw):
        return base64.b64encode(self._cipher.encrypt(self._get_padding(raw)))

    def decrypt(self, enc):
        return self._cipher.decrypt(base64.b64decode(enc)).rstrip(self.padding)