def setUp(self):
        itau_data = get_itau_data_from_file()
        self.header_arquivo = itau_data['header_arquivo']
        self.seg_p = itau_data['seg_p1']
        self.seg_p_str = itau_data['seg_p1_str']
        self.seg_q = itau_data['seg_q1']
        self.seg_q_str = itau_data['seg_q1_str']
def decrypt(self, enc):
        # enc = base64.b64decode(enc)
        iv = enc[:AES.block_size]
        cipher = AES.new(self.key, AES.MODE_CBC, iv)
        return self._unpad(cipher.decrypt(enc[AES.block_size:])).decode('utf-8')