:mod:`vizbase.memo`
===================

.. py:module:: vizbase.memo


Module Contents
---------------

.. function:: init_aes(shared_secret, nonce)

   Initialize AES instance.

   :param hex shared_secret: Shared Secret to use as encryption key
   :param int nonce: Random nonce
   :return: AES instance and checksum of the encryption key
   :rtype: length 2 tuple


.. function:: encode_memo(priv, pub, nonce, message, **kwargs)

   Encode a message with a shared secret between Alice and Bob.

   :param PrivateKey priv: Private Key (of Alice)
   :param PublicKey pub: Public Key (of Bob)
   :param int nonce: Random nonce
   :param str message: Memo message
   :return: Encrypted message
   :rtype: hex


.. function:: decode_memo(priv, message)

   Decode a message with a shared secret between Alice and Bob.

   :param PrivateKey priv: Private Key (of Bob)
   :param base58encoded message: Encrypted Memo message
   :return: Decrypted message
   :rtype: str
   :raise ValueError: if message cannot be decoded as valid UTF-8
          string


.. function:: involved_keys(message)

   decode structure.


.. function:: _pad(raw_message, bs)


.. function:: _unpad(raw_message, bs)