I'm looking to develop a chat server using - preferably - python 3.
The chat should have the following functionalities and constraints:
- username/password Authentication.
- Message retention when recipient is offline
- No server-side message saving (other than for the retention for offline users)
- Message encryption
- No mandatory database connection
This is the best case scenario. I can then modify the behavior so that it fits my needs. That's why I'm looking for the closest solution to this. My researches didn't allow me to find a library that had at least 3 of these requirements clearly implemented.