Check how an encrypted message is attached to the Non-Interactive-Auth message
Created by: claucece
As we are currently implementing the revision number 2 of the OTRv4 specification, we need to include a consistent way of attaching an encrypted message to the Non-Interactive-Auth message.
Please, refer to the "Attaching an Encrypted Message to Non-Interactive-Auth Message in XZDH" section of the OTRv4 spec.
Correctly attach the message to the Non-Interactive-Auth message.
Correctly initialize the double ratchet algorithm for this case.
Correctly derive the double ratchet algorithm keys.
Correctly encrypt and decrypt the message.
Check that the Non-Interactive-Auth message correctly works.