Axolotl has a well defined message structure using established crypto functions. All of them, for example, except Curve25519 are in Crypto++. You can probably f

Axolotl has a well defined message structure using established crypto functions. All of them, for example, except Curve25519 are in Crypto++. You can probably fairly easily bake your own, albeit I'd use the olm from Matrix and just make theirs work well first.