RedMatrix by Friendica

[HaakonME]

https://github.com/redmatrix/redmatrix from the Friendica developers might suite your project's goals about federation with Friendica and Owncloud without a valid CA SSL.

[rabuzarus]

as far as I know red needs valid CA SSL to communicate over SSL

but maybe valid CA SSL will be available soon for everyone. Have a look at https://letsencrypt.org