How to get HTTPS on Arduino?
MCUs mounted on Arduinos don't have the horse power to handle https connections.

Yún does handle https on the linux side, with software like curl, wget or python. Your sketch can just delegate the task to the linux side.

While curl works fine, despite having python preinstalled, you need to manually install python-openssl, since it's not available out of the box (due to disk space constraints)