First of all let me start by stating the fact that I am a bit noobish in servers and web services.
I have setup ownCloud both on a shared hosting and on a private server and what I would like is to add a iframe to the public download page.
I've editted ../apps/files_sharing/templates/public.php to add my iframe code for my facebook page, but it stays white and doesn't load.
Chrome console states the following: Refused to frame '[FB LINK HERE]' because it violates the following Content Security Policy directive: "frame-src 'self'".
This is a description, was is the actual question?
More about CSP: https://en.wikipedia.org/wiki/Content_Security_Policy And you see perhaps the reason this is enabled in owncloud by default. You could just turn it off but that removes also the protection it provides. So you are looking in a special app/feature to allow the use of integrating owncloud as an iframe to external services?