in Openfire’s Admin UI go to:
Server Settings -> External Components -> “Plain-text (with STARTTLS) connections” and choose “Required”.
A user expects that STARTTLS is used, but in fact it’s not.
I know that STARTTLS is not specfied for XEP-0114, but I’ve recently learned that Oracle XMPP Server supports it nonetheless, if the version attribute in the stream header is set (“1.0”).
Even if I set it to “1.0” Openfire offers no stream features for external components (which is fine).
But if it’s not supported, it shouldn’t be configurable.