XEP-0060 is supported by Prosody since a long time ago, as a component. I think you just need to enable it. See https://prosody.im/doc/pubsub, you need yet another extra subdomain and should include it to your server certificate.
Okay, I see the issue. The problem here is PubSub component in Prosody doesn't support Section 7.1.5 (a.k.a. publish-options) of XEP-0060, which affects the usability of OMEMO. Anyone has the plan to implement it?
So to allow for OMEMO with non-contacts or contacts without presence authorization we don't need publishing-options? Issue link by Xmpp Texting: FTW says it is necessary
Just announced on prosody MUC: https://github.com/iNPUTmice/omemo_all_access
> Traditionally OMEMO encrypted messages could only be exchanged after gaining mutual presence subscription due to the OMEMO key material being stored in PEP.
> XEP-0060 defines a method of changing the access model of a PEP node from presence to open. However Prosody does not yet support access models on PEP nodes.
> This module disables access control for all OMEMO PEP nodes (=all nodes in the namespace of eu.siacs.conversations.axolotl.*), giving everyone access to the OMEMO key material and allowing them to start OMEMO sessions with users on this server.
I pushed some in-progress publish-options support to trunk. It must ONLY be used for testing, and not on production servers with real data, Therefore it is currently disabled by default.
Thanks to Jonas Wielicki for providing tests and bugfixes for this feature. I've now enabled it by default (so it will be active in tomorrow's nightly build).
Marking as fixed our most-starred issue on the tracker :)