[Feature request]: XEP-0420

[Sami32]

https://xmpp.org/extensions/xep-0420.html

[yurtpage]

The underlying library Smack supports the XEP:

End-to-end encryption of arbitrary extension elements. Smack provides elements and providers to be used by encryption mechanisms.

But I don't know any XMPP client that uses the XEP. Why it's so important?

[Sami32]

It seem that the newest version of XEP-0384 uses XEP-0420, so there is now padding to disguise the actual message length (XEP-0420 borrows this again from XEP-0373: OpenPGP for XMPP).
https://download.igniterealtime.org/smack/docs/4.2.2/documentation/extensions/omemo.html

They seem on the way to add it to an experimental section:
https://codeberg.org/mellium/xmpp/pulls/385

Please, feel free to close this request as you feel.

Edit:
I just discovered that they also plan to add XEP-0420 support:
https://slixmpp-omemo.readthedocs.io/en/latest/index.html

https://xmpp.org/extensions/#xep-0420-implementations

[cmeng-git]

Do you know any XEP-0384 smack library implementation uses

Just reliaze that smack 4.4.8 uses

[Sami32]

Yep, in fact i just realized that it was supported by Smack library since their 4.2 version:

igniterealtime/Smack#133
I also see that XEP-0420 is also mentioned as experimentaly supported:
https://download.igniterealtime.org/smack/dailybuilds/documentation/extensions/

It seem that their stable 4.5.0 version is near release, so it should have the latest XEP-0384 0.9 version:
https://central.sonatype.com/artifact/org.igniterealtime.smack/smack-omemo/4.5.0-beta6
https://mvnrepository.com/artifact/org.igniterealtime.smack/smack-omemo-signal

Edit:
As a side note, aTalk XEP-0384 support on the xmpp.org status webpage is not green:
https://xmpp.org/extensions/#xep-0384-implementations

[cmeng-git]

Found that smack 4.5.0 does provide support for XEP-0420: Stanza Content Encryption, however the current supported omemo is only for XEP-0384: OMEMO Encryption version 0.3.0.

[cmeng-git]

Another concern is that I am unable to find any current xmpp client that support XEP-0384 version 0.9. I am also unable to fingure out the possibility of co-existence of both new and old XEP-0384. Any xmpp client that implements v0.9 will be a lone ranger in this area.

[Sami32]

I have no knowledge about a XMPP application using the XEP-0384 version 0.3 and 0.9 at the same time.

Few applications have these extensions implemented and recently many of these XMPP applications repositories have been archived, like QXmpp (Kaidan relying on it) or UWPX (github.com/UWPX/UWPX-Client)...

So the best i saw was XEP-0384 version 0.8.3 and XEP-0420 version 0.4.1 together:

https://xmpp.org/extensions/#xep-0384-implementations

https://xmpp.org/extensions/#xep-0420-implementations

[cmeng-git]

aTalk incorrectly specifies its XEP-0384 version supported in its doap file. Currently it supports only 0.3.

If aTalk proceeds to implement for 0.9, it means NONE of the existing clients e.g. conversations, gajim, Dino etc is able to communcate with aTalk using omemo. This is less acceptable for users, unless aTalk is able to support both 0.3 and 0.9 i.e. conexistence.

The provded link QXmpp is a library, no sure which xmpp client is using it.

[Sami32]

Oh...ok, i wasn't aware of this misreporting.
Kaidan use QXmpp library.

Now i understand your point, that make sens.

After reading this, i'm wondering if that it is even worst considering?