OMEMO fails to decrypt messages from "Legacy OMEMO"

[poVoq]

Expected behavior

When joining a already existing 1:1 chat that was created with another XMPP client it fails to decrypt messages from external clients using "Legacy OMEMO" (was edited)

Actual behavior

It exchanges keys with own devices and also sends the new device key to the remote contact, so one can send omemo encrypted messages and on other clients your own messages also get decrypted from the carbon copy, but incoming messages from remote contacts edit: using "Legacy OMEMO" are not decrypted and only show:
This message is encrypted with Legacy OMEMO (eu.siacs.conversations.axolotl)

Steps to reproduce the behavior

1. Create a 1:1 omemo encryted chat with Gajim and the other side is using Poezio
2. Open JSXC and the chat
3. Send messages fine but not receive any messages in a decrypted way.

Environment

• JSXC version: 4.3.1
• Host system and version: custom
• Browser vendor and version: Firefox latest (Linux)

Edit: I guess that might be an issue with Poezio not using the latest OMEMO standard?

[poVoq]

I tried talking to pep. who maintains the poezio-omemo plugin and he seems to think it is a key-exchange issue. In the xml-console from Gajim I can see that the device ID of the JSXC is used to send carbons from Gajim, but messages from Poezio do not include the JSXC device ID.

I assume that this is an Poezio issue, but maybe JSXC is also requesting the key in a way that Poezio can not understand?

[sualko]

I assume that this is an Poezio issue, but maybe JSXC is also requesting the key in a way that Poezio can not understand?

Maybe you have to accept the new (jsxc) device in Poezio. I do not want to exclude that this is a jsxc issue, but if Gajim is using the jsxc device id it's more likely that this is an issue with Poezio.

If I have some time, I will look into it.

Btw. do you know what legacy OMEMO is?

[Neustradamus]

@poVoq: Have you progressed on this issue?
It is solved or always here?