Conversations: OMEMO broken (on Android 5.1 and older?)

[STPKITT]

• Version: 2.3.1+fcr
• Device: Samsung Galaxy SIII mini
• Android Version: Lollipop 5.1.1 (CyanogenMod 12.1) 20150706
• Server name: tested on jabber.at, jabber-germany.de, trashserver.net
• Conversations source: F-Droid

Since updating to Conversations 2.3.1+fcr OMEMO on the device listed above encrypted messages are not received at all and sending a message with OMEMO enabled immediately results in "Delivery failed" / "Zustellung fehlgeschlagen" while unencrypted messaging works fine.
I personally don't have that problem on a Galaxy S5 running LineageOS 15.1 (Android 8.1.0).
Members of [email protected] tried the same Conversations version on multiple Android 6 & 8 devices and on one Android 7 device and also had no problem using OMEMO.
So until now it looks like a problem on devices running Android 5.1 and maybe older.

Debug output

2018-10-10 10:00:41,INFORMATION,Timeline,Android-System,Timeline: Activity_windows_visible id: ActivityRecord{33eef5b6 u0 eu.siacs.conversations/.ui.ConversationsActivity t27968} time:27703418
2018-10-10 10:00:44,DEBUG,conversations,Conversations,AxolotlService ([email protected]): Finding devices without session for [email protected]
2018-10-10 10:00:44,WARNING,conversations,Conversations,AxolotlService ([email protected]): Have no target devices in PEP!
2018-10-10 10:00:44,DEBUG,conversations,Conversations,AxolotlService ([email protected]): Cache miss: 40f4b65b-e124-4372-8e5f-e778096e5e8a
2018-10-10 10:00:44,WARNING,conversations,Conversations,AxolotlService ([email protected]): Failed to encrypt message: java.security.InvalidAlgorithmParameterException: Expected IV length of 12 but was 16

[ghc2018]

Can confirm this bug on Android 5.1 on a Wiko Rainbow Jam Smartphone.

This bug isn't present on my Samsung Tab 10.1 running Android 7.0.

[tapete]

I also can confirm this bug on android 5.1.1. I erroneously thought this problem was related to ISN. After 5 hours of troubleshooting in prosody I found out that unencrypted messages work fine. I tried to reset all omemo keys but it did not help. I deinstalled conversations and installed the older 2.3.0 version but this also did not help. Then I installed conversations legacy and this worked fine.

[STPKITT]

@tapete Thanks for reporting! I think 2.2.9 was the last version in which OMEMO worked on old Androids.

[iNPUTmice]

Possibly fixed in 409bf3c0cbf0a33e08819bb858cfcb6489f6fb5b

[zuglufttier]

Can confirm this problem with a client on Android 5.1.1. Will there be a new version soon?

[STPKITT]

I certainly hope so, I'm currently bound to Gajim.

[licaon-kter]

Already released on F-Droid too.

[STPKITT]

Thanks for that information, it's indeed available now and I tried sending and receiving OMEMO messages and it all seems to work fine again. I'd say this issue can be closed then but I'll leave that decision to the bosses :-)

[licaon-kter]

@STPKITT close it if fixed

[STPKITT]

Well I can only test on Android 5.1, but the issue also affected Android 6 AFAIK.