"Unable to decrypt messages"

[fbievan]

Tracking this issue here
As noted here this seems to a fairly common problem.

After unsuccessfully trying to recreate your solution in that thread, I'm making a issue here.

Logs needed
Diagnostics needed

When I can- I'll go look into debug on my homeservers. Till then- this is just for tracking

[MangoCubes]

This is most likely a client issue rather than server because I occasionally encounter this. Unfortunately, I cannot recreate it reliably; It seems to happen randomly and I simply can't find what triggers this. :( I will test with updated Trixnity library first, and if that doesn't work, I am thinking of digging deep into the cryptography and the source code. I happen to be in a security lab now, and might do something related to Matrix as my next research topic.

[fbievan]

This is most likely a client issue rather than server because I occasionally encounter this. Unfortunately, I cannot recreate it reliably; It seems to happen randomly and I simply can't find what triggers this. :( I will test with updated Trixnity library first, and if that doesn't work, I am thinking of digging deep into the cryptography and the source code. I happen to be in a security lab now, and might do something related to Matrix as my next research topic.

Seems to happen consistent for me, I want to see what's different about what the clients are sending, to find out what the root cause is.

I'm using a conduit homeserver in my testing.

The only messages I can see from the bot is unencrypted ones.

There is a delay of unencrypted messages to encrypted messages when starting a new room is started by receiving an sms.

Not drawing any conclusions yet.

[MangoCubes]

Your setup is definitely different from mine as I test on my home server and the official Matrix server, both of which are running on Synapse server. Still, the issue happens on there, but not consistently. I suppose I could resort to having messages sent unencrypted if explicitly specified.

[MangoCubes]

I updated the Trixnity library this app uses, but the issue persists. It seems that the events are read before they are decrypted, but I can't figure out how to ensure the events are read after they are encrypted. I'll have to dig in further to sort this out. Interestingly, the library now provides bot mode, which may make things a bit less complicated. I'm currently rewriting the whole thing with this. Hopefully this bot mode is simple enough that I don't have to deal with this bug anymore.

Here's the APK if you want to test it with latest API though.
app-release.zip

[fbievan]

I updated the Trixnity library this app uses, but the issue persists. It seems that the events are read before they are decrypted, but I can't figure out how to ensure the events are read after they are encrypted. I'll have to dig in further to sort this out. Interestingly, the library now provides bot mode, which may make things a bit less complicated. I'm currently rewriting the whole thing with this. Hopefully this bot mode is simple enough that I don't have to deal with this bug anymore.

Here's the APK if you want to test it with latest API though. app-release.zip

Cool, I'll continue watching in the mean time.

[benkuly]

The bot mode just disables some features of Trixnity, making it faster and saving less data into database.

[benkuly]

Could you describe the decryption problem a bit more? Maybe I can help (as maintained of Trixnity).

[MangoCubes]

Yes! I know you! :)

I forgot to push the updated version, but here is the gist of it:

remotrix/app/src/main/java/ch/skew/remotrix/background/CommandService.kt

Line 460 in 9984a23

client.room.getTimelineEventsFromNowOn(decryptionTimeout = 10.seconds).collect { ev ->

Currently, I am using getTimelineEventsFromNowOn, which if I understand correctly, receives events and triggers decryption if necessary. In the newer API, it resolves into one of the three:

• If decryption fails, it resolves to Failure
• If decryption is completed, it resolves to Success
• If decryption is not completed, it resolves into null

This is the issue I am having. I am noticing that a fair number of messages are resolving to null instead of failure or success. I can't figure out a way to get the message after it is fully decrypted, or after it fails so I can diagnose further.

Thank you again.

[benkuly]

It's null because decryption timed out, which usually happens, when the sender did not send us the Megolm session...