When wanting to add a desktop Delta as 2nd device to a phone, it wants me to scan a QRCode on the phone from a desktop without camera.
Ok it can otherwise copy the payload by clipboard and another channel.
Ok, did so.
Does not work because they need to be on the same L2 network. That will never happen because the phone has strict VPN.
Then I had to transfer backups. OK.
Export. It exports it to /storage/emulated/userid/Download/ .
Thats super risky because everything can write to it.
There have been some proposals to reverse the scanning flow, but that would not help with the VPN. If you trust your browser and TLS, you can paste the payload (which is a URL) into a browser; that still doesn’t help with the VPN.
My client (Deltatouch on Mobian) lets me pick the export directory. I think the Android client disabled exports at one point because Android forbade doing it securely.
You can also verify your fingerprints after transfer.
Maybe there should be a secure way to send a profile backup using Deltachat? Then you make a fresh desktop account, scan it from the phone, and send the backup via the resulting chat.
Personally, I think the Chatmail relays should only serve to retrieve messages (with a certain “ID”) once (multiple devices could do this safely because of this “ID”).
Afterward, using some process that must not only be “the same local network”, allow devices syncing directly, either via a direct connection (say, a VPN in the classic sense), or similar to how Syncthing works, using relays to establish communication that is still end-to-end encrypted.
The fact that turning on multi-device in Delta Chat just retains encrypted messages on the relay seems quite hacky to me, and also increases storage resource usage on those relays. I’d be much happier if devices could optionally establish communications via their chatmail relay (or some other) to sync messages between each other instead (and since they are a user’s devices, the user already assigns trust to them).