[whispersystems] Discussion of approach for export/import features

[Johan Wevers]

I'm looking for some guidance on advancing Signal's export/import features; please let me know if I'm in the wrong
place. Neither github nor https://whispersystems.discoursehosting.net/ seemed appropriate.

Frankly, I've given up on this. I did a pull request
(https://github.com/WhisperSystems/Signal-Android/pull/5907) that got
rejected. Moxie seems to want compatibility with a 3rd party tool "sms
backup and restore", which seems an overly complicated method, but
refuses to explain why he does not want the current encrypted backup (it
is mostly his own code I reintroduced, with some tweaks to not backup
the .so libraries and quit Signal after restore) back in the program for
the time being.

I can only guess for the reasons behind this, and unless I see a good
reason WHY he is so persistent on this method I don't feel like putting
any work in it. I build my own version for this reason. Added advantage
is that it won't expire either, that nasty "feature" is easily removed.

Now people have to use an own compiled version or use a root backup tool
like Titanium when they want to properly transfer data to another
device. Even adb backup doesn't work anymore after version 2.28 to
prevent Google from backupping the conversations in the cloud.

[Moxie Marlinspike]

I've read the history of discussion and attempts at this feature, and I feel like limiting the scope and splitting the
tasks may be more achievable. While I'd like to see the full encrypted backup like everyone else, I want to confine my
work to a few small features and try to iteratively build this up. This should also allow others to pick up when I stop.

Hey Charlie, that sounds like a great approach.

1) Group conversations aren't exported with enough metadata to allow for reassembly.
2) Images are skipped entirely.
3) Other media types are skipped. (may follow easily from images, but things like large videos may pose some challenges
when base64'd and dumped into an XML attribute...)
4) Conversation archived state.
5) Signal preferences.
6) Conversation/contact preferences (notifications, muting, colours, etc)
7) Block lists.
8) User identity/keys/registration.
9) A smooth way of transferring this export between devices for the common "new phone" case.

All these look good, except for "registration," which we'll never want
to back up.

Obviously a lot of these constitute a supserset of what the SMS Backup &
Restore format supports, but it should be possible to define them in a
way that degrades well. We're going to have to use some data format,
might as well use one that provides some portability, unless we find
that it's really impossible to use that one for some reason.

a) Is this an acceptable direction for the export/import features?
b) Is merging several small improvements like this acceptable? (as FREEBIEs, compensation irrelevant)

Yep

- moxie

[Joel Whitehouse]

In a recent iPhone software update, a contact of mine started Signal up
again, and it asked to re-register his number; he'd also lost his
message history, signal-desktop pairing, etc. In his words:

"the app auto updates in the background. I opened it to send a message
and it was completely reset."

Is there any way to get it back?
Has anyone else observed this behavior?

[Raphael Brandis]

Sounds like this bug (fixed in version 2.6.13):

https://github.com/WhisperSystems/Signal-iOS/issues/1627

No idea if it's possible to recover from this state.

Post by Joel Whitehouse
In a recent iPhone software update, a contact of mine started Signal
up again, and it asked to re-register his number; he'd also lost his
"the app auto updates in the background. I opened it to send a message
and it was completely reset."
Is there any way to get it back?
Has anyone else observed this behavior?