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Comment by Silhouette | Hacker News Reader

So when will we be able to make real backups of Signal messages using the iOS app?

Privacy is valuable, but important messages without ability to make backups is already very risky given the inherent fallibility (and steal-ability) of mobile devices. Having data loss bugs in conjunction with that is delete-the-app-and-use-something-else unforgivable.

Unless I've missed something, it's still impossible by construction to export your message history as a real backup on iOS, even if you are happy that it's being done entirely locally and the receiving system is adequately secured.

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There's a hacky way to back up messages sent on IOS, if you sync messages to desktop client, because it stores messages in a SQLite database. While encrypted, encryption key for the database is kept as plaintext in a JSON file. :)

On Windows:

1. Download "DB Browser for SQLite" https://sqlitebrowser.org/

2. Unpack it and run "DB Browser for SQLCipher.exe".

3. Open database, select "%APPDATA%\Signal\sql\db.sqlite".

4. In the following dialog, select "Raw key" type and enter the encryption key stored in "%APPDATA%\Signal\config.json" into Password field (prefix it with 0x).

5. Now you can work with the database, including exporting its contents to unencrypted SQLite, CSV and JSON.

The process should be similar on other platforms.

The Signal desktop client is a poster child for “lousy Electron app” and a sucky user experience. I don’t use Signal a lot and get maybe three or four messages a day in total. Every time I launch the desktop client it counts the messages one by one like a small child would.

Yes, I instantly get sad each time I fire it up. Aside being the lousiest of Electron apps, it has no security features at all. Just pair once with your phone and anyone gaining access to your computer can read your messages. Are the messages on my computer encrypted? I don't know. I wish I could set up a strong password.

While encrypted, encryption key for the database is kept as plaintext in a JSON file.

...which is kept right next to the encrypted DB and presumably has the same permissions, so what's the point?

A more secure delete, for one.

Not really considering SQLite databases can use WAL commits and it’s easy to view those previous commits.

SQLCipher encrypts the WAL.[1]

[1] https://www.zetetic.net/sqlcipher/design/

From your source, it uses the same key:

> Write Ahead Log Files - Using the new WAL mode (i.e. PRAGMA journal_mode = WAL;), page data stored in the WAL file is encrypted using the datbase key. Pages in the rollback journal are encrypted using the same key as the main database. Verification: create an encrypted database, start a transaction, make changes, and then inspect the -wal file using hexdump or a similar program.

So destroying the key makes both unrecoverable.

Yes, Except the key isn’t destroyed it’s in the json file next to the main db file. Meaning user’s deleted messages could still be recovered.

Even if the user went as far as deleting the json file, it could still possibly be recovered due to the way the FS ‘deletes’ files.

I think the other posters are saying it’s much easier to shred a small file than it is to shred a multiple GB database, although these days it doesn’t matter so much for a database that small. It’s super efficient for file systems though.

Yes. And I'm talking generally. I don't know what Signal does.

Thank you. I haven't been able to try it immediately as I don't normally use the desktop client, but that looks like a workaround that could be useful.

What's up with yours and ttty's comments?

> When will we be able to make real backups of Signal messages using the iOS app? Privacy is valuable, but important messages without ability to make backups is already very risky. Having data loss bugs is unforgivable.

> So when will we be able to make real backups of Signal messages using the iOS app? Privacy is valuable, but important messages without ability to make backups is already very risky given the inherent fallibility (and steal-ability) of mobile devices. Having data loss bugs in conjunction with that is delete-the-app-and-use-something-else unforgivable.

Very fishy.

I don't think Silhouette had anything to do with this. The other user has been posting junk content which is either autogenerated, glued together from other content, or both. The comment where they copied from Silhouette (https://news.ycombinator.com/item?id=26842183) also copied from https://github.com/signalapp/Signal-Android/issues/11160#iss..., and probably other places too. I asked them to stop (https://news.ycombinator.com/item?id=26837415) and they didn't, so I've banned the account (https://news.ycombinator.com/item?id=26846079).

ttty has been posting comments that seem to be auto-summarised versions of other sources (or even complete copies). dang told them to stop (https://news.ycombinator.com/item?id=26837415) but they haven't.

(Edit: and now they're downvoting me for pointing it out?)

(Edit 2: It's now getting ridiculous: https://news.ycombinator.com/threads?id=ttty)

Bad bots

Feels more like a human-templated response from a fiverr job or something.

Looks like an extractive algorithm, so I doubt it's a fiverr job.

I don't understand. You're asking why concerns about trying to prevent backups of a user's own data are relevant in a discussion about a bug that reportedly causes catastrophic data loss?

I think they're more wondering why two separate users are posting nearly word-for-word identical comments.

I don't know. When I wrote my comment, it was the second comment in the entire discussion, and it seemed like an important issue to raise. Someone upvoted. Someone replied with a workaround, and I replied to thank them. I haven't seen this other comment that some of you seem to be referring to, so I assume it was subsequently deleted, but whatever it was had nothing to do with me.

It would be nice if we could avoid silly conspiracy theories and meta discussions on HN, but if anyone really wants to check, the link to my profile is right above this comment. It's the one that has been an HN member for well over a decade. You can't see that most of my comments across a broad range of issues get a few upvotes, but you can see that very few go down overall and I average around 1000/year in karma, which I think is a reasonable benchmark for being a real person who is contributing constructively here.

The other user is apparently a bot.

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