[BUG] Won't start when restored from Seedvault backup

[o-alquimista]

Describe the bug

When the app data is backed up and restored with Seedvault (an Auto Backup provider), the app won't start at all.

These logs were collected with adb logcat -t '2026-04-12 14:20:00.0', which starts immediately before the attempt to open APS was made.

aps.log

This is probably the error:

--------- beginning of crash
04-12 14:23:54.566  8058  8058 E AndroidRuntime: FATAL EXCEPTION: main
04-12 14:23:54.566  8058  8058 E AndroidRuntime: Process: app.passwordstore.agrahn, PID: 8058
04-12 14:23:54.566  8058  8058 E AndroidRuntime: java.lang.RuntimeException: Unable to create application app.passwordstore.Application: javax.crypto.AEADBadTagException

Steps to reproduce

Steps to reproduce the behavior:

1. Setup Seedvault.
2. Setup Android Password Store with a cloned remote git repository accessed by SSH key, and add a few passwords encrypted with a GPG key.
3. Perform a system backup.
4. Wipe APS' data and uninstall it — maybe just wiping data is enough, but untested by me.
5. Restore APS' data with the backup created in step 3. It should first install the app, then restore its data. It should complete with no issues.

Expected behavior

For now, I'm wiping the app data and reconfiguring it from scratch; only then it works.

The app should run with the restored data.

Screenshots

No response

Device information

• Device: Motorola Moto G32 (devon)
• OS: LineageOS 23 (Android 16)
• App version: 1.16.2

Additional context

No response

[agrahn]

Re-installing the app invalidates all Android Keystore (i. e. hardware) backed encryption and signing keys that were created during the previous installation, such as the in-app generated SSH key pair and the symmetric AES-key for persistent caching of sensitive information. So, a crash is very likely to occur after starting the restored app.

[o-alquimista]

Isn't it possible to catch the error and regenerate the keys? Anything to prevent the crash, and preserve the app settings and the password repository.

Otherwise, if Auto Backup isn't supported, I think it's best to completely disable it. Seedvault pretends to be making a device-to-device transfer, so setting allowBackup=false isn't enough.

[agrahn]

allowBackup=false

In fact, I have not heard about seedvault before. How is it used in connection with Android devices?

[o-alquimista]

It's pretty much like the Google Drive backup (using the same Auto Backup API), but offers more flexibility. I can store the backups on a flash stick, or transfer it via WebDAV or Nextcloud. But it can only be used on custom ROMs that integrate it, such as LineageOS and derivatives.

After choosing a backup location to initialize (with an encryption passphrase), you can make a new snapshot of the system. Restoring data from a snapshot can be done at any time, with the option to restore all apps or just the ones you select.