Allow unlocking any persistent volume when multiple ones are available

Change the greeter to support multiple encrypted persistence partitions. When the user enters a password, try that password against partition in turn until it finds a match.

Use cases:

• Allow multiple users to share a tails device whilst still maintaining privacy.
• Support plausible deniability / rubber hose protection - users can create several partitions and when pressed reveal the password to a unimportant partition

The code change for this is very simple. I’ve included a patch.

(Ideally the persistence-setup tool could be extended to support this, but that’s much more work).

Feature Branch: tails:feature/15653-15656-greeter-unlock,greeter:feature/15653-15656-greeter-unlock

Attachments

• greeter.patch
• greeter2.patch

Related issues

• Related to #5929

Original created by @Gaff on 15653 (Redmine)