Update GPG verification always fails

[Florian W.]

Since the GPG validation in recovery is now working correctly, I noticed another bug in system-image-upgrader that seems to prevent all updates from being applied, even if they are signed by a trusted image-signing key. Instead, the recovery log contains "Invalid signature" and the device reboots without applying the update. From a user POV it's difficult to notice that the update didn't work.

The bad code is probably:
            if ! verify_signature device-signing /cache/recovery/$2 && \
               ! verify_signature image-signing /cache/recovery/$2; then

This should probably be $3 instead of $2.

I tested this with $3 and updates were applied correctly instead of showing "Invalid signature". However, I haven't tested the opposite, i.e. if it discards updates with bad signature.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.