update-smart-drivedb: embedded GPG key expires in 2020

[Lucas Kanashiro]

In Focal, the update-smart-drivedb script has an embedded GPG key which seems to expire in 2020:

$ grep -A2 "Signing Key" /usr/sbin/update-smart-drivedb
# Smartmontools Signing Key (through 2020)
# <email address hidden>
# Key ID 721042C5

We need to keep that in mind to update the key as soon as upstream releases a new one.

[Paride Legovini (paride)]

Hi, I noticed a couple of things while looking what this is about:

1. The KeyID is mentioned in the update-smart-drivedb(8) manpage too, so when we upgrade the key the manpage has to be updated too. (I'd use the full fingerprint rather than the KeyID.)

2. LP: #1893202.

[Christian Franke (christian-franke)]

Key 721042C5 lifetime has been extended to 2025. Old update scripts should still work as gpg does not refuse verification if (signature_timestamp > pubkey_expiry_time).