Comment 5 for bug 1874362

I was able to backport the update-smart-drivedb.in file with gpg verification support:

https://github.com/smartmontools/smartmontools/blob/master/smartmontools/update-smart-drivedb.in

To make it work in Bionic and Xenial I needed to make the following changes:

- Update the GPG public key used to sign the drivedb.h file for versions 6.4 (Xenial) and 6.5 (Bionic). Upstream uses a different key for those old releases, I added the following GPG key:

# gpg --list-keys DFD22559
pub 2048R/DFD22559 2016-10-24 [expires: 2024-12-31]
uid Smartmontools Signing Key (ext. to 2024) <email address hidden>
uid Smartmontools Signing Key (through 2018) <email address hidden>
uid Smartmontools Signing Key (through 2018) <email address hidden>

- This new version of update-smart-drivedb also uses some variables defined via configure script which are not available in the old releases. To workaround that I set those variable inside the script with the same values we have in Focal. Those variables are:

  + ENABLE_SCRIPTPATH_TRUE and ENABLE_SCRIPTPATH_FALSE: in Focal this is enabled, so true was used.
  + scriptpath: this variable contains the search paths for binaries, I set it to "/usr/local/bin:/usr/bin:/bin" as in Focal.
  + GPG: this variable points to the GPG binary, I set it to "gpg" as in Focal.

With those changes in place I was able to run update-smart-drivedb with GPG verification support (also tried some of the new options). To give all the options available to users we will also need to suggest some other packages like it was done here:

https://salsa.debian.org/debian/smartmontools/-/commit/c894f39ddcbc48f478bad9d

My plan is to propose MPs with those changes to collect some feedback.