Fix poptReadDefaultConfig() error checking.

This makes it so we don't exit with an error just because there's no
default popt config.

Signed-off-by: Peter Jones <pjones@redhat.com>
Use libefivar for guid declarations and parsing.

Signed-off-by: Peter Jones <pjones@redhat.com>
Allow aarch64 in the rhel build macros.

Signed-off-by: Peter Jones <pjones@redhat.com>
[pesigcheck] Always verify at a time within the validity window.

Since it's not okay to ever check the times, just pick the notBefore
time from the certificate we're verifying against.

Signed-off-by: Peter Jones <pjones@redhat.com>