In modern Poky the facade is gone and the data dictionary needs
to be accessed directly. This commit is catching up with it. It
was build tested on dora as well. I have not checked if it is
changing the checksums of a dora build.
The previous patch made sure a truncated key would be re-generated
but it broke the case that there is no key at all. This code is
handling both cases now. Use quotes as code outside this method
is using them too. Use the -a and not the && operator to work with
the busybox version of [ and ].