efi_signature_parse_sigdb() is a helper function will be used to parse
signature database variable and instantiate a signature store structure
in later patches.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
In this commit, implemented are a couple of helper functions which will be
used to materialize variable authentication as well as image authentication
in later patches.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>