futility: Add support for verifying recovery MRC cache

This functionality allows factory to ensure that the recovery MRC cache
trained during finalization has the right signature and the checksum on
the data can be verified.

BUG=chrome-os-partner:59661
BRANCH=None
TEST=Verified checksum on recovery mrc cache.

Change-Id: Ic5bd9910b4542037ad86f6fb7a7d83b97be5c792
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/409680
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
2 files changed