bdb: Add bdb_extend

bdb_extend prints out secrets derived from the given BDS based on
the given BDB.

BUG=chromium:649555
BRANCH=none
TEST=make runtests. Ran bdb_extend -s bds.bin -b bdb.bin (with/without -m)

Change-Id: I8d9f73468992dad4cb93a422c0eae0977be9a16f
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/385539
4 files changed