Initial cryptoc implementation.

This commit includes a portable, endian-neutral
implementation of NIST SP 800-90A HMAC DRBG,
P256, SHA, and SHA256.

This code comes from the same source as
https://github.com/google/omaha/tree/master/omaha/base/security

BRANCH=none
BUG=chrome-os-partner:43025,chrome-os-partner:47524
TEST=builds under chroot

Change-Id: Ib0dd555dedca0d6ceb49dca86bce0462119d1a36
Signed-off-by: nagendra modadugu <ngm@google.com>
Reviewed-on: https://chromium-review.googlesource.com/343992
Commit-Ready: Nagendra Modadugu <ngm@google.com>
Tested-by: Nagendra Modadugu <ngm@google.com>
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
22 files changed