Add hwid digest field to GBB header

This adds a field in the GBB header to store the sha256 digest of
the HWID string, and updates gbb_utility so that it stores the
digest when it modifies the HWID. Because this is a new field,
the GBB_MINOR_VER is incremented.

BUG=chromium:415227
BRANCH=ToT
TEST=make runtests, VBOOT2=1 make runtests

Since the GBB is in the RO firmware, there should be no side
effects for existing devices (but even without that, they should
handle a minor version change without complaint).

Change-Id: Icdb2a0b564677b0b65e58df897d2ec5af3964998
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/221360

1 files changed, 8 insertions, 0 deletions

diff --git a/futility/futility.h b/futility/futility.h
index 7892c5ad..52c007cc 100644
--- a/futility/futility.h
+++ b/futility/futility.h
@@ -71,6 +71,14 @@ int futil_looks_like_gbb(GoogleBinaryBlockHeader *gbb, uint32_t len);
 int futil_valid_gbb_header(GoogleBinaryBlockHeader *gbb, uint32_t len,
 			   uint32_t *maxlen);
 
+/* For GBB v1.2 and later, update the hwid_digest */
+void update_hwid_digest(GoogleBinaryBlockHeader *gbb);
+
+/* For GBB v1.2 and later, print the stored digest of the HWID (and whether
+ * it's correct). Return true if it is correct. */
+int print_hwid_digest(GoogleBinaryBlockHeader *gbb,
+		      const char *banner, const char *footer);
+
 /* Copies a file or dies with an error message */
 void futil_copy_file_or_die(const char *infile, const char *outfile);