2lib: Fix struct vb2_hash the way it was meant to bestabilize-quickfix-12871.27.Bstabilize-12871.91.Bstabilize-12871.65.Bstabilize-12871.57.Bstabilize-12871.253.Bstabilize-12871.24.Bstabilize-12871.103.Bstabilize-12871.102.Brelease-R81-12871.B

My goal in CL:1963614 was to write struct vb2_hash such that it can
match the exisiting binary representation of the CBFS hash attribute,
but no longer be dependent on endianness. Unfortunately I screwed up...
if you want to match the binary representation of a big-endian integer
for small numbers, the important byte you're interested in is the *last*
one, not the first.

Thankfully we still have time to fix the issue before this struct is
really used anywhere, so this patch does that and adds a test to double
check I got it right this time.

Also clarify comments about how vboot is allowed to use this struct a
bit to match the indended usage I'm planning in coreboot. In doing that
I realized that you actually don't want to make it easy to sizeof() the
|bytes| portion of the struct (because functions shouldn't rely on that
size anyway, they should only touch what's valid for a given hash
algorithm), so taking that out which also makes it a little more
comfortable to work with the struct.

BRANCH=none
BUG=none
TEST=make runtests

Change-Id: I7e1a19f36d75acb69e5d1bfa79700c9d878f9703
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2019952

1 files changed, 1 insertions, 1 deletions

diff --git a/firmware/2lib/2sha_utility.c b/firmware/2lib/2sha_utility.c
index 8c6f4b80..378f4c8a 100644
--- a/firmware/2lib/2sha_utility.c
+++ b/firmware/2lib/2sha_utility.c
@@ -221,7 +221,7 @@ vb2_error_t vb2_hash_verify(const void *buf, uint32_t size,
 					   hash_buf, hash_size);
 	if (rv)
 		return rv;
-	if (memcmp(hash_buf, hash->bytes.raw, hash_size))
+	if (memcmp(hash_buf, hash->raw, hash_size))
 		return VB2_ERROR_SHA_MISMATCH;
 	else
 		return VB2_SUCCESS;