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author | Bill Richardson <wfrichar@chromium.org> | 2014-10-22 17:42:20 -0700 |
---|---|---|
committer | chrome-internal-fetch <chrome-internal-fetch@google.com> | 2014-10-31 20:55:28 +0000 |
commit | f4f395e1ca724ef8795cfe86a9edbf15f14eacd1 (patch) | |
tree | f76bbb265c340603f18fa74e1b4e3934006a94e1 /Makefile | |
parent | e1486c3234b7dc6fc5b58681b271a65a09141e20 (diff) | |
download | vboot-f4f395e1ca724ef8795cfe86a9edbf15f14eacd1.tar.gz |
Extend HWID digest into PCR1 (GBB v1.2 only)
GBB header v1.2 adds a digest of the HWID string to the blob (and
maintains it when updated with the current futility/gbb_utility).
This CL causes VbSelectFirmware() to extend PCR1 with that HWID
digest (only for GBB header v1.2 and later, of course).
Tests are updated.
This also adds a "pcr" command to futility to help determine that
the change is working on the hardware (adds 4K bytes or fewer to
the size of the executable).
BUG=chromium:415714
BRANCH=ToT (and maybe others?)
TEST=make runtests, manual install on HW
To test on hardware, build and update a system with this change
(both the disk image and the RO firmware).
NOTE: The BIOS image must be built in a chroot that is using the
current version of futility. You may need to update your chroot
if your BIOS image still produces v1.1 GBB headers. Check with:
futility show <firmware_image.bin> | grep -B1 'digest:'
Boot the new system with a new test image, then follow these steps:
Read the BIOS:
# flashrom -r /tmp/bios.bin
Make sure the GBB has a valid digest for the HWID.
# futility show /tmp/bios.bin | grep -B1 'digest:'
HWID: SAMUS TEST 8028
digest: 4172d24f40bf72cc0ab8... <valid>
#
Extract only the sha1sum-sized part of the HWID digest:
# futility show /tmp/bios.bin | awk '/digest:/ {print $2}' | colrm 41
4172d24f40bf72cc0ab878b4c589b8fe9cf4405e
#
Simulate extending that value in a PCR using the futility "pcr"
command:
# futility pcr 4172d24f40bf72cc0ab878b4c589b8fe9cf4405e
PCR: 0000000000000000000000000000000000000000
+ 4172d24f40bf72cc0ab878b4c589b8fe9cf4405e
PCR: b6e5ffd2d898a7b15236ad22ca25f53ac1f40776
#
Finally, look at the value of PCR1. It should match the last line
of the futility pcr output:
# head /sys/class/misc/tpm0/device/pcrs | grep PCR-01
PCR-01: B6 E5 FF D2 D8 98 A7 B1 52 36 AD 22 CA 25 F5 3A C1 F4 07 76
#
Change-Id: I09cf855f1a24616cc1a9ddb676670edbc76827d2
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/226408
Reviewed-by: Darren Krahn <dkrahn@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Diffstat (limited to 'Makefile')
-rw-r--r-- | Makefile | 1 |
1 files changed, 1 insertions, 0 deletions
@@ -545,6 +545,7 @@ FUTIL_SRCS = \ futility/cmd_dev_sign_file.c \ futility/cmd_dump_kernel_config.c \ futility/cmd_load_fmap.c \ + futility/cmd_pcr.c \ futility/cmd_show.c \ futility/cmd_sign.c \ futility/cmd_vbutil_firmware.c \ |