futility: Compute / verify root key hash
Ryu will store a hash of the GBB root key in a struct inside its boot
block. Add a vb2_ryu_root_key_hash struct for that.
If 'futility gbb_utility' is used to set the root key, also look for a
root key hash struct and fill it in. No error if not found, because
this needs to work on other platforms where the struct is not present.
This way, we don't need to change the signing scripts.
Added a --roothash option which can be used to check if the root key
hash is found, and if so, whether it's empty, valid, or invalid.
BUG=chromium:511405
BRANCH=ryu
TEST=manual
Take any existing image.bin.
cp image.bin image.orig
gbb_utility --roothash image.bin
- ryu root hash not found
Extract the root key
gbb_utility -k rootkey.bin image.bin
- exported root_key to file: rootkey.bin
Now, append a blank ryu root hash struct to it
echo '0000000: 5274 4b79 4861 7368 0100 0000 3000 0000' | xxd -r >> image.bin
echo '0000000: 0000 0000 0000 0000 0000 0000 0000 0000' | xxd -r >> image.bin
echo '0000000: 0000 0000 0000 0000 0000 0000 0000 0000' | xxd -r >> image.bin
Nothing is set yet
gbb_utility --roothash image.bin
- ryu root hash is unset
Setting the root key also sets the root hash
gbb_utility -s -k rootkey.bin image.bin
- import root_key from rootkey.bin: success
- calculate ryu root hash: success
successfully saved new image to: image.bin
See, it verifies
gbb_utility --roothash image.bin
- ryu root hash verified
Now, append a bad ryu root hash struct to it
cp image.orig image.bin
echo '0000000: 5274 4b79 4861 7368 0100 0000 3000 0000' | xxd -r >> image.bin
echo '0000000: 0001 0000 0000 0000 0000 0000 0000 0000' | xxd -r >> image.bin
echo '0000000: 0000 0000 0000 0000 0000 0000 0000 0000' | xxd -r >> image.bin
See, it fails
gbb_utility --roothash image.bin
- ryu root hash does not verify
Make sure the library doesn't contain the magic string
strings `which futility` | grep RtKyHash
(should be no output)
Change-Id: Ib46f93cac0f2b532bada4b187ae48efcf4926702
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/286237
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
5 files changed
