make_dev_firmware.sh should use key.versions file
The 'key.versions' file is used by the image signing scripts to
ensure that newly generated keys and re-signed buildbot images
have the correct version numbers to avoid rollback in
officially-signed Chrome OS images.
If a skilled user is re-keying her Chromebook to use personal
keys in normal mode (which requires disabling WP and changing the
GBB and VBLOCK_A/B), she can avoid clearing the TPM rollback
counters if make_dev_firmware.sh will obtain the firmware_version
from the key.versions file in her personal key directory.
BUG=none
BRANCH=none
TEST=make runtests, manual tests
Extract an MP-signed BIOS from a Chromebook Peppy.
flashrom -p host -r peppy.bin
Resign it without this CL:
make_dev_firmware.sh -f peppy.bin -k tests/devkeys -t dev_peppy.bin
Resign it with this CL:
make_dev_firmware.sh -f peppy.bin -k tests/devkeys -t dev_peppy_new.bin
Confirm no difference:
cmp dev_peppy.bin dev_peppy_new.bin
Temporarily edit tests/devkeys/key.versions to contain
firmware_key_version=2
firmware_version=3
kernel_key_version=4
kernel_version=5
Resign again:
make_dev_firmware.sh -f peppy.bin -k tests/devkeys -t dev_peppy_new2.bin
Confirm that the only difference is the firmware version in VBLOCK_A/B:
futility show dev_peppy_new*.bin
Change-Id: I133f1b58fb969eaeb239a44a4800750c4eee1d5f
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/383887
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/image_signing/common_minimal.sh b/scripts/image_signing/common_minimal.sh
index fa56676..a591ae4 100644
--- a/scripts/image_signing/common_minimal.sh
+++ b/scripts/image_signing/common_minimal.sh
@@ -338,6 +338,15 @@
# Misc functions
# ----------------------------------------------------------------------------
+# Parses the version file containing key=value lines
+# Args: key file
+# Returns: value
+get_version() {
+ local key="$1"
+ local file="$2"
+ awk -F= -vkey="${key}" '$1 == key { print $NF }' "${file}"
+}
+
# Returns true if all files in parameters exist.
# Args: List of files
ensure_files_exist() {
diff --git a/scripts/image_signing/make_dev_firmware.sh b/scripts/image_signing/make_dev_firmware.sh
index c44e671..9509769 100755
--- a/scripts/image_signing/make_dev_firmware.sh
+++ b/scripts/image_signing/make_dev_firmware.sh
@@ -122,6 +122,8 @@
local dev_firmware_keyblock="$FLAGS_keys/dev_firmware.keyblock"
local dev_firmware_prvkey="$FLAGS_keys/dev_firmware_data_key.vbprivk"
local kernel_sub_pubkey="$FLAGS_keys/kernel_subkey.vbpubk"
+ local version_file="$FLAGS_keys/key.versions"
+ local firmware_version=
local is_from_live=0
local backup_image=
@@ -140,6 +142,11 @@
ensure_files_exist "$FLAGS_from" || exit 1
fi
+ if [ -e "$version_file" ]; then
+ firmware_version=$(get_version "firmware_version" "$version_file")
+ fi
+ : ${firmware_version:=1}
+
debug_msg "Checking software write protection status"
disable_write_protection ||
if is_debug_mode; then
@@ -200,9 +207,8 @@
local unsigned_image="$(make_temp_file)"
local optional_opts=""
if [ -n "$FLAGS_preamble_flags" ]; then
- # optional_opts: VERSION FLAGS
- debug_msg "Setting new VERSION=1, FLAGS=$FLAGS_preamble_flags"
- optional_opts="1 $FLAGS_preamble_flags"
+ debug_msg "Setting FLAGS=$FLAGS_preamble_flags"
+ optional_opts="$FLAGS_preamble_flags"
fi
cp -f "$IMAGE" "$unsigned_image"
"$SCRIPT_BASE/resign_firmwarefd.sh" \
@@ -213,6 +219,7 @@
"$dev_firmware_prvkey" \
"$dev_firmware_keyblock" \
"$kernel_sub_pubkey" \
+ "$firmware_version" \
$optional_opts >"$EXEC_LOG" 2>&1 ||
err_die "Failed to re-sign firmware. (message: $(cat "$EXEC_LOG"))"
if is_debug_mode; then
