make_dev_ssd: new script to change SSD image to dev key

The make_dev_ssd.sh is made for devinstall shim to
change SSD kernels to be signed by dev keys.

 - Kernel A, B will be resigned with dev keys (ignore if A/B seems not bootable)
 - Adding param --remove_rootfs_verification can even disable rootfs hash check

This CL also includes some shared refine/fix to make_dev_firmware.sh

BUG=chrome-os-partner:1276
TEST=sudo ./make_dev_ssd.sh; (seeing Kernel A is resigned and B is ignored)
     then reboot without developer mode (OK),
          rootdev shows /dev/dm-0, rootdev -s shows /dev/sda3
     sudo ./make_dev_ssd.sh --remove_rootfs_verification;
     then reboot without developer mode (OK), rootdev shows /dev/sda3

Change-Id: Ic20f734b2af42e50a43c19a565a166a39d57a7fd

Review URL: http://codereview.chromium.org/3772013

scripts/image_signing/common.sh

@@ -12,12 +12,20 @@ GPT=cgpt
 # The tag when the rootfs is changed.
 TAG_NEEDS_TO_BE_SIGNED="/root/.need_to_be_signed"
 
-# Load shflags
+# Finds and loads the 'shflags' library, or return as failed.
-if [ -f /usr/lib/shflags ]; then
+load_shflags() {
-  . /usr/lib/shflags
+  # Load shflags
-else
+  if [ -f /usr/lib/shflags ]; then
-  . "${SCRIPT_DIR}/lib/shflags/shflags"
+    . /usr/lib/shflags
-fi
+  elif [ -f "${SCRIPT_DIR}/shflags" ]; then
+    . "${SCRIPT_DIR}/shflags"
+  elif [ -f "${SCRIPT_DIR}/lib/shflags/shflags" ]; then
+    . "${SCRIPT_DIR}/lib/shflags/shflags"
+  else
+    echo "ERROR: Cannot find the required shflags library."
+    return 1
+  fi
+}
 
 # List of Temporary files and mount points.
 TEMP_FILE_LIST=$(mktemp)
@@ -46,27 +54,18 @@ tag_as_needs_to_be_resigned() {
 
 # Determines if the target file system has the tag for resign
 # Args: MOUNTDIRECTORY
-# Returns: $FLAGS_TRUE if the tag is there, otherwise $FLAGS_FALSE
+# Returns: true if the tag is there otherwise false
 has_needs_to_be_resigned_tag() {
   local mount_dir="$1"
-  if [ -f "$mount_dir/$TAG_NEEDS_TO_BE_SIGNED" ]; then
+  [ -f "$mount_dir/$TAG_NEEDS_TO_BE_SIGNED" ]
-    return ${FLAGS_TRUE}
-  else
-    return ${FLAGS_FALSE}
-  fi
 }
 
 # Determines if the target file system is a Chrome OS root fs
 # Args: MOUNTDIRECTORY
-# Returns: $FLAGS_TRUE if MOUNTDIRECTORY looks like root fs,
+# Returns: true if MOUNTDIRECTORY looks like root fs, otherwise false
-#          otherwise $FLAGS_FALSE
 is_rootfs_partition() {
   local mount_dir="$1"
-  if [ -f "$mount_dir/$(dirname "$TAG_NEEDS_TO_BE_SIGNED")" ]; then
+  [ -f "$mount_dir/$(dirname "$TAG_NEEDS_TO_BE_SIGNED")" ]
-    return ${FLAGS_TRUE}
-  else
-    return ${FLAGS_FALSE}
-  fi
 }
 
 # Mount a partition read-only from an image into a local directory
@@ -149,5 +148,18 @@ cleanup_temps_and_mounts() {
   rm -rf $TEMP_DIR_LIST $TEMP_FILE_LIST
 }
 
+# Returns true if all files in parameters exist.
+ensure_files_exist() {
+  local filename return_value=0
+  for filename in "$@"; do
+    if [ ! -f "$filename" -a ! -b "$filename" ]; then
+      echo "ERROR: Cannot find required file: $filename"
+      return_value=1
+    fi
+  done
+
+  return $return_value
+}
+
 trap "cleanup_temps_and_mounts" EXIT
 

scripts/image_signing/make_dev_firmware.sh

@@ -5,19 +5,23 @@
 # found in the LICENSE file.
 #
 # This script can change key (usually developer keys) in a firmware binary
-# image or system live firmware, and assign proper HWID, BMPFV as well.
+# image or system live firmware (EEPROM), and assign proper HWID, BMPFV as well.
 
 SCRIPT_BASE="$(dirname "$0")"
 . "$SCRIPT_BASE/common.sh"
+load_shflags || exit 1
 
 # Constants used by DEFINE_*
+VBOOT_BASE='/usr/share/vboot'
+DEFAULT_KEYS_FOLDER="$VBOOT_BASE/devkeys"
+DEFAULT_BMPFV_FILE="$DEFAULT_KEYS_FOLDER/firmware_bmpfv.bin"
 DEFAULT_BACKUP_FOLDER='/mnt/stateful_partition/backups'
 
 # DEFINE_string name default_value description flag
 DEFINE_string from "" "Path of input file (empty for system live firmware)" "f"
 DEFINE_string to "" "Path of output file (empty for system live firmware)" "t"
-DEFINE_string keys "$SCRIPT_BASE/keys" "Path of folder of dev keys" "k"
+DEFINE_string keys "$DEFAULT_KEYS_FOLDER" "Path to folder of dev keys" "k"
-DEFINE_string bmpfv "$SCRIPT_BASE/rsrc/bmpfv.bin" "Path to the new bitmap FV" ""
+DEFINE_string bmpfv "$DEFAULT_BMPFV_FILE" "Path to the new bitmap FV" ""
 DEFINE_boolean force_backup \
   $FLAGS_TRUE "Create backup even if source is not live" ""
 DEFINE_string backup_dir \
@@ -33,10 +37,10 @@ eval set -- "$FLAGS_ARGV"
 set -e
 
 # the image we are (temporary) working with
-IMAGE=$(make_temp_file)
+IMAGE="$(make_temp_file)"
 
 # a log file to keep the output results of executed command
-EXEC_LOG=$(make_temp_file)
+EXEC_LOG="$(make_temp_file)"
 
 # Functions
 # ----------------------------------------------------------------------------
@@ -77,6 +81,7 @@ read_image() {
 write_image() {
   if [ -z "$FLAGS_to" ]; then
     echo "Writing system live firmware..."
+    # TODO(hungte) we can enable partial write to make this faster
     if is_debug_mode; then
       flashrom -V -w "$IMAGE"
     else
@@ -96,6 +101,8 @@ echo_dev_hwid() {
 
   # NOTE: Some DEV firmware image files may put GUID in HWID.
   # These are not officially supported and they will see "{GUID} DEV".
+  # Also there's some length limitation in chromeos_acpi/HWID, so
+  # a "{GUID} DEV" will become "{GUID} " in that case.
 
   if [ "$hwid" != "$hwid_no_dev" ]; then
     hwid="$hwid_no_dev"
@@ -105,21 +112,6 @@ echo_dev_hwid() {
   echo "$hwid_dev"
 }
 
-# Checks if the files given by parameters all exist.
-check_exist_or_die() {
-  local file is_success=$FLAGS_TRUE
-  for file in "$@"; do
-    if [ ! -s "$file" ]; then
-      echo "ERROR: Cannot find required file: $file"
-      is_success=$FLAGS_FALSE
-    fi
-  done
-
-  if [ "$is_success" = $FLAGS_FALSE ]; then
-    exit 1
-  fi
-}
-
 # Main
 # ----------------------------------------------------------------------------
 main() {
@@ -133,19 +125,20 @@ main() {
   local is_from_live=0
   local backup_image=
 
-  debug_msg "Pre-requisition check"
+  debug_msg "Prerequisite check"
-  check_exist_or_die \
+  ensure_files_exist \
     "$root_pubkey" \
     "$recovery_pubkey" \
     "$firmware_keyblock" \
     "$firmware_prvkey" \
     "$kernel_sub_pubkey" \
-    "$new_bmpfv"
+    "$new_bmpfv" ||
+    exit 1
 
   if [ -z "$FLAGS_from" ]; then
     is_from_live=1
   else
-    check_exist_or_die "$FLAGS_from"
+    ensure_files_exist "$FLAGS_from"
   fi
 
   # TODO(hungte) check if GPIO.3 (WP) is enabled
@@ -156,27 +149,26 @@ main() {
 
   debug_msg "Prepare to backup the file"
   if [ -n "$is_from_live" -o $FLAGS_force_backup = $FLAGS_TRUE ]; then
-    backup_image=$(make_temp_file)
+    backup_image="$(make_temp_file)"
     debug_msg "Creating backup file to $backup_image..."
     cp -f "$IMAGE" "$backup_image"
   fi
 
   # TODO(hungte) We can use vbutil_firmware to check if the current firmware is
-  # valid, so that we can know both they key, vbutil_firmware are working fine.
+  # valid so that we know keys and vbutil_firmware are all working fine.
 
   echo "Preparing new firmware image..."
-
   debug_msg "Extract current HWID and rootkey"
   local old_hwid
-  old_hwid=$(gbb_utility --get --hwid "$IMAGE" 2>"$EXEC_LOG" |
+  old_hwid="$(gbb_utility --get --hwid "$IMAGE" 2>"$EXEC_LOG" |
-             grep '^hardware_id:' |
+              grep '^hardware_id:' |
-             sed 's/^hardware_id: //')
+              sed 's/^hardware_id: //')"
 
   debug_msg "Decide new HWID"
   if [ -z "$old_hwid" ]; then
     err_die "Cannot find current HWID. (message: $(cat "$EXEC_LOG"))"
   fi
-  local new_hwid=$(echo_dev_hwid "$old_hwid")
+  local new_hwid="$(echo_dev_hwid "$old_hwid")"
 
   debug_msg "Replace GBB parts (gbb_utility allows changing on-the-fly)"
   gbb_utility --set \
@@ -188,7 +180,7 @@ main() {
     err_die "Failed to change GBB Data. (message: $(cat "$EXEC_LOG"))"
 
   debug_msg "Resign the firmware code (A/B) with new keys"
-  local unsigned_image=$(make_temp_file)
+  local unsigned_image="$(make_temp_file)"
   cp -f "$IMAGE" "$unsigned_image"
   "$SCRIPT_BASE/resign_firmwarefd.sh" \
     "$unsigned_image" \
@@ -200,21 +192,22 @@ main() {
 
   # TODO(hungte) compare if the image really needs to be changed.
 
-  debug_msg "Backup files when reading from system live image."
+  debug_msg "Check if we need to make backup file(s)"
   if [ -n "$backup_image" ]; then
-    local backup_hwid_name=$(echo "$old_hwid" | sed 's/ /_/g')
+    local backup_hwid_name="$(echo "$old_hwid" | sed 's/ /_/g')"
-    local backup_date_time=$(date +'%Y%m%d_%H%M%S')
+    local backup_date_time="$(date +'%Y%m%d_%H%M%S')"
     local backup_file_name="firmware_${backup_hwid_name}_${backup_date_time}.fd"
     local backup_file_path="$FLAGS_backup_dir/$backup_file_name"
     if mkdir -p "$FLAGS_backup_dir" &&
        cp -f "$backup_image" "$backup_file_path"; then
       echo "Backup of current firmware image is stored in: $backup_file_path"
     else
-      echo "Cannot create file in $FLAGS_backup_dir... Ignore backups."
+      echo "WARNING: Cannot create file in $FLAGS_backup_dir... Ignore backups."
     fi
   fi
 
   # TODO(hungte) use vbutil_firmware to check if the new firmware is valid.
+  # Or, do verification in resign_firmwarefd.sh and trust it.
 
   debug_msg "Write the image"
   write_image ||
@@ -224,7 +217,7 @@ main() {
   if [ -z "$FLAGS_to" ]; then
     echo "Successfully changed firmware to Developer Keys. New HWID: $new_hwid"
   else
-    echo "Firmware image '$FLAGS_to' now uses Developer Keys. HWID: $new_hwid"
+    echo "Firmware '$FLAGS_to' now uses Developer Keys. New HWID: $new_hwid"
   fi
 }
 

scripts/image_signing/make_dev_ssd.sh

@@ -0,0 +1,236 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# This script can change key (usually developer keys) and kernel config
+# of a kernels on SSD.
+
+SCRIPT_BASE="$(dirname "$0")"
+. "$SCRIPT_BASE/common.sh"
+load_shflags || exit 1
+
+# Constants used by DEFINE_*
+VBOOT_BASE='/usr/share/vboot'
+DEFAULT_KEYS_FOLDER="$VBOOT_BASE/devkeys"
+DEFAULT_BACKUP_FOLDER='/mnt/stateful_partition/backups'
+
+# DEFINE_string name default_value description flag
+DEFINE_string image "/dev/sda" "Path to device or image file" "i"
+DEFINE_string keys "$DEFAULT_KEYS_FOLDER" "Path to folder of dev keys" "k"
+DEFINE_boolean remove_rootfs_verification \
+  $FLAGS_FALSE "Modify kernel boot config to disable rootfs verification" ""
+DEFINE_string backup_dir \
+  "$DEFAULT_BACKUP_FOLDER" "Path of directory to store kernel backups" ""
+DEFINE_boolean debug $FLAGS_FALSE "Provide debug messages" "d"
+
+# Parse command line
+FLAGS "$@" || exit 1
+eval set -- "$FLAGS_ARGV"
+
+# Globals
+# ----------------------------------------------------------------------------
+set -e
+
+# a log file to keep the output results of executed command
+EXEC_LOG="$(make_temp_file)"
+
+# Functions
+# ----------------------------------------------------------------------------
+# Reports error message and exit(1)
+err_die() {
+  echo "ERROR: $*" 1>&2
+  exit 1
+}
+
+# Returns true if we're running in debug mode
+is_debug_mode() {
+  [ "$FLAGS_debug" = $FLAGS_TRUE ]
+}
+
+# Prints messages (in parameters) in debug mode
+debug_msg() {
+  if is_debug_mode; then
+    echo "DEBUG: $*" 1>&2
+  fi
+}
+
+# Removes rootfs verification from kernel boot parameter
+remove_rootfs_verification() {
+  echo "$*" | sed '
+    s|dm_verity[^ ]\+||g
+    s| ro | rw |
+    s|verity /dev/sd%D%P /dev/sd%D%P ||
+    s| root=/dev/dm-0 | root=/dev/sd%D%P |
+    s|dm="[^"]\+" ||'
+}
+
+# Wrapped version of dd
+mydd() {
+  # oflag=sync is safer, but since we need bs=512, syncing every block would be
+  # very slow.
+  dd "$@" >"$EXEC_LOG" 2>&1 ||
+    err_die "Failed in [dd $@], Message: $(cat "$EXEC_LOG")"
+}
+
+# Prints a more friendly name from kernel index number
+cros_kernel_name() {
+  case $1 in
+    2)
+      echo "Kernel A"
+      ;;
+    4)
+      echo "Kernel B"
+      ;;
+    *)
+      err_die "unknown kernel index: $1"
+  esac
+}
+
+# Resigns a kernel on SSD or image.
+resign_ssd_kernel() {
+  # bs=512 is the fixed block size for dd and cgpt
+  local bs=512
+  local ssd_device="$1"
+
+  # reasonable size for current kernel partition
+  local min_kernel_size=32000
+  local max_kernel_size=65536
+  local resigned_kernels=0
+
+  for kernel_index in 2 4; do
+    local old_blob="$(make_temp_file)"
+    local new_blob="$(make_temp_file)"
+    local name="$(cros_kernel_name $kernel_index)"
+
+    debug_msg "Probing $name information"
+    local offset size
+    offset="$(partoffset "$ssd_device" "$kernel_index")" ||
+      err_die "Failed to get partition $kernel_index offset from $ssd_device"
+    size="$(partsize "$ssd_device" "$kernel_index")" ||
+      err_die "Failed to get partition $kernel_index size from $ssd_device"
+    if [ ! $size -gt $min_kernel_size ]; then
+      echo "WARNING: $name seems too small ($size), ignored."
+      continue
+    fi
+    if [ ! $size -le $max_kernel_size ]; then
+      echo "WARNING: $name seems too large ($size), ignored."
+      continue
+    fi
+
+    debug_msg "Reading $name from partition $kernel_index"
+    mydd if="$ssd_device" of="$old_blob" bs=$bs skip=$offset count=$size
+
+    debug_msg "Checking if $name is valid"
+    local old_kernel_config
+    if ! old_kernel_config="$(dump_kernel_config "$old_blob" 2>"$EXEC_LOG")"
+    then
+      debug_msg "dump_kernel_config error message: $(cat "$EXEC_LOG")"
+      echo "WARNING: $name: no kernel boot information, ignored."
+      continue
+    fi
+
+    debug_msg "Decide and prepare signing parameters"
+    local resign_command
+    # TODO(hungte) $KERNEL_KEYBLOCK and $new_kernel_config should also be
+    # quoted, but quoting inside would cause extra quote... We should find some
+    # better way to do this, for example using eval.
+    if [ ${FLAGS_remove_rootfs_verification} = $FLAGS_TRUE ]; then
+      local new_kernel_config_file="$(make_temp_file)"
+      remove_rootfs_verification "$old_kernel_config" >"$new_kernel_config_file"
+      resign_command="--config $new_kernel_config_file"
+      debug_msg "New kernel config: $(cat $new_kernel_config_file)"
+      echo "$name: Disabled rootfs verification."
+    else
+      resign_command="--vblockonly --keyblock $KERNEL_KEYBLOCK"
+    fi
+
+    debug_msg "Re-signing $name from $old_blob to $new_blob"
+    debug_msg "Using key: $KERNEL_DATAKEY, command: $resign_command"
+    vbutil_kernel \
+      --repack "$new_blob" \
+      $resign_command \
+      --signprivate "$KERNEL_DATAKEY" \
+      --oldblob "$old_blob" >"$EXEC_LOG" 2>&1 ||
+      err_die "Failed to resign $name. Message: $(cat "$EXEC_LOG")"
+
+    debug_msg "Creating new kernel image (vboot+code+config)"
+    local new_kern="$(make_temp_file)"
+    cp "$old_blob" "$new_kern"
+    mydd if="$new_blob" of="$new_kern" conv=notrunc
+
+    if is_debug_mode; then
+      debug_msg "for debug purposes, check *.dbgbin"
+      cp "$old_blob" old_blob.dbgbin
+      cp "$new_blob" new_blob.dbgbin
+      cp "$new_kern" new_kern.dbgbin
+    fi
+
+    debug_msg "Verifying new kernel and keys"
+    vbutil_kernel \
+      --verify "$new_kern" \
+      --signpubkey "$KERNEL_PUBKEY" --verbose >"$EXEC_LOG" 2>&1 ||
+      err_die "Failed to verify new $name. Message: $(cat "$EXEC_LOG")"
+
+    debug_msg "Backup old kernel blob"
+    local backup_date_time="$(date +'%Y%m%d_%H%M%S')"
+    local backup_name="$(echo "$name" | sed 's/ /_/g; s/^K/k/')"
+    local backup_file_name="${backup_name}_${backup_date_time}.bin"
+    local backup_file_path="$FLAGS_backup_dir/$backup_file_name"
+    if mkdir -p "$FLAGS_backup_dir" &&
+      cp -f "$old_blob" "$backup_file_path"; then
+      echo "Backup of $name is stored in: $backup_file_path"
+    else
+      echo "WARNING: Cannot create file in $FLAGS_backup_dir... Ignore backups."
+    fi
+
+    debug_msg "Writing $name to partition $kernel_index"
+    mydd \
+      if="$new_kern" \
+      of="$ssd_device" \
+      seek=$offset \
+      bs=$bs \
+      count=$size \
+      conv=notrunc
+    resigned_kernels=$(($resigned_kernels + 1))
+
+    # Sometimes doing "dump_kernel_config" or other I/O now (or after return to
+    # shell) will get the data before modification. Not a problem now, but for
+    # safety, let's try to sync more.
+    sync; sync; sync
+
+    echo "$name: Re-signed with developer keys successfully."
+  done
+  return $resigned_kernels
+}
+
+# Main
+# ----------------------------------------------------------------------------
+main() {
+  local num_signed=0
+  # Check parameters
+  KERNEL_KEYBLOCK="$FLAGS_keys/kernel.keyblock"
+  KERNEL_DATAKEY="$FLAGS_keys/kernel_data_key.vbprivk"
+  KERNEL_PUBKEY="$FLAGS_keys/kernel_subkey.vbpubk"
+
+  debug_msg "Prerequisite check"
+  ensure_files_exist \
+    "$KERNEL_KEYBLOCK" \
+    "$KERNEL_DATAKEY" \
+    "$KERNEL_PUBKEY" \
+    "$FLAGS_image" ||
+    exit 1
+
+  resign_ssd_kernel "$FLAGS_image" || num_signed=$?
+
+  debug_msg "Complete."
+  if [ $num_signed -gt 0 -a $num_signed -le 2 ]; then
+    # signed 1 or two kernels
+    echo "Successfully re-signed $num_signed kernel(s) on device $FLAGS_image".
+  else
+    err_die "Failed re-signing kernels."
+  fi
+}
+
+main