platform_build/tools/releasetools/validate_target_files.py
Tianjie Xu 9c384d2ca5 Verify the contents in install-recovery.sh
Check the SHA1 of recovery.img and boot.img embedded in the
install-recovery.sh.

Bug: 35411009
Test: validation script detects mismatch for both full recovery and
recovery-from-boot.
Change-Id: I5f07a869d9fa17fad26a22ef9ca3ecb06b1b28e3
2017-06-20 17:28:35 -07:00

221 lines
7.4 KiB
Python
Executable file

#!/usr/bin/env python
# Copyright (C) 2017 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Validate a given (signed) target_files.zip.
It performs checks to ensure the integrity of the input zip.
- It verifies the file consistency between the ones in IMAGES/system.img (read
via IMAGES/system.map) and the ones under unpacked folder of SYSTEM/. The
same check also applies to the vendor image if present.
"""
import common
import logging
import os.path
import re
import sparse_img
import sys
def _GetImage(which, tmpdir):
assert which in ('system', 'vendor')
path = os.path.join(tmpdir, 'IMAGES', which + '.img')
mappath = os.path.join(tmpdir, 'IMAGES', which + '.map')
# Map file must exist (allowed to be empty).
assert os.path.exists(path) and os.path.exists(mappath)
clobbered_blocks = '0'
return sparse_img.SparseImage(path, mappath, clobbered_blocks)
def _CalculateFileSha1(file_name, unpacked_name, round_up=False):
"""Calculate the SHA-1 for a given file. Round up its size to 4K if needed."""
def RoundUpTo4K(value):
rounded_up = value + 4095
return rounded_up - (rounded_up % 4096)
assert os.path.exists(unpacked_name)
with open(unpacked_name, 'r') as f:
file_data = f.read()
file_size = len(file_data)
if round_up:
file_size_rounded_up = RoundUpTo4K(file_size)
file_data += '\0' * (file_size_rounded_up - file_size)
return common.File(file_name, file_data).sha1
def ValidateFileAgainstSha1(input_tmp, file_name, file_path, expected_sha1):
"""Check if the file has the expected SHA-1."""
logging.info('Validating the SHA-1 of {}'.format(file_name))
unpacked_name = os.path.join(input_tmp, file_path)
assert os.path.exists(unpacked_name)
actual_sha1 = _CalculateFileSha1(file_name, unpacked_name, False)
assert actual_sha1 == expected_sha1, \
'SHA-1 mismatches for {}. actual {}, expected {}'.format(
file_name, actual_sha1, expected_sha1)
def ValidateFileConsistency(input_zip, input_tmp):
"""Compare the files from image files and unpacked folders."""
def CheckAllFiles(which):
logging.info('Checking %s image.', which)
image = _GetImage(which, input_tmp)
prefix = '/' + which
for entry in image.file_map:
if not entry.startswith(prefix):
continue
# Read the blocks that the file resides. Note that it will contain the
# bytes past the file length, which is expected to be padded with '\0's.
ranges = image.file_map[entry]
blocks_sha1 = image.RangeSha1(ranges)
# The filename under unpacked directory, such as SYSTEM/bin/sh.
unpacked_name = os.path.join(
input_tmp, which.upper(), entry[(len(prefix) + 1):])
file_sha1 = _CalculateFileSha1(entry, unpacked_name, True)
assert blocks_sha1 == file_sha1, \
'file: %s, range: %s, blocks_sha1: %s, file_sha1: %s' % (
entry, ranges, blocks_sha1, file_sha1)
logging.info('Validating file consistency.')
# Verify IMAGES/system.img.
CheckAllFiles('system')
# Verify IMAGES/vendor.img if applicable.
if 'VENDOR/' in input_zip.namelist():
CheckAllFiles('vendor')
# Not checking IMAGES/system_other.img since it doesn't have the map file.
def ValidateInstallRecoveryScript(input_tmp, info_dict):
"""Validate the SHA-1 embedded in install-recovery.sh.
install-recovery.sh is written in common.py and has the following format:
1. full recovery:
...
if ! applypatch -c type:device:size:SHA-1; then
applypatch /system/etc/recovery.img type:device sha1 size && ...
...
2. recovery from boot:
...
applypatch [-b bonus_args] boot_info recovery_info recovery_sha1 \
recovery_size patch_info && ...
...
For full recovery, we want to calculate the SHA-1 of /system/etc/recovery.img
and compare it against the one embedded in the script. While for recovery
from boot, we want to check the SHA-1 for both recovery.img and boot.img
under IMAGES/.
"""
script_path = 'SYSTEM/bin/install-recovery.sh'
if not os.path.exists(os.path.join(input_tmp, script_path)):
logging.info('{} does not exist in input_tmp'.format(script_path))
return
logging.info('Checking {}'.format(script_path))
with open(os.path.join(input_tmp, script_path), 'r') as script:
lines = script.read().strip().split('\n')
assert len(lines) >= 6
check_cmd = re.search(r'if ! applypatch -c \w+:.+:\w+:(\w+);',
lines[1].strip())
expected_recovery_check_sha1 = check_cmd.group(1)
patch_cmd = re.search(r'(applypatch.+)&&', lines[2].strip())
applypatch_argv = patch_cmd.group(1).strip().split()
full_recovery_image = info_dict.get("full_recovery_image") == "true"
if full_recovery_image:
assert len(applypatch_argv) == 5
# Check we have the same expected SHA-1 of recovery.img in both check mode
# and patch mode.
expected_recovery_sha1 = applypatch_argv[3].strip()
assert expected_recovery_check_sha1 == expected_recovery_sha1
ValidateFileAgainstSha1(input_tmp, 'recovery.img',
'SYSTEM/etc/recovery.img', expected_recovery_sha1)
else:
# We're patching boot.img to get recovery.img where bonus_args is optional
if applypatch_argv[1] == "-b":
assert len(applypatch_argv) == 8
boot_info_index = 3
else:
assert len(applypatch_argv) == 6
boot_info_index = 1
# boot_info: boot_type:boot_device:boot_size:boot_sha1
boot_info = applypatch_argv[boot_info_index].strip().split(':')
assert len(boot_info) == 4
ValidateFileAgainstSha1(input_tmp, file_name='boot.img',
file_path='IMAGES/boot.img', expected_sha1=boot_info[3])
recovery_sha1_index = boot_info_index + 2
expected_recovery_sha1 = applypatch_argv[recovery_sha1_index]
assert expected_recovery_check_sha1 == expected_recovery_sha1
ValidateFileAgainstSha1(input_tmp, file_name='recovery.img',
file_path='IMAGES/recovery.img',
expected_sha1=expected_recovery_sha1)
logging.info('Done checking {}'.format(script_path))
def main(argv):
def option_handler():
return True
args = common.ParseOptions(
argv, __doc__, extra_opts="",
extra_long_opts=[],
extra_option_handler=option_handler)
if len(args) != 1:
common.Usage(__doc__)
sys.exit(1)
logging_format = '%(asctime)s - %(filename)s - %(levelname)-8s: %(message)s'
date_format = '%Y/%m/%d %H:%M:%S'
logging.basicConfig(level=logging.INFO, format=logging_format,
datefmt=date_format)
logging.info("Unzipping the input target_files.zip: %s", args[0])
input_tmp, input_zip = common.UnzipTemp(args[0])
ValidateFileConsistency(input_zip, input_tmp)
info_dict = common.LoadInfoDict(input_tmp)
ValidateInstallRecoveryScript(input_tmp, info_dict)
# TODO: Check if the OTA keys have been properly updated (the ones on /system,
# in recovery image).
logging.info("Done.")
if __name__ == '__main__':
try:
main(sys.argv[1:])
finally:
common.Cleanup()