| #!/usr/bin/env python |
| # |
| # Copyright (C) 2019 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. |
| |
| import logging |
| import os.path |
| import re |
| import shlex |
| import shutil |
| import zipfile |
| |
| import common |
| |
| logger = logging.getLogger(__name__) |
| |
| OPTIONS = common.OPTIONS |
| |
| APEX_PAYLOAD_IMAGE = 'apex_payload.img' |
| |
| |
| class ApexInfoError(Exception): |
| """An Exception raised during Apex Information command.""" |
| |
| def __init__(self, message): |
| Exception.__init__(self, message) |
| |
| |
| class ApexSigningError(Exception): |
| """An Exception raised during Apex Payload signing.""" |
| |
| def __init__(self, message): |
| Exception.__init__(self, message) |
| |
| |
| class ApexApkSigner(object): |
| """Class to sign the apk files in a apex payload image and repack the apex""" |
| |
| def __init__(self, apex_path, key_passwords, codename_to_api_level_map): |
| self.apex_path = apex_path |
| self.key_passwords = key_passwords |
| self.codename_to_api_level_map = codename_to_api_level_map |
| |
| def ProcessApexFile(self, apk_keys, payload_key, signing_args=None): |
| """Scans and signs the apk files and repack the apex |
| |
| Args: |
| apk_keys: A dict that holds the signing keys for apk files. |
| |
| Returns: |
| The repacked apex file containing the signed apk files. |
| """ |
| list_cmd = ['deapexer', 'list', self.apex_path] |
| entries_names = common.RunAndCheckOutput(list_cmd).split() |
| apk_entries = [name for name in entries_names if name.endswith('.apk')] |
| |
| # No need to sign and repack, return the original apex path. |
| if not apk_entries: |
| logger.info('No apk file to sign in %s', self.apex_path) |
| return self.apex_path |
| |
| for entry in apk_entries: |
| apk_name = os.path.basename(entry) |
| if apk_name not in apk_keys: |
| raise ApexSigningError('Failed to find signing keys for apk file {} in' |
| ' apex {}. Use "-e <apkname>=" to specify a key' |
| .format(entry, self.apex_path)) |
| if not any(dirname in entry for dirname in ['app/', 'priv-app/', |
| 'overlay/']): |
| logger.warning('Apk path does not contain the intended directory name:' |
| ' %s', entry) |
| |
| payload_dir, has_signed_apk = self.ExtractApexPayloadAndSignApks( |
| apk_entries, apk_keys) |
| if not has_signed_apk: |
| logger.info('No apk file has been signed in %s', self.apex_path) |
| return self.apex_path |
| |
| return self.RepackApexPayload(payload_dir, payload_key, signing_args) |
| |
| def ExtractApexPayloadAndSignApks(self, apk_entries, apk_keys): |
| """Extracts the payload image and signs the containing apk files.""" |
| payload_dir = common.MakeTempDir() |
| extract_cmd = ['deapexer', 'extract', self.apex_path, payload_dir] |
| common.RunAndCheckOutput(extract_cmd) |
| |
| has_signed_apk = False |
| for entry in apk_entries: |
| apk_path = os.path.join(payload_dir, entry) |
| assert os.path.exists(self.apex_path) |
| |
| key_name = apk_keys.get(os.path.basename(entry)) |
| if key_name in common.SPECIAL_CERT_STRINGS: |
| logger.info('Not signing: %s due to special cert string', apk_path) |
| continue |
| |
| logger.info('Signing apk file %s in apex %s', apk_path, self.apex_path) |
| # Rename the unsigned apk and overwrite the original apk path with the |
| # signed apk file. |
| unsigned_apk = common.MakeTempFile() |
| os.rename(apk_path, unsigned_apk) |
| common.SignFile(unsigned_apk, apk_path, key_name, self.key_passwords, |
| codename_to_api_level_map=self.codename_to_api_level_map) |
| has_signed_apk = True |
| return payload_dir, has_signed_apk |
| |
| def RepackApexPayload(self, payload_dir, payload_key, signing_args=None): |
| """Rebuilds the apex file with the updated payload directory.""" |
| apex_dir = common.MakeTempDir() |
| # Extract the apex file and reuse its meta files as repack parameters. |
| common.UnzipToDir(self.apex_path, apex_dir) |
| arguments_dict = { |
| 'manifest': os.path.join(apex_dir, 'apex_manifest.pb'), |
| 'build_info': os.path.join(apex_dir, 'apex_build_info.pb'), |
| 'key': payload_key, |
| } |
| for filename in arguments_dict.values(): |
| assert os.path.exists(filename), 'file {} not found'.format(filename) |
| |
| # The repack process will add back these files later in the payload image. |
| for name in ['apex_manifest.pb', 'apex_manifest.json', 'lost+found']: |
| path = os.path.join(payload_dir, name) |
| if os.path.isfile(path): |
| os.remove(path) |
| elif os.path.isdir(path): |
| shutil.rmtree(path) |
| |
| # TODO(xunchang) the signing process can be improved by using |
| # '--unsigned_payload_only'. But we need to parse the vbmeta earlier for |
| # the signing arguments, e.g. algorithm, salt, etc. |
| payload_img = os.path.join(apex_dir, APEX_PAYLOAD_IMAGE) |
| generate_image_cmd = ['apexer', '--force', '--payload_only', |
| '--do_not_check_keyname', '--apexer_tool_path', |
| os.getenv('PATH')] |
| for key, val in arguments_dict.items(): |
| generate_image_cmd.extend(['--' + key, val]) |
| |
| # Add quote to the signing_args as we will pass |
| # --signing_args "--signing_helper_with_files=%path" to apexer |
| if signing_args: |
| generate_image_cmd.extend(['--signing_args', '"{}"'.format(signing_args)]) |
| |
| # optional arguments for apex repacking |
| manifest_json = os.path.join(apex_dir, 'apex_manifest.json') |
| if os.path.exists(manifest_json): |
| generate_image_cmd.extend(['--manifest_json', manifest_json]) |
| generate_image_cmd.extend([payload_dir, payload_img]) |
| if OPTIONS.verbose: |
| generate_image_cmd.append('-v') |
| common.RunAndCheckOutput(generate_image_cmd) |
| |
| # Add the payload image back to the apex file. |
| common.ZipDelete(self.apex_path, APEX_PAYLOAD_IMAGE) |
| with zipfile.ZipFile(self.apex_path, 'a') as output_apex: |
| common.ZipWrite(output_apex, payload_img, APEX_PAYLOAD_IMAGE, |
| compress_type=zipfile.ZIP_STORED) |
| return self.apex_path |
| |
| |
| def SignApexPayload(avbtool, payload_file, payload_key_path, payload_key_name, |
| algorithm, salt, hash_algorithm, no_hashtree, signing_args=None): |
| """Signs a given payload_file with the payload key.""" |
| # Add the new footer. Old footer, if any, will be replaced by avbtool. |
| cmd = [avbtool, 'add_hashtree_footer', |
| '--do_not_generate_fec', |
| '--algorithm', algorithm, |
| '--key', payload_key_path, |
| '--prop', 'apex.key:{}'.format(payload_key_name), |
| '--image', payload_file, |
| '--salt', salt, |
| '--hash_algorithm', hash_algorithm] |
| if no_hashtree: |
| cmd.append('--no_hashtree') |
| if signing_args: |
| cmd.extend(shlex.split(signing_args)) |
| |
| try: |
| common.RunAndCheckOutput(cmd) |
| except common.ExternalError as e: |
| raise ApexSigningError( |
| 'Failed to sign APEX payload {} with {}:\n{}'.format( |
| payload_file, payload_key_path, e)) |
| |
| # Verify the signed payload image with specified public key. |
| logger.info('Verifying %s', payload_file) |
| VerifyApexPayload(avbtool, payload_file, payload_key_path, no_hashtree) |
| |
| |
| def VerifyApexPayload(avbtool, payload_file, payload_key, no_hashtree=False): |
| """Verifies the APEX payload signature with the given key.""" |
| cmd = [avbtool, 'verify_image', '--image', payload_file, |
| '--key', payload_key] |
| if no_hashtree: |
| cmd.append('--accept_zeroed_hashtree') |
| try: |
| common.RunAndCheckOutput(cmd) |
| except common.ExternalError as e: |
| raise ApexSigningError( |
| 'Failed to validate payload signing for {} with {}:\n{}'.format( |
| payload_file, payload_key, e)) |
| |
| |
| def ParseApexPayloadInfo(avbtool, payload_path): |
| """Parses the APEX payload info. |
| |
| Args: |
| avbtool: The AVB tool to use. |
| payload_path: The path to the payload image. |
| |
| Raises: |
| ApexInfoError on parsing errors. |
| |
| Returns: |
| A dict that contains payload property-value pairs. The dict should at least |
| contain Algorithm, Salt, Tree Size and apex.key. |
| """ |
| if not os.path.exists(payload_path): |
| raise ApexInfoError('Failed to find image: {}'.format(payload_path)) |
| |
| cmd = [avbtool, 'info_image', '--image', payload_path] |
| try: |
| output = common.RunAndCheckOutput(cmd) |
| except common.ExternalError as e: |
| raise ApexInfoError( |
| 'Failed to get APEX payload info for {}:\n{}'.format( |
| payload_path, e)) |
| |
| # Extract the Algorithm / Hash Algorithm / Salt / Prop info / Tree size from |
| # payload (i.e. an image signed with avbtool). For example, |
| # Algorithm: SHA256_RSA4096 |
| PAYLOAD_INFO_PATTERN = ( |
| r'^\s*(?P<key>Algorithm|Hash Algorithm|Salt|Prop|Tree Size)\:\s*(?P<value>.*?)$') |
| payload_info_matcher = re.compile(PAYLOAD_INFO_PATTERN) |
| |
| payload_info = {} |
| for line in output.split('\n'): |
| line_info = payload_info_matcher.match(line) |
| if not line_info: |
| continue |
| |
| key, value = line_info.group('key'), line_info.group('value') |
| |
| if key == 'Prop': |
| # Further extract the property key-value pair, from a 'Prop:' line. For |
| # example, |
| # Prop: apex.key -> 'com.android.runtime' |
| # Note that avbtool writes single or double quotes around values. |
| PROPERTY_DESCRIPTOR_PATTERN = r'^\s*(?P<key>.*?)\s->\s*(?P<value>.*?)$' |
| |
| prop_matcher = re.compile(PROPERTY_DESCRIPTOR_PATTERN) |
| prop = prop_matcher.match(value) |
| if not prop: |
| raise ApexInfoError( |
| 'Failed to parse prop string {}'.format(value)) |
| |
| prop_key, prop_value = prop.group('key'), prop.group('value') |
| if prop_key == 'apex.key': |
| # avbtool dumps the prop value with repr(), which contains single / |
| # double quotes that we don't want. |
| payload_info[prop_key] = prop_value.strip('\"\'') |
| |
| else: |
| payload_info[key] = value |
| |
| # Sanity check. |
| for key in ('Algorithm', 'Salt', 'apex.key', 'Hash Algorithm'): |
| if key not in payload_info: |
| raise ApexInfoError( |
| 'Failed to find {} prop in {}'.format(key, payload_path)) |
| |
| return payload_info |
| |
| |
| def SignApex(avbtool, apex_data, payload_key, container_key, container_pw, |
| apk_keys, codename_to_api_level_map, |
| no_hashtree, signing_args=None): |
| """Signs the current APEX with the given payload/container keys. |
| |
| Args: |
| apex_data: Raw APEX data. |
| payload_key: The path to payload signing key (w/ extension). |
| container_key: The path to container signing key (w/o extension). |
| container_pw: The matching password of the container_key, or None. |
| apk_keys: A dict that holds the signing keys for apk files. |
| codename_to_api_level_map: A dict that maps from codename to API level. |
| no_hashtree: Don't include hashtree in the signed APEX. |
| signing_args: Additional args to be passed to the payload signer. |
| |
| Returns: |
| The path to the signed APEX file. |
| """ |
| apex_file = common.MakeTempFile(prefix='apex-', suffix='.apex') |
| with open(apex_file, 'wb') as apex_fp: |
| apex_fp.write(apex_data) |
| |
| APEX_PUBKEY = 'apex_pubkey' |
| |
| # 1. Extract the apex payload image and sign the containing apk files. Repack |
| # the apex file after signing. |
| apk_signer = ApexApkSigner(apex_file, container_pw, |
| codename_to_api_level_map) |
| apex_file = apk_signer.ProcessApexFile(apk_keys, payload_key, signing_args) |
| |
| # 2a. Extract and sign the APEX_PAYLOAD_IMAGE entry with the given |
| # payload_key. |
| payload_dir = common.MakeTempDir(prefix='apex-payload-') |
| with zipfile.ZipFile(apex_file) as apex_fd: |
| payload_file = apex_fd.extract(APEX_PAYLOAD_IMAGE, payload_dir) |
| zip_items = apex_fd.namelist() |
| |
| payload_info = ParseApexPayloadInfo(avbtool, payload_file) |
| SignApexPayload( |
| avbtool, |
| payload_file, |
| payload_key, |
| payload_info['apex.key'], |
| payload_info['Algorithm'], |
| payload_info['Salt'], |
| payload_info['Hash Algorithm'], |
| no_hashtree, |
| signing_args) |
| |
| # 2b. Update the embedded payload public key. |
| payload_public_key = common.ExtractAvbPublicKey(avbtool, payload_key) |
| common.ZipDelete(apex_file, APEX_PAYLOAD_IMAGE) |
| if APEX_PUBKEY in zip_items: |
| common.ZipDelete(apex_file, APEX_PUBKEY) |
| apex_zip = zipfile.ZipFile(apex_file, 'a') |
| common.ZipWrite(apex_zip, payload_file, arcname=APEX_PAYLOAD_IMAGE) |
| common.ZipWrite(apex_zip, payload_public_key, arcname=APEX_PUBKEY) |
| common.ZipClose(apex_zip) |
| |
| # 3. Align the files at page boundary (same as in apexer). |
| aligned_apex = common.MakeTempFile(prefix='apex-container-', suffix='.apex') |
| common.RunAndCheckOutput(['zipalign', '-f', '4096', apex_file, aligned_apex]) |
| |
| # 4. Sign the APEX container with container_key. |
| signed_apex = common.MakeTempFile(prefix='apex-container-', suffix='.apex') |
| |
| # Specify the 4K alignment when calling SignApk. |
| extra_signapk_args = OPTIONS.extra_signapk_args[:] |
| extra_signapk_args.extend(['-a', '4096']) |
| |
| common.SignFile( |
| aligned_apex, |
| signed_apex, |
| container_key, |
| container_pw, |
| codename_to_api_level_map=codename_to_api_level_map, |
| extra_signapk_args=extra_signapk_args) |
| |
| return signed_apex |
