From 88e79573f7a558f6a8dfbbf8d2d20cce1f8d9dda Mon Sep 17 00:00:00 2001 From: jack9603301 Date: Sun, 18 Jul 2021 22:33:10 +0800 Subject: [PATCH] add sha256 validation --- apt-sync.py | 97 ++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 81 insertions(+), 16 deletions(-) diff --git a/apt-sync.py b/apt-sync.py index 1eb9dcd..b32bad9 100755 --- a/apt-sync.py +++ b/apt-sync.py @@ -98,6 +98,48 @@ def mkdir_with_dot_tmp(folder: Path)->Tuple[Path, Path]: shutil.rmtree(str(tmpdir)) tmpdir.mkdir(parents=True, exist_ok=True) return (folder, tmpdir) + +def flush_package_info(content: str, package_info = {}, new_or_old = True): + + for pkg in content.split('\n\n'): + if len(pkg) < 10: # ignore blanks + continue + try: + pkg_filename = pattern_package_name.search(pkg).group(1) + pkg_size = int(pattern_package_size.search(pkg).group(1)) + pkg_checksum = pattern_package_sha256.search(pkg).group(1) + if pkg_filename not in package_info: + if new_or_old: + pkg_info = { + 'size': pkg_size, + 'sha256': { + 'new': pkg_checksum, + 'old': None + } + } + else: + pkg_info = { + 'size': None, + 'sha256': { + 'new': None, + 'old': pkg_checksum + } + } + else: + pkg_info = package_info[pkg_filename] + if new_or_old: + pkg_info['size'] = pkg_size + pkg_info['sha256']['new'] = pkg_checksum + else: + pkg_info['sha256']['old'] = pkg_checksum + package_info.update({ + pkg_filename: pkg_info + }) + except: + print("Failed to parse one package description", flush=True) + traceback.print_exc() + return package_info + return package_info def move_files_in(src: Path, dst: Path): empty = True @@ -110,6 +152,9 @@ def move_files_in(src: Path, dst: Path): print(f"{src} is empty") def apt_mirror(base_url: str, dist: str, repo: str, arch: str, dest_base_dir: Path, deb_set: Dict[str, int])->int: + + package_info = {} + if not dest_base_dir.is_dir(): print("Destination directory is empty, cannot continue") return 1 @@ -134,6 +179,7 @@ def apt_mirror(base_url: str, dist: str, repo: str, arch: str, dest_base_dir: Pa pkgidx_dir,pkgidx_tmp_dir = mkdir_with_dot_tmp(comp_dir / arch_dir) with open(release_file, "r") as fd: pkgidx_content=None + pkgidx_content_old = None cnt_start=False for line in fd: if cnt_start: @@ -146,6 +192,8 @@ def apt_mirror(base_url: str, dist: str, repo: str, arch: str, dest_base_dir: Pa filename.startswith(f"Contents-{arch}"): fn = Path(filename) pkgidx_file = dist_dir / fn.parent / ".tmp" / fn.name + if pkgidx_file.stem == 'Packages': + pkgidx_file_old = Path(f'{dist_dir}/{filename}') else: print(f"Ignore the file {filename}") continue @@ -176,12 +224,35 @@ def apt_mirror(base_url: str, dist: str, repo: str, arch: str, dest_base_dir: Pa pkgidx_content = content.decode('utf-8') else: print("unsupported format") + continue + + package_info = flush_package_info(pkgidx_content, package_info = package_info, new_or_old = True) + + if os.path.exists(pkgidx_file_old): + continue + + with pkgidx_file_old.open('rb') as t: content = t.read() + if pkgidx_content_old is None and pkgidx_file_old.stem == 'Packages': + print(f"getting packages index content from {pkgidx_file_old.name}", flush=True) + suffix = pkgidx_file.suffix + if suffix == '.xz': + pkgidx_content_old = lzma.decompress(content).decode('utf-8') + elif suffix == '.bz2': + pkgidx_content_old = bz2.decompress(content).decode('utf-8') + elif suffix == '.gz': + pkgidx_content_old = gzip.decompress(content).decode('utf-8') + elif suffix == '': + pkgidx_content_old = content.decode('utf-8') + + package_info = flush_package_info(pkgidx_content_old, package_info = package_info, new_or_old = False) + # Currently only support SHA-256 checksum, because # "Clients may not use the MD5Sum and SHA1 fields for security purposes, and must require a SHA256 or a SHA512 field." # from https://wiki.debian.org/DebianRepository/Format#A.22Release.22_files if line.startswith('SHA256:'): cnt_start = True + if not cnt_start: print("Cannot find SHA-256 checksum") return 1 @@ -216,20 +287,14 @@ def collect_tmp_dir(): err = 0 deb_count = 0 deb_size = 0 - for pkg in pkgidx_content.split('\n\n'): - if len(pkg) < 10: # ignore blanks - continue - try: - pkg_filename = pattern_package_name.search(pkg).group(1) - pkg_size = int(pattern_package_size.search(pkg).group(1)) - pkg_checksum = pattern_package_sha256.search(pkg).group(1) - except: - print("Failed to parse one package description", flush=True) - traceback.print_exc() - err = 1 - continue + for pkg_filename, pkg_info in package_info.items(): + pkg_size = pkg_info['size'] + pkg_checksum = pkg_info['sha256'] deb_count += 1 deb_size += pkg_size + + if pkg_checksum['new'] is None and pkg_size is None: + continue dest_filename = dest_base_dir / pkg_filename dest_dir = dest_filename.parent @@ -237,8 +302,8 @@ def collect_tmp_dir(): dest_dir.mkdir(parents=True, exist_ok=True) if dest_filename.suffix == '.deb': deb_set[str(dest_filename.relative_to(dest_base_dir))] = pkg_size - if dest_filename.is_file() and dest_filename.stat().st_size == pkg_size: - print(f"Skipping {pkg_filename}, size {pkg_size}") + if dest_filename.is_file() and dest_filename.stat().st_size == pkg_size and pkg_checksum['old'] == pkg_checksum['new']: + print(f"Skipping {pkg_filename}, size {pkg_size}, sha256 {pkg_checksum['new']}") continue pkg_url=f"{base_url}/{pkg_filename}" @@ -253,8 +318,8 @@ def collect_tmp_dir(): with dest_tmp_filename.open("rb") as f: for block in iter(lambda: f.read(1024**2), b""): sha.update(block) - if sha.hexdigest() != pkg_checksum: - print(f"Invalid checksum of {dest_filename}, expected {pkg_checksum}") + if sha.hexdigest() != pkg_checksum['new']: + print(f"Invalid checksum of {dest_filename}, expected {pkg_checksum['new']}") dest_tmp_filename.unlink() continue dest_tmp_filename.rename(dest_filename)