mirror of
https://github.com/python/cpython.git
synced 2025-10-31 05:31:20 +00:00
345 lines
12 KiB
Python
345 lines
12 KiB
Python
"""Tool for generating Software Bill of Materials (SBOM) for Python's dependencies"""
|
|
import os
|
|
import re
|
|
import hashlib
|
|
import json
|
|
import glob
|
|
from pathlib import Path, PurePosixPath, PureWindowsPath
|
|
import subprocess
|
|
import sys
|
|
import urllib.request
|
|
import typing
|
|
|
|
CPYTHON_ROOT_DIR = Path(__file__).parent.parent.parent
|
|
|
|
# Before adding a new entry to this list, double check that
|
|
# the license expression is a valid SPDX license expression:
|
|
# See: https://spdx.org/licenses
|
|
ALLOWED_LICENSE_EXPRESSIONS = {
|
|
"Apache-2.0",
|
|
"Apache-2.0 OR BSD-2-Clause",
|
|
"BSD-2-Clause",
|
|
"BSD-3-Clause",
|
|
"CC0-1.0",
|
|
"ISC",
|
|
"LGPL-2.1-only",
|
|
"MIT",
|
|
"MPL-2.0",
|
|
"Python-2.0.1",
|
|
}
|
|
|
|
# Properties which are required for our purposes.
|
|
REQUIRED_PROPERTIES_PACKAGE = frozenset([
|
|
"SPDXID",
|
|
"name",
|
|
"versionInfo",
|
|
"downloadLocation",
|
|
"checksums",
|
|
"licenseConcluded",
|
|
"externalRefs",
|
|
"primaryPackagePurpose",
|
|
])
|
|
|
|
|
|
class PackageFiles(typing.NamedTuple):
|
|
"""Structure for describing the files of a package"""
|
|
include: list[str] | None
|
|
exclude: list[str] | None = None
|
|
|
|
|
|
# SBOMS don't have a method to specify the sources of files
|
|
# so we need to do that external to the SBOM itself. Add new
|
|
# values to 'exclude' if we create new files within tracked
|
|
# directories that aren't sourced from third-party packages.
|
|
PACKAGE_TO_FILES = {
|
|
"mpdecimal": PackageFiles(
|
|
include=["Modules/_decimal/libmpdec/**"]
|
|
),
|
|
"expat": PackageFiles(
|
|
include=["Modules/expat/**"],
|
|
exclude=[
|
|
"Modules/expat/expat_config.h",
|
|
]
|
|
),
|
|
"macholib": PackageFiles(
|
|
include=["Lib/ctypes/macholib/**"],
|
|
exclude=[
|
|
"Lib/ctypes/macholib/README.ctypes",
|
|
"Lib/ctypes/macholib/fetch_macholib",
|
|
"Lib/ctypes/macholib/fetch_macholib.bat",
|
|
],
|
|
),
|
|
"libb2": PackageFiles(
|
|
include=["Modules/_blake2/impl/**"]
|
|
),
|
|
"hacl-star": PackageFiles(
|
|
include=["Modules/_hacl/**"],
|
|
exclude=[
|
|
"Modules/_hacl/refresh.sh",
|
|
"Modules/_hacl/README.md",
|
|
"Modules/_hacl/python_hacl_namespace.h",
|
|
]
|
|
),
|
|
}
|
|
|
|
|
|
def spdx_id(value: str) -> str:
|
|
"""Encode a value into characters that are valid in an SPDX ID"""
|
|
return re.sub(r"[^a-zA-Z0-9.\-]+", "-", value)
|
|
|
|
|
|
def error_if(value: bool, error_message: str) -> None:
|
|
"""Prints an error if a comparison fails along with a link to the devguide"""
|
|
if value:
|
|
print(error_message)
|
|
print("See 'https://devguide.python.org/developer-workflow/sbom' for more information.")
|
|
sys.exit(1)
|
|
|
|
|
|
def filter_gitignored_paths(paths: list[str]) -> list[str]:
|
|
"""
|
|
Filter out paths excluded by the gitignore file.
|
|
The output of 'git check-ignore --non-matching --verbose' looks
|
|
like this for non-matching (included) files:
|
|
|
|
'::<whitespace><path>'
|
|
|
|
And looks like this for matching (excluded) files:
|
|
|
|
'.gitignore:9:*.a Tools/lib.a'
|
|
"""
|
|
# Filter out files in gitignore.
|
|
# Non-matching files show up as '::<whitespace><path>'
|
|
git_check_ignore_proc = subprocess.run(
|
|
["git", "check-ignore", "--verbose", "--non-matching", *paths],
|
|
cwd=CPYTHON_ROOT_DIR,
|
|
check=False,
|
|
stdout=subprocess.PIPE,
|
|
)
|
|
# 1 means matches, 0 means no matches.
|
|
assert git_check_ignore_proc.returncode in (0, 1)
|
|
|
|
# Paths may or may not be quoted, Windows quotes paths.
|
|
git_check_ignore_re = re.compile(r"^::\s+(\"([^\"]+)\"|(.+))\Z")
|
|
|
|
# Return the list of paths sorted
|
|
git_check_ignore_lines = git_check_ignore_proc.stdout.decode().splitlines()
|
|
git_check_not_ignored = []
|
|
for line in git_check_ignore_lines:
|
|
if match := git_check_ignore_re.fullmatch(line):
|
|
git_check_not_ignored.append(match.group(2) or match.group(3))
|
|
return sorted(git_check_not_ignored)
|
|
|
|
|
|
def get_externals() -> list[str]:
|
|
"""
|
|
Parses 'PCbuild/get_externals.bat' for external libraries.
|
|
Returns a list of (git tag, name, version) tuples.
|
|
"""
|
|
get_externals_bat_path = CPYTHON_ROOT_DIR / "PCbuild/get_externals.bat"
|
|
externals = re.findall(
|
|
r"set\s+libraries\s*=\s*%libraries%\s+([a-zA-Z0-9.-]+)\s",
|
|
get_externals_bat_path.read_text()
|
|
)
|
|
return externals
|
|
|
|
|
|
def check_sbom_packages(sbom_data: dict[str, typing.Any]) -> None:
|
|
"""Make a bunch of assertions about the SBOM package data to ensure it's consistent."""
|
|
|
|
for package in sbom_data["packages"]:
|
|
# Properties and ID must be properly formed.
|
|
error_if(
|
|
"name" not in package,
|
|
"Package is missing the 'name' field"
|
|
)
|
|
|
|
# Verify that the checksum matches the expected value
|
|
# and that the download URL is valid.
|
|
if "checksums" not in package or "CI" in os.environ:
|
|
download_location = package["downloadLocation"]
|
|
resp = urllib.request.urlopen(download_location)
|
|
error_if(resp.status != 200, f"Couldn't access URL: {download_location}'")
|
|
|
|
package["checksums"] = [{
|
|
"algorithm": "SHA256",
|
|
"checksumValue": hashlib.sha256(resp.read()).hexdigest()
|
|
}]
|
|
|
|
missing_required_keys = REQUIRED_PROPERTIES_PACKAGE - set(package.keys())
|
|
error_if(
|
|
bool(missing_required_keys),
|
|
f"Package '{package['name']}' is missing required fields: {missing_required_keys}",
|
|
)
|
|
error_if(
|
|
package["SPDXID"] != spdx_id(f"SPDXRef-PACKAGE-{package['name']}"),
|
|
f"Package '{package['name']}' has a malformed SPDXID",
|
|
)
|
|
|
|
# Version must be in the download and external references.
|
|
version = package["versionInfo"]
|
|
error_if(
|
|
version not in package["downloadLocation"],
|
|
f"Version '{version}' for package '{package['name']} not in 'downloadLocation' field",
|
|
)
|
|
error_if(
|
|
any(version not in ref["referenceLocator"] for ref in package["externalRefs"]),
|
|
(
|
|
f"Version '{version}' for package '{package['name']} not in "
|
|
f"all 'externalRefs[].referenceLocator' fields"
|
|
),
|
|
)
|
|
|
|
# HACL* specifies its expected rev in a refresh script.
|
|
if package["name"] == "hacl-star":
|
|
hacl_refresh_sh = (CPYTHON_ROOT_DIR / "Modules/_hacl/refresh.sh").read_text()
|
|
hacl_expected_rev_match = re.search(
|
|
r"expected_hacl_star_rev=([0-9a-f]{40})",
|
|
hacl_refresh_sh
|
|
)
|
|
hacl_expected_rev = hacl_expected_rev_match and hacl_expected_rev_match.group(1)
|
|
|
|
error_if(
|
|
hacl_expected_rev != version,
|
|
"HACL* SBOM version doesn't match value in 'Modules/_hacl/refresh.sh'"
|
|
)
|
|
|
|
# License must be on the approved list for SPDX.
|
|
license_concluded = package["licenseConcluded"]
|
|
error_if(
|
|
license_concluded != "NOASSERTION",
|
|
f"License identifier must be 'NOASSERTION'"
|
|
)
|
|
|
|
|
|
def create_source_sbom() -> None:
|
|
sbom_path = CPYTHON_ROOT_DIR / "Misc/sbom.spdx.json"
|
|
sbom_data = json.loads(sbom_path.read_bytes())
|
|
|
|
# We regenerate all of this information. Package information
|
|
# should be preserved though since that is edited by humans.
|
|
sbom_data["files"] = []
|
|
sbom_data["relationships"] = []
|
|
|
|
# Ensure all packages in this tool are represented also in the SBOM file.
|
|
actual_names = {package["name"] for package in sbom_data["packages"]}
|
|
expected_names = set(PACKAGE_TO_FILES)
|
|
error_if(
|
|
actual_names != expected_names,
|
|
f"Packages defined in SBOM tool don't match those defined in SBOM file: {actual_names}, {expected_names}",
|
|
)
|
|
|
|
check_sbom_packages(sbom_data)
|
|
|
|
# We call 'sorted()' here a lot to avoid filesystem scan order issues.
|
|
for name, files in sorted(PACKAGE_TO_FILES.items()):
|
|
package_spdx_id = spdx_id(f"SPDXRef-PACKAGE-{name}")
|
|
exclude = files.exclude or ()
|
|
for include in sorted(files.include or ()):
|
|
# Find all the paths and then filter them through .gitignore.
|
|
paths = glob.glob(include, root_dir=CPYTHON_ROOT_DIR, recursive=True)
|
|
paths = filter_gitignored_paths(paths)
|
|
error_if(
|
|
len(paths) == 0,
|
|
f"No valid paths found at path '{include}' for package '{name}",
|
|
)
|
|
|
|
for path in paths:
|
|
|
|
# Normalize the filename from any combination of slashes.
|
|
path = str(PurePosixPath(PureWindowsPath(path)))
|
|
|
|
# Skip directories and excluded files
|
|
if not (CPYTHON_ROOT_DIR / path).is_file() or path in exclude:
|
|
continue
|
|
|
|
# SPDX requires SHA1 to be used for files, but we provide SHA256 too.
|
|
data = (CPYTHON_ROOT_DIR / path).read_bytes()
|
|
# We normalize line-endings for consistent checksums.
|
|
# This is a rudimentary check for binary files.
|
|
if b"\x00" not in data:
|
|
data = data.replace(b"\r\n", b"\n")
|
|
checksum_sha1 = hashlib.sha1(data).hexdigest()
|
|
checksum_sha256 = hashlib.sha256(data).hexdigest()
|
|
|
|
file_spdx_id = spdx_id(f"SPDXRef-FILE-{path}")
|
|
sbom_data["files"].append({
|
|
"SPDXID": file_spdx_id,
|
|
"fileName": path,
|
|
"checksums": [
|
|
{"algorithm": "SHA1", "checksumValue": checksum_sha1},
|
|
{"algorithm": "SHA256", "checksumValue": checksum_sha256},
|
|
],
|
|
})
|
|
|
|
# Tie each file back to its respective package.
|
|
sbom_data["relationships"].append({
|
|
"spdxElementId": package_spdx_id,
|
|
"relatedSpdxElement": file_spdx_id,
|
|
"relationshipType": "CONTAINS",
|
|
})
|
|
|
|
# Update the SBOM on disk
|
|
sbom_path.write_text(json.dumps(sbom_data, indent=2, sort_keys=True))
|
|
|
|
|
|
def create_externals_sbom() -> None:
|
|
sbom_path = CPYTHON_ROOT_DIR / "Misc/externals.spdx.json"
|
|
sbom_data = json.loads(sbom_path.read_bytes())
|
|
|
|
externals = get_externals()
|
|
externals_name_to_version = {}
|
|
externals_name_to_git_tag = {}
|
|
for git_tag in externals:
|
|
name, _, version = git_tag.rpartition("-")
|
|
externals_name_to_version[name] = version
|
|
externals_name_to_git_tag[name] = git_tag
|
|
|
|
# Ensure all packages in this tool are represented also in the SBOM file.
|
|
actual_names = {package["name"] for package in sbom_data["packages"]}
|
|
expected_names = set(externals_name_to_version)
|
|
error_if(
|
|
actual_names != expected_names,
|
|
f"Packages defined in SBOM tool don't match those defined in SBOM file: {actual_names}, {expected_names}",
|
|
)
|
|
|
|
# Set the versionInfo and downloadLocation fields for all packages.
|
|
for package in sbom_data["packages"]:
|
|
package_version = externals_name_to_version[package["name"]]
|
|
|
|
# Update the version information in all the locations.
|
|
package["versionInfo"] = package_version
|
|
for external_ref in package["externalRefs"]:
|
|
if external_ref["referenceType"] != "cpe23Type":
|
|
continue
|
|
# Version is the fifth field of a CPE.
|
|
cpe23ref = external_ref["referenceLocator"]
|
|
external_ref["referenceLocator"] = re.sub(
|
|
r"\A(cpe(?::[^:]+){4}):[^:]+:",
|
|
fr"\1:{package_version}:",
|
|
cpe23ref
|
|
)
|
|
|
|
download_location = (
|
|
f"https://github.com/python/cpython-source-deps/archive/refs/tags/{externals_name_to_git_tag[package['name']]}.tar.gz"
|
|
)
|
|
download_location_changed = download_location != package["downloadLocation"]
|
|
package["downloadLocation"] = download_location
|
|
|
|
# If the download URL has changed we want one to get recalulated.
|
|
if download_location_changed:
|
|
package.pop("checksums", None)
|
|
|
|
check_sbom_packages(sbom_data)
|
|
|
|
# Update the SBOM on disk
|
|
sbom_path.write_text(json.dumps(sbom_data, indent=2, sort_keys=True))
|
|
|
|
|
|
def main() -> None:
|
|
create_source_sbom()
|
|
create_externals_sbom()
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main()
|