pyrox.dev
1#! /usr/bin/env nix-shell
2#! nix-shell -i python -p "python38.withPackages (ps: [ps.PyGithub])" git gnupg
3
4# This is automatically called by ../update.sh.
5
6from __future__ import annotations
7
8import json
9import os
10import re
11import subprocess
12import sys
13from dataclasses import dataclass
14from pathlib import Path
15from tempfile import TemporaryDirectory
16from typing import (
17 Dict,
18 Iterator,
19 List,
20 Optional,
21 Sequence,
22 Tuple,
23 TypedDict,
24 Union,
25)
26
27from github import Github
28from github.GitRelease import GitRelease
29
30VersionComponent = Union[int, str]
31Version = List[VersionComponent]
32
33
34PatchData = TypedDict("PatchData", {"name": str, "url": str, "sha256": str, "extra": str})
35Patch = TypedDict("Patch", {
36 "patch": PatchData,
37 "version": str,
38 "sha256": str,
39})
40
41
42@dataclass
43class ReleaseInfo:
44 version: Version
45 release: GitRelease
46
47
48HERE = Path(__file__).resolve().parent
49NIXPKGS_KERNEL_PATH = HERE.parent
50NIXPKGS_PATH = HERE.parents[4]
51HARDENED_GITHUB_REPO = "anthraxx/linux-hardened"
52HARDENED_TRUSTED_KEY = HERE / "anthraxx.asc"
53HARDENED_PATCHES_PATH = HERE / "patches.json"
54MIN_KERNEL_VERSION: Version = [4, 14]
55
56
57def run(*args: Union[str, Path]) -> subprocess.CompletedProcess[bytes]:
58 try:
59 return subprocess.run(
60 args,
61 check=True,
62 stdout=subprocess.PIPE,
63 stderr=subprocess.PIPE,
64 encoding="utf-8",
65 )
66 except subprocess.CalledProcessError as err:
67 print(
68 f"error: `{err.cmd}` failed unexpectedly\n"
69 f"status code: {err.returncode}\n"
70 f"stdout:\n{err.stdout.strip()}\n"
71 f"stderr:\n{err.stderr.strip()}",
72 file=sys.stderr,
73 )
74 sys.exit(1)
75
76
77def nix_prefetch_url(url: str) -> Tuple[str, Path]:
78 output = run("nix-prefetch-url", "--print-path", url).stdout
79 sha256, path = output.strip().split("\n")
80 return sha256, Path(path)
81
82
83def verify_openpgp_signature(
84 *, name: str, trusted_key: Path, sig_path: Path, data_path: Path,
85) -> bool:
86 with TemporaryDirectory(suffix=".nixpkgs-gnupg-home") as gnupg_home_str:
87 gnupg_home = Path(gnupg_home_str)
88 run("gpg", "--homedir", gnupg_home, "--import", trusted_key)
89 keyring = gnupg_home / "pubring.kbx"
90 try:
91 subprocess.run(
92 ("gpgv", "--keyring", keyring, sig_path, data_path),
93 check=True,
94 stderr=subprocess.PIPE,
95 encoding="utf-8",
96 )
97 return True
98 except subprocess.CalledProcessError as err:
99 print(
100 f"error: signature for {name} failed to verify!",
101 file=sys.stderr,
102 )
103 print(err.stderr, file=sys.stderr, end="")
104 return False
105
106
107def fetch_patch(*, name: str, release_info: ReleaseInfo) -> Optional[Patch]:
108 release = release_info.release
109 extra = f'-{release_info.version[-1]}'
110
111 def find_asset(filename: str) -> str:
112 try:
113 it: Iterator[str] = (
114 asset.browser_download_url
115 for asset in release.get_assets()
116 if asset.name == filename
117 )
118 return next(it)
119 except StopIteration:
120 raise KeyError(filename)
121
122 patch_filename = f"{name}.patch"
123 try:
124 patch_url = find_asset(patch_filename)
125 sig_url = find_asset(patch_filename + ".sig")
126 except KeyError:
127 print(f"error: {patch_filename}{{,.sig}} not present", file=sys.stderr)
128 return None
129
130 sha256, patch_path = nix_prefetch_url(patch_url)
131 _, sig_path = nix_prefetch_url(sig_url)
132 sig_ok = verify_openpgp_signature(
133 name=name,
134 trusted_key=HARDENED_TRUSTED_KEY,
135 sig_path=sig_path,
136 data_path=patch_path,
137 )
138 if not sig_ok:
139 return None
140
141 kernel_ver = release_info.release.tag_name.replace("-hardened1", "")
142 major = kernel_ver.split('.')[0]
143 sha256_kernel, _ = nix_prefetch_url(f"mirror://kernel/linux/kernel/v{major}.x/linux-{kernel_ver}.tar.xz")
144
145 return Patch(
146 patch=PatchData(name=patch_filename, url=patch_url, sha256=sha256, extra=extra),
147 version=kernel_ver,
148 sha256=sha256_kernel
149 )
150
151
152def parse_version(version_str: str) -> Version:
153 version: Version = []
154 for component in re.split('\.|\-', version_str):
155 try:
156 version.append(int(component))
157 except ValueError:
158 version.append(component)
159 return version
160
161
162def version_string(version: Version) -> str:
163 return ".".join(str(component) for component in version)
164
165
166def major_kernel_version_key(kernel_version: Version) -> str:
167 return version_string(kernel_version[:-1])
168
169
170def commit_patches(*, kernel_key: str, message: str) -> None:
171 new_patches_path = HARDENED_PATCHES_PATH.with_suffix(".new")
172 with open(new_patches_path, "w") as new_patches_file:
173 json.dump(patches, new_patches_file, indent=4, sort_keys=True)
174 new_patches_file.write("\n")
175 os.rename(new_patches_path, HARDENED_PATCHES_PATH)
176 message = f"linux/hardened/patches/{kernel_key}: {message}"
177 print(message)
178 if os.environ.get("COMMIT"):
179 run(
180 "git",
181 "-C",
182 NIXPKGS_PATH,
183 "commit",
184 f"--message={message}",
185 HARDENED_PATCHES_PATH,
186 )
187
188
189# Load the existing patches.
190patches: Dict[str, Patch]
191with open(HARDENED_PATCHES_PATH) as patches_file:
192 patches = json.load(patches_file)
193
194# Get the set of currently packaged kernel versions.
195kernel_versions = {}
196for filename in os.listdir(NIXPKGS_KERNEL_PATH):
197 filename_match = re.fullmatch(r"linux-(\d+)\.(\d+)\.nix", filename)
198 if filename_match:
199 nix_version_expr = f"""
200 with import {NIXPKGS_PATH} {{}};
201 (callPackage {NIXPKGS_KERNEL_PATH / filename} {{}}).version
202 """
203 kernel_version_json = run(
204 "nix-instantiate", "--eval", "--json", "--expr", nix_version_expr,
205 ).stdout
206 kernel_version = parse_version(json.loads(kernel_version_json))
207 if kernel_version < MIN_KERNEL_VERSION:
208 continue
209 kernel_key = major_kernel_version_key(kernel_version)
210 kernel_versions[kernel_key] = kernel_version
211
212# Remove patches for unpackaged kernel versions.
213for kernel_key in sorted(patches.keys() - kernel_versions.keys()):
214 commit_patches(kernel_key=kernel_key, message="remove")
215
216g = Github(os.environ.get("GITHUB_TOKEN"))
217repo = g.get_repo(HARDENED_GITHUB_REPO)
218failures = False
219
220# Match each kernel version with the best patch version.
221releases = {}
222for release in repo.get_releases():
223 version = parse_version(release.tag_name)
224 # needs to look like e.g. 5.6.3-hardened1
225 if len(version) < 4:
226 continue
227
228 if not (isinstance(version[-2], int)):
229 continue
230
231 kernel_version = version[:-1]
232
233 kernel_key = major_kernel_version_key(kernel_version)
234 try:
235 packaged_kernel_version = kernel_versions[kernel_key]
236 except KeyError:
237 continue
238
239 release_info = ReleaseInfo(version=version, release=release)
240
241 if kernel_version == packaged_kernel_version:
242 releases[kernel_key] = release_info
243 else:
244 # Fall back to the latest patch for this major kernel version,
245 # skipping patches for kernels newer than the packaged one.
246 if '.'.join(str(x) for x in kernel_version) > '.'.join(str(x) for x in packaged_kernel_version):
247 continue
248 elif (
249 kernel_key not in releases or releases[kernel_key].version < version
250 ):
251 releases[kernel_key] = release_info
252
253# Update hardened-patches.json for each release.
254for kernel_key in sorted(releases.keys()):
255 release_info = releases[kernel_key]
256 release = release_info.release
257 version = release_info.version
258 version_str = release.tag_name
259 name = f"linux-hardened-{version_str}"
260
261 old_version: Optional[Version] = None
262 old_version_str: Optional[str] = None
263 update: bool
264 try:
265 old_filename = patches[kernel_key]["patch"]["name"]
266 old_version_str = old_filename.replace("linux-hardened-", "").replace(
267 ".patch", ""
268 )
269 old_version = parse_version(old_version_str)
270 update = old_version < version
271 except KeyError:
272 update = True
273
274 if update:
275 patch = fetch_patch(name=name, release_info=release_info)
276 if patch is None:
277 failures = True
278 else:
279 patches[kernel_key] = patch
280 if old_version:
281 message = f"{old_version_str} -> {version_str}"
282 else:
283 message = f"init at {version_str}"
284 commit_patches(kernel_key=kernel_key, message=message)
285
286missing_kernel_versions = kernel_versions.keys() - patches.keys()
287
288if missing_kernel_versions:
289 print(
290 f"warning: no patches for kernel versions "
291 + ", ".join(missing_kernel_versions),
292 file=sys.stderr,
293 )
294
295if failures:
296 sys.exit(1)