X-Git-Url: http://git.scottworley.com/pinch/blobdiff_plain/2f96f32a70f6ed975758e2bbcd88fa5f3ee95615..72d3478ad2577fcb6a8d2ffdaff2beb8e8579dd7:/pinch.py diff --git a/pinch.py b/pinch.py index f974d1c..89e053b 100644 --- a/pinch.py +++ b/pinch.py @@ -5,20 +5,41 @@ import operator import os import os.path import shutil +import subprocess import tempfile +import types import urllib.parse import urllib.request import xml.dom.minidom from typing import ( - Any, Dict, Iterable, List, + NewType, Sequence, Tuple, ) +Digest16 = NewType('Digest16', str) +Digest32 = NewType('Digest32', str) + + +class ChannelTableEntry(types.SimpleNamespace): + digest: Digest16 + file: str + size: int + url: str + + +class Channel(types.SimpleNamespace): + channel_html: bytes + forwarded_url: str + git_revision: str + release_name: str + table: Dict[str, ChannelTableEntry] + url: str + class VerificationError(Exception): pass @@ -86,74 +107,109 @@ def compare(a: str, return filecmp.cmpfiles(a, b, files, shallow=False) -def fetch(v: Verification, channel_url: str) -> Dict[str, Any]: - info: Dict[str, Any] = {'url': channel_url} +def fetch(v: Verification, channel_url: str) -> Channel: + channel = Channel() + channel.url = channel_url v.status('Fetching channel') request = urllib.request.urlopen( 'https://channels.nixos.org/nixos-20.03', timeout=10) - info['channel_html'] = request.read() - info['forwarded_url'] = request.geturl() + channel.channel_html = request.read() + channel.forwarded_url = request.geturl() v.result(request.status == 200) - v.check('Got forwarded', info['url'] != info['forwarded_url']) - return info + v.check('Got forwarded', channel.url != channel.forwarded_url) + return channel -def parse(v: Verification, info: Dict[str, Any]) -> None: +def parse_channel(v: Verification, channel: Channel) -> None: v.status('Parsing channel description as XML') - d = xml.dom.minidom.parseString(info['channel_html']) + d = xml.dom.minidom.parseString(channel.channel_html) v.ok() - v.status('Extracting git commit') + v.status('Extracting release name:') + title_name = d.getElementsByTagName( + 'title')[0].firstChild.nodeValue.split()[2] + h1_name = d.getElementsByTagName('h1')[0].firstChild.nodeValue.split()[2] + v.status(title_name) + v.result(title_name == h1_name) + channel.release_name = title_name + + v.status('Extracting git commit:') git_commit_node = d.getElementsByTagName('tt')[0] - info['git_commit'] = git_commit_node.firstChild.nodeValue + channel.git_commit = git_commit_node.firstChild.nodeValue + v.status(channel.git_commit) v.ok() v.status('Verifying git commit label') v.result(git_commit_node.previousSibling.nodeValue == 'Git commit ') v.status('Parsing table') - info['table'] = {} + channel.table = {} for row in d.getElementsByTagName('tr')[1:]: name = row.childNodes[0].firstChild.firstChild.nodeValue url = row.childNodes[0].firstChild.getAttribute('href') size = int(row.childNodes[1].firstChild.nodeValue) - digest = row.childNodes[2].firstChild.firstChild.nodeValue - info['table'][name] = {'url': url, 'digest': digest, 'size': size} + digest = Digest16(row.childNodes[2].firstChild.firstChild.nodeValue) + channel.table[name] = ChannelTableEntry(url=url, digest=digest, size=size) v.ok() -def fetch_resources(v: Verification, info: Dict[str, Any]) -> None: - +def digest_file(filename: str) -> Digest16: + hasher = hashlib.sha256() + with open(filename, 'rb') as f: + # pylint: disable=cell-var-from-loop + for block in iter(lambda: f.read(4096), b''): + hasher.update(block) + return Digest16(hasher.hexdigest()) + + +def to_Digest16(v: Verification, digest32: Digest32) -> Digest16: + v.status('Converting digest to base16') + process = subprocess.run( + ['nix', 'to-base16', '--type', 'sha256', digest32], capture_output=True) + v.result(process.returncode == 0) + return Digest16(process.stdout.decode().strip()) + + +def to_Digest32(v: Verification, digest16: Digest16) -> Digest32: + v.status('Converting digest to base32') + process = subprocess.run( + ['nix', 'to-base32', '--type', 'sha256', digest16], capture_output=True) + v.result(process.returncode == 0) + return Digest32(process.stdout.decode().strip()) + + +def fetch_with_nix_prefetch_url( + v: Verification, + url: str, + digest: Digest16) -> str: + v.status('Fetching %s' % url) + process = subprocess.run( + ['nix-prefetch-url', '--print-path', url, digest], capture_output=True) + v.result(process.returncode == 0) + prefetch_digest, path, empty = process.stdout.decode().split('\n') + assert empty == '' + v.check("Verifying nix-prefetch-url's digest", + to_Digest16(v, Digest32(prefetch_digest)) == digest) + v.status("Verifying file digest") + file_digest = digest_file(path) + v.result(file_digest == digest) + return path + + +def fetch_resources(v: Verification, channel: Channel) -> None: for resource in ['git-revision', 'nixexprs.tar.xz']: - fields = info['table'][resource] - v.status('Fetching resource "%s"' % resource) - url = urllib.parse.urljoin(info['forwarded_url'], fields['url']) - request = urllib.request.urlopen(url, timeout=10) - if fields['size'] < 4096: - fields['content'] = request.read() - else: - with tempfile.NamedTemporaryFile(suffix='.nixexprs.tar.xz', delete=False) as tmp_file: - shutil.copyfileobj(request, tmp_file) - fields['file'] = tmp_file.name - v.result(request.status == 200) - v.status('Verifying digest for "%s"' % resource) - if fields['size'] < 4096: - actual_hash = hashlib.sha256(fields['content']).hexdigest() - else: - hasher = hashlib.sha256() - with open(fields['file'], 'rb') as f: - # pylint: disable=cell-var-from-loop - for block in iter(lambda: f.read(4096), b''): - hasher.update(block) - actual_hash = hasher.hexdigest() - v.result(actual_hash == fields['digest']) - v.check('Verifying git commit on main page matches git commit in table', - info['table']['git-revision']['content'].decode() == info['git_commit']) - - -def extract_channel(v: Verification, info: Dict[str, Any]) -> None: + fields = channel.table[resource] + url = urllib.parse.urljoin(channel.forwarded_url, fields.url) + fields.file = fetch_with_nix_prefetch_url(v, url, fields.digest) + v.status('Verifying git commit on main page matches git commit in table') + v.result( + open( + channel.table['git-revision'].file).read(999) == channel.git_commit) + + +def check_channel_contents(v: Verification, channel: Channel) -> None: with tempfile.TemporaryDirectory() as d: - v.status('Extracting nixexprs.tar.xz') - shutil.unpack_archive(info['table']['nixexprs.tar.xz']['file'], d) + v.status('Extracting %s' % channel.table['nixexprs.tar.xz'].file) + shutil.unpack_archive(channel.table['nixexprs.tar.xz'].file, d) v.ok() v.status('Removing temporary directory') v.ok() @@ -161,11 +217,11 @@ def extract_channel(v: Verification, info: Dict[str, Any]) -> None: def main() -> None: v = Verification() - info = fetch(v, 'https://channels.nixos.org/nixos-20.03') - parse(v, info) - fetch_resources(v, info) - extract_channel(v, info) - print(info) + channel = fetch(v, 'https://channels.nixos.org/nixos-20.03') + parse_channel(v, channel) + fetch_resources(v, channel) + check_channel_contents(v, channel) + print(channel) main()