File size: 3,601 Bytes
7e7a152 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | """Verify the complete release and safely extract its data into the code tree."""
import argparse, hashlib, json, os, tarfile
from pathlib import Path, PurePosixPath
def digest(path):
with path.open('rb') as f:
h=hashlib.sha256()
for b in iter(lambda:f.read(1024*1024),b''):h.update(b)
return h.hexdigest()
def safe_target(root, name):
p=PurePosixPath(name)
if p.is_absolute() or '..' in p.parts or not p.parts or p.parts[0] not in ('datasets','metadata'):
raise ValueError('Unsafe archive path: '+name)
target=root.joinpath(*p.parts)
if not target.resolve().is_relative_to(root.resolve()): raise ValueError('Path escapes destination')
for parent in [target]+list(target.parents):
if parent==root:break
if parent.is_symlink():raise ValueError('Refusing destination symlink')
return target
def extract(repo, destination):
manifest=json.loads((repo/'metadata/archives.json').read_text())
files_path=repo/'metadata/files.jsonl'
if digest(files_path)!=manifest['files_manifest_sha256']:raise ValueError('File manifest checksum mismatch')
rows=[json.loads(s) for s in files_path.read_text().splitlines() if s.strip()]
expected={r['path']:r for r in rows}
if len(expected)!=len(rows) or len(rows)!=manifest['file_count']:raise ValueError('Invalid manifest counts')
seen=set(); destination.mkdir(parents=True,exist_ok=True)
for archive in manifest['archives']:
ap=PurePosixPath(archive['path'])
if ap.is_absolute() or '..' in ap.parts or ap.parts[0]!='archives':raise ValueError('Invalid archive path')
path=repo.joinpath(*ap.parts)
if path.stat().st_size!=archive['size'] or digest(path)!=archive['sha256']:raise ValueError('Archive checksum mismatch: '+archive['path'])
count=0
with tarfile.open(path,'r:gz') as tar:
for m in tar:
if not m.isfile():raise ValueError('Only regular files are permitted')
if m.name.startswith('__shards__/'):continue
if m.name not in expected or m.name in seen:raise ValueError('Unexpected or repeated member')
row=expected[m.name]
if row['archive']!=archive['path'] or row['size']!=m.size:raise ValueError('Manifest member mismatch')
dest=safe_target(destination,m.name)
if dest.exists():
if not dest.is_file() or digest(dest)!=row['sha256']:raise ValueError('Existing file differs: '+m.name)
else:
dest.parent.mkdir(parents=True,exist_ok=True)
temp=dest.with_name(dest.name+'.extract-partial')
# Exclusive creation avoids overwriting any existing user file.
with temp.open('xb') as out, tar.extractfile(m) as inp:
for b in iter(lambda:inp.read(1024*1024),b''):out.write(b)
if digest(temp)!=row['sha256']:raise ValueError('Extracted file checksum mismatch')
temp.replace(dest)
seen.add(m.name);count+=1
if count!=archive['file_count']:raise ValueError('Archive member count mismatch')
print('Verified',archive['path'],count,'files',flush=True)
if seen!=set(expected):raise ValueError('Incomplete extraction')
print('Complete:',len(seen),'verified files')
if __name__=='__main__':
p=argparse.ArgumentParser();p.add_argument('--destination',type=Path,default=Path('code'));args=p.parse_args()
extract(Path(__file__).resolve().parents[1],args.destination.resolve())
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