"""Verify delivered payload hashes, rejecting traversal and missing files."""
from pathlib import Path
import hashlib,json,sys
ROOT=Path(__file__).resolve().parents[1]
def main():
    entries=[]
    for line in (ROOT/'SHA256SUMS.txt').read_text().splitlines():
        if not line.strip():continue
        digest,name=line.split('  ',1)
        path=(ROOT/name).resolve()
        if not path.is_relative_to(ROOT):raise RuntimeError('unsafe manifest path')
        if not path.is_file():raise RuntimeError(f'missing file: {name}')
        actual=hashlib.sha256(path.read_bytes()).hexdigest()
        if actual!=digest:raise RuntimeError(f'SHA-256 mismatch: {name}')
        entries.append(name)
    print(f'PASS: {len(entries)} file SHA-256 hashes match.')
if __name__=='__main__':main()