| """Small shared file-IO helpers for credential/manifest JSON under ``~/.flash``.""" |
|
|
| from __future__ import annotations |
|
|
| import contextlib |
| import json |
| import os |
| from pathlib import Path |
|
|
|
|
| def read_json_or_empty(path: Path) -> dict: |
| """Parse a JSON object file, returning ``{}`` if it's missing or unreadable.""" |
| try: |
| return json.loads(path.read_text()) |
| except (OSError, ValueError): |
| return {} |
|
|
|
|
| def secure_json_write(path: Path, data: dict) -> None: |
| """Write ``data`` as JSON with private permissions (the file may hold a secret). |
| |
| Creates the parent dir (0700) and opens the file 0600 from the start — never |
| write_text + chmod, which leaves it umask-readable in between. ``O_NOFOLLOW`` |
| (where available) refuses to follow a symlink planted at ``path`` so the write |
| can't be redirected to clobber an arbitrary file. |
| """ |
| path.parent.mkdir(parents=True, exist_ok=True) |
| with contextlib.suppress(OSError): |
| os.chmod(path.parent, 0o700) |
| flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC | getattr(os, "O_NOFOLLOW", 0) |
| fd = os.open(path, flags, 0o600) |
| with os.fdopen(fd, "w") as f: |
| json.dump(data, f, indent=2, sort_keys=True) |
| with contextlib.suppress(OSError): |
| os.chmod(path, 0o600) |
|
|
