Security

What has been checked

The parts that came from elsewhere carry other people's review. age and scrypt come from the age crate. The Secure Enclave, HKDF and AES-GCM come from CryptoKit. The hardware guarantee is Apple's.

What is ours is the composition, and these are the checks on it:

• A second implementation, Python's cryptography, opens what CryptoKit sealed. Two libraries agreeing is the evidence the construction is standard rather than something invented here. It also checks that a stranger's key, a flipped tag byte and a swapped ephemeral key are all refused, and that no ephemeral key repeats. Run it with tests/ecies.py.
• The reference age CLI opens the secret files, so the store is standard age and stays readable with off the shelf tools if passbox goes away.
• Tampered and truncated files are refused: secrets, the recovery wrap, audit records, and grants, which fail closed to no grants at all.
• The base64 the helper is fed matches the RFC 4648 vectors.

Disclaimer

This is not proven and it is not fault proof.

It is young, and no independent security review has happened yet. Cross-implementation tests raise confidence, but they do not replace an audit.

Use it for the secrets your agents reach for. Keep another copy of anything you cannot afford to lose. Findings are welcome.