#646 fixed the Windows build after #386 with `_` arms in the two
matches in windows.rs. That module is cfg(windows), so Linux and macOS
CI never compile it, and the next PublicKey variant will either break
the Windows build again or, now, fall into `_` without anyone choosing.
The store's two decisions move into keys.rs, which every platform
builds, with every variant named and no `_` arm:
- PublicKey::store_signing_key: RSA, or ECDSA with 256/384 bits, or
None for the kinds PdfCraft only verifies with (P-521, brainpool,
Ed25519, Unsupported).
- PublicKey::store_signature_der: CNG's raw r||s as DER (RSA as is);
the verify-only kinds return SignError::Unsupported, as since #646.
windows.rs calls both, with no `_` arms left. Behaviour is unchanged.
tests/store_keys.rs runs everywhere: every variant's answer (with an
exhaustive match, so a new variant must be added to it), the P-256 and
P-384 conversion round-tripped through PublicKey::verify (code that
used to compile only on Windows), and malformed CNG signatures erroring
rather than panicking.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
