uselesskey-core-keypair-material
Reusable PKCS#8/SPKI key-material helpers for uselesskey fixture crates.
This microcrate owns the shared helper surface used by RSA/ECDSA/Ed25519 fixture generation:
- PKCS#8 and SPKI accessors
- tempfile sinks for PEM outputs
- deterministic negative fixture helpers
- stable
kidderivation from SPKI bytes
It is intentionally small and narrowly scoped for SRP.