passnote_crypto 1.0.0

Crypto for Passnote: XChaCha20-Poly1305, Argon2id key derivation from a BIP39 passphrase, X25519/Ed25519 device identity, and SPAKE2 pairing.

Changelog

1.0.0

First release.

• XChaChaPoly1305Cipher: authenticated encryption for every frame and record (24-byte random nonce, 16-byte tag).
• Key derivation from a BIP39 passphrase: BIP39 seed then Argon2id, with a PBKDF2-HMAC-SHA256 alternative for FIPS environments, plus passphrase generation and validation.
• DeviceIdentity: X25519 and Ed25519 device keypairs with key wrap (X25519 ephemeral agreement, HKDF-SHA256, AES-256-GCM), signing and verification, and a deterministic identity derived from a recovery phrase.
• Spake2: the pairing exchange (P-256, RFC 9382) behind the nine-digit one-time code.
• roomTag: the one-way discovery tag.
• Known-answer test vectors for every primitive in test/vectors/, asserted in CI and regenerable with tool/generate_vectors.dart.