An implementation of HPKE with flexible crypto backends.

From the RFC:

This scheme provides a variant of public-key encryption of arbitrary-sized plaintexts for a recipient public key. It also includes three authenticated variants, including one which authenticates possession of a pre-shared key, and two optional ones which authenticate possession of a KEM private key.

This version is compatible with draft-12, which is expected to be equivalent to the RFC.

• Base
• PSK
• Auth
• AuthPSK

• DH KEM x25519
• DH KEM P256

• AES GCM 128
• AES GCM 256
• ChaCha20 Poly1305
• Exporter only

• HKDF SHA-256
• HKDF SHA-384
• HKDF SHA-512

This crate does not implement the cryptographic primitives used itself. Instead it expects an implementation of the HpkeCrypto trait.