# HPKE

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An implementation of [HPKE (RFC 9180)] 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.


## Supported HPKE modes

- Base
- PSK
- Auth
- AuthPSK

## Supported cipher suites

### KEM

- DH KEM x25519
- DH KEM P256

### AEAD

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

### KDF

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

# Crypto Backends

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

[github-actions-badge]: https://img.shields.io/github/actions/workflow/status/franziskuskiefer/hpke-rs/rust.yml?label=build%20%26%20tests&logo=github&style=for-the-badge&branch=main
[github-actions-link]: https://github.com/franziskuskiefer/hpke-rs/actions/workflows/rust.yml?query=branch%3Amain
[crate-badge]: https://img.shields.io/crates/v/hpke-rs.svg?style=for-the-badge
[crate-link]: https://crates.io/crates/hpke-rs
[docs-badge]: https://img.shields.io/badge/docs-rs-blue.svg?style=for-the-badge
[docs-link]: https://docs.rs/hpke-rs
[evercrypt]: https://github.com/franziskuskiefer/evercrypt-rust
[hpke (RFC 9180)]: https://www.rfc-editor.org/rfc/rfc9180.html
[hpkecrypto]: https://docs.rs/hpke-rs-crypto
[rustc-image]: https://img.shields.io/badge/rustc-1.56+-blue.svg?style=for-the-badge