PyHPKE - A Python implementation of HPKE

PyHPKE is a HPKE (Hybrid Public Key Encryption) implementation written in Python.

You can install PyHPKE with pip:

$ pip install pyhpke

And then, you can use it as follows:

from pyhpke import AEADId, CipherSuite, KDFId, KEMId, KEMKey

# The sender side:
suite_s = CipherSuite.new(KEMId.DHKEM_P256_HKDF_SHA256, KDFId.HKDF_SHA256, AEADId.AES128_GCM)
pkr = KEMKey.from_jwk(  # from_pem is also available.
    {
        "kid": "01",
        "kty": "EC",
        "crv": "P-256",
        "x": "Ze2loSV3wrroKUN_4zhwGhCqo3Xhu1td4QjeQ5wIVR0",
        "y": "HlLtdXARY_f55A3fnzQbPcm6hgr34Mp8p-nuzQCE0Zw",
    }
)
enc, sender = suite_s.create_sender_context(pkr)
ct = sender.seal(b"Hello world!")

# The recipient side:
suite_r = CipherSuite.new(KEMId.DHKEM_P256_HKDF_SHA256, KDFId.HKDF_SHA256, AEADId.AES128_GCM)
skr = KEMKey.from_jwk(
    {
        "kid": "01",
        "kty": "EC",
        "crv": "P-256",
        "x": "Ze2loSV3wrroKUN_4zhwGhCqo3Xhu1td4QjeQ5wIVR0",
        "y": "HlLtdXARY_f55A3fnzQbPcm6hgr34Mp8p-nuzQCE0Zw",
        "d": "r_kHyZ-a06rmxM3yESK84r1otSg-aQcVStkRhA-iCM8",
    }
)
recipient = suite_r.create_recipient_context(enc, skr)
pt = recipient.open(ct)

assert pt == b"Hello world!"

Index

Installation
Supported HPKE Modes and Cipher Suites
Warnings and Restrictions
Usage
API Reference
Test
Contributing

Installation

You can install PyHPKE with pip:

$ pip install pyhpke

Supported HPKE Modes and Cipher Suites

PyHPKE supports all of the HPKE modes and cipher suites defined in RFC9180 below.

modes
- ✅ Base
- ✅ PSK
- ✅ Auth
- ✅ AuthPSK
KEMs (Key Encapsulation Machanisms)
- ✅ DHKEM (P-256, HKDF-SHA256)
- ✅ DHKEM (P-384, HKDF-SHA384)
- ✅ DHKEM (P-521, HKDF-SHA512)
- ✅ DHKEM (X25519, HKDF-SHA256)
- ✅ DHKEM (X448, HKDF-SHA512)
KDFs (Key Derivation Functions)
- ✅ HKDF-SHA256
- ✅ HKDF-SHA384
- ✅ HKDF-SHA512
AEADs (Authenticated Encryption with Associated Data)
- ✅ AES-128-GCM
- ✅ AES-256-GCM
- ✅ ChaCha20Poly1305
- ✅ Export Only

Warnings and Restrictions

Although this library has been passed all of the following official test vectors, it has not been formally audited.

RFC9180 official test vectors provided on github.com/cfrg/draft-irtf-cfrg-hpke

Usage

from pyhpke import AEADId, CipherSuite, KDFId, KEMId, KEMKey

# The sender side:
suite_s = CipherSuite.new(KEMId.DHKEM_P256_HKDF_SHA256, KDFId.HKDF_SHA256, AEADId.AES128_GCM)
pkr = KEMKey.from_jwk(
    {
        "kid": "01",
        "kty": "EC",
        "crv": "P-256",
        "x": "Ze2loSV3wrroKUN_4zhwGhCqo3Xhu1td4QjeQ5wIVR0",
        "y": "HlLtdXARY_f55A3fnzQbPcm6hgr34Mp8p-nuzQCE0Zw",
    }
)
enc, sender = suite_s.create_sender_context(pkr)
ct = sender.seal(b"Hello world!")

# The recipient side:
suite_r = CipherSuite.new(KEMId.DHKEM_P256_HKDF_SHA256, KDFId.HKDF_SHA256, AEADId.AES128_GCM)
skr = KEMKey.from_jwk(
    {
        "kid": "01",
        "kty": "EC",
        "crv": "P-256",
        "x": "Ze2loSV3wrroKUN_4zhwGhCqo3Xhu1td4QjeQ5wIVR0",
        "y": "HlLtdXARY_f55A3fnzQbPcm6hgr34Mp8p-nuzQCE0Zw",
        "d": "r_kHyZ-a06rmxM3yESK84r1otSg-aQcVStkRhA-iCM8",
    }
)
recipient = suite_r.create_recipient_context(enc, skr)
pt = recipient.open(ct)

assert pt == b"Hello world!"

API Reference

See Documentation.

Test

You can run tests from the project root after cloning with:

$ tox

Contributing

We welcome all kind of contributions, filing issues, suggesting new features or sending PRs.

dajiaji / pyhpke