hpke-js

hpke-js

A TypeScript Hybrid Public Key Encryption (HPKE) implementation build on top of Web Cryptography API. This library works for both browser-based applications and node.js based applications.

Index

• Supported Features
• Installation
• Usage
  • Base mode
  • PSK mode
  • Auth mode
  • AuthPSK mode
• Contributing
• References

Supported Features

HPKE Modes

Modes	Browser	Node.js
Base	✅	✅
PSK	✅	✅
Auth	✅	✅
AuthPSK

Key Encapsulation Machanisms (KEMs)

KEMs	Browser	Node.js
DHKEM (P-256, HKDF-SHA256)	✅	✅
DHKEM (P-384, HKDF-SHA384)	✅	✅
DHKEM (P-521, HKDF-SHA512)	✅	✅
DHKEM (X25519, HKDF-SHA256)
DHKEM (X448, HKDF-SHA512)

Key Derivation Functions (KDFs)

KDFs	Browser	Node.js
HKDF-SHA256	✅	✅
HKDF-SHA384	✅	✅
HKDF-SHA512	✅	✅

Authenticated Encryption with Associated Data (AEAD) Functions

AEADs	Browser	Node.js
AES-128-GCM	✅	✅
AES-256-GCM	✅	✅
ChaCha20Poly1305
Export Only	✅	✅

Installation

Install with npm:

npm install hpke-js

Usage

This section shows some typical usage examples. See API Documentation for details.

Base mode

On Node.js:

const { Kem, Kdf, Aead, CipherSuite } = require("hpke-js");

async function doHpke() {
  // setup
  const suite = new CipherSuite({
    kem: Kem.DhkemP256HkdfSha256,
    kdf: Kdf.HkdfSha256,
    aead: Aead.Aes128Gcm
  });

  const rkp = await suite.generateKeyPair();

  const sender = await suite.createSenderContext({
    recipientPublicKey: rkp.publicKey
  });

  const recipient = await suite.createRecipientContext({
    recipientKey: rkp,
    enc: sender.enc,
  });

  // encrypt
  const ct = await sender.seal(new TextEncoder().encode("my-secret-message"));

  // decrypt
  const pt = await recipient.open(ct);

  console.log("decrypted: ", new TextDecoder().decode(pt));
  // decripted: my-secret-message
}

doHpke();

PSK mode

On Node.js:

const { Kem, Kdf, Aead, CipherSuite } = require("hpke-js");

async function doHpke() {
  // setup
  const suite = new CipherSuite({
    kem: Kem.DhkemP256HkdfSha256,
    kdf: Kdf.HkdfSha256,
    aead: Aead.Aes128Gcm
  });

  const rkp = await suite.generateKeyPair();

  const sender = await suite.createSenderContext({
    recipientPublicKey: rkp.publicKey,
    psk: {
      id: new TextEncoder().encode("our-pre-shared-key-id"),
      key: new TextEncoder().encode("our-pre-shared-key"),
    }
  });

  const recipient = await suite.createRecipientContext({
    recipientKey: rkp,
    enc: sender.enc,
    psk: {
      id: new TextEncoder().encode("our-pre-shared-key-id"),
      key: new TextEncoder().encode("our-pre-shared-key"),
    }
  });

  // encrypt
  const ct = await sender.seal(new TextEncoder().encode("my-secret-message"));

  // decrypt
  const pt = await recipient.open(ct);

  console.log("decrypted: ", new TextDecoder().decode(pt));
  // decripted: my-secret-message
}

doHpke();

Auth mode

On Node.js:

const { Kem, Kdf, Aead, CipherSuite } = require("hpke-js");

async function doHpke() {
  // setup
  const suite = new CipherSuite({
    kem: Kem.DhkemP256HkdfSha256,
    kdf: Kdf.HkdfSha256,
    aead: Aead.Aes128Gcm
  });

  const rkp = await suite.generateKeyPair();
  const skp = await suite.generateKeyPair();

  const sender = await suite.createSenderContext({
    recipientPublicKey: rkp.publicKey,
    senderKey: skp
  });

  const recipient = await suite.createRecipientContext({
    recipientKey: rkp,
    enc: sender.enc,
    senderPublicKey: skp.publicKey
  });

  // encrypt
  const ct = await sender.seal(new TextEncoder().encode("my-secret-message"));

  // decrypt
  const pt = await recipient.open(ct);

  console.log("decrypted: ", new TextDecoder().decode(pt));
  // decripted: my-secret-message
}

doHpke();

AuthPSK mode

On Node.js:

const { Kem, Kdf, Aead, CipherSuite } = require("hpke-js");

async function doHpke() {
  // setup
  const suite = new CipherSuite({
    kem: Kem.DhkemP256HkdfSha256,
    kdf: Kdf.HkdfSha256,
    aead: Aead.Aes128Gcm
  });

  const rkp = await suite.generateKeyPair();
  const skp = await suite.generateKeyPair();

  const sender = await suite.createSenderContext({
    recipientPublicKey: rkp.publicKey,
    senderKey: skp,
    psk: {
      id: new TextEncoder().encode("our-pre-shared-key-id"),
      key: new TextEncoder().encode("our-pre-shared-key"),
    }
  });

  const recipient = await suite.createRecipientContext({
    recipientKey: rkp,
    enc: sender.enc,
    senderPublicKey: skp.publicKey,
    psk: {
      id: new TextEncoder().encode("our-pre-shared-key-id"),
      key: new TextEncoder().encode("our-pre-shared-key"),
    }
  });

  // encrypt
  const ct = await sender.seal(new TextEncoder().encode("my-secret-message"));

  // decrypt
  const pt = await recipient.open(ct);

  console.log("decrypted: ", new TextDecoder().decode(pt));
  // decripted: my-secret-message
}

doHpke();

Contributing

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

References

• RFC9180: Hybrid Public Key Encryption

Changelog

Version 0.2.2

Released 2022-05-06

• Fix bug on using Web Crypto API on Node.js environment.