@hpke/core

@hpke/core

A TypeScript Hybrid Public Key Encryption (HPKE) core module implemented using only Web Cryptography API. It does not support the X448-based KEM and the ChaCha20Poly1305 AEAD, but it has no external module dependencies. It's small in size and tree-shaking friendly.

Documentation: jsr.io | pages (only for the latest ver.)

Index

• Installation
  • Node.js
  • Deno
  • Web Browsers
• Usage
• Contributing

Installation

Where possible, it is recommended to use @hpke/core along with extension modules (such as @hpke/chacha20poly1305) instead of hpke-js.

Node.js

You can install the package with npm, yarn or pnpm.

# Using npm:
npm install @hpke/core
yarn add @hpke/core
pnpm install @hpke/core
# Using jsr:
npx jsr add @hpke/core
yarn add jsr:@hpke/core
pnpm add jsr:@hpke/core

The above manner can be used with other JavaScript runtimes that support npm, such as Cloudflare Workers and Bun.

Then, you can use the module from code like this:

import {
  Aes128Gcm,
  CipherSuite,
  DhkemP256HkdfSha256,
  HkdfSha256,
} from "@hpke/core";

Deno

For Deno, it is recommended to use the jsr.io registry.

deno add jsr:@hpke/core

Web Browsers

Followings are how to use this module with typical CDNs. Other CDNs can be used as well.

Using esm.sh:

<!-- use a specific version -->
<script type="module">
  import {
    Aes128Gcm,
    CipherSuite,
    DhkemP256HkdfSha256,
    HkdfSha256,
  } from "https://esm.sh/@hpke/core@<SEMVER>";
  // ...
</script>

<!-- use the latest stable version -->
<script type="module">
  import {
    Aes128Gcm,
    CipherSuite,
    DhkemP256HkdfSha256,
    HkdfSha256,
  } from "https://esm.sh/@hpke/core";
  // ...
</script>

Using unpkg:

<!-- use a specific version -->
<script type="module">
  import * as hpke from "https://unpkg.com/@hpke/core@<SEMVER>/esm/mod.js";
  // ...
</script>

Usage

This section shows some typical usage examples.

Node.js

import {
  Aes128Gcm,
  CipherSuite,
  DhkemP256HkdfSha256,
  HkdfSha256,
} from "@hpke/core";

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

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

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

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

  // encrypt
  const ct = await sender.seal(new TextEncoder().encode("Hello world!"));

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

  // Hello world!
  console.log(new TextDecoder().decode(pt));
}

try {
  doHpke();
} catch (err) {
  console.log("failed:", err.message);
}

Deno

import {
  Aes128Gcm,
  CipherSuite,
  DhkemP256HkdfSha256,
  HkdfSha256,
} from "@hpke/core";

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

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

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

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

  // encrypt
  const ct = await sender.seal(new TextEncoder().encode("Hello world!"));

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

  // Hello world!
  console.log(new TextDecoder().decode(pt));
}

try {
  doHpke();
} catch (_err: unknown) {
  console.log("doHPKE() failed.");
}

Web Browsers

<html>
  <head></head>
  <body>
    <script type="module">
      import {
        Aes128Gcm,
        CipherSuite,
        DhkemP256HkdfSha256,
        HkdfSha256,
      } from "https://esm.sh/@hpke/core";

      globalThis.doHpke = async () => {
        const suite = new CipherSuite({
          kem: new DhkemP256HkdfSha256(),
          kdf: new HkdfSha256(),
          aead: new Aes128Gcm(),
        });

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

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

        const recipient = await suite.createRecipientContext({
          recipientKey: rkp.privateKey, // rkp (CryptoKeyPair) is also acceptable.
          enc: sender.enc,
        });

        // encrypt
        const ct = await sender.seal(
          new TextEncoder().encode("hello world!"),
        );

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

          // hello world!
          alert(new TextDecoder().decode(pt));
        } catch (err) {
          alert("failed to decrypt.");
        }
      };
    </script>
    <button type="button" onclick="doHpke()">do HPKE</button>
  </body>
</html>

Contributing

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

Similar packages

Other packages similar to @hpke/core

@hpke/dhkem-x25519

An algorithm package in the same ecosystem that supplies an X25519-based HPKE KEM. It complements the core interfaces rather than providing the same broad protocol framework on its own.

@noble/ciphers

Provides audited, standalone JavaScript cryptographic primitives, including authenticated encryption options. It can cover some low-level encryption needs, but it is not a complete HPKE implementation with HPKE setup, encapsulation, and context management.

libsodium-wrappers

JavaScript wrappers for libsodium’s cryptographic functions, including public-key and authenticated-encryption tools. It offers a broader general-purpose cryptography API, but its primitives and interfaces are not a drop-in implementation of the HPKE protocol.