hpke-js

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A TypeScript Hybrid Public Key Encryption (HPKE) implementation build on top of Web Cryptography API. This module works on web browsers, Node.js and Deno.

Index

Supported Features

HPKE Modes

Base PSK Auth AuthPSK
✅ ✅ ✅ ✅

Key Encapsulation Machanisms (KEMs)

KEMs Browser Node.js Deno
DHKEM (P-256, HKDF-SHA256) ✅ ✅ ✅ v1.23.0-
DHKEM (P-384, HKDF-SHA384) ✅ ✅
DHKEM (P-521, HKDF-SHA512) ✅ ✅
DHKEM (X25519, HKDF-SHA256) ✅ ✅ ✅ @stablelib/x25519 is used
until Secure Curves is implemented
on browsers.
DHKEM (X448, HKDF-SHA512) ✅ ✅ ✅ x448-js is used
until Secure Curves is implemented
on browsers.

Key Derivation Functions (KDFs)

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

Authenticated Encryption with Associated Data (AEAD) Functions

AEADs Browser Node.js Deno
AES-128-GCM ✅ ✅ ✅
AES-256-GCM ✅ ✅ ✅
ChaCha20Poly1305 ✅ ✅ ✅ @stablelib/chacha20poly1305 is used.
Export Only ✅ ✅ ✅

Supported Environments

  • Web Browser: Web Cryptography API supported browsers
    • Confirmed: Chrome, Firefox, Edge, Safari, Opera, Vivaldi, Brave
  • Node.js: 16.x, 17.x, 18.x
  • Deno: 1.x

Warnings and Restrictions

Installation

Web Browser

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

Using esm.sh:

<!-- use a specific version -->
<script type="module">
  import * as hpke from "https://esm.sh/hpke-js@0.11.5";
  // ...
</script>

<!-- use the latest stable version -->
<script type="module">
  import * as hpke from "https://esm.sh/hpke-js";
  // ...
</script>

Using unpkg:

<!-- use a specific version -->
<script type="module">
  import * as hpke from "https://unpkg.com/hpke-js@0.11.5/esm/mod.js";
  // ...
</script>

Node.js

Using npm:

npm install hpke-js

Using yarn:

yarn add hpke-js

Deno

Using deno.land:

// use a specific version
import * as hpke from "https://deno.land/x/hpke@v0.11.5/mod.ts";

// use the latest stable version
import * as hpke from "https://deno.land/x/hpke/mod.ts";

Usage

This section shows some typical usage examples.

Base mode

Browsers:

<html>
  <head></head>
  <body>
    <script type="module">
      // import * as hpke from "https://esm.sh/hpke-js@0.11.5";
      import { Kem, Kdf, Aead, CipherSuite } from "https://esm.sh/hpke-js@0.11.5";

      globalThis.doHpke = async () => {

        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("hello world!"));
      
        try {
          // decrypt
          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>

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

    console.log("decrypted: ", new TextDecoder().decode(pt));
    // decrypted: my-secret-message
  } catch (err) {
    console.log("failed to decrypt.");
  }
}

doHpke();

Deno:

import { Kem, Kdf, Aead, CipherSuite } from "https://deno.land/x/hpke@v0.11.5/mod.ts";

async function doHpke() {
  // setup
  const suite = new CipherSuite({
    kem: Kem.DhkemX25519HkdfSha256,
    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"));

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

    console.log("decrypted: ", new TextDecoder().decode(pt));
    // decrypted: my-secret-message
  } catch (_err: unknown) {
    console.log("failed to decrypt.");
  }
}

doHpke();

Base mode with Single-Shot APIs

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 pt = new TextEncoder().encode('my-secret-message'),

  // encrypt
  const { ct, enc } = await suite.seal({ recipientPublicKey: rkp.publicKey }, pt);

  // decrypt
  try {
  const pt = await suite.open({ recipientKey: rkp, enc: enc }, ct);

  console.log('decrypted: ', new TextDecoder().decode(pt));
  // decrypted: my-secret-message
  } catch (err) {
    console.log("failed to decrypt.");
  }
}

doHpke();

Base mode with bidirectional encryption

Node.js:

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

const te = new TextEncoder();
const td = new TextDecoder();

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,
  });

  // setup bidirectional encryption
  await sender.setupBidirectional(
    te.encode("seed-for-key"),
    te.encode("seed-for-nonce"),
  );
  await recipient.setupBidirectional(
    te.encode("seed-for-key"),
    te.encode("seed-for-nonce"),
  );

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

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

    console.log("recipient decrypted: ", td.decode(pt));
    // decrypted: my-secret-message-s
  } catch (err) {
    console.log("failed to decrypt.");
  }

  // encrypt reversely
  const rct = await recipient.seal(te.encode("my-secret-message-r"));

  // decrypt reversely
  try {
    const rpt = await sender.open(rct);

    console.log("sender decrypted: ", td.decode(rpt));
    // decrypted: my-secret-message-r
  } catch (err) {
    console.log("failed to decrypt.");
  }
}

doHpke();

Base mode with export-only AEAD

Node.js:

  const suite = new CipherSuite({
    kem: Kem.DhkemP256HkdfSha256,
    kdf: Kdf.HkdfSha256,
    aead: Aead.ExportOnly,
  });

  const rkp = await suite.generateKeyPair();

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

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

  const te = new TextEncoder();

  // export
  const pskS = sender.export(te.encode('jugemujugemu'), 32);
  const pskR = recipient.export(te.encode('jugemujugemu'), 32);
  // pskR === pskS
}

doHpke();

PSK mode

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"),
      // a PSK MUST have at least 32 bytes.
      key: new TextEncoder().encode("jugemujugemugokounosurikirekaija"),
    },
  });

  const recipient = await suite.createRecipientContext({
    recipientKey: rkp,
    enc: sender.enc,
    psk: {
      id: new TextEncoder().encode("our-pre-shared-key-id"),
      // a PSK MUST have at least 32 bytes.
      key: new TextEncoder().encode("jugemujugemugokounosurikirekaija"),
    },
  });

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

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

    console.log("decrypted: ", new TextDecoder().decode(pt));
    // decrypted: my-secret-message
  } catch (err) {
    console.log("failed to decrypt:", err.message);
  }
}

doHpke();

Auth mode

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"));

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

    console.log("decrypted: ", new TextDecoder().decode(pt));
    // decrypted: my-secret-message
  } catch (err) {
    console.log("failed to decrypt:", err.message);
  }
}

doHpke();

AuthPSK mode

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"),
      // a PSK MUST have at least 32 bytes.
      key: new TextEncoder().encode("jugemujugemugokounosurikirekaija"),
    },
  });

  const recipient = await suite.createRecipientContext({
    recipientKey: rkp,
    enc: sender.enc,
    senderPublicKey: skp.publicKey,
    psk: {
      id: new TextEncoder().encode("our-pre-shared-key-id"),
      // a PSK MUST have at least 32 bytes.
      key: new TextEncoder().encode("jugemujugemugokounosurikirekaija"),
    },
  });

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

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

    console.log("decrypted: ", new TextDecoder().decode(pt));
    // decrypted: my-secret-message
  } catch (err) {
    console.log("failed to decrypt:", err.message);
  }
}

doHpke();

Contributing

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

References