As of Feb 18th 2020, the release of jose@^1.23.0 supports ECDH-ES for both X25519 and X448 on Node.js runtime with improved diffie-hellman support. This module is no longer needed, is deprecated and repository archived.

This is a plugin for the jose package that implements Key Agreement with Elliptic Curve Diffie-Hellman Ephemeral Static for X25519 OKP keys.

1. It's backed by libsodium instead of node crypto, unfortunately Node.js does not support this ECDH yet
2. It'll get deprecated once Node.js fills the missing feature gap and the functionality will be implemented in the jose module instead

Installing

npm install jose // jose ^1.16.0 declared as a peer dependency
npm install jose-x25519-ecdh

const jose = require('jose')
const x25519 = require('jose-x25519-ecdh')

(async () => {
  await x25519 // wait for libsodium to be ready!

  {
    const key = jose.JWK.generateSync('OKP', 'X25519')
    console.log(key.algorithms())
    console.log(jose.JWE.encrypt('foobar', key))
  }
})()

Note: X25519 OKP keys are only supported in Node.js runtime >= 12.0.0 and are not supported in electron due to BoringSSL not having the curve implemented.

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