ecdh-sodium

ecdh-sodium is a wrapper over libsodium ecdh. Browserify+

npm install ecdh-sodium

Using

const Ecdh = require('ecdh-sodium');

let alice = Ecdh.generate();
let bob = Ecdh.generate();

let aliceSecret = alice.computeSecret(bob.publicKey, 'buffer', 'base64');
let bobSecret = bob.computeSecret(alice.publicKey, 'buffer', 'base64');

true === (aliceSecret === bobSecret);

By private key

let bob = Ecdh.fromPrivateKey('8263086244a5ed93ae5b884258a7d2179ade9e04ba1582f9dadff6d9bc8c4023', 'hex');
let alice = Ecdh.fromPrivateKey('xo0bJpgcr9lf2DCFXpS2FTUmdlmvvw0cS1VvWkYKUqE=', 'base64');

let bobSecret = bob.computeSecret(alice.publicKey);
let aliceSecret = alice.computeSecret(bob.publicKey);

true === (bobSecret.base64 === aliceSecret.base64);

Tests

npm test