browser-key.js

// Uses Buffer from https://github.com/feross/buffer

function toArrayBuffer(buffer) {
  return buffer.buffer.slice(
    buffer.byteOffset,
    buffer.byteOffset + buffer.byteLength
  );
}

async function run() {
  let encoder = new TextEncoder('utf-8');
  let password = encoder.encode('random-password');
  let salt = toArrayBuffer(Buffer.from('random-salt'));

  let passwordKey = await window.crypto.subtle.importKey(
    'raw',
    password,
    { name: 'PBKDF2' },
    false,
    ['deriveBits', 'deriveKey']
  );

  let derivedKey = await crypto.subtle.deriveKey(
    {
      name: 'PBKDF2',
      hash: 'SHA-256', // This is wrong, should be 512!
      salt: salt,
      iterations: 10000
    },
    passwordKey,
    { name: 'AES-GCM', length: 256 },
    true,
    ['encrypt', 'decrypt']
  );

  let exported = await crypto.subtle.exportKey('raw', derivedKey);
  console.log('salt:', Buffer.from(salt).toString('base64'));
  console.log('key:', Buffer.from(exported).toString('base64'));
}

run();

node-key.js

let crypto = require('crypto');

let buffer = crypto.pbkdf2Sync(
  'random-password',
  'random-salt',
  10000,
  32,
  'sha512'
);

console.log(buffer.toString('base64'));