Interoperability between webcrypto and crypto modules in Node.js

webcrypto-interop.js

const crypto = require('node:crypto')
const {webcrypto} = crypto
const {subtle} = webcrypto

async function generateKeys() {
  const {
    publicKey,
    privateKey
  } = await subtle.generateKey({
    name: 'RSA-OAEP',
    modulusLength: 1024,
    publicExponent: new Uint8Array([1, 0, 1]),
    length: 256,
    hash: 'SHA-1',
  }, true, ['encrypt', 'decrypt']);
  return {publicKey, privateKey}
}

async function aesDecrypt(ciphertext, key) {
  const dec = new TextDecoder();
  const plaintext = await subtle.decrypt({
    name: 'RSA-OAEP',
  }, key, ciphertext);

  return dec.decode(plaintext);
}

async function run() {
  const plaintext = 'hello world'

  const {publicKey, privateKey} = await generateKeys()

  const pem = '-----BEGIN PUBLIC KEY-----\n'+Buffer.from(await subtle.exportKey('spki', publicKey)).toString('base64')+'\n-----END PUBLIC KEY-----'
  const pk = crypto.createPublicKey(pem)
  const encrypted = crypto.publicEncrypt({key: pk}, Buffer.from(plaintext));
  console.log(await aesDecrypt(encrypted, privateKey))
}

run().catch(console.error)