jwks.js

const fs = require("fs");
const jose = require("node-jose");

const jwktopem = require("jwk-to-pem");
const jwt = require("jsonwebtoken");

// Generate a new JWKS
// const keyStore = jose.JWK.createKeyStore();
// keyStore.generate("RSA", 2048, { alg: "RS256", use: "sig" }).then((result) => {
//   fs.writeFileSync(
//     "keys.json",
//     JSON.stringify(keyStore.toJSON(true), null, "  ")
//   );
// });

async function getPublicKey(jwks) {
  const ks = fs.readFileSync("keys.json");
  const keyStore = await jose.JWK.asKeyStore(ks.toString());
  const publicKey = keyStore.toJSON();
  console.log("publicKey: ", publicKey);
  return publicKey;
}

// getPublicKey();

async function createToken() {
  const ks = fs.readFileSync("keys.json");
  const keyStore = await jose.JWK.asKeyStore(ks.toString());
  const [key] = keyStore.all({ use: "sig" });

  const opt = { compact: true, jwk: key, fields: { typ: "jwt" } };
  const payload = JSON.stringify({
    exp: Math.floor((Date.now() + 3600 * 1000) / 1000),
    iat: Math.floor(Date.now() / 1000),
    data: "Hello World",
  });
  const token = await jose.JWS.createSign(opt, key).update(payload).final();
  console.log("token: ", token);

  return token;
}

// createToken();

// Async Function `main`
async function main() {
  const token = await createToken();
  // const { data } = await axios.get('http://localhost:4040/jwks')
  const data = await getPublicKey();
  const [firstKey] = data.keys;
  const publicKey = jwktopem(firstKey);
  try {
    const decoded = jwt.verify(token, publicKey);
    console.log("Decoded:", decoded);
  } catch (e) {
    console.log("Error:", e);
  }
}

main();

NodeJS JWKS Implementation