Sign a JWS with an HMAC Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetMacKey, which sets the symmetric MAC key for a signature. The key bytes are supplied in a named encoding such as hex or base64.

import { JsonObject, Jws } from '@chilkat/react-native'

function chilkatExample() {
  const jws = new Jws();

  // Protected header specifying HMAC-SHA256.
  const header = new JsonObject();
  header.updateString('alg', 'HS256');
  try {
    jws.setProtectedHeader(0, header);
  } catch {
    console.log(jws.lastErrorText);
    return;
  }

  const bIncludeBom = false;
  try {
    jws.setPayload('This is the content to sign.', 'utf-8', bIncludeBom);
  } catch {
    console.log(jws.lastErrorText);
    return;
  }

  // Set the symmetric MAC key for signature 0.  The key bytes are provided in the named encoding (here
  // base64).  In production, obtain the key from a secure source rather than hard-coding it.
  const base64Key = 'YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=';
  try {
    jws.setMacKey(0, base64Key, 'base64');
  } catch {
    console.log(jws.lastErrorText);
    return;
  }

  let jwsCompact: string;
  try {
    jwsCompact = jws.createJws();
  } catch {
    console.log(jws.lastErrorText);
    return;
  }

  console.log(jwsCompact);
}