Validate a JWS with a Public Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetPublicKey, which sets the public key used to validate a signature of a loaded JWS.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

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

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

  // Load the JWS compact serialization.
  const jwsCompact = 'eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>';
  try {
    jws.loadJws(jwsCompact);
  } catch {
    console.log(jws.lastErrorText);
    return;
  }

  // The file path is relative to the application's current working directory.  An absolute path
  // may also be used.  Supply the path appropriate to your own environment.
  // Load the signer's public key and set it for validating signature 0.
  const pubKey = new PublicKey();
  try {
    pubKey.loadFromFile('qa_data/signer_pubkey.pem');
  } catch {
    console.log(pubKey.lastErrorText);
    return;
  }

  try {
    jws.setPublicKey(0, pubKey);
  } catch {
    console.log(jws.lastErrorText);
    return;
  }

  // Validate the signature.  Validate returns 1 when valid, 0 when not, or a negative value on error.
  const v = jws.validate(0);
  if (v < 0) {
    console.log(jws.lastErrorText);
    return;
  }

  if (v !== 1) {
    console.log('The signature is not valid.');
    return;
  }

  console.log('The signature is valid.');
}