Dart

Export a Public Key as a JWK

Demonstrates the Chilkat PublicKey.GetJwk method, which returns the public key as a compact JWK (JSON Web Key). It takes no arguments; binary values use Base64url without padding and the member order is stable across calls.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: JWK is the JSON key format used across modern web security — JWT, OAuth, OpenID Connect. Exporting a public key to JWK is exactly what you do to publish it in a JWK Set (a jwks_uri endpoint) so others can verify your signatures. The stable member order matters because it makes the output reproducible, which is important when the JWK feeds into a thumbprint.

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Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Load a public key to export.  LoadFromFile inspects the content, so it accepts DER, PEM, XML,
  // JWK, and other supported representations.
  final pubKey = CkPublicKey();
  try {
    pubKey.loadFromFile('qa_data/public.pem');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Export the public key as a compact JWK (JSON Web Key).  Binary values use Base64url without
  // padding, and the member order is stable across calls.
  final String jwk;
  try {
    jwk = pubKey.getJwk();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print(jwk);
}