Java

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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Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.PublicKey;

public class ChilkatExample {

    public static void main(String[] args) {
        // Load a public key to export.  LoadFromFile inspects the content, so it accepts DER, PEM, XML,
        // JWK, and other supported representations.
        PublicKey pubKey = new PublicKey();
        String jwk;
        try {
            pubKey.loadFromFile("qa_data/public.pem");

            // 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.
            jwk = pubKey.getJwk();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println(jwk);
    }
}