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 com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    CkJws jws = new CkJws();

    //  Load the JWS compact serialization.
    String jwsCompact = "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>";
    success = jws.LoadJws(jwsCompact);
    if (success == false) {
        System.out.println(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.
    CkPublicKey pubKey = new CkPublicKey();
    success = pubKey.LoadFromFile("qa_data/signer_pubkey.pem");
    if (success == false) {
        System.out.println(pubKey.lastErrorText());
        return;
        }

    success = jws.SetPublicKey(0,pubKey);
    if (success == false) {
        System.out.println(jws.lastErrorText());
        return;
        }

    //  Validate the signature.  Validate returns 1 when valid, 0 when not, or a negative value on error.
    int v = jws.Validate(0);
    if (v < 0) {
        System.out.println(jws.lastErrorText());
        return;
        }

    if (v != 1) {
        System.out.println("The signature is not valid.");
        return;
        }

    System.out.println("The signature is valid.");
  }
}