Validate a JWS Signature

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.Validate, which validates exactly one signature, identified by a zero-based index, using the key configured at that same index.

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;
        }

    //  Provide the key for signature 0 (here an HMAC key).
    String base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=";
    success = jws.SetMacKey(0,base64Key,"base64");
    if (success == false) {
        System.out.println(jws.lastErrorText());
        return;
        }

    //  Validate the signature identified by the zero-based index, using the key configured at that index.
    //  Validate returns 1 when the signature or MAC is cryptographically valid, 0 when it is 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.");
  }
}