Android™

Create JWT using a Brainpool EC Key

See more JSON Web Token (JWT) Examples

Demonstrates how to create a JWT using an EC private key. This is for JOSE headers having an "alg" member with any of the following values:

• BP160R1
• BP192R1
• BP224R1
• BP256R1
• BP320R1
• BP384R1
• BP512R1

This example also demonstrates how to include time constraints:

• nbf: Not Before Time
• exp: Expiration Time
• iat: Issue At Time

Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    //  Demonstrates how to create a JWT using a brainpool EC private key.

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    CkPrivateKey privKey = new CkPrivateKey();

    //  Load a brainpool EC key.
    success = privKey.LoadPemFile("c:/qa_data/pem/ec_brainpool_privKey.pem");
    if (success != true) {
        Log.i(TAG, privKey.lastErrorText());
        return;
        }

    //  You can examine the curve name of the key you just loaded by getting the private in XML format:
    //  <ECCKeyValue curve="CURVE_NAME">...</ECCKeyValue>
    Log.i(TAG, privKey.getXml());

    CkJwt jwt = new CkJwt();

    //  Build the JOSE header
    CkJsonObject jose = new CkJsonObject();
    //  Use the brainpool curve name matching the private key you just loaded.
    //  Use "BP256R1", or "BP384R1", etc.   
    success = jose.AppendString("alg","BP256R1");
    success = jose.AppendString("typ","JWT");

    //  Now build the JWT claims (also known as the payload)
    CkJsonObject claims = new CkJsonObject();
    success = claims.AppendString("iss","http://example.org");
    success = claims.AppendString("sub","John");
    success = claims.AppendString("aud","http://example.com");

    //  Set the timestamp of when the JWT was created to now.
    int curDateTime = jwt.GenNumericDate(0);
    success = claims.AddIntAt(-1,"iat",curDateTime);

    //  Set the "not process before" timestamp to now.
    success = claims.AddIntAt(-1,"nbf",curDateTime);

    //  Set the timestamp defining an expiration time (end time) for the token
    //  to be now + 1 hour (3600 seconds)
    success = claims.AddIntAt(-1,"exp",curDateTime + 3600);

    //  Produce the smallest possible JWT:
    jwt.put_AutoCompact(true);

    //  Create the JWT token.  This is where the ECC signature is created.
    String token = jwt.createJwtPk(jose.emit(),claims.emit(),privKey);

    Log.i(TAG, token);

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}