(Android™) JWE using ECDH-ES, BP-256, A256GCM

See more JSON Web Encryption (JWE) Examples

Create a JWE with the following header:

	{
	  "alg": "ECDH-ES",
	  "enc": "A256GCM",
	  "exp": 1621957030,
	  "cty": "NJWT",
	  "epk": {
	    "kty": "EC",
	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
	    "crv": "BP-256"
	  }
	}

Note: This example requires Chilkat v9.5.0.87 or greater.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// 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);

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

    boolean success;

    // Load our brainpool BP-256 public key.

    // 	{
    // 	  "use": "enc",
    // 	  "kid": "puk_idp_enc",
    // 	  "kty": "EC",
    // 	  "crv": "BP-256",
    // 	  "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w",
    // 	  "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
    // 	}

    CkJsonObject json = new CkJsonObject();
    json.UpdateString("use","enc");
    json.UpdateString("kid","puk_idp_enc");
    json.UpdateString("kty","EC");
    json.UpdateString("crv","BP-256");
    json.UpdateString("x","QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w");
    json.UpdateString("y","AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu");

    CkPublicKey pubkey = new CkPublicKey();

    success = pubkey.LoadFromString(json.emit());
    if (success == false) {
        Log.i(TAG, pubkey.lastErrorText());
        return;
        }

    // Build our protected header:

    // 	{
    // 	  "alg": "ECDH-ES",
    // 	  "enc": "A256GCM",
    // 	  "exp": 1621957030,
    // 	  "cty": "NJWT",
    // 	  "epk": {
    // 	    "kty": "EC",
    // 	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
    // 	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
    // 	    "crv": "BP-256"
    // 	  }
    // 	}

    // Use jwt only for getting the current date/time + 3600 seconds.
    CkJwt jwt = new CkJwt();

    CkJsonObject jweProtHdr = new CkJsonObject();
    jweProtHdr.UpdateString("alg","ECDH-ES");
    jweProtHdr.UpdateString("enc","A256GCM");
    jweProtHdr.UpdateInt("exp",jwt.GenNumericDate(3600));
    jweProtHdr.UpdateString("cty","NJWT");
    jweProtHdr.UpdateString("epk.kty","EC");
    jweProtHdr.UpdateString("epk.x","QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w");
    jweProtHdr.UpdateString("epk.y","AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu");
    jweProtHdr.UpdateString("epk.crv","BP-256");

    CkJwe jwe = new CkJwe();
    jwe.SetProtectedHeader(jweProtHdr);
    jwe.SetPublicKey(0,pubkey);

    String plainText = "This is the text to be encrypted.";
    String strJwe = jwe.encrypt(plainText,"utf-8");
    if (jwe.get_LastMethodSuccess() != true) {
        Log.i(TAG, jwe.lastErrorText());
        return;
        }

    Log.i(TAG, strJwe);

    Log.i(TAG, "Success.");

  }

  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."
  }
}