(Android™) Load ECC Private Key from JWK Format (JSON Web Key)

Demonstrates how to load an ECC private key from JWK (JSON Web Key) format.

Note: This example requires Chilkat v9.5.0.66 or later.

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);

    // Note: This example requires Chilkat v9.5.0.66 or later.
    boolean success;

    // First build a JWK sample to load..
    CkJsonObject json = new CkJsonObject();
    json.UpdateString("kty","EC");
    json.UpdateString("crv","P-256");
    json.UpdateString("x","oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE");
    json.UpdateString("y","vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU");
    json.UpdateString("d","EbVzfPnZPxfAyxqEZV05laAoJAl-_6Xt2O4mOB611sM");

    // The JSON contains the following:
    // { 
    //   "kty": "EC",
    //   "crv": "P-256",
    //   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
    //   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
    //   "d": "EbVzfPnZPxfAyxqEZV05laAoJAl-_6Xt2O4mOB611sM"
    // }

    // Note: The JSON can contain other members, such as "use", "kid", or anything else.  These will be ignored.
    json.put_EmitCompact(false);

    // Show the JWK string to be loaded:
    String jwkStr = json.emit();

    CkPrivateKey privKey = new CkPrivateKey();
    success = privKey.LoadJwk(jwkStr);
    if (success != true) {
        Log.i(TAG, privKey.lastErrorText());
        return;
        }

    // OK.. the JWK is loaded.  It can be used in whatever way desired...

    // The key can be retrieved in any other format, such as XML or PEM..
    Log.i(TAG, privKey.getXml());

    // XML output:
    // <ECCKeyValue curve="secp256r1">MHcCAQEEIBG1c3z52T8XwMsahGVdOZWgKCQJfv+l7djuJjgetdbDoAoGCCqGSM49AwEHoEQDQgAEoBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxG+9DLFmRSMlBQ9T/RsLLc+PmpB1+7yPAR+oR5gZn3kJQ==</ECCKeyValue>

    Log.i(TAG, privKey.getPkcs8EncryptedPem("secret"));

    // PEM output
    // 
    // -----BEGIN ENCRYPTED PRIVATE KEY-----
    // MIHFMEAGCSqGSIb3DQEFDTAzMBsGCSqGSIb3DQEFDDAOBAiku9rUjavLQQICCAAw
    // FAYIKoZIhvcNAwcECGsl/5nLai+JBIGAVIqKAdfcRQNLl1t3x+n8OZ92d1H+qgjS
    // Hs83wn2joJK4nlqy+rzosZxQ3e8NTJQyUEWZWcjqMj/N0phS3QWtcD/qbda5oEcv
    // QgtU60cZ4ql3truefAmlZz2PdpOfqtYhxlvjJQxnyojn4ntj69OwLOt9SZbaBQQi
    // KUL8KXT4Pq8=
    // -----END ENCRYPTED PRIVATE KEY-----

  }

  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."
  }
}