(Android™) Generate an RSA Key and Get as Base64 DER

Demonstrates how to generate a 2048-bit RSA key and return the public and private parts as unencrypted Base64 encoded DER.

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

    CkRsa rsa = new CkRsa();

    // Generate a 2048-bit key.  Chilkat RSA supports
    boolean success = rsa.GenerateKey(2048);
    if (success != true) {
        Log.i(TAG, rsa.lastErrorText());
        return;
        }

    // Get the public part of the key.
    CkPublicKey pubKey = rsa.ExportPublicKeyObj();

    // There are two possible formats for representing the RSA public key 
    // in ASN.1 (DER).  The possible formats are PKCS1 and PKCS8.
    // We can get either by setting bChoosePkcs1 to true or false.
    boolean bChoosePkcs1 = true;
    String pubKeyBase64Der = pubKey.getEncoded(bChoosePkcs1,"base64");
    Log.i(TAG, "Public Key Base64 DER:");
    Log.i(TAG, pubKeyBase64Der);

    // Now get the private key as Base64 DER:
    // Get the private part of the key.
    // (Note: A public key is actually just a subset of the private key.  
    //  If you have the private key, you also have the public key.
    //  Thus Chilkat provides a method to get the public key from the private key.)
    CkPrivateKey privKey = rsa.ExportPrivateKeyObj();

    // Again, we can get PKCS1 or PKCS8, but with different methods:
    String privKeyPkcs1 = privKey.getPkcs1ENC("base64");
    Log.i(TAG, "Private Key PKCS1 Base64 DER:");
    Log.i(TAG, privKeyPkcs1);

    String privKeyPkcs8 = privKey.getPkcs8ENC("base64");
    Log.i(TAG, "Private Key PKCS8 Base64 DER:");
    Log.i(TAG, privKeyPkcs8);


  }

  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."
  }
}