Android™

RSA Encrypt Randomly Generated AES Key

See more RSA Examples

Demonstrates how to RSA encrypt a randomly generated AES key. 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;

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

    // First generate a 256-bit AES key (32 bytes).
    CkPrng prng = new CkPrng();
    CkBinData bdAesKey = new CkBinData();
    success = prng.GenRandomBd(32,bdAesKey);

    // Use a public key from a certificate for RSA encryption.
    CkCert cert = new CkCert();

    success = cert.LoadFromFile("qa_data/pem/mf_public_rsa.pem");
    if (success == false) {
        Log.i(TAG, cert.lastErrorText());
        return;
        }

    CkPublicKey pubKey = new CkPublicKey();
    cert.GetPublicKey(pubKey);

    CkRsa rsa = new CkRsa();
    success = rsa.UsePublicKey(pubKey);
    if (success == false) {
        Log.i(TAG, rsa.lastErrorText());
        return;
        }

    // RSA encrypt our 32-byte AES key.
    // The contents of bdAesKey are replaced with result of the RSA encryption.
    success = rsa.EncryptBd(bdAesKey,false);
    if (success == false) {
        Log.i(TAG, rsa.lastErrorText());
        return;
        }

    // Return the result as a base64 string
    String encryptedAesKey = bdAesKey.getEncoded("base64");

    Log.i(TAG, "encrypted AES key = " + encryptedAesKey);

  }

  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."
  }
}