(Android™) RSA Encrypt with Modulus and Exponent

Demonstrates how to RSA encrypt with a given modulus and exponent.

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();

    // Assuming you already have a base64 modulus and exponent,
    // wrap it in XML like this:
    String modulus = "qMBRpdYrAy5aMmo31NErUizh5sbweguSmh4wlK6uJEIDl+kwTlROnE34KOFExeTbJSX0WygPi+vWl0yNq7buIMUKpytossAAWut5khO3CQJxTk7G2gnEPNUUXHiExGgNrLzcSLv8YIlfVALhoRWyC67KOL+a+3taNq3h+BHeWhM=";
    String exponent = "AQAB";

    CkXml xml = new CkXml();
    xml.put_Tag("RSAPublicKey");
    xml.NewChild2("Modulus",modulus);
    xml.NewChild2("Exponent",exponent);

    // Encrypt with the public key.
    String publicKey = xml.getXml();
    boolean success = rsa.ImportPublicKey(publicKey);

    boolean usePrivateKey = false;
    String plainText = "message in a bottle";

    rsa.put_EncodingMode("base64");
    String encryptedStrBase64 = rsa.encryptStringENC(plainText,usePrivateKey);
    Log.i(TAG, encryptedStrBase64);

  }

  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."
  }
}