(Android™) Load RSA Public Key from Hex Modulus and Exponent

Load an RSA public key from a hex 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);

    boolean success;

    // Load a 128-byte (1024-bit) modulus + exponent into a Chilkat public key object..
    String modulus = "BF5F4AF9A018B5F324A0C10448C0D3248D9BE78967FDC551A27876AC5789ADCBA8245D3D942AE3799563D895DA801E765D225A54FA15DAB2C4731DD817DCF94A9AD62197074C2349442093A206234BF3747F0E88AA6F538355684CC1FB26FCE029C9050A1DAF9F507C2BABF6EFC9FB16320C8036721BE0279FBB76122C41E429";

    String exponent = "00000003";

    // We'll need to re-encode from hex to base64..
    CkBinData bdModulus = new CkBinData();
    bdModulus.AppendEncoded(modulus,"hex");
    CkBinData bdExponent = new CkBinData();
    bdExponent.AppendEncoded(exponent,"hex");

    CkXml xml = new CkXml();
    xml.put_Tag("RsaKeyValue");
    xml.NewChild2("Modulus",bdModulus.getEncoded("base64"));
    xml.NewChild2("Exponent",bdExponent.getEncoded("base64"));

    // Now load into the pubkey object..
    CkPublicKey pubkey = new CkPublicKey();
    success = pubkey.LoadFromString(xml.getXml());
    if (success == false) {
        Log.i(TAG, pubkey.lastErrorText());
        return;
        }

    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."
  }
}