rsakeygen.java

java applet code for generating RSA key pair

package RSA;

import javacard.framework.*;
import javacard.security.*;
import javacardx.crypto.*;

public class RSAKeyGen extends Applet {

	// code of CLA byte in the command APDU header
	  final static byte CLA =(byte)0x80;

	  // codes of INS byte in the command APDU header
	  final static byte INS_CREATE_RSA_KEYPAIR = (byte) 0x20;

	  // RSA
	  private KeyPair rsaPair;
	  private RSAPublicKey rsaPubKey;
	  private RSAPrivateKey rsaPrivKey;


	  public static void install(byte[] bArray, short bOffset, byte bLength)
		{
			new RSAKeyGen(bArray, bOffset, bLength);
		}

	  /**
	  * Performs memory allocations, initialization, and applet registration.
	  *
	  * @param bArray to pass to register() method.
	  * @param bOffset to pass to register() method.
	  * @param bLength to pass to register() method.
	  */
		protected RSAKeyGen(byte[] bArray, short bOffset, byte bLength)
		{
			rsaPair = new KeyPair(KeyPair.ALG_RSA_CRT,(short)1024);
			register();
		}

	  /**
	  * Dispatches APDU commands.
	  * @param apdu APDU object
	  */
		public void process(APDU apdu)
		{
	    if (selectingApplet())
	        return;

	    byte[] buffer = apdu.getBuffer();

	    if (buffer[ISO7816.OFFSET_CLA] != CLA)
	       ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED);

	    switch (buffer[ISO7816.OFFSET_INS]) {
	      case INS_CREATE_RSA_KEYPAIR:
	      	genRSAKeyPair(apdu);
	      	return;
	      default:
	      	ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
	    }
		}


	    public void genRSAKeyPair(APDU apdu) {
			rsaPair.genKeyPair();
	   }

}