/* CREATED BY KEVIN PECHIN ON 01/02/2008
 * PURPOSE: THIS WILL GENERATE PUBLIC/PRIVATE KEYS IN RSA FORMAT AND PERFORM A TEST ON THE KEYS
  */
import java.security.*;
import javax.crypto.Cipher;
import java.io.FileOutputStream;

public class kGenerateRSAKeys {

    public static void main(String[] args) throws Exception {
		try {
			Cipher rsa;
			KeyPair Kpair;

			// CREATE A KEYFACTORY OBJECT AND SET IT TO RSA
			KeyFactory factory = KeyFactory.getInstance("RSA");
			// GENERATE A KEYPAIR USING RSA
			KeyPairGenerator KpairGen = KeyPairGenerator.getInstance("RSA");
			KpairGen.initialize(1024, new SecureRandom());
			Kpair = KpairGen.generateKeyPair();

			// INITIALIZE FOR RSA CIPHER ENCRYPTION AND DECRYPTION
			rsa = Cipher.getInstance("RSA");

			// TEST ENCRYPTION
			rsa.init(Cipher.ENCRYPT_MODE, Kpair.getPublic());
			byte[] encryptedItem = rsa.doFinal("If you see this it is working".getBytes());

			// TEST DECRYPTION
			rsa.init(Cipher.DECRYPT_MODE, Kpair.getPrivate());
			byte[] decryptedItem = rsa.doFinal(encryptedItem);
			String recovered = new String(decryptedItem);
			System.out.println("Decrypted Item: " + recovered);

	        // SAVE PUBLIC/PRIVATE KEYS
	        byte[] encodedKeySpec = Kpair.getPrivate().getEncoded();
	        FileOutputStream eksos = new FileOutputStream("private_RSA.key");
	        eksos.write(encodedKeySpec);
	        eksos.close();
			
	        byte[] encodedKeySpec1 = Kpair.getPublic().getEncoded();
	        FileOutputStream eksos1 = new FileOutputStream("public_RSA.key");
	        eksos1.write(encodedKeySpec1);
	        eksos1.close();
		}
		catch (Exception e) {
			System.out.println(e.toString());
		}
    }
}