/*

 * Emulator game server Aion 2.7 from the command of developers 'Aion-Knight Dev. Team' is

 * free software; you can redistribute it and/or modify it under the terms of

 * GNU affero general Public License (GNU GPL)as published by the free software

 * security (FSF), or to License version 3 or (at your option) any later

 * version.

 *

 * This program is distributed in the hope that it will be useful, but WITHOUT ANY

 * WARRANTY; without even the implied warranties related to

 * CONSUMER PROPERTIES and SUITABILITY FOR CERTAIN PURPOSES. For details, see

 * General Public License is the GNU.

 *

 * You should have received a copy of the GNU affero general Public License along with this program.

 * If it is not, write to the Free Software Foundation, Inc., 675 Mass Ave,

 * Cambridge, MA 02139, USA

 *

 * Web developers : http://aion-knight.ru

 * Support of the game client : Aion 2.7- 'Arena of Death' (Innova)

 * The version of the server : Aion-Knight 2.7 (Beta version)

 */



package loginserver.network.ncrypt;



import java.security.GeneralSecurityException;

import java.security.KeyPairGenerator;

import java.security.spec.RSAKeyGenParameterSpec;

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import org.apache.log4j.Logger;

import commons.utils.Rnd;



/**

 * Key generator. It generates keys or keyPairs for Blowfish and RSA

 */

public class KeyGen

{

    /**

     * Logger for this class.

     */

    private static final Logger log = Logger.getLogger(KeyGen.class);



    /**

     * Key generator for blowfish

     */

    private static KeyGenerator blowfishKeyGen;



    /**

     * Public/Static RSA KeyPairs with encrypted modulus N

     */

    private static EncryptedRSAKeyPair[] encryptedRSAKeyPairs;



    /**

     * Initialize Key Generator (Blowfish keygen and RSA keygen)

     *

     * @throws GeneralSecurityException

     */

    public static void init() throws GeneralSecurityException

    {

        log.info("Initializing Key Generator...");



        blowfishKeyGen = KeyGenerator.getInstance("Blowfish");



        KeyPairGenerator rsaKeyPairGenerator = KeyPairGenerator.getInstance("RSA");



        RSAKeyGenParameterSpec spec = new RSAKeyGenParameterSpec(1024, RSAKeyGenParameterSpec.F4);



        rsaKeyPairGenerator.initialize(spec);



        encryptedRSAKeyPairs = new EncryptedRSAKeyPair[10];



        for (int i = 0; i < 10; i++)

        {

            encryptedRSAKeyPairs[i] = new EncryptedRSAKeyPair(rsaKeyPairGenerator.generateKeyPair());

        }



        // Pre-init RSA cipher.. saving about 300ms

        Cipher rsaCipher = Cipher.getInstance("RSA/ECB/nopadding");



        rsaCipher.init(Cipher.DECRYPT_MODE, encryptedRSAKeyPairs[0].getRSAKeyPair().getPrivate());

    }



    /**

     * Generate and return blowfish key

     *

     * @return Random generated blowfish key

     */

    public static SecretKey generateBlowfishKey()

    {

        return blowfishKeyGen.generateKey();

    }



    /**

     * Get common RSA Public/Static Key Pair with encrypted modulus N

     *

     * @return encryptedRSAkeypairs

     */

    public static EncryptedRSAKeyPair getEncryptedRSAKeyPair()

    {

        return encryptedRSAKeyPairs[Rnd.nextInt(10)];

    }

}