/*

 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

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

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

import java.security.GeneralSecurityException;

import java.security.Provider;

import java.security.Security;

import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.IvParameterSpec;

import javax.crypto.spec.PBEKeySpec;

import javax.crypto.spec.SecretKeySpec;

/**

 * Wrapper class to test a given SecretKeyFactory.PBKDF2 algorithm.

 */

public class PBKDF2Wrapper extends AbstractPBEWrapper {

    /**

     * Default salt size.

     */

    public static final int PBKDF2_SALT_SIZE = 64;

    /**

     * Default key length.

     */

    public static final int PKDF2_DEFAULT_KEY_LEN = 128;

    /**

     * Default transformation.

     */

    public static final String CIPHER_TRANSFORMATION = "AES/CBC/PKCS5Padding";

    /**

     * Algorithm name.

     */

    public static final String KEY_ALGORITHM = "AES";

    /**

     * Initialization vector length.

     */

    private static final int IV_LENGTH = 16;

    /**

     * The buffer with the IV.

     */

    private final byte[] iv;

    /**

     * PBKDF2Wrapper constructor. Instantiate Cipher using

     * "AES/CBC/PKCS5Padding" transformation. Generate a secret key using PKDF2

     * algorithms given in the "algo" parameter.

     *

     * @param algo AES-based PBE algorithm.

     * @param passwd password phrase.

     * @throws GeneralSecurityException all security exceptions are thrown.

     */

    public PBKDF2Wrapper(PBEAlgorithm algo, String passwd)

            throws GeneralSecurityException {

        super(algo, passwd, PBKDF2_SALT_SIZE);

        iv = TestUtilities.generateBytes(IV_LENGTH);

    }

    /**

     * Initiate the Cipher object for PBKDF2 algorithm using given "mode".

     *

     * @param mode Cipher mode: encrypt or decrypt

     * @return Cipher object for PBKDF2 algorithm

     * @throws GeneralSecurityException all security exceptions are thrown.

     */

    @Override

    protected Cipher initCipher(int mode) throws GeneralSecurityException {

        Provider provider = Security.getProvider("SunJCE");

        if (provider == null) {

            throw new RuntimeException("SunJCE provider does not exist.");

        }

        // Generate secret key

        PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray(),

                salt, DEFAULT_ITERATION, PKDF2_DEFAULT_KEY_LEN);

        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(baseAlgo);

        SecretKey key = keyFactory.generateSecret(pbeKeySpec);

        // get Cipher instance

        Cipher cipher = Cipher.getInstance(CIPHER_TRANSFORMATION, provider);

        cipher.init(mode,

                new SecretKeySpec(key.getEncoded(),KEY_ALGORITHM),

                new IvParameterSpec(iv));

        return cipher;

    }

}