PBKDF2.java

/*
 * Copyright (c) 2013-2018 ymnk, JCraft,Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions
 * and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 *
 * 3. The names of the authors may not be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL JCRAFT, INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.jcraft.jsch.jce;

import java.security.spec.InvalidKeySpecException;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;

abstract class PBKDF2 implements com.jcraft.jsch.PBKDF2 {
  private SecretKeyFactory skf;
  private byte[] salt;
  private int iterations;

  abstract String getName();

  @Override
  public void init(byte[] salt, int iterations) throws Exception {
    skf = SecretKeyFactory.getInstance(getName());
    this.salt = salt;
    this.iterations = iterations;
  }

  @Override
  public byte[] getKey(byte[] _pass, int size) {
    char[] pass = new char[_pass.length];
    for (int i = 0; i < _pass.length; i++) {
      pass[i] = (char) (_pass[i] & 0xff);
    }
    try {
      PBEKeySpec spec = new PBEKeySpec(pass, salt, iterations, size * 8);
      byte[] key = skf.generateSecret(spec).getEncoded();
      return key;
    } catch (InvalidKeySpecException e) {
    }
    return null;
  }
}