package gnu.crypto.jce;  // -*- c-basic-offset: 3 -*-

// ---------------------------------------------------------------------------
// $Id: PBKDF2SecretKeyFactory.java,v 1.3 2005/10/06 04:24:14 rsdio Exp $
//
// Copyright (C) 2003 Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
//
// GNU Crypto 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 for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; see the file COPYING.  If not, write to the
//
//    Free Software Foundation Inc.,
//    51 Franklin Street, Fifth Floor,
//    Boston, MA 02110-1301
//    USA
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library.  Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
//
// As a special exception, the copyright holders of this library give
// you permission to link this library with independent modules to
// produce an executable, regardless of the license terms of these
// independent modules, and to copy and distribute the resulting
// executable under terms of your choice, provided that you also meet,
// for each linked independent module, the terms and conditions of the
// license of that module.  An independent module is a module which is
// not derived from or based on this library.  If you modify this
// library, you may extend this exception to your version of the
// library, but you are not obligated to do so.  If you do not wish to
// do so, delete this exception statement from your version.
//
// ---------------------------------------------------------------------------

import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;

import java.util.HashMap;

import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactorySpi;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;

import gnu.crypto.prng.IPBE;
import gnu.crypto.prng.IRandom;
import gnu.crypto.prng.LimitReachedException;
import gnu.crypto.prng.PRNGFactory;

public abstract class PBKDF2SecretKeyFactory extends SecretKeyFactorySpi {

   // Constants and fields.
   // ------------------------------------------------------------------------

   protected String macName;

   private static final int DEFAULT_ITERATION_COUNT = 1000;
   private static final int DEFAULT_KEY_LEN = 32;

   // Constructor.
   // ------------------------------------------------------------------------

   protected PBKDF2SecretKeyFactory(String macName) {
      this.macName = macName;
   }

   // Instance methods.
   // ------------------------------------------------------------------------

   protected SecretKey engineGenerateSecret(KeySpec spec)
      throws InvalidKeySpecException
   {
      if (!(spec instanceof PBEKeySpec)) {
         throw new InvalidKeySpecException("not a PBEKeySpec");
      }
      IRandom kdf = PRNGFactory.getInstance("PBKDF2-"+macName);
      HashMap attr = new HashMap();
      attr.put(IPBE.PASSWORD, ((PBEKeySpec) spec).getPassword());
      byte[] salt = ((PBEKeySpec) spec).getSalt();
      if (salt == null) {
         salt = new byte[0];
      }
      attr.put(IPBE.SALT, salt);
      int ic = ((PBEKeySpec) spec).getIterationCount();
      if (ic <= 0) {
         ic = DEFAULT_ITERATION_COUNT;
      }
      attr.put(IPBE.ITERATION_COUNT, new Integer(ic));
      kdf.init(attr);
      int len = ((PBEKeySpec) spec).getKeyLength();
      if (len <= 0) {
         len = DEFAULT_KEY_LEN;
      }
      byte[] dk = new byte[len];
      try {
         kdf.nextBytes(dk, 0, len);
      } catch (LimitReachedException lre) {
         throw new IllegalArgumentException(lre.toString());
      }

      return new SecretKeySpec(dk, "PBKDF2");
   }

   protected KeySpec engineGetKeySpec(SecretKey key, Class clazz)
      throws InvalidKeySpecException
   {
      throw new InvalidKeySpecException("not supported");
   }

   protected SecretKey engineTranslateKey(SecretKey key) {
      return new SecretKeySpec(key.getEncoded(), key.getAlgorithm());
   }

   // Inner classes.
   // ------------------------------------------------------------------------

   public static class HMacHaval extends PBKDF2SecretKeyFactory {
      public HMacHaval() {
         super("HMAC-HAVAL");
      }
   }

   public static class HMacMD2 extends PBKDF2SecretKeyFactory {
      public HMacMD2() {
         super("HMAC-MD2");
      }
   }

   public static class HMacMD4 extends PBKDF2SecretKeyFactory {
      public HMacMD4() {
         super("HMAC-MD4");
      }
   }

   public static class HMacMD5 extends PBKDF2SecretKeyFactory {
      public HMacMD5() {
         super("HMAC-MD5");
      }
   }

   public static class HMacRipeMD128 extends PBKDF2SecretKeyFactory {
      public HMacRipeMD128() {
         super("HMAC-RIPEMD128");
      }
   }

   public static class HMacRipeMD160 extends PBKDF2SecretKeyFactory {
      public HMacRipeMD160() {
         super("HMAC-RIPEMD160");
      }
   }

   public static class HMacSHA1 extends PBKDF2SecretKeyFactory {
      public HMacSHA1() {
         super("HMAC-SHA1");
      }
   }

   public static class HMacSHA256 extends PBKDF2SecretKeyFactory {
      public HMacSHA256() {
         super("HMAC-SHA256");
      }
   }

   public static class HMacSHA384 extends PBKDF2SecretKeyFactory {
      public HMacSHA384() {
         super("HMAC-SHA384");
      }
   }

   public static class HMacSHA512 extends PBKDF2SecretKeyFactory {
      public HMacSHA512() {
         super("HMAC-SHA512");
      }
   }

   public static class HMacTiger extends PBKDF2SecretKeyFactory {
      public HMacTiger() {
         super("HMAC-TIGER");
      }
   }

   public static class HMacWhirlpool extends PBKDF2SecretKeyFactory {
      public HMacWhirlpool() {
         super("HMAC-WHIRLPOOL");
      }
   }
}
