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    1   /*
    2    * Copyright (c) 1997, 2007, Oracle and/or its affiliates. All rights reserved.
    3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    4    *
    5    * This code is free software; you can redistribute it and/or modify it
    6    * under the terms of the GNU General Public License version 2 only, as
    7    * published by the Free Software Foundation.  Oracle designates this
    8    * particular file as subject to the "Classpath" exception as provided
    9    * by Oracle in the LICENSE file that accompanied this code.
   10    *
   11    * This code is distributed in the hope that it will be useful, but WITHOUT
   12    * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   13    * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   14    * version 2 for more details (a copy is included in the LICENSE file that
   15    * accompanied this code).
   16    *
   17    * You should have received a copy of the GNU General Public License version
   18    * 2 along with this work; if not, write to the Free Software Foundation,
   19    * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   20    *
   21    * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   22    * or visit www.oracle.com if you need additional information or have any
   23    * questions.
   24    */
   25   
   26   package com.sun.crypto.provider;
   27   
   28   import java.security.KeyRep;
   29   import java.security.InvalidKeyException;
   30   import javax.crypto.SecretKey;
   31   import javax.crypto.spec.DESKeySpec;
   32   
   33   /**
   34    * This class represents a DES key.
   35    *
   36    * @author Jan Luehe
   37    *
   38    */
   39   
   40   final class DESKey implements SecretKey {
   41   
   42       static final long serialVersionUID = 7724971015953279128L;
   43   
   44       private byte[] key;
   45   
   46       /**
   47        * Uses the first 8 bytes of the given key as the DES key.
   48        *
   49        * @param key the buffer with the DES key bytes.
   50        *
   51        * @exception InvalidKeyException if less than 8 bytes are available for
   52        * the key.
   53        */
   54       DESKey(byte[] key) throws InvalidKeyException {
   55           this(key, 0);
   56       }
   57   
   58       /**
   59        * Uses the first 8 bytes in <code>key</code>, beginning at
   60        * <code>offset</code>, as the DES key
   61        *
   62        * @param key the buffer with the DES key bytes.
   63        * @param offset the offset in <code>key</code>, where the DES key bytes
   64        * start.
   65        *
   66        * @exception InvalidKeyException if less than 8 bytes are available for
   67        * the key.
   68        */
   69       DESKey(byte[] key, int offset) throws InvalidKeyException {
   70           if (key == null || key.length - offset < DESKeySpec.DES_KEY_LEN) {
   71               throw new InvalidKeyException("Wrong key size");
   72           }
   73           this.key = new byte[DESKeySpec.DES_KEY_LEN];
   74           System.arraycopy(key, offset, this.key, 0, DESKeySpec.DES_KEY_LEN);
   75           DESKeyGenerator.setParityBit(this.key, 0);
   76       }
   77   
   78       public byte[] getEncoded() {
   79           // Return a copy of the key, rather than a reference,
   80           // so that the key data cannot be modified from outside
   81           return (byte[])this.key.clone();
   82       }
   83   
   84       public String getAlgorithm() {
   85           return "DES";
   86       }
   87   
   88       public String getFormat() {
   89           return "RAW";
   90       }
   91   
   92       /**
   93        * Calculates a hash code value for the object.
   94        * Objects that are equal will also have the same hashcode.
   95        */
   96       public int hashCode() {
   97           int retval = 0;
   98           for (int i = 1; i < this.key.length; i++) {
   99               retval += this.key[i] * i;
  100           }
  101           return(retval ^= "des".hashCode());
  102       }
  103   
  104       public boolean equals(Object obj) {
  105           if (this == obj)
  106               return true;
  107   
  108           if (!(obj instanceof SecretKey))
  109               return false;
  110   
  111           String thatAlg = ((SecretKey)obj).getAlgorithm();
  112           if (!(thatAlg.equalsIgnoreCase("DES")))
  113               return false;
  114   
  115           byte[] thatKey = ((SecretKey)obj).getEncoded();
  116           boolean ret = java.util.Arrays.equals(this.key, thatKey);
  117           java.util.Arrays.fill(thatKey, (byte)0x00);
  118           return ret;
  119       }
  120   
  121       /**
  122        * readObject is called to restore the state of this key from
  123        * a stream.
  124        */
  125       private void readObject(java.io.ObjectInputStream s)
  126            throws java.io.IOException, ClassNotFoundException
  127       {
  128           s.defaultReadObject();
  129           key = (byte[])key.clone();
  130       }
  131   
  132       /**
  133        * Replace the DES key to be serialized.
  134        *
  135        * @return the standard KeyRep object to be serialized
  136        *
  137        * @throws java.io.ObjectStreamException if a new object representing
  138        * this DES key could not be created
  139        */
  140       private Object writeReplace() throws java.io.ObjectStreamException {
  141           return new KeyRep(KeyRep.Type.SECRET,
  142                           getAlgorithm(),
  143                           getFormat(),
  144                           getEncoded());
  145       }
  146   
  147       /**
  148        * Ensures that the bytes of this key are
  149        * set to zero when there are no more references to it.
  150        */
  151       protected void finalize() throws Throwable {
  152           try {
  153               if (this.key != null) {
  154                   java.util.Arrays.fill(this.key, (byte)0x00);
  155                   this.key = null;
  156               }
  157           } finally {
  158               super.finalize();
  159           }
  160       }
  161   }

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