gomp-20050608-branch/libjava/classpath/javax/crypto/spec/PBEKeySpec.java

   1 /* PBEKeySpec.java -- Wrapper for password-based keys.
   2    Copyright (C) 2004  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package javax.crypto.spec;
  40
  41 import java.security.spec.KeySpec;
  42
  43 /**
  44  * A wrapper for a password-based key, used for password-based
  45  * encryption (PBE).
  46  *
  47  * <p>Examples of password-based encryption algorithms include:
  48  *
  49  * <ul>
  50  * <li><a href="http://www.rsasecurity.com/rsalabs/pkcs/pkcs-5/">PKCS #5
  51  * - Password-Based Cryptography Standard</a></li>
  52  * <li><a href="http://www.rsasecurity.com/rsalabs/pkcs/pkcs-12/">PKCS
  53  * #12 - Personal Information Exchange Syntax Standard</a></li>
  54  * </ul>
  55  *
  56  * @author Casey Marshall (csm@gnu.org)
  57  * @since 1.4
  58  * @see javax.crypto.SecretKeyFactory
  59  * @see PBEParameterSpec
  60  */
  61 public class PBEKeySpec implements KeySpec
  62 {
  63
  64   // Fields.
  65   // ------------------------------------------------------------------------
  66
  67   /** The iteration count. */
  68   private int iterationCount;
  69
  70   /** The generated key length. */
  71   private int keyLength;
  72
  73   /** The password. */
  74   private char[] password;
  75
  76   /** The salt. */
  77   private byte[] salt;
  78
  79   // Constructors.
  80   // ------------------------------------------------------------------------
  81
  82   /**
  83    * Create a new PBE key spec with just a password.
  84    *
  85    * @param password The password char array.
  86    */
  87   public PBEKeySpec(char[] password)
  88   {
  89     this(password, null, 0, 0);
  90   }
  91
  92   /**
  93    * Create a PBE key spec with a password, salt, and iteration count.
  94    *
  95    * @param password       The password char array.
  96    * @param salt           The salt bytes.
  97    * @param iterationCount The iteration count.
  98    */
  99   public PBEKeySpec(char[] password, byte[] salt, int iterationCount)
 100   {
 101     this(password, salt, iterationCount, 0);
 102   }
 103
 104   /**
 105    * Create a PBE key spec with a password, salt, iteration count, and
 106    * key length.
 107    *
 108    * @param password       The password char array.
 109    * @param salt           The salt bytes.
 110    * @param iterationCount The iteration count.
 111    * @param keyLength      The generated key length.
 112    */
 113   public PBEKeySpec(char[] password, byte[] salt, int iterationCount,
 114                     int keyLength)
 115   {
 116     this.password = password;
 117     this.salt = salt;
 118     this.iterationCount = iterationCount;
 119     this.keyLength = keyLength;
 120   }
 121
 122   // Instance methods.
 123   // ------------------------------------------------------------------------
 124
 125   /**
 126    * Clear the password array by filling it with null characters.
 127    */
 128   public final void clearPassword()
 129   {
 130     if (password == null) return;
 131     for (int i = 0; i < password.length; i++)
 132       {
 133         password[i] = '\u0000';
 134       }
 135   }
 136
 137   /**
 138    * Get the iteration count, or 0 if it has not been specified.
 139    *
 140    * @return The iteration count, or 0 if it has not been specified.
 141    */
 142   public final int getIterationCount()
 143   {
 144     return iterationCount;
 145   }
 146
 147   /**
 148    * Get the generated key length, or 0 if it has not been specified.
 149    *
 150    * @return The key length, or 0 if it has not been specified.
 151    */
 152   public final int getKeyLength()
 153   {
 154     return keyLength;
 155   }
 156
 157   /**
 158    * Get the password character array.
 159    *
 160    * @return The password.
 161    */
 162   public final char[] getPassword()
 163   {
 164     return password;
 165   }
 166
 167   /**
 168    * Get the salt bytes.
 169    *
 170    * @return The salt.
 171    */
 172   public final byte[] getSalt()
 173   {
 174     return salt;
 175   }
 176 }