Source for gnu.javax.crypto.kwa.KeyWrappingAlgorithmFactory

   1: /* KeyWrappingAlgorithmFactory.java -- FIXME: briefly describe file purpose
   2:    Copyright (C) 2006 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 gnu.javax.crypto.kwa;
  40: 
  41: import gnu.java.security.Registry;
  42: 
  43: import java.util.Collections;
  44: import java.util.HashSet;
  45: import java.util.Set;
  46: 
  47: /**
  48:  * A Factory class for the Key Wrapping Algorithm implementations.
  49:  */
  50: public class KeyWrappingAlgorithmFactory
  51: {
  52:   /** Names of Key Wrapping Algorihms cached for speed. */
  53:   private static Set names;
  54: 
  55:   /** Trivial constructor to enforce Singleton pattern. */
  56:   private KeyWrappingAlgorithmFactory()
  57:   {
  58:     super();
  59:   }
  60: 
  61:   /**
  62:    * Returns an instance of a key-wrapping algorithm given its name.
  63:    *
  64:    * @param name the case-insensitive name of the key-wrapping algorithm.
  65:    * @return an instance of the designated key-wrapping algorithm, or
  66:    *         <code>null</code> if none was found.
  67:    * @exception InternalError if the implementation does not pass its self-test.
  68:    */
  69:   public static final IKeyWrappingAlgorithm getInstance(String name)
  70:   {
  71:     if (name == null)
  72:       return null;
  73:     name = name.trim();
  74:     IKeyWrappingAlgorithm result = null;
  75:     if (name.equalsIgnoreCase(Registry.AES_KWA)
  76:         || name.equalsIgnoreCase(Registry.AES128_KWA)
  77:         || name.equalsIgnoreCase(Registry.AES192_KWA)
  78:         || name.equalsIgnoreCase(Registry.AES256_KWA)
  79:         || name.equalsIgnoreCase(Registry.RIJNDAEL_KWA))
  80:       result = new AESKeyWrap();
  81:     else if (name.equalsIgnoreCase(Registry.TRIPLEDES_KWA)
  82:         || name.equalsIgnoreCase(Registry.DESEDE_KWA))
  83:       result = new TripleDESKeyWrap();
  84: 
  85:     return result;
  86:   }
  87: 
  88:   /**
  89:    * Returns a {@link Set} of key wrapping algorithm names supported by this
  90:    * <i>Factory</i>.
  91:    *
  92:    * @return a {@link Set} of key wrapping algorithm names (Strings).
  93:    */
  94:   public static synchronized final Set getNames()
  95:   {
  96:     if (names == null)
  97:       {
  98:         HashSet hs = new HashSet();
  99:         hs.add(Registry.AES_KWA);
 100:         hs.add(Registry.AES128_KWA);
 101:         hs.add(Registry.AES192_KWA);
 102:         hs.add(Registry.AES256_KWA);
 103:         hs.add(Registry.RIJNDAEL_KWA);
 104:         hs.add(Registry.TRIPLEDES_KWA);
 105:         hs.add(Registry.DESEDE_KWA);
 106:         names = Collections.unmodifiableSet(hs);
 107:       }
 108:     return names;
 109:   }
 110: }