gomp-20050608-branch/libjava/classpath/java/security/KeyFactorySpi.java

   1 /* KeyFactorySpi.java --- Key Factory Service Provider Interface
   2    Copyright (C) 1999, 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 java.security;
  40
  41 import java.security.spec.InvalidKeySpecException;
  42 import java.security.spec.KeySpec;
  43
  44 /**
  45  * KeyFactorySpi is the Service Provider Interface (SPI) for the
  46  * KeyFactory class. This is the interface for providers to
  47  * supply to implement a key factory for an algorithm.
  48  *
  49  * Key factories are used to convert keys (opaque cryptographic
  50  * keys of type Key) into key specifications (transparent
  51  * representations of the underlying key material).
  52  *
  53  * Key factories are bi-directional. They allow a key class
  54  * to be converted into a key specification (key material) and
  55  * back again.
  56  *
  57  * For example DSA public keys can be specified as
  58  * DSAPublicKeySpec or X509EncodedKeySpec. The key factory
  59  * translate these key specifications.
  60  *
  61  * @since JDK 1.2
  62  * @author Mark Benvenuto
  63  */
  64 public abstract class KeyFactorySpi
  65 {
  66   /**
  67    * Constucts a new KeyFactorySpi.
  68    */
  69   public KeyFactorySpi()
  70   {
  71   }
  72
  73   /**
  74    * Generates a public key from the provided key specification.
  75    *
  76    * @param keySpec key specification
  77    *
  78    * @return the public key
  79    *
  80    * @throws InvalidKeySpecException invalid key specification for
  81    * this key factory to produce a public key
  82    */
  83   protected abstract PublicKey engineGeneratePublic(KeySpec keySpec)
  84     throws InvalidKeySpecException;
  85
  86
  87   /**
  88    * Generates a private key from the provided key specification.
  89    *
  90    * @param keySpec key specification
  91    *
  92    * @return the private key
  93    *
  94    * @throws InvalidKeySpecException invalid key specification for
  95    * this key factory to produce a private key
  96    */
  97   protected abstract PrivateKey engineGeneratePrivate(KeySpec keySpec)
  98     throws InvalidKeySpecException;
  99
 100   /**
 101    * Returns a key specification for the given key. keySpec
 102    * identifies the specification class to return the key
 103    * material in.
 104    *
 105    * @param key the key
 106    * @param keySpec the specification class to return the
 107    * key material in.
 108    *
 109    * @return the key specification in an instance of the requested
 110    * specification class
 111    *
 112    * @throws InvalidKeySpecException the requested key specification
 113    * is inappropriate for this key or the key is
 114    * unrecognized.
 115    */
 116   protected abstract KeySpec engineGetKeySpec(Key key, Class keySpec)
 117     throws InvalidKeySpecException;
 118
 119
 120   /**
 121    * Translates the key from an unknown or untrusted provider
 122    * into a key for this key factory.
 123    *
 124    * @param the key from an unknown or untrusted provider
 125    *
 126    * @return the translated key
 127    *
 128    * @throws InvalidKeySpecException if the key cannot be
 129    * processed by this key factory
 130    */
 131   protected abstract Key engineTranslateKey(Key key)
 132     throws InvalidKeyException;
 133 }