libjava/java/security/KeyFactorySpi.java

   1 /* KeyFactorySpi.java --- Key Factory Service Provider Interface
   2    Copyright (C) 1999 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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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 package java.security;
  39 import java.security.spec.KeySpec;
  40 import java.security.spec.InvalidKeySpecException;
  41
  42 /**
  43    KeyFactorySpi is the Service Provider Interface (SPI) for the
  44    KeyFactory class. This is the interface for providers to
  45    supply to implement a key factory for an algorithm.
  46
  47    Key factories are used to convert keys (opaque cryptographic
  48    keys of type Key) into key specifications (transparent
  49    representations of the underlying key material).
  50
  51    Key factories are bi-directional. They allow a key class
  52    to be converted into a key specification (key material) and
  53    back again.
  54
  55    For example DSA public keys can be specified as
  56    DSAPublicKeySpec or X509EncodedKeySpec. The key factory
  57    translate these key specifications.
  58
  59    @since JDK 1.2
  60    @author Mark Benvenuto
  61  */
  62 public abstract class KeyFactorySpi
  63 {
  64   /**
  65      Constucts a new KeyFactorySpi.
  66    */
  67   public KeyFactorySpi()
  68   {
  69   }
  70
  71   /**
  72      Generates a public key from the provided key specification.
  73
  74      @param keySpec key specification
  75
  76      @return the public key
  77
  78      @throws InvalidKeySpecException invalid key specification for
  79      this key factory to produce a public key
  80    */
  81   protected abstract PublicKey engineGeneratePublic(KeySpec keySpec)
  82     throws InvalidKeySpecException;
  83
  84
  85   /**
  86      Generates a private key from the provided key specification.
  87
  88      @param keySpec key specification
  89
  90      @return the private key
  91
  92      @throws InvalidKeySpecException invalid key specification for
  93      this key factory to produce a private key
  94    */
  95   protected abstract PrivateKey engineGeneratePrivate(KeySpec keySpec)
  96     throws InvalidKeySpecException;
  97
  98   /**
  99      Returns a key specification for the given key. keySpec
 100      identifies the specification class to return the key
 101      material in.
 102
 103      @param key the key
 104      @param keySpec the specification class to return the
 105      key material in.
 106
 107      @return the key specification in an instance of the requested
 108      specification class
 109
 110      @throws InvalidKeySpecException the requested key specification
 111      is inappropriate for this key or the key is
 112      unrecognized.
 113    */
 114   protected abstract KeySpec engineGetKeySpec(Key key, Class keySpec)
 115     throws InvalidKeySpecException;
 116
 117
 118   /**
 119      Translates the key from an unknown or untrusted provider
 120      into a key for this key factory.
 121
 122      @param the key from an unknown or untrusted provider
 123
 124      @return the translated key
 125
 126      @throws InvalidKeySpecException if the key cannot be
 127      processed by this key factory
 128    */
 129   protected abstract Key engineTranslateKey(Key key)
 130     throws InvalidKeyException;
 131 }