Source for java.security.KeyFactorySpi

   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 <T extends KeySpec> T engineGetKeySpec(Key key,
 117:                                                             Class<T> keySpec)
 118:     throws InvalidKeySpecException;
 119: 
 120: 
 121:   /**
 122:    * Translates the key from an unknown or untrusted provider
 123:    * into a key for this key factory.
 124:    *
 125:    * @param key key from an unknown or untrusted provider
 126:    *
 127:    * @return the translated key
 128:    *
 129:    * @throws InvalidKeyException if the key cannot be 
 130:    * processed by this key factory
 131:    */
 132:   protected abstract Key engineTranslateKey(Key key)
 133:     throws InvalidKeyException;
 134: }