001 /* KeyFactorySpi.java --- Key Factory Service Provider Interface
002 Copyright (C) 1999, 2004 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
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013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
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019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
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025
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027 permission to link this library with independent modules to produce an
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034 this exception to your version of the library, but you are not
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036 exception statement from your version. */
037
038
039 package java.security;
040
041 import java.security.spec.InvalidKeySpecException;
042 import java.security.spec.KeySpec;
043
044 /**
045 * KeyFactorySpi is the Service Provider Interface (SPI) for the
046 * KeyFactory class. This is the interface for providers to
047 * supply to implement a key factory for an algorithm.
048 *
049 * Key factories are used to convert keys (opaque cryptographic
050 * keys of type Key) into key specifications (transparent
051 * representations of the underlying key material).
052 *
053 * Key factories are bi-directional. They allow a key class
054 * to be converted into a key specification (key material) and
055 * back again.
056 *
057 * For example DSA public keys can be specified as
058 * DSAPublicKeySpec or X509EncodedKeySpec. The key factory
059 * translate these key specifications.
060 *
061 * @since JDK 1.2
062 * @author Mark Benvenuto
063 */
064 public abstract class KeyFactorySpi
065 {
066 /**
067 * Constucts a new KeyFactorySpi.
068 */
069 public KeyFactorySpi()
070 {
071 }
072
073 /**
074 * Generates a public key from the provided key specification.
075 *
076 * @param keySpec key specification
077 *
078 * @return the public key
079 *
080 * @throws InvalidKeySpecException invalid key specification for
081 * this key factory to produce a public key
082 */
083 protected abstract PublicKey engineGeneratePublic(KeySpec keySpec)
084 throws InvalidKeySpecException;
085
086
087 /**
088 * Generates a private key from the provided key specification.
089 *
090 * @param keySpec key specification
091 *
092 * @return the private key
093 *
094 * @throws InvalidKeySpecException invalid key specification for
095 * this key factory to produce a private key
096 */
097 protected abstract PrivateKey engineGeneratePrivate(KeySpec keySpec)
098 throws InvalidKeySpecException;
099
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 }