J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2004 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package java.security; |
| 27 | |
| 28 | import java.security.spec.KeySpec; |
| 29 | import java.security.spec.InvalidKeySpecException; |
| 30 | |
| 31 | /** |
| 32 | * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>) |
| 33 | * for the <code>KeyFactory</code> class. |
| 34 | * All the abstract methods in this class must be implemented by each |
| 35 | * cryptographic service provider who wishes to supply the implementation |
| 36 | * of a key factory for a particular algorithm. |
| 37 | * |
| 38 | * <P> Key factories are used to convert <I>keys</I> (opaque |
| 39 | * cryptographic keys of type <code>Key</code>) into <I>key specifications</I> |
| 40 | * (transparent representations of the underlying key material), and vice |
| 41 | * versa. |
| 42 | * |
| 43 | * <P> Key factories are bi-directional. That is, they allow you to build an |
| 44 | * opaque key object from a given key specification (key material), or to |
| 45 | * retrieve the underlying key material of a key object in a suitable format. |
| 46 | * |
| 47 | * <P> Multiple compatible key specifications may exist for the same key. |
| 48 | * For example, a DSA public key may be specified using |
| 49 | * <code>DSAPublicKeySpec</code> or |
| 50 | * <code>X509EncodedKeySpec</code>. A key factory can be used to translate |
| 51 | * between compatible key specifications. |
| 52 | * |
| 53 | * <P> A provider should document all the key specifications supported by its |
| 54 | * key factory. |
| 55 | * |
| 56 | * @author Jan Luehe |
| 57 | * |
| 58 | * |
| 59 | * @see KeyFactory |
| 60 | * @see Key |
| 61 | * @see PublicKey |
| 62 | * @see PrivateKey |
| 63 | * @see java.security.spec.KeySpec |
| 64 | * @see java.security.spec.DSAPublicKeySpec |
| 65 | * @see java.security.spec.X509EncodedKeySpec |
| 66 | * |
| 67 | * @since 1.2 |
| 68 | */ |
| 69 | |
| 70 | public abstract class KeyFactorySpi { |
| 71 | |
| 72 | /** |
| 73 | * Generates a public key object from the provided key |
| 74 | * specification (key material). |
| 75 | * |
| 76 | * @param keySpec the specification (key material) of the public key. |
| 77 | * |
| 78 | * @return the public key. |
| 79 | * |
| 80 | * @exception InvalidKeySpecException if the given key specification |
| 81 | * is inappropriate for this key factory to produce a public key. |
| 82 | */ |
| 83 | protected abstract PublicKey engineGeneratePublic(KeySpec keySpec) |
| 84 | throws InvalidKeySpecException; |
| 85 | |
| 86 | /** |
| 87 | * Generates a private key object from the provided key |
| 88 | * specification (key material). |
| 89 | * |
| 90 | * @param keySpec the specification (key material) of the private key. |
| 91 | * |
| 92 | * @return the private key. |
| 93 | * |
| 94 | * @exception InvalidKeySpecException if the given key specification |
| 95 | * is inappropriate for this key factory to produce a private key. |
| 96 | */ |
| 97 | protected abstract PrivateKey engineGeneratePrivate(KeySpec keySpec) |
| 98 | throws InvalidKeySpecException; |
| 99 | |
| 100 | /** |
| 101 | * Returns a specification (key material) of the given key |
| 102 | * object. |
| 103 | * <code>keySpec</code> identifies the specification class in which |
| 104 | * the key material should be returned. It could, for example, be |
| 105 | * <code>DSAPublicKeySpec.class</code>, to indicate that the |
| 106 | * key material should be returned in an instance of the |
| 107 | * <code>DSAPublicKeySpec</code> class. |
| 108 | * |
| 109 | * @param key the key. |
| 110 | * |
| 111 | * @param keySpec the specification class in which |
| 112 | * the key material should be returned. |
| 113 | * |
| 114 | * @return the underlying key specification (key material) in an instance |
| 115 | * of the requested specification class. |
| 116 | |
| 117 | * @exception InvalidKeySpecException if the requested key specification is |
| 118 | * inappropriate for the given key, or the given key cannot be dealt with |
| 119 | * (e.g., the given key has an unrecognized format). |
| 120 | */ |
| 121 | protected abstract <T extends KeySpec> |
| 122 | T engineGetKeySpec(Key key, Class<T> keySpec) |
| 123 | throws InvalidKeySpecException; |
| 124 | |
| 125 | /** |
| 126 | * Translates a key object, whose provider may be unknown or |
| 127 | * potentially untrusted, into a corresponding key object of this key |
| 128 | * factory. |
| 129 | * |
| 130 | * @param key the key whose provider is unknown or untrusted. |
| 131 | * |
| 132 | * @return the translated key. |
| 133 | * |
| 134 | * @exception InvalidKeyException if the given key cannot be processed |
| 135 | * by this key factory. |
| 136 | */ |
| 137 | protected abstract Key engineTranslateKey(Key key) |
| 138 | throws InvalidKeyException; |
| 139 | |
| 140 | } |