001/* KeyFactorySpi.java --- Key Factory Service Provider Interface 002 Copyright (C) 1999, 2004 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.security; 040 041import java.security.spec.InvalidKeySpecException; 042import 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 */ 064public 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}