3909N/A * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 2362N/A * published by the Free Software Foundation. Oracle designates this 0N/A * particular file as subject to the "Classpath" exception as provided 2362N/A * by Oracle in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2362N/A * or visit www.oracle.com if you need additional information or have any 0N/A * Key factories are used to convert <I>keys</I> (opaque 0N/A * cryptographic keys of type <code>Key</code>) into <I>key specifications</I> 0N/A * (transparent representations of the underlying key material), and vice 0N/A * <P> Key factories are bi-directional. That is, they allow you to build an 0N/A * opaque key object from a given key specification (key material), or to 0N/A * retrieve the underlying key material of a key object in a suitable format. 0N/A * <P> Multiple compatible key specifications may exist for the same key. 0N/A * For example, a DSA public key may be specified using 0N/A * <code>DSAPublicKeySpec</code> or 0N/A * <code>X509EncodedKeySpec</code>. A key factory can be used to translate 0N/A * between compatible key specifications. 0N/A * <P> The following is an example of how to use a key factory in order to 0N/A * instantiate a DSA public key from its encoding. 0N/A * Assume Alice has received a digital signature from Bob. 0N/A * Bob also sent her his public key (in encoded format) to verify 0N/A * his signature. Alice then performs the following actions: 0N/A * X509EncodedKeySpec bobPubKeySpec = new X509EncodedKeySpec(bobEncodedPubKey); 0N/A * KeyFactory keyFactory = KeyFactory.getInstance("DSA"); 0N/A * PublicKey bobPubKey = keyFactory.generatePublic(bobPubKeySpec); 0N/A * Signature sig = Signature.getInstance("DSA"); 0N/A * sig.verify(signature); 3465N/A * <p> Every implementation of the Java platform is required to support the 3465N/A * following standard <code>KeyFactory</code> algorithms: 3465N/A * <li><tt>DiffieHellman</tt></li> 3465N/A * These algorithms are described in the <a href= 3465N/A * KeyFactory section</a> of the 3465N/A * Java Cryptography Architecture Standard Algorithm Name Documentation. 3465N/A * Consult the release documentation for your implementation to see if any 3465N/A * other algorithms are supported. 0N/A * @see java.security.spec.KeySpec 0N/A * @see java.security.spec.DSAPublicKeySpec 0N/A * @see java.security.spec.X509EncodedKeySpec 0N/A // The algorithm associated with this key factory 0N/A // The provider implementation (delegate) 0N/A // lock for mutex during provider selection 0N/A // remaining services to try in provider selection 0N/A // null once provider is selected 0N/A * Creates a KeyFactory object. 0N/A * @param keyFacSpi the delegate 0N/A * @param provider the provider 0N/A * @param algorithm the name of the algorithm 0N/A * to associate with this <tt>KeyFactory</tt> 0N/A // fetch and instantiate initial spi 0N/A * Returns a KeyFactory object that converts 0N/A * <p> This method traverses the list of registered security Providers, 0N/A * starting with the most preferred Provider. 0N/A * A new KeyFactory object encapsulating the 0N/A * KeyFactorySpi implementation from the first 0N/A * Provider that supports the specified algorithm is returned. 0N/A * <p> Note that the list of registered providers may be retrieved via 0N/A * the {@link Security#getProviders() Security.getProviders()} method. 0N/A * @param algorithm the name of the requested key algorithm. 3465N/A * See the KeyFactory section in the <a href= 3465N/A * Java Cryptography Architecture Standard Algorithm Name Documentation</a> 0N/A * for information about standard algorithm names. 0N/A * @return the new KeyFactory object. 0N/A * @exception NoSuchAlgorithmException if no Provider supports a 0N/A * KeyFactorySpi implementation for the 0N/A * specified algorithm. 0N/A * Returns a KeyFactory object that converts 0N/A * <p> A new KeyFactory object encapsulating the 0N/A * KeyFactorySpi implementation from the specified provider 0N/A * is returned. The specified provider must be registered 0N/A * in the security provider list. 0N/A * <p> Note that the list of registered providers may be retrieved via 0N/A * the {@link Security#getProviders() Security.getProviders()} method. 0N/A * @param algorithm the name of the requested key algorithm. 3465N/A * See the KeyFactory section in the <a href= 3465N/A * Java Cryptography Architecture Standard Algorithm Name Documentation</a> 0N/A * for information about standard algorithm names. 0N/A * @param provider the name of the provider. 0N/A * @return the new KeyFactory object. 0N/A * @exception NoSuchAlgorithmException if a KeyFactorySpi 0N/A * implementation for the specified algorithm is not 0N/A * available from the specified provider. 0N/A * @exception NoSuchProviderException if the specified provider is not 0N/A * registered in the security provider list. 0N/A * @exception IllegalArgumentException if the provider name is null 0N/A * Returns a KeyFactory object that converts 0N/A * <p> A new KeyFactory object encapsulating the 0N/A * KeyFactorySpi implementation from the specified Provider 0N/A * object is returned. Note that the specified Provider object 0N/A * does not have to be registered in the provider list. 0N/A * @param algorithm the name of the requested key algorithm. 3465N/A * See the KeyFactory section in the <a href= 3465N/A * Java Cryptography Architecture Standard Algorithm Name Documentation</a> 0N/A * for information about standard algorithm names. 0N/A * @param provider the provider. 0N/A * @return the new KeyFactory object. 0N/A * @exception NoSuchAlgorithmException if a KeyFactorySpi 0N/A * implementation for the specified algorithm is not available 0N/A * from the specified Provider object. 0N/A * @exception IllegalArgumentException if the specified provider is null. 0N/A * Returns the provider of this key factory object. 0N/A * @return the provider of this key factory object 0N/A // disable further failover after this call 0N/A * Gets the name of the algorithm 0N/A * associated with this <tt>KeyFactory</tt>. 0N/A * @return the name of the algorithm associated with this 0N/A * <tt>KeyFactory</tt> 0N/A * Update the active KeyFactorySpi of this class and return the next 0N/A * implementation for failover. If no more implemenations are 0N/A * available, this method returns null. However, the active spi of 0N/A * this class is never set to null. 0N/A // somebody else did a failover concurrently 0N/A * Generates a public key object from the provided key specification 0N/A * @param keySpec the specification (key material) of the public key. 0N/A * @return the public key. 0N/A * @exception InvalidKeySpecException if the given key specification 0N/A * is inappropriate for this key factory to produce a public key. 0N/A * Generates a private key object from the provided key specification 0N/A * @param keySpec the specification (key material) of the private key. 0N/A * @return the private key. 0N/A * @exception InvalidKeySpecException if the given key specification 0N/A * is inappropriate for this key factory to produce a private key. 0N/A * Returns a specification (key material) of the given key object. 0N/A * <code>keySpec</code> identifies the specification class in which 0N/A * the key material should be returned. It could, for example, be 0N/A * <code>DSAPublicKeySpec.class</code>, to indicate that the 0N/A * key material should be returned in an instance of the 0N/A * <code>DSAPublicKeySpec</code> class. 0N/A * @param key the key. 0N/A * @param keySpec the specification class in which 0N/A * the key material should be returned. 0N/A * @return the underlying key specification (key material) in an instance 0N/A * of the requested specification class. 0N/A * @exception InvalidKeySpecException if the requested key specification is 0N/A * inappropriate for the given key, or the given key cannot be processed 0N/A * (e.g., the given key has an unrecognized algorithm or format). 0N/A * Translates a key object, whose provider may be unknown or potentially 0N/A * untrusted, into a corresponding key object of this key factory. 0N/A * @param key the key whose provider is unknown or untrusted. 0N/A * @return the translated key. 0N/A * @exception InvalidKeyException if the given key cannot be processed 0N/A * by this key factory.