/* * Copyright (c) 1997, 2007, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.crypto; import java.security.*;import java.security.spec.*; /** * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>) * for the <code>SecretKeyFactory</code> class. * All the abstract methods in this class must be implemented by each * cryptographic service provider who wishes to supply the implementation * of a secret-key factory for a particular algorithm. * * <P> A provider should document all the key specifications supported by its * secret key factory. * For example, the DES secret-key factory supplied by the "SunJCE" provider * supports <code>DESKeySpec</code> as a transparent representation of DES * keys, and that provider's secret-key factory for Triple DES keys supports * <code>DESedeKeySpec</code> as a transparent representation of Triple DES * keys. * * @author Jan Luehe * * @see SecretKey * @see javax.crypto.spec.DESKeySpec * @see javax.crypto.spec.DESedeKeySpec * @since 1.4 */ public abstract class SecretKeyFactorySpi {     /**     * Generates a <code>SecretKey</code> object from the     * provided key specification (key material).     *     * @param keySpec the specification (key material) of the secret key     *     * @return the secret key     *     * @exception InvalidKeySpecException if the given key specification     * is inappropriate for this secret-key factory to produce a secret key.     */    protected abstract SecretKey engineGenerateSecret(KeySpec keySpec)        throws InvalidKeySpecException;     /**     * Returns a specification (key material) of the given key     * object in the requested format.     *     * @param key the key     *     * @param keySpec the requested format in which the key material shall be     * returned     *     * @return the underlying key specification (key material) in the     * requested format     *     * @exception InvalidKeySpecException if the requested key specification is     * inappropriate for the given key (e.g., the algorithms associated with     * <code>key</code> and <code>keySpec</code> do not match, or     * <code>key</code> references a key on a cryptographic hardware device     * whereas <code>keySpec</code> is the specification of a software-based     * key), or the given key cannot be dealt with     * (e.g., the given key has an algorithm or format not supported by this     * secret-key factory).     */    protected abstract KeySpec engineGetKeySpec(SecretKey key, Class keySpec)        throws InvalidKeySpecException;     /**     * Translates a key object, whose provider may be unknown or     * potentially untrusted, into a corresponding key object of this     * secret-key factory.     *     * @param key the key whose provider is unknown or untrusted     *     * @return the translated key     *     * @exception InvalidKeyException if the given key cannot be processed     * by this secret-key factory.     */    protected abstract SecretKey engineTranslateKey(SecretKey key)        throws InvalidKeyException;}