/*
 * Copyright (c) 1997, 2017, 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 java.security;

import java.security.spec.AlgorithmParameterSpec;

This class defines the Service Provider Interface (SPI) for the AlgorithmParameterGenerator class, which is used to generate a set of parameters to be used with a certain algorithm.

All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a parameter generator for a particular algorithm.

In case the client does not explicitly initialize the AlgorithmParameterGenerator (via a call to an engineInit method), each provider must supply (and document) a default initialization. See the Keysize Restriction sections of the {@extLink security_guide_jdk_providers JDK Providers} document for information on the AlgorithmParameterGenerator defaults used by JDK providers. However, note that defaults may vary across different providers. Additionally, the default value for a provider may change in a future version. Therefore, it is recommended to explicitly initialize the AlgorithmParameterGenerator instead of relying on provider-specific defaults.

Author:Jan Luehe
See Also:
Since:1.2
/** * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>) * for the {@code AlgorithmParameterGenerator} class, which * is used to generate a set of parameters to be used with a certain algorithm. * * <p> All the abstract methods in this class must be implemented by each * cryptographic service provider who wishes to supply the implementation * of a parameter generator for a particular algorithm. * * <p> In case the client does not explicitly initialize the * AlgorithmParameterGenerator (via a call to an {@code engineInit} * method), each provider must supply (and document) a default initialization. * See the Keysize Restriction sections of the * {@extLink security_guide_jdk_providers JDK Providers} * document for information on the AlgorithmParameterGenerator defaults * used by JDK providers. * However, note that defaults may vary across different providers. * Additionally, the default value for a provider may change in a future * version. Therefore, it is recommended to explicitly initialize the * AlgorithmParameterGenerator instead of relying on provider-specific defaults. * * @author Jan Luehe * * * @see AlgorithmParameterGenerator * @see AlgorithmParameters * @see java.security.spec.AlgorithmParameterSpec * * @since 1.2 */
public abstract class AlgorithmParameterGeneratorSpi {
Initializes this parameter generator for a certain size and source of randomness.
Params:
  • size – the size (number of bits).
  • random – the source of randomness.
/** * Initializes this parameter generator for a certain size * and source of randomness. * * @param size the size (number of bits). * @param random the source of randomness. */
protected abstract void engineInit(int size, SecureRandom random);
Initializes this parameter generator with a set of algorithm-specific parameter generation values.
Params:
  • genParamSpec – the set of algorithm-specific parameter generation values.
  • random – the source of randomness.
Throws:
/** * Initializes this parameter generator with a set of * algorithm-specific parameter generation values. * * @param genParamSpec the set of algorithm-specific parameter generation values. * @param random the source of randomness. * * @exception InvalidAlgorithmParameterException if the given parameter * generation values are inappropriate for this parameter generator. */
protected abstract void engineInit(AlgorithmParameterSpec genParamSpec, SecureRandom random) throws InvalidAlgorithmParameterException;
Generates the parameters.
Returns:the new AlgorithmParameters object.
/** * Generates the parameters. * * @return the new AlgorithmParameters object. */
protected abstract AlgorithmParameters engineGenerateParameters(); }