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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * 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.

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 * 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

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 * accompanied this code).

 *

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 * 2 along with this work; if not, write to the Free Software Foundation,

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package java.security;

import java.io.*;

import java.security.spec.AlgorithmParameterSpec;

import java.security.spec.InvalidParameterSpecException;

/**

 * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)

 * for the {@code AlgorithmParameters} class, which is used to manage

 * algorithm parameters.

 *

 * <p> All the abstract methods in this class must be implemented by each

 * cryptographic service provider who wishes to supply parameter management

 * for a particular algorithm.

 *

 * @author Jan Luehe

 *

 *

 * @see AlgorithmParameters

 * @see java.security.spec.AlgorithmParameterSpec

 * @see java.security.spec.DSAParameterSpec

 *

 * @since 1.2

 */

public abstract class AlgorithmParametersSpi {

    /**

     * Constructor for subclasses to call.

     */

    public AlgorithmParametersSpi() {}

    /**

     * Initializes this parameters object using the parameters

     * specified in {@code paramSpec}.

     *

     * @param paramSpec the parameter specification.

     *

     * @throws    InvalidParameterSpecException if the given parameter

     * specification is inappropriate for the initialization of this parameter

     * object.

     */

    protected abstract void engineInit(AlgorithmParameterSpec paramSpec)

        throws InvalidParameterSpecException;

    /**

     * Imports the specified parameters and decodes them

     * according to the primary decoding format for parameters.

     * The primary decoding format for parameters is ASN.1, if an ASN.1

     * specification for this type of parameters exists.

     *

     * @param params the encoded parameters.

     *

     * @throws    IOException on decoding errors

     */

    protected abstract void engineInit(byte[] params)

        throws IOException;

    /**

     * Imports the parameters from {@code params} and

     * decodes them according to the specified decoding format.

     * If {@code format} is null, the

     * primary decoding format for parameters is used. The primary decoding

     * format is ASN.1, if an ASN.1 specification for these parameters

     * exists.

     *

     * @param params the encoded parameters.

     *

     * @param format the name of the decoding format.

     *

     * @throws    IOException on decoding errors

     */

    protected abstract void engineInit(byte[] params, String format)

        throws IOException;

    /**

     * Returns a (transparent) specification of this parameters

     * object.

     * {@code paramSpec} identifies the specification class in which

     * the parameters should be returned. It could, for example, be

     * {@code DSAParameterSpec.class}, to indicate that the

     * parameters should be returned in an instance of the

     * {@code DSAParameterSpec} class.

     *

     * @param <T> the type of the parameter specification to be returned

     *

     * @param paramSpec the specification class in which

     * the parameters should be returned.

     *

     * @return the parameter specification.

     *

     * @throws    InvalidParameterSpecException if the requested parameter

     * specification is inappropriate for this parameter object.

     */

    protected abstract

        <T extends AlgorithmParameterSpec>

        T engineGetParameterSpec(Class<T> paramSpec)

        throws InvalidParameterSpecException;

    /**

     * Returns the parameters in their primary encoding format.

     * The primary encoding format for parameters is ASN.1, if an ASN.1

     * specification for this type of parameters exists.

     *

     * @return the parameters encoded using their primary encoding format.

     *

     * @throws    IOException on encoding errors.

     */

    protected abstract byte[] engineGetEncoded() throws IOException;

    /**

     * Returns the parameters encoded in the specified format.

     * If {@code format} is null, the

     * primary encoding format for parameters is used. The primary encoding

     * format is ASN.1, if an ASN.1 specification for these parameters

     * exists.

     *

     * @param format the name of the encoding format.

     *

     * @return the parameters encoded using the specified encoding scheme.

     *

     * @throws    IOException on encoding errors.

     */

    protected abstract byte[] engineGetEncoded(String format)

        throws IOException;

    /**

     * Returns a formatted string describing the parameters.

     *

     * @return a formatted string describing the parameters.

     */

    protected abstract String engineToString();

}