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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

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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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package java.security.spec;

import jdk.internal.access.JavaSecuritySpecAccess;

import jdk.internal.access.SharedSecrets;

import java.util.Arrays;

/**

 * This class represents a public or private key in encoded format.

 *

 * @author Jan Luehe

 *

 *

 * @see java.security.Key

 * @see java.security.KeyFactory

 * @see KeySpec

 * @see X509EncodedKeySpec

 * @see PKCS8EncodedKeySpec

 *

 * @since 1.2

 */

public abstract class EncodedKeySpec implements KeySpec {

    private byte[] encodedKey;

    private String algorithmName;

    static {

        SharedSecrets.setJavaSecuritySpecAccess(

                new JavaSecuritySpecAccess() {

                    @Override

                    public void clearEncodedKeySpec(EncodedKeySpec keySpec) {

                        keySpec.clear();

                    }

                });

    }

                    /**

     * Creates a new {@code EncodedKeySpec} with the given encoded key.

     *

     * @param encodedKey the encoded key. The contents of the

     * array are copied to protect against subsequent modification.

     * @throws NullPointerException if {@code encodedKey}

     * is null.

     */

    public EncodedKeySpec(byte[] encodedKey) {

        this.encodedKey = encodedKey.clone();

    }

    /**

     * Creates a new {@code EncodedKeySpec} with the given encoded key.

     * This constructor is useful when subsequent callers of the

     * {@code EncodedKeySpec} object might not know the algorithm

     * of the key.

     *

     * @param encodedKey the encoded key. The contents of the

     * array are copied to protect against subsequent modification.

     * @param algorithm the algorithm name of the encoded key

     * See the KeyFactory section in the <a href=

     * "{@docRoot}/../specs/security/standard-names.html#keyfactory-algorithms">

     * Java Security Standard Algorithm Names Specification</a>

     * for information about standard algorithm names.

     * @throws NullPointerException if {@code encodedKey}

     * or {@code algorithm} is null.

     * @throws IllegalArgumentException if {@code algorithm} is

     * the empty string {@code ""}

     * @since 9

     */

    protected EncodedKeySpec(byte[] encodedKey, String algorithm) {

        if (algorithm == null) {

            throw new NullPointerException("algorithm name may not be null");

        }

        if (algorithm.isEmpty()) {

            throw new IllegalArgumentException("algorithm name "

                                             + "may not be empty");

        }

        this.encodedKey = encodedKey.clone();

        this.algorithmName = algorithm;

    }

    /**

     * Returns the name of the algorithm of the encoded key.

     *

     * @return the name of the algorithm, or null if not specified

     * @since 9

     */

    public String getAlgorithm() {

        return algorithmName;

    }

    /**

     * Returns the encoded key.

     *

     * @return the encoded key. Returns a new array each time

     * this method is called.

     */

    public byte[] getEncoded() {

        return this.encodedKey.clone();

    }

    /**

     * Returns the name of the encoding format associated with this

     * key specification.

     *

     * <p>If the opaque representation of a key

     * (see {@link java.security.Key Key}) can be transformed

     * (see {@link java.security.KeyFactory KeyFactory})

     * into this key specification (or a subclass of it),

     * {@code getFormat} called

     * on the opaque key returns the same value as the

     * {@code getFormat} method

     * of this key specification.

     *

     * @return a string representation of the encoding format.

     */

    public abstract String getFormat();

    /**

     * Clear the encoding inside.

     */

    void clear() {

        Arrays.fill(encodedKey, (byte)0);

    }

}