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

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 * 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,

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package sun.security.ec;

import java.io.*;

import java.security.interfaces.XECPrivateKey;

import java.util.Optional;

import java.security.*;

import java.security.spec.*;

import sun.security.pkcs.PKCS8Key;

import sun.security.x509.AlgorithmId;

import sun.security.util.*;

public final class XDHPrivateKeyImpl extends PKCS8Key implements XECPrivateKey {

    private static final long serialVersionUID = 1L;

    private final AlgorithmParameterSpec paramSpec;

    private byte[] k;

    XDHPrivateKeyImpl(XECParameters params, byte[] k)

        throws InvalidKeyException {

        this.paramSpec = new NamedParameterSpec(params.getName());

        this.k = k.clone();

        this.algid = new AlgorithmId(params.getOid());

        encodeKey();

        checkLength(params);

    }

    XDHPrivateKeyImpl(byte[] encoded) throws InvalidKeyException {

        decode(encoded);

        XECParameters params = XECParameters.get(

            InvalidKeyException::new, algid);

        paramSpec = new NamedParameterSpec(params.getName());

        decodeKey();

        checkLength(params);

    }

    private void decodeKey() throws InvalidKeyException {

        try {

            DerInputStream derStream = new DerInputStream(key);

            k = derStream.getOctetString();

        } catch (IOException ex) {

            throw new InvalidKeyException(ex);

        }

    }

    private void encodeKey() {

        DerOutputStream derKey = new DerOutputStream();

        try {

            derKey.putOctetString(k);

            this.key = derKey.toByteArray();

        } catch (IOException ex) {

            throw new ProviderException(ex);

        }

    }

    void checkLength(XECParameters params) throws InvalidKeyException {

        if (params.getBytes() != this.k.length) {

            throw new InvalidKeyException(

                "key length must be " + params.getBytes());

        }

    }

    public byte[] getK() {

        return k.clone();

    }

    @Override

    public String getAlgorithm() {

        return "XDH";

    }

    @Override

    public AlgorithmParameterSpec getParams() {

        return paramSpec;

    }

    @Override

    public Optional<byte[]> getScalar() {

        return Optional.of(getK());

    }

}