src/java.base/share/classes/sun/security/provider/DSAPublicKeyImpl.java

/*
 * Copyright (c) 2005, 2023, 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
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package sun.security.provider;

import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.math.BigInteger;
import java.security.KeyRep;
import java.security.InvalidKeyException;

/**
 * An X.509 public key for the Digital Signature Algorithm.
 * <p>
 * The difference between DSAPublicKeyImpl and DSAPublicKey is that
 * DSAPublicKeyImpl calls writeReplace with KeyRep, and DSAPublicKey
 * calls writeObject.
 * <p>
 * See the comments in DSAKeyFactory, 4532506, and 6232513.
 *
 */

public final class DSAPublicKeyImpl extends DSAPublicKey {

    @java.io.Serial
    private static final long serialVersionUID = 7819830118247182730L;

    /**
     * Make a DSA public key out of a public key and three parameters.
     * The p, q, and g parameters may be null, but if so, parameters will need
     * to be supplied from some other source before this key can be used in
     * cryptographic operations.  PKIX RFC2459bis explicitly allows DSA public
     * keys without parameters, where the parameters are provided in the
     * issuer's DSA public key.
     *
     * @param y the actual key bits
     * @param p DSA parameter p, may be null if all of p, q, and g are null.
     * @param q DSA parameter q, may be null if all of p, q, and g are null.
     * @param g DSA parameter g, may be null if all of p, q, and g are null.
     */
    public DSAPublicKeyImpl(BigInteger y, BigInteger p, BigInteger q,
                        BigInteger g)
                throws InvalidKeyException {
        super(y, p, q, g);
    }

    /**
     * Make a DSA public key from its DER encoding (X.509).
     */
    public DSAPublicKeyImpl(byte[] encoded) throws InvalidKeyException {
        super(encoded);
    }

    @java.io.Serial
    private Object writeReplace() throws java.io.ObjectStreamException {
        return new KeyRep(KeyRep.Type.PUBLIC,
                        getAlgorithm(),
                        getFormat(),
                        getEncoded());
    }

    /**
     * Restores the state of this object from the stream.
     * <p>
     * Deserialization of this object is not supported.
     *
     * @param  stream the {@code ObjectInputStream} from which data is read
     * @throws IOException if an I/O error occurs
     * @throws ClassNotFoundException if a serialized class cannot be loaded
     */
    @java.io.Serial
    private void readObject(ObjectInputStream stream)
            throws IOException, ClassNotFoundException {
        throw new InvalidObjectException(
                "DSAPublicKeyImpl keys are not directly deserializable");
    }
}