/*

 * Copyright (c) 2018, 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

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 */

package sun.security.ssl;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.security.GeneralSecurityException;

import sun.security.ssl.SSLHandshake.HandshakeMessage;

import sun.security.ssl.SSLCipher.SSLReadCipher;

import sun.security.ssl.SSLCipher.SSLWriteCipher;

import javax.crypto.SecretKey;

import javax.crypto.spec.IvParameterSpec;

/**

 * Pack of the KeyUpdate handshake message.

 */

final class KeyUpdate {

    static final SSLProducer kickstartProducer =

        new KeyUpdateKickstartProducer();

    static final SSLConsumer handshakeConsumer =

        new KeyUpdateConsumer();

    static final HandshakeProducer handshakeProducer =

        new KeyUpdateProducer();

    /**

     * The KeyUpdate handshake message.

     *

     * The KeyUpdate handshake message is used to indicate that the sender is

     * updating its sending cryptographic keys.

     *

     *       enum {

     *           update_not_requested(0), update_requested(1), (255)

     *       } KeyUpdateRequest;

     *

     *       struct {

     *           KeyUpdateRequest request_update;

     *       } KeyUpdate;

     */

    static final class KeyUpdateMessage extends HandshakeMessage {

        static final byte NOTREQUSTED = 0;

        static final byte REQUSTED = 1;

        private byte status;

        HandshakeOutStream hos;

        KeyUpdateMessage(HandshakeContext context, byte status) {

            super(context);

            this.status = status;

            if (status > 1) {

                new IOException("KeyUpdate message value invalid: " + status);

            }

        }

        KeyUpdateMessage(HandshakeContext context, ByteBuffer m)

                throws IOException{

            super(context);

            if (m.remaining() != 1) {

                throw new IOException("KeyUpdate has an unexpected length of "+

                        m.remaining());

            }

            status = m.get();

            if (status > 1) {

                new IOException("KeyUpdate message value invalid: " + status);

            }

        }

        KeyUpdateMessage(PostHandshakeContext context, byte status) {

            super(context);

            this.status = status;

            if (status > 1) {

                new IOException("KeyUpdate message value invalid: " + status);

            }

        }

        @Override

        public SSLHandshake handshakeType() {

            return SSLHandshake.KEY_UPDATE;

        }

        @Override

        public int messageLength() {

            // one byte enum

            return 1;

        }

        @Override

        public void send(HandshakeOutStream s) throws IOException {

            s.write(status);

        }

        @Override

        public String toString() {

            throw new UnsupportedOperationException("Not supported yet.");

        }

        byte getStatus() {

            return status;

        }

    }

    private static final

            class KeyUpdateKickstartProducer implements SSLProducer {

        // Prevent instantiation of this class.

        private KeyUpdateKickstartProducer() {

            // blank

        }

        // Produce kickstart handshake message.

        @Override

        public byte[] produce(ConnectionContext context) throws IOException {

            HandshakeContext hc = (HandshakeContext)context;

            handshakeProducer.produce(hc,

                    new KeyUpdateMessage(hc, KeyUpdateMessage.REQUSTED));

            return null;

        }

    }

    /**

     * The "KeyUpdate" handshake message consumer.

     */

    private static final class KeyUpdateConsumer implements SSLConsumer {

        // Prevent instantiation of this class.

        private KeyUpdateConsumer() {

            // blank

        }

        @Override

        public void consume(ConnectionContext context,

                ByteBuffer message) throws IOException {

            // The consuming happens in client side only.

            HandshakeContext hc = (HandshakeContext)context;

            KeyUpdateMessage km = new KeyUpdateMessage(hc, message);

            if (km.getStatus() == KeyUpdateMessage.NOTREQUSTED) {

                return;

            }

            SSLTrafficKeyDerivation kdg =

                    SSLTrafficKeyDerivation.valueOf(hc.conContext.protocolVersion);

            if (kdg == null) {

                // unlikely

                hc.conContext.fatal(Alert.INTERNAL_ERROR,

                        "Not supported key derivation: " +

                                hc.conContext.protocolVersion);

                return;

            }

            SSLKeyDerivation skd = kdg.createKeyDerivation(hc,

                    hc.conContext.inputRecord.readCipher.baseSecret);

            SecretKey nplus1 = skd.deriveKey("TlsUpdateNplus1", null);

            if (skd == null) {

                // unlikely

                hc.conContext.fatal(Alert.INTERNAL_ERROR,

                        "no key derivation");

                return;

            }

            SSLKeyDerivation kd = kdg.createKeyDerivation(hc, nplus1);

            SecretKey key = kd.deriveKey("TlsKey", null);

            IvParameterSpec ivSpec =

                    new IvParameterSpec(kd.deriveKey("TlsIv", null)

                            .getEncoded());

            try {

                SSLReadCipher rc =

                        hc.negotiatedCipherSuite.bulkCipher.createReadCipher(

                                Authenticator.valueOf(hc.conContext.protocolVersion),

                                hc.conContext.protocolVersion, key, ivSpec,

                                hc.sslContext.getSecureRandom());

                hc.conContext.inputRecord.changeReadCiphers(rc);

                hc.conContext.inputRecord.readCipher.baseSecret = nplus1;

                if (SSLLogger.isOn && SSLLogger.isOn("ssl")) {

                    SSLLogger.fine("KeyUpdate: read key updated");

                }

            } catch (GeneralSecurityException e) {

                throw new IOException(e);

            }

            // Send Reply

            handshakeProducer.produce(hc,

                    new KeyUpdateMessage(hc, KeyUpdateMessage.NOTREQUSTED));

        }

    }

    /**

     * The "KeyUpdate" handshake message producer.

     */

    private static final class KeyUpdateProducer implements HandshakeProducer {

        // Prevent instantiation of this class.

        private KeyUpdateProducer() {

            // blank

        }

        @Override

        public byte[] produce(ConnectionContext context,

                HandshakeMessage message) throws IOException {

            // The producing happens in server side only.

            HandshakeContext hc = (HandshakeContext)context;

            KeyUpdateMessage km = (KeyUpdateMessage)message;

            SecretKey secret;

            if (km.getStatus() == KeyUpdateMessage.REQUSTED) {

                secret = hc.conContext.outputRecord.writeCipher.baseSecret;

            } else {

                km.write(hc.handshakeOutput);

                hc.handshakeOutput.flush();

                return null;

            }

            SSLTrafficKeyDerivation kdg =

                    SSLTrafficKeyDerivation.valueOf(hc.conContext.protocolVersion);

            if (kdg == null) {

                // unlikely

                hc.conContext.fatal(Alert.INTERNAL_ERROR,

                        "Not supported key derivation: " +

                                hc.conContext.protocolVersion);

                return null;

            }

            // update the application traffic read keys.

            SSLKeyDerivation skd = kdg.createKeyDerivation(hc, secret);

            if (skd == null) {

                // unlikely

                hc.conContext.fatal(Alert.INTERNAL_ERROR,"no key derivation");

                return null;

            }

            SecretKey nplus1 = skd.deriveKey("TlsUpdateNplus1", null);

            SSLKeyDerivation kd =

                    kdg.createKeyDerivation(hc, nplus1);

            SecretKey key = kd.deriveKey("TlsKey", null);

            IvParameterSpec ivSpec =

                    new IvParameterSpec(kd.deriveKey("TlsIv", null)

                            .getEncoded());

            SSLWriteCipher wc;

            try {

                wc = hc.negotiatedCipherSuite.bulkCipher.createWriteCipher(

                        Authenticator.valueOf(hc.conContext.protocolVersion),

                        hc.conContext.protocolVersion, key, ivSpec,

                        hc.sslContext.getSecureRandom());

            } catch (GeneralSecurityException gse){

                hc.conContext.fatal(Alert.INTERNAL_ERROR,

                        "Failure to derive application secrets", gse);

                return null;

            }

            km.write(hc.handshakeOutput);

            hc.handshakeOutput.flush();

            hc.conContext.outputRecord.changeWriteCiphers(wc, false);

            hc.conContext.outputRecord.writeCipher.baseSecret = nplus1;

            if (SSLLogger.isOn && SSLLogger.isOn("ssl")) {

                SSLLogger.fine("KeyUpdate: write key updated");

            }

            return null;

        }

    }

}