/*

 * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates.

 * 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

 * questions.

 */

package sun.security.ssl;

import java.io.IOException;

import java.nio.ByteBuffer;

import javax.net.ssl.SSLProtocolException;

import static sun.security.ssl.SSLExtension.CH_EXTENDED_MASTER_SECRET;

import sun.security.ssl.SSLExtension.ExtensionConsumer;

import static sun.security.ssl.SSLExtension.SH_EXTENDED_MASTER_SECRET;

import sun.security.ssl.SSLExtension.SSLExtensionSpec;

import sun.security.ssl.SSLHandshake.HandshakeMessage;

/**

 */

final class ExtendedMasterSecretExtension {

    static final HandshakeProducer chNetworkProducer =

            new CHExtendedMasterSecretProducer();

    static final ExtensionConsumer chOnLoadConsumer =

            new CHExtendedMasterSecretConsumer();

    static final HandshakeAbsence chOnLoadAbsence =

            new CHExtendedMasterSecretAbsence();

    static final HandshakeProducer shNetworkProducer =

            new SHExtendedMasterSecretProducer();

    static final ExtensionConsumer shOnLoadConsumer =

            new SHExtendedMasterSecretConsumer();

    static final HandshakeAbsence shOnLoadAbsence =

            new SHExtendedMasterSecretAbsence();

    static final SSLStringizer emsStringizer =

            new ExtendedMasterSecretStringizer();

    /**

     * The "extended_master_secret" extension.

     */

    static final class ExtendedMasterSecretSpec implements SSLExtensionSpec {

        // A nominal object that does not holding any real renegotiation info.

        static final ExtendedMasterSecretSpec NOMINAL =

                new ExtendedMasterSecretSpec();

        private ExtendedMasterSecretSpec() {

            // blank

        }

        private ExtendedMasterSecretSpec(ByteBuffer m) throws IOException {

            // Parse the extension.

            if (m.hasRemaining()) {

                throw new SSLProtocolException(

                    "Invalid extended_master_secret extension data: " +

                    "not empty");

            }

        }

        @Override

        public String toString() {

            return "<empty>";

        }

    }

    private static final

            class ExtendedMasterSecretStringizer implements SSLStringizer {

        @Override

        public String toString(ByteBuffer buffer) {

            try {

                return (new ExtendedMasterSecretSpec(buffer)).toString();

            } catch (IOException ioe) {

                // For debug logging only, so please swallow exceptions.

                return ioe.getMessage();

            }

        }

    }

    /**

     * Network data producer of a "extended_master_secret" extension in

     * the ClientHello handshake message.

     */

    private static final

            class CHExtendedMasterSecretProducer implements HandshakeProducer {

        // Prevent instantiation of this class.

        private CHExtendedMasterSecretProducer() {

            // blank

        }

        @Override

        public byte[] produce(ConnectionContext context,

                HandshakeMessage message) throws IOException {

            // The producing happens in client side only.

            ClientHandshakeContext chc = (ClientHandshakeContext)context;

            // Is it a supported and enabled extension?

            if (!chc.sslConfig.isAvailable(CH_EXTENDED_MASTER_SECRET) ||

                    !SSLConfiguration.useExtendedMasterSecret ||

                    !chc.conContext.protocolVersion.useTLS10PlusSpec()) {

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

                    SSLLogger.fine(

                        "Ignore unavailable extended_master_secret extension");

                }

                return null;

            }

            if (chc.handshakeSession == null ||

                    chc.handshakeSession.useExtendedMasterSecret) {

                byte[] extData = new byte[0];

                chc.handshakeExtensions.put(CH_EXTENDED_MASTER_SECRET,

                        ExtendedMasterSecretSpec.NOMINAL);

                return extData;

            }

            return null;

        }

    }

    /**

     * Network data producer of a "extended_master_secret" extension in

     * the ServerHello handshake message.

     */

    private static final

            class CHExtendedMasterSecretConsumer implements ExtensionConsumer {

        // Prevent instantiation of this class.

        private CHExtendedMasterSecretConsumer() {

            // blank

        }

        @Override

        public void consume(ConnectionContext context,

            HandshakeMessage message, ByteBuffer buffer) throws IOException {

            // The consuming happens in server side only.

            ServerHandshakeContext shc = (ServerHandshakeContext)context;

            // Is it a supported and enabled extension?

            if (!shc.sslConfig.isAvailable(CH_EXTENDED_MASTER_SECRET) ||

                    !SSLConfiguration.useExtendedMasterSecret ||

                    !shc.negotiatedProtocol.useTLS10PlusSpec()) {

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

                    SSLLogger.fine("Ignore unavailable extension: " +

                            CH_EXTENDED_MASTER_SECRET.name);

                }

                return;     // ignore the extension

            }

            // Parse the extension.

            ExtendedMasterSecretSpec spec;

            try {

                spec = new ExtendedMasterSecretSpec(buffer);

            } catch (IOException ioe) {

                shc.conContext.fatal(Alert.UNEXPECTED_MESSAGE, ioe);

                return;     // fatal() always throws, make the compiler happy.

            }

            if (shc.isResumption && shc.resumingSession != null &&

                    !shc.resumingSession.useExtendedMasterSecret) {

                // For abbreviated handshake request, If the original

                // session did not use the "extended_master_secret"

                // extension but the new ClientHello contains the

                // extension, then the server MUST NOT perform the

                // abbreviated handshake.  Instead, it SHOULD continue

                // with a full handshake.

                shc.isResumption = false;

                shc.resumingSession = null;

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

                    SSLLogger.fine(

                        "abort session resumption which did not use " +

                        "Extended Master Secret extension");

                }

            }

            // Update the context.

            //

            shc.handshakeExtensions.put(

                CH_EXTENDED_MASTER_SECRET, ExtendedMasterSecretSpec.NOMINAL);

            // No impact on session resumption.

        }

    }

    /**

     * The absence processing if a "extended_master_secret" extension is

     * not present in the ClientHello handshake message.

     */

    private static final

            class CHExtendedMasterSecretAbsence implements HandshakeAbsence {

        @Override

        public void absent(ConnectionContext context,

                HandshakeMessage message) throws IOException {

            // The producing happens in server side only.

            ServerHandshakeContext shc = (ServerHandshakeContext)context;

            // Is it a supported and enabled extension?

            if (!shc.sslConfig.isAvailable(CH_EXTENDED_MASTER_SECRET) ||

                    !SSLConfiguration.useExtendedMasterSecret) {

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

                    SSLLogger.fine("Ignore unavailable extension: " +

                            CH_EXTENDED_MASTER_SECRET.name);

                }

                return;     // ignore the extension

            }

            if (shc.negotiatedProtocol.useTLS10PlusSpec() &&

                    !SSLConfiguration.allowLegacyMasterSecret) {

                // For full handshake, if the server receives a ClientHello

                // without the extension, it SHOULD abort the handshake if

                // it does not wish to interoperate with legacy clients.

                //

                // As if extended master extension is required for full

                // handshake, it MUST be used in abbreviated handshake too.

                shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,

                    "Extended Master Secret extension is required");

            }

            if (shc.isResumption && shc.resumingSession != null) {

                if (shc.resumingSession.useExtendedMasterSecret) {

                    // For abbreviated handshake request, if the original

                    // session used the "extended_master_secret" extension

                    // but the new ClientHello does not contain it, the

                    // server MUST abort the abbreviated handshake.

                    shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,

                            "Missing Extended Master Secret extension " +

                            "on session resumption");

                } else {

                    // For abbreviated handshake request, if neither the

                    // original session nor the new ClientHello uses the

                    // extension, the server SHOULD abort the handshake.

                    if (!SSLConfiguration.allowLegacyResumption) {

                        shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,

                            "Missing Extended Master Secret extension " +

                            "on session resumption");

                    } else {  // Otherwise, continue with a full handshake.

                        shc.isResumption = false;

                        shc.resumingSession = null;

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

                            SSLLogger.fine(

                                "abort session resumption, " +

                                "missing Extended Master Secret extension");

                        }

                    }

                }

            }

        }

    }

    /**

     * Network data producer of a "extended_master_secret" extension in

     * the ServerHello handshake message.

     */

    private static final

            class SHExtendedMasterSecretProducer implements HandshakeProducer {

        // Prevent instantiation of this class.

        private SHExtendedMasterSecretProducer() {

            // blank

        }

        @Override

        public byte[] produce(ConnectionContext context,

                HandshakeMessage message) throws IOException {

            // The producing happens in server side only.

            ServerHandshakeContext shc = (ServerHandshakeContext)context;

            if (shc.handshakeSession.useExtendedMasterSecret) {

                byte[] extData = new byte[0];

                shc.handshakeExtensions.put(SH_EXTENDED_MASTER_SECRET,

                        ExtendedMasterSecretSpec.NOMINAL);

                return extData;

            }

            return null;

        }

    }

    /**

     * Network data consumer of a "extended_master_secret" extension in

     * the ServerHello handshake message.

     */

    private static final

            class SHExtendedMasterSecretConsumer implements ExtensionConsumer {

        // Prevent instantiation of this class.

        private SHExtendedMasterSecretConsumer() {

            // blank

        }

        @Override

        public void consume(ConnectionContext context,

            HandshakeMessage message, ByteBuffer buffer) throws IOException {

            // The producing happens in client side only.

            ClientHandshakeContext chc = (ClientHandshakeContext)context;

            // In response to the client extended_master_secret extension

            // request, which is mandatory for ClientHello message.

            ExtendedMasterSecretSpec requstedSpec = (ExtendedMasterSecretSpec)

                    chc.handshakeExtensions.get(CH_EXTENDED_MASTER_SECRET);

            if (requstedSpec == null) {

                chc.conContext.fatal(Alert.UNSUPPORTED_EXTENSION,

                        "Server sent the extended_master_secret " +

                        "extension improperly");

            }

            // Parse the extension.

            ExtendedMasterSecretSpec spec;

            try {

                spec = new ExtendedMasterSecretSpec(buffer);

            } catch (IOException ioe) {

                chc.conContext.fatal(Alert.UNEXPECTED_MESSAGE, ioe);

                return;     // fatal() always throws, make the compiler happy.

            }

            if (chc.isResumption && chc.resumingSession != null &&

                    !chc.resumingSession.useExtendedMasterSecret) {

                chc.conContext.fatal(Alert.UNSUPPORTED_EXTENSION,

                        "Server sent an unexpected extended_master_secret " +

                        "extension on session resumption");

            }

            // Update the context.

            chc.handshakeExtensions.put(

                SH_EXTENDED_MASTER_SECRET, ExtendedMasterSecretSpec.NOMINAL);

            // No impact on session resumption.

        }

    }

    /**

     * The absence processing if a "extended_master_secret" extension is

     * not present in the ServerHello handshake message.

     */

    private static final

            class SHExtendedMasterSecretAbsence implements HandshakeAbsence {

        @Override

        public void absent(ConnectionContext context,

                HandshakeMessage message) throws IOException {

            // The producing happens in client side only.

            ClientHandshakeContext chc = (ClientHandshakeContext)context;

            if (SSLConfiguration.useExtendedMasterSecret &&

                    !SSLConfiguration.allowLegacyMasterSecret) {

                // For full handshake, if a client receives a ServerHello

                // without the extension, it SHOULD abort the handshake if

                // it does not wish to interoperate with legacy servers.

                chc.conContext.fatal(Alert.HANDSHAKE_FAILURE,

                        "Extended Master Secret extension is required");

            }

            if (chc.isResumption && chc.resumingSession != null) {

                if (chc.resumingSession.useExtendedMasterSecret) {

                    // For abbreviated handshake, if the original session used

                    // the "extended_master_secret" extension but the new

                    // ServerHello does not contain the extension, the client

                    // MUST abort the handshake.

                    chc.conContext.fatal(Alert.HANDSHAKE_FAILURE,

                            "Missing Extended Master Secret extension " +

                            "on session resumption");

                } else if (SSLConfiguration.useExtendedMasterSecret &&

                        !SSLConfiguration.allowLegacyResumption &&

                        chc.negotiatedProtocol.useTLS10PlusSpec()) {

                    // Unlikely, abbreviated handshake should be discarded.

                    chc.conContext.fatal(Alert.HANDSHAKE_FAILURE,

                        "Extended Master Secret extension is required");

                }

            }

        }

    }

}