/*

 * 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.Closeable;

import java.io.IOException;

import java.security.AccessControlContext;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import javax.net.ssl.HandshakeCompletedEvent;

import javax.net.ssl.HandshakeCompletedListener;

import javax.net.ssl.SSLEngineResult.HandshakeStatus;

import javax.net.ssl.SSLException;

import javax.net.ssl.SSLSocket;

import sun.security.ssl.SupportedGroupsExtension.NamedGroup;

/**

 * SSL/(D)TLS transportation context.

 */

class TransportContext implements ConnectionContext, Closeable {

    final SSLTransport              transport;

    // registered plaintext consumers

    final Map<Byte, SSLConsumer>    consumers;

    final AccessControlContext      acc;

    final SSLContextImpl            sslContext;

    final SSLConfiguration          sslConfig;

    final InputRecord               inputRecord;

    final OutputRecord              outputRecord;

    // connection status

    boolean                         isUnsureMode;

    boolean                         isNegotiated = false;

    boolean                         isBroken = false;

    boolean                         isInputCloseNotified = false;

    boolean                         isOutputCloseNotified = false;

    Exception                       closeReason = null;

    // negotiated security parameters

    SSLSessionImpl                  conSession;

    ProtocolVersion                 protocolVersion;

    String                          applicationProtocol= null;

    // handshake context

    HandshakeContext                handshakeContext = null;

    // connection reserved status for handshake.

    boolean                         secureRenegotiation = false;

    byte[]                          clientVerifyData;

    byte[]                          serverVerifyData;

    // connection sensitive configuration

    List<NamedGroup>                serverRequestedNamedGroups;

    CipherSuite cipherSuite;

    private static final byte[] emptyByteArray = new byte[0];

    // Please never use the transport parameter other than storing a

    // reference to this object.

    //

    // Called by SSLEngineImpl

    TransportContext(SSLContextImpl sslContext, SSLTransport transport,

            InputRecord inputRecord, OutputRecord outputRecord) {

        this(sslContext, transport, new SSLConfiguration(sslContext, true),

                inputRecord, outputRecord, true);

    }

    // Please never use the transport parameter other than storing a

    // reference to this object.

    //

    // Called by SSLSocketImpl

    TransportContext(SSLContextImpl sslContext, SSLTransport transport,

            InputRecord inputRecord, OutputRecord outputRecord,

            boolean isClientMode) {

        this(sslContext, transport,

                new SSLConfiguration(sslContext, isClientMode),

                inputRecord, outputRecord, false);

    }

    // Please never use the transport parameter other than storing a

    // reference to this object.

    //

    // Called by SSLSocketImpl with an existing SSLConfig

    TransportContext(SSLContextImpl sslContext, SSLTransport transport,

            SSLConfiguration sslConfig,

            InputRecord inputRecord, OutputRecord outputRecord) {

        this(sslContext, transport, (SSLConfiguration)sslConfig.clone(),

                inputRecord, outputRecord, false);

    }

    private TransportContext(SSLContextImpl sslContext, SSLTransport transport,

            SSLConfiguration sslConfig, InputRecord inputRecord,

            OutputRecord outputRecord, boolean isUnsureMode) {

        this.transport = transport;

        this.sslContext = sslContext;

        this.inputRecord = inputRecord;

        this.outputRecord = outputRecord;

        this.sslConfig = sslConfig;

        if (this.sslConfig.maximumPacketSize == 0) {

            this.sslConfig.maximumPacketSize = outputRecord.getMaxPacketSize();

        }

        this.isUnsureMode = isUnsureMode;

        // initial security parameters

        this.conSession = SSLSessionImpl.nullSession;

        this.protocolVersion = this.sslConfig.maximumProtocolVersion;

        this.clientVerifyData = emptyByteArray;

        this.serverVerifyData = emptyByteArray;

        this.acc = AccessController.getContext();

        this.consumers = new HashMap<>();

    }

    // Dispatch plaintext to a specific consumer.

    void dispatch(Plaintext plaintext) throws IOException {

        if (plaintext == null) {

            return;

        }

        ContentType ct = ContentType.valueOf(plaintext.contentType);

        if (ct == null) {

            fatal(Alert.UNEXPECTED_MESSAGE,

                "Unknown content type: " + plaintext.contentType);

            return;

        }

        switch (ct) {

            case HANDSHAKE:

                byte type = HandshakeContext.getHandshakeType(this,

                        plaintext);

                if (handshakeContext == null) {

                    if (type == SSLHandshake.KEY_UPDATE.id ||

                            type == SSLHandshake.NEW_SESSION_TICKET.id) {

                        if (isNegotiated &&

                                protocolVersion.useTLS13PlusSpec()) {

                            handshakeContext = new PostHandshakeContext(this);

                        } else {

                            fatal(Alert.UNEXPECTED_MESSAGE,

                                    "Unexpected post-handshake message: " +

                                    SSLHandshake.nameOf(type));

                        }

                    } else {

                        handshakeContext = sslConfig.isClientMode ?

                                new ClientHandshakeContext(sslContext, this) :

                                new ServerHandshakeContext(sslContext, this);

                        outputRecord.initHandshaker();

                    }

                }

                handshakeContext.dispatch(type, plaintext);

                break;

            case ALERT:

                Alert.alertConsumer.consume(this, plaintext.fragment);

                break;

            default:

                SSLConsumer consumer = consumers.get(plaintext.contentType);

                if (consumer != null) {

                    consumer.consume(this, plaintext.fragment);

                } else {

                    fatal(Alert.UNEXPECTED_MESSAGE,

                        "Unexpected content: " + plaintext.contentType);

                }

        }

    }

    void kickstart() throws IOException {

        if (isUnsureMode) {

            throw new IllegalStateException("Client/Server mode not yet set.");

        }

        if (outputRecord.isClosed() || inputRecord.isClosed() || isBroken) {

            if (closeReason != null) {

                throw new SSLException(

                        "Cannot kickstart, the connection is broken or closed",

                        closeReason);

            } else {

                throw new SSLException(

                        "Cannot kickstart, the connection is broken or closed");

            }

        }

        // initialize the handshaker if necessary

        if (handshakeContext == null) {

            //  TLS1.3 post-handshake

            if (isNegotiated && protocolVersion.useTLS13PlusSpec()) {

                handshakeContext = new PostHandshakeContext(this);

            } else {

                handshakeContext = sslConfig.isClientMode ?

                        new ClientHandshakeContext(sslContext, this) :

                        new ServerHandshakeContext(sslContext, this);

                outputRecord.initHandshaker();

            }

        }

        // kickstart the handshake if needed

        //

        // Need no kickstart message on server side unless the connection

        // has been established.

        if(isNegotiated || sslConfig.isClientMode) {

           handshakeContext.kickstart();

        }

    }

    void keyUpdate() throws IOException {

        kickstart();

    }

    boolean isPostHandshakeContext() {

        return handshakeContext != null &&

                (handshakeContext instanceof PostHandshakeContext);

    }

    // Note: close_notify is delivered as a warning alert.

    void warning(Alert alert) {

        // For initial handshaking, don't send a warning alert message to peer

        // if handshaker has not started.

        if (isNegotiated || handshakeContext != null) {

            try {

                outputRecord.encodeAlert(Alert.Level.WARNING.level, alert.id);

            } catch (IOException ioe) {

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

                    SSLLogger.warning(

                        "Warning: failed to send warning alert " + alert, ioe);

                }

            }

        }

    }

    void fatal(Alert alert,

            String diagnostic) throws SSLException {

        fatal(alert, diagnostic, null);

    }

    void fatal(Alert alert, Throwable cause) throws SSLException {

        fatal(alert, null, cause);

    }

    void fatal(Alert alert,

            String diagnostic, Throwable cause) throws SSLException {

        fatal(alert, diagnostic, false, cause);

    }

    // Note: close_notify is not delivered via fatal() methods.

    void fatal(Alert alert, String diagnostic,

            boolean recvFatalAlert, Throwable cause) throws SSLException {

        // If we've already shutdown because of an error, there is nothing we

        // can do except rethrow the exception.

        //

        // Most exceptions seen here will be SSLExceptions. We may find the

        // occasional Exception which hasn't been converted to a SSLException,

        // so we'll do it here.

        if (closeReason != null) {

            if (cause == null) {

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

                    SSLLogger.warning(

                            "Closed transport, general or untracked problem");

                }

                throw alert.createSSLException(

                        "Closed transport, general or untracked problem");

            }

            if (cause instanceof SSLException) {

                throw (SSLException)cause;

            } else {    // unlikely, but just in case.

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

                    SSLLogger.warning(

                            "Closed transport, unexpected rethrowing", cause);

                }

                throw alert.createSSLException("Unexpected rethrowing", cause);

            }

        }

        // If we have no further information, make a general-purpose

        // message for folks to see.  We generally have one or the other.

        if (diagnostic == null) {

            if (cause == null) {

                diagnostic = "General/Untracked problem";

            } else {

                diagnostic = cause.getMessage();

            }

        }

        if (cause == null) {

            cause = alert.createSSLException(diagnostic);

        }

        // shutdown the transport

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

            SSLLogger.severe("Fatal (" + alert + "): " + diagnostic, cause);

        }

        // remember the close reason

        if (cause instanceof SSLException) {

            closeReason = (SSLException)cause;

        } else {

            // Including RuntimeException, but we'll throw those down below.

            closeReason = alert.createSSLException(diagnostic, cause);

        }

        // close inbound

        try {

            inputRecord.close();

        } catch (IOException ioe) {

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

                SSLLogger.warning("Fatal: input record closure failed", ioe);

            }

        }

        // invalidate the session

        if (conSession != null) {

            conSession.invalidate();

        }

        if (handshakeContext != null &&

                handshakeContext.handshakeSession != null) {

            handshakeContext.handshakeSession.invalidate();

        }

        // send fatal alert

        //

        // If we haven't even started handshaking yet, or we are the recipient

        // of a fatal alert, no need to generate a fatal close alert.

        if (!recvFatalAlert && !isOutboundDone() && !isBroken &&

                (isNegotiated || handshakeContext != null)) {

            try {

                outputRecord.encodeAlert(Alert.Level.FATAL.level, alert.id);

            } catch (IOException ioe) {

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

                    SSLLogger.warning(

                        "Fatal: failed to send fatal alert " + alert, ioe);

                }

            }

        }

        // close outbound

        try {

            outputRecord.close();

        } catch (IOException ioe) {

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

                SSLLogger.warning("Fatal: output record closure failed", ioe);

            }

        }

        // terminal handshake context

        if (handshakeContext != null) {

            handshakeContext = null;

        }

        // terminal the transport

        try {

            transport.shutdown();

        } catch (IOException ioe) {

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

                SSLLogger.warning("Fatal: transport closure failed", ioe);

            }

        } finally {

            isBroken = true;

        }

        if (closeReason instanceof SSLException) {

            throw (SSLException)closeReason;

        } else {

            throw (RuntimeException)closeReason;

        }

    }

    void setUseClientMode(boolean useClientMode) {

        /*

         * If we need to change the client mode and the enabled

         * protocols and cipher suites haven't specifically been

         * set by the user, change them to the corresponding

         * default ones.

         */

        if (sslConfig.isClientMode != useClientMode) {

            // Once handshaking has begun, the mode can not be reset for the

            // life of this engine.

            if (handshakeContext != null || isNegotiated) {

                throw new IllegalArgumentException(

                    "Cannot change mode after SSL traffic has started");

            }

            if (sslContext.isDefaultProtocolVesions(

                    sslConfig.enabledProtocols)) {

                sslConfig.enabledProtocols =

                        sslContext.getDefaultProtocolVersions(!useClientMode);

            }

            if (sslContext.isDefaultCipherSuiteList(

                    sslConfig.enabledCipherSuites)) {

                sslConfig.enabledCipherSuites =

                        sslContext.getDefaultCipherSuites(!useClientMode);

            }

            sslConfig.isClientMode = useClientMode;

        }

        isUnsureMode = false;

    }

    // The OutputRecord is closed and not buffered output record.

    boolean isOutboundDone() {

        return outputRecord.isClosed() && outputRecord.isEmpty();

    }

    // The OutputRecord is closed, but buffered output record may be still

    // waiting for delivery to the underlying connection.

    boolean isOutboundClosed() {

        return outputRecord.isClosed();

    }

    boolean isInboundDone() {

        return inputRecord.isClosed();

    }

    boolean isClosed() {

        return isOutboundClosed() && isInboundDone();

    }

    @Override

    public void close() throws IOException {

        if (!isOutboundDone()) {

            closeOutbound();

        }

        if (!isInboundDone()) {

            closeInbound();

        }

    }

    void closeInbound() {

        if (isInboundDone()) {

            return;

        }

        try {

            if (isInputCloseNotified) {     // passive close

                passiveInboundClose();

            } else {                        // initiative close

                initiateInboundClose();

            }

        } catch (IOException ioe) {

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

                SSLLogger.warning("inbound closure failed", ioe);

            }

        }

    }

    void closeOutbound() {

        if (isOutboundDone()) {

            return;

        }

        try {

             initiateOutboundClose();

        } catch (IOException ioe) {

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

                SSLLogger.warning("outbound closure failed", ioe);

            }

        }

    }

    // Close the connection passively.  The closure could be kickoff by

    // receiving a close_notify alert or reaching end_of_file of the socket.

    private void passiveInboundClose() throws IOException {

        if (!isInboundDone()) {

            inputRecord.close();

        }

        // For TLS 1.2 and prior version, it is required to respond with

        // a close_notify alert of its own and close down the connection

        // immediately, discarding any pending writes.

        if (!isOutboundDone() && !isOutputCloseNotified) {

            try {

                // send a close_notify alert

                warning(Alert.CLOSE_NOTIFY);

            } finally {

                // any data received after a closure alert is ignored.

                isOutputCloseNotified = true;

                outputRecord.close();

            }

        }

        transport.shutdown();

    }

    // Initiate a close by sending a close_notify alert.

    private void initiateInboundClose() throws IOException {

        // TLS 1.3 does not define how to initiate and close a TLS connection

        // gracefully.  We will always send a close_notify alert, and close

        // the underlying transportation layer if needed.

        if (!isInboundDone() && !isInputCloseNotified) {

            try {

                // send a close_notify alert

                warning(Alert.CLOSE_NOTIFY);

            } finally {

                // any data received after a closure alert is ignored.

                isInputCloseNotified = true;

                inputRecord.close();

            }

        }