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	/*
	* Copyright (c) 2015, 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 java.security.AlgorithmConstraints;
	import java.security.GeneralSecurityException;
	import java.text.MessageFormat;
	import java.util.Arrays;
	import java.util.LinkedList;
	import java.util.List;
	import java.util.Locale;
	import java.util.Map;
	import java.util.Optional;
	import javax.crypto.SecretKey;
	import javax.crypto.spec.IvParameterSpec;
	import javax.net.ssl.SSLException;
	import javax.net.ssl.SSLHandshakeException;
	import javax.net.ssl.SSLProtocolException;
	import sun.security.ssl.CipherSuite.KeyExchange;
	import sun.security.ssl.ClientHello.ClientHelloMessage;
	import sun.security.ssl.SSLCipher.SSLReadCipher;
	import sun.security.ssl.SSLCipher.SSLWriteCipher;
	import sun.security.ssl.SSLHandshake.HandshakeMessage;
	import sun.security.ssl.SupportedVersionsExtension.SHSupportedVersionsSpec;

	/**
	* Pack of the ServerHello/HelloRetryRequest handshake message.
	*/
	final class ServerHello {
	static final SSLConsumer handshakeConsumer =
	new ServerHelloConsumer();
	static final HandshakeProducer t12HandshakeProducer =
	new T12ServerHelloProducer();
	static final HandshakeProducer t13HandshakeProducer =
	new T13ServerHelloProducer();
	static final HandshakeProducer hrrHandshakeProducer =
	new T13HelloRetryRequestProducer();

	static final HandshakeProducer hrrReproducer =
	new T13HelloRetryRequestReproducer();

	private static final HandshakeConsumer t12HandshakeConsumer =
	new T12ServerHelloConsumer();
	private static final HandshakeConsumer t13HandshakeConsumer =
	new T13ServerHelloConsumer();

	private static final HandshakeConsumer d12HandshakeConsumer =
	new T12ServerHelloConsumer();
	private static final HandshakeConsumer d13HandshakeConsumer =
	new T13ServerHelloConsumer();

	private static final HandshakeConsumer t13HrrHandshakeConsumer =
	new T13HelloRetryRequestConsumer();
	private static final HandshakeConsumer d13HrrHandshakeConsumer =
	new T13HelloRetryRequestConsumer();

	/**
	* The ServerHello handshake message.
	*/
	static final class ServerHelloMessage extends HandshakeMessage {
	final ProtocolVersion serverVersion; // TLS 1.3 legacy
	final RandomCookie serverRandom;
	final SessionId sessionId; // TLS 1.3 legacy
	final CipherSuite cipherSuite;
	final byte compressionMethod; // TLS 1.3 legacy
	final SSLExtensions extensions;

	// The HelloRetryRequest producer needs to use the ClientHello message
	// for cookie generation. Please don't use this field for other
	// purpose unless it is really necessary.
	final ClientHelloMessage clientHello;

	// Reserved for HelloRetryRequest consumer. Please don't use this
	// field for other purpose unless it is really necessary.
	final ByteBuffer handshakeRecord;

	ServerHelloMessage(HandshakeContext context,
	ProtocolVersion serverVersion, SessionId sessionId,
	CipherSuite cipherSuite, RandomCookie serverRandom,
	ClientHelloMessage clientHello) {
	super(context);

	this.serverVersion = serverVersion;
	this.serverRandom = serverRandom;
	this.sessionId = sessionId;
	this.cipherSuite = cipherSuite;
	this.compressionMethod = 0x00; // Don't support compression.
	this.extensions = new SSLExtensions(this);

	// Reserve the ClientHello message for cookie generation.
	this.clientHello = clientHello;

	// The handshakeRecord field is used for HelloRetryRequest consumer
	// only. It's fine to set it to null for generating side of the
	// ServerHello/HelloRetryRequest message.
	this.handshakeRecord = null;
	}

	ServerHelloMessage(HandshakeContext context,
	ByteBuffer m) throws IOException {
	super(context);

	// Reserve for HelloRetryRequest consumer if needed.
	this.handshakeRecord = m.duplicate();

	byte major = m.get();
	byte minor = m.get();
	this.serverVersion = ProtocolVersion.valueOf(major, minor);
	if (this.serverVersion == null) {
	// The client should only request for known protocol versions.
	context.conContext.fatal(Alert.PROTOCOL_VERSION,
	"Unsupported protocol version: " +
	ProtocolVersion.nameOf(major, minor));
	}

	this.serverRandom = new RandomCookie(m);
	this.sessionId = new SessionId(Record.getBytes8(m));
	try {
	sessionId.checkLength(serverVersion.id);
	} catch (SSLProtocolException ex) {
	handshakeContext.conContext.fatal(Alert.ILLEGAL_PARAMETER, ex);
	}

	int cipherSuiteId = Record.getInt16(m);
	this.cipherSuite = CipherSuite.valueOf(cipherSuiteId);
	if (cipherSuite == null \|\| !context.isNegotiable(cipherSuite)) {
	context.conContext.fatal(Alert.ILLEGAL_PARAMETER,
	"Server selected improper ciphersuite " +
	CipherSuite.nameOf(cipherSuiteId));
	}

	this.compressionMethod = m.get();
	if (compressionMethod != 0) {
	context.conContext.fatal(Alert.ILLEGAL_PARAMETER,
	"compression type not supported, " + compressionMethod);
	}

	SSLExtension[] supportedExtensions;
	if (serverRandom.isHelloRetryRequest()) {
	supportedExtensions = context.sslConfig.getEnabledExtensions(
	SSLHandshake.HELLO_RETRY_REQUEST);
	} else {
	supportedExtensions = context.sslConfig.getEnabledExtensions(
	SSLHandshake.SERVER_HELLO);
	}

	if (m.hasRemaining()) {
	this.extensions =
	new SSLExtensions(this, m, supportedExtensions);
	} else {
	this.extensions = new SSLExtensions(this);
	}

	// The clientHello field is used for HelloRetryRequest producer
	// only. It's fine to set it to null for receiving side of
	// ServerHello/HelloRetryRequest message.
	this.clientHello = null; // not used, let it be null;
	}

	@Override
	public SSLHandshake handshakeType() {
	return serverRandom.isHelloRetryRequest() ?
	SSLHandshake.HELLO_RETRY_REQUEST : SSLHandshake.SERVER_HELLO;
	}

	@Override
	public int messageLength() {
	// almost fixed header size, except session ID and extensions:
	// major + minor = 2
	// random = 32
	// session ID len field = 1
	// cipher suite = 2
	// compression = 1
	// extensions: if present, 2 + length of extensions
	// In TLS 1.3, use of certain extensions is mandatory.
	return 38 + sessionId.length() + extensions.length();
	}

	@Override
	public void send(HandshakeOutStream hos) throws IOException {
	hos.putInt8(serverVersion.major);
	hos.putInt8(serverVersion.minor);
	hos.write(serverRandom.randomBytes);
	hos.putBytes8(sessionId.getId());
	hos.putInt8((cipherSuite.id >> 8) & 0xFF);
	hos.putInt8(cipherSuite.id & 0xff);
	hos.putInt8(compressionMethod);

	extensions.send(hos); // In TLS 1.3, use of certain
	// extensions is mandatory.
	}

	@Override
	public String toString() {
	MessageFormat messageFormat = new MessageFormat(
	"\"{0}\": '{'\n" +
	" \"server version\" : \"{1}\",\n" +
	" \"random\" : \"{2}\",\n" +
	" \"session id\" : \"{3}\",\n" +
	" \"cipher suite\" : \"{4}\",\n" +
	" \"compression methods\" : \"{5}\",\n" +
	" \"extensions\" : [\n" +
	"{6}\n" +
	" ]\n" +
	"'}'",
	Locale.ENGLISH);
	Object[] messageFields = {
	serverRandom.isHelloRetryRequest() ?
	"HelloRetryRequest" : "ServerHello",
	serverVersion.name,
	Utilities.toHexString(serverRandom.randomBytes),
	sessionId.toString(),
	cipherSuite.name + "(" +
	Utilities.byte16HexString(cipherSuite.id) + ")",
	Utilities.toHexString(compressionMethod),
	Utilities.indent(extensions.toString(), " ")
	};

	return messageFormat.format(messageFields);
	}
	}

	/**
	* The "ServerHello" handshake message producer.
	*/
	private static final class T12ServerHelloProducer
	implements HandshakeProducer {

	// Prevent instantiation of this class.
	private T12ServerHelloProducer() {
	// blank
	}

	@Override
	public byte[] produce(ConnectionContext context,
	HandshakeMessage message) throws IOException {
	// The producing happens in server side only.
	ServerHandshakeContext shc = (ServerHandshakeContext)context;
	ClientHelloMessage clientHello = (ClientHelloMessage)message;

	// If client hasn't specified a session we can resume, start a
	// new one and choose its cipher suite and compression options,
	// unless new session creation is disabled for this connection!
	if (!shc.isResumption \|\| shc.resumingSession == null) {
	if (!shc.sslConfig.enableSessionCreation) {
	throw new SSLException(
	"Not resumption, and no new session is allowed");
	}

	if (shc.localSupportedSignAlgs == null) {
	shc.localSupportedSignAlgs =
	SignatureScheme.getSupportedAlgorithms(
	shc.algorithmConstraints, shc.activeProtocols);
	}

	SSLSessionImpl session =
	new SSLSessionImpl(shc, CipherSuite.C_NULL);
	session.setMaximumPacketSize(shc.sslConfig.maximumPacketSize);
	shc.handshakeSession = session;

	// consider the handshake extension impact
	SSLExtension[] enabledExtensions =
	shc.sslConfig.getEnabledExtensions(
	SSLHandshake.CLIENT_HELLO, shc.negotiatedProtocol);
	clientHello.extensions.consumeOnTrade(shc, enabledExtensions);

	// negotiate the cipher suite.
	KeyExchangeProperties credentials =
	chooseCipherSuite(shc, clientHello);
	if (credentials == null) {
	shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
	"no cipher suites in common");

	return null; // make the compiler happy
	}
	shc.negotiatedCipherSuite = credentials.cipherSuite;
	shc.handshakeKeyExchange = credentials.keyExchange;
	shc.handshakeSession.setSuite(credentials.cipherSuite);
	shc.handshakePossessions.addAll(
	Arrays.asList(credentials.possessions));
	shc.handshakeHash.determine(
	shc.negotiatedProtocol, shc.negotiatedCipherSuite);

	// Check the incoming OCSP stapling extensions and attempt
	// to get responses. If the resulting stapleParams is non
	// null, it implies that stapling is enabled on the server side.
	shc.stapleParams = StatusResponseManager.processStapling(shc);
	shc.staplingActive = (shc.stapleParams != null);

	// update the responders
	SSLKeyExchange ke = credentials.keyExchange;
	if (ke != null) {
	for (Map.Entry<Byte, HandshakeProducer> me :
	ke.getHandshakeProducers(shc)) {
	shc.handshakeProducers.put(
	me.getKey(), me.getValue());
	}
	}

	if ((ke != null) &&
	(shc.sslConfig.clientAuthType !=
	ClientAuthType.CLIENT_AUTH_NONE) &&
	!shc.negotiatedCipherSuite.isAnonymous()) {
	for (SSLHandshake hs :
	ke.getRelatedHandshakers(shc)) {
	if (hs == SSLHandshake.CERTIFICATE) {
	shc.handshakeProducers.put(
	SSLHandshake.CERTIFICATE_REQUEST.id,
	SSLHandshake.CERTIFICATE_REQUEST);
	break;
	}
	}
	}
	shc.handshakeProducers.put(SSLHandshake.SERVER_HELLO_DONE.id,
	SSLHandshake.SERVER_HELLO_DONE);
	} else {
	shc.handshakeSession = shc.resumingSession;
	shc.negotiatedProtocol =
	shc.resumingSession.getProtocolVersion();
	shc.negotiatedCipherSuite = shc.resumingSession.getSuite();
	shc.handshakeHash.determine(
	shc.negotiatedProtocol, shc.negotiatedCipherSuite);
	}

	// Generate the ServerHello handshake message.
	ServerHelloMessage shm = new ServerHelloMessage(shc,
	shc.negotiatedProtocol,
	shc.handshakeSession.getSessionId(),
	shc.negotiatedCipherSuite,
	new RandomCookie(shc),
	clientHello);
	shc.serverHelloRandom = shm.serverRandom;

	// Produce extensions for ServerHello handshake message.
	SSLExtension[] serverHelloExtensions =
	shc.sslConfig.getEnabledExtensions(
	SSLHandshake.SERVER_HELLO, shc.negotiatedProtocol);
	shm.extensions.produce(shc, serverHelloExtensions);
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine("Produced ServerHello handshake message", shm);
	}

	// Output the handshake message.
	shm.write(shc.handshakeOutput);
	shc.handshakeOutput.flush();

	if (shc.isResumption && shc.resumingSession != null) {
	SSLTrafficKeyDerivation kdg =
	SSLTrafficKeyDerivation.valueOf(shc.negotiatedProtocol);
	if (kdg == null) {
	// unlikely
	shc.conContext.fatal(Alert.INTERNAL_ERROR,
	"Not supported key derivation: " +
	shc.negotiatedProtocol);
	} else {
	shc.handshakeKeyDerivation = kdg.createKeyDerivation(
	shc, shc.resumingSession.getMasterSecret());
	}

	// update the responders
	shc.handshakeProducers.put(SSLHandshake.FINISHED.id,
	SSLHandshake.FINISHED);
	}

	// The handshake message has been delivered.
	return null;
	}

	private static KeyExchangeProperties chooseCipherSuite(
	ServerHandshakeContext shc,
	ClientHelloMessage clientHello) throws IOException {
	List<CipherSuite> preferred;
	List<CipherSuite> proposed;
	if (shc.sslConfig.preferLocalCipherSuites) {
	preferred = shc.activeCipherSuites;
	proposed = clientHello.cipherSuites;
	} else {
	preferred = clientHello.cipherSuites;
	proposed = shc.activeCipherSuites;
	}

	List<CipherSuite> legacySuites = new LinkedList<>();
	for (CipherSuite cs : preferred) {
	if (!HandshakeContext.isNegotiable(
	proposed, shc.negotiatedProtocol, cs)) {
	continue;
	}

	if (shc.sslConfig.clientAuthType ==
	ClientAuthType.CLIENT_AUTH_REQUIRED) {
	if ((cs.keyExchange == KeyExchange.K_DH_ANON) \|\|
	(cs.keyExchange == KeyExchange.K_ECDH_ANON)) {
	continue;
	}
	}

	SSLKeyExchange ke = SSLKeyExchange.valueOf(
	cs.keyExchange, shc.negotiatedProtocol);
	if (ke == null) {
	continue;
	}
	if (!ServerHandshakeContext.legacyAlgorithmConstraints.permits(
	null, cs.name, null)) {
	legacySuites.add(cs);
	continue;
	}

	SSLPossession[] hcds = ke.createPossessions(shc);
	if ((hcds == null) \|\| (hcds.length == 0)) {
	continue;
	}

	// The cipher suite has been negotiated.
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine("use cipher suite " + cs.name);
	}

	return new KeyExchangeProperties(cs, ke, hcds);
	}

	for (CipherSuite cs : legacySuites) {
	SSLKeyExchange ke = SSLKeyExchange.valueOf(
	cs.keyExchange, shc.negotiatedProtocol);
	if (ke != null) {
	SSLPossession[] hcds = ke.createPossessions(shc);
	if ((hcds != null) && (hcds.length != 0)) {
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.warning(
	"use legacy cipher suite " + cs.name);
	}
	return new KeyExchangeProperties(cs, ke, hcds);
	}
	}
	}

	shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
	"no cipher suites in common");

	return null; // make the compiler happy.
	}

	private static final class KeyExchangeProperties {
	final CipherSuite cipherSuite;
	final SSLKeyExchange keyExchange;
	final SSLPossession[] possessions;

	private KeyExchangeProperties(CipherSuite cipherSuite,
	SSLKeyExchange keyExchange, SSLPossession[] possessions) {
	this.cipherSuite = cipherSuite;
	this.keyExchange = keyExchange;
	this.possessions = possessions;
	}
	}
	}

	/**
	* The "ServerHello" handshake message producer.
	*/
	private static final
	class T13ServerHelloProducer implements HandshakeProducer {
	// Prevent instantiation of this class.
	private T13ServerHelloProducer() {
	// blank
	}

	@Override
	public byte[] produce(ConnectionContext context,
	HandshakeMessage message) throws IOException {
	// The producing happens in server side only.
	ServerHandshakeContext shc = (ServerHandshakeContext)context;
	ClientHelloMessage clientHello = (ClientHelloMessage)message;

	// If client hasn't specified a session we can resume, start a
	// new one and choose its cipher suite and compression options,
	// unless new session creation is disabled for this connection!
	if (!shc.isResumption \|\| shc.resumingSession == null) {
	if (!shc.sslConfig.enableSessionCreation) {
	throw new SSLException(
	"Not resumption, and no new session is allowed");
	}

	if (shc.localSupportedSignAlgs == null) {
	shc.localSupportedSignAlgs =
	SignatureScheme.getSupportedAlgorithms(
	shc.algorithmConstraints, shc.activeProtocols);
	}

	SSLSessionImpl session =
	new SSLSessionImpl(shc, CipherSuite.C_NULL);
	session.setMaximumPacketSize(shc.sslConfig.maximumPacketSize);
	shc.handshakeSession = session;

	// consider the handshake extension impact
	SSLExtension[] enabledExtensions =
	shc.sslConfig.getEnabledExtensions(
	SSLHandshake.CLIENT_HELLO, shc.negotiatedProtocol);
	clientHello.extensions.consumeOnTrade(shc, enabledExtensions);

	// negotiate the cipher suite.
	CipherSuite cipherSuite = chooseCipherSuite(shc, clientHello);
	if (cipherSuite == null) {
	shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
	"no cipher suites in common");
	return null; // make the compiler happy
	}
	shc.negotiatedCipherSuite = cipherSuite;
	shc.handshakeSession.setSuite(cipherSuite);
	shc.handshakeHash.determine(
	shc.negotiatedProtocol, shc.negotiatedCipherSuite);
	} else {
	shc.handshakeSession = shc.resumingSession;

	// consider the handshake extension impact
	SSLExtension[] enabledExtensions =
	shc.sslConfig.getEnabledExtensions(
	SSLHandshake.CLIENT_HELLO, shc.negotiatedProtocol);
	clientHello.extensions.consumeOnTrade(shc, enabledExtensions);

	shc.negotiatedProtocol =
	shc.resumingSession.getProtocolVersion();
	shc.negotiatedCipherSuite = shc.resumingSession.getSuite();
	shc.handshakeHash.determine(
	shc.negotiatedProtocol, shc.negotiatedCipherSuite);

	setUpPskKD(shc,
	shc.resumingSession.consumePreSharedKey().get());

	// The session can't be resumed again---remove it from cache
	SSLSessionContextImpl sessionCache = (SSLSessionContextImpl)
	shc.sslContext.engineGetServerSessionContext();
	sessionCache.remove(shc.resumingSession.getSessionId());
	}

	// update the responders
	shc.handshakeProducers.put(SSLHandshake.ENCRYPTED_EXTENSIONS.id,
	SSLHandshake.ENCRYPTED_EXTENSIONS);
	shc.handshakeProducers.put(SSLHandshake.FINISHED.id,
	SSLHandshake.FINISHED);

	// Generate the ServerHello handshake message.
	ServerHelloMessage shm = new ServerHelloMessage(shc,
	ProtocolVersion.TLS12, // use legacy version
	clientHello.sessionId, // echo back
	shc.negotiatedCipherSuite,
	new RandomCookie(shc),
	clientHello);
	shc.serverHelloRandom = shm.serverRandom;

	// Produce extensions for ServerHello handshake message.
	SSLExtension[] serverHelloExtensions =
	shc.sslConfig.getEnabledExtensions(
	SSLHandshake.SERVER_HELLO, shc.negotiatedProtocol);
	shm.extensions.produce(shc, serverHelloExtensions);
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine("Produced ServerHello handshake message", shm);
	}

	// Output the handshake message.
	shm.write(shc.handshakeOutput);
	shc.handshakeOutput.flush();

	// Change client/server handshake traffic secrets.
	// Refresh handshake hash
	shc.handshakeHash.update();

	// Change client/server handshake traffic secrets.
	SSLKeyExchange ke = shc.handshakeKeyExchange;
	if (ke == null) {
	// unlikely
	shc.conContext.fatal(Alert.INTERNAL_ERROR,
	"Not negotiated key shares");
	return null; // make the compiler happy
	}

	SSLKeyDerivation handshakeKD = ke.createKeyDerivation(shc);
	SecretKey handshakeSecret = handshakeKD.deriveKey(
	"TlsHandshakeSecret", null);

	SSLTrafficKeyDerivation kdg =
	SSLTrafficKeyDerivation.valueOf(shc.negotiatedProtocol);
	if (kdg == null) {
	// unlikely
	shc.conContext.fatal(Alert.INTERNAL_ERROR,
	"Not supported key derivation: " +
	shc.negotiatedProtocol);
	return null; // make the compiler happy
	}

	SSLKeyDerivation kd =
	new SSLSecretDerivation(shc, handshakeSecret);

	// update the handshake traffic read keys.
	SecretKey readSecret = kd.deriveKey(
	"TlsClientHandshakeTrafficSecret", null);
	SSLKeyDerivation readKD =
	kdg.createKeyDerivation(shc, readSecret);
	SecretKey readKey = readKD.deriveKey(
	"TlsKey", null);
	SecretKey readIvSecret = readKD.deriveKey(
	"TlsIv", null);
	IvParameterSpec readIv =
	new IvParameterSpec(readIvSecret.getEncoded());
	SSLReadCipher readCipher;
	try {
	readCipher =
	shc.negotiatedCipherSuite.bulkCipher.createReadCipher(
	Authenticator.valueOf(shc.negotiatedProtocol),
	shc.negotiatedProtocol, readKey, readIv,
	shc.sslContext.getSecureRandom());
	} catch (GeneralSecurityException gse) {
	// unlikely
	shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
	"Missing cipher algorithm", gse);
	return null; // make the compiler happy
	}

	shc.baseReadSecret = readSecret;
	shc.conContext.inputRecord.changeReadCiphers(readCipher);

	// update the handshake traffic write secret.
	SecretKey writeSecret = kd.deriveKey(
	"TlsServerHandshakeTrafficSecret", null);
	SSLKeyDerivation writeKD =
	kdg.createKeyDerivation(shc, writeSecret);
	SecretKey writeKey = writeKD.deriveKey(
	"TlsKey", null);
	SecretKey writeIvSecret = writeKD.deriveKey(
	"TlsIv", null);
	IvParameterSpec writeIv =
	new IvParameterSpec(writeIvSecret.getEncoded());
	SSLWriteCipher writeCipher;
	try {
	writeCipher =
	shc.negotiatedCipherSuite.bulkCipher.createWriteCipher(
	Authenticator.valueOf(shc.negotiatedProtocol),
	shc.negotiatedProtocol, writeKey, writeIv,
	shc.sslContext.getSecureRandom());
	} catch (GeneralSecurityException gse) {
	// unlikely
	shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
	"Missing cipher algorithm", gse);
	return null; // make the compiler happy
	}

	shc.baseWriteSecret = writeSecret;
	shc.conContext.outputRecord.changeWriteCiphers(
	writeCipher, (clientHello.sessionId.length() != 0));

	// Update the context for master key derivation.
	shc.handshakeKeyDerivation = kd;

	// The handshake message has been delivered.
	return null;
	}

	private static CipherSuite chooseCipherSuite(
	ServerHandshakeContext shc,
	ClientHelloMessage clientHello) throws IOException {
	List<CipherSuite> preferred;
	List<CipherSuite> proposed;
	if (shc.sslConfig.preferLocalCipherSuites) {
	preferred = shc.activeCipherSuites;
	proposed = clientHello.cipherSuites;
	} else {
	preferred = clientHello.cipherSuites;
	proposed = shc.activeCipherSuites;
	}

	CipherSuite legacySuite = null;
	AlgorithmConstraints legacyConstraints =
	ServerHandshakeContext.legacyAlgorithmConstraints;
	for (CipherSuite cs : preferred) {
	if (!HandshakeContext.isNegotiable(
	proposed, shc.negotiatedProtocol, cs)) {
	continue;
	}

	if ((legacySuite == null) &&
	!legacyConstraints.permits(null, cs.name, null)) {
	legacySuite = cs;
	continue;
	}

	// The cipher suite has been negotiated.
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine("use cipher suite " + cs.name);
	}
	return cs;
	}

	if (legacySuite != null) {
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.warning(
	"use legacy cipher suite " + legacySuite.name);
	}
	return legacySuite;
	}

	// no cipher suites in common
	return null;
	}
	}

	/**
	* The "HelloRetryRequest" handshake message producer.
	*/
	private static final
	class T13HelloRetryRequestProducer implements HandshakeProducer {
	// Prevent instantiation of this class.
	private T13HelloRetryRequestProducer() {
	// blank
	}

	@Override
	public byte[] produce(ConnectionContext context,
	HandshakeMessage message) throws IOException {
	ServerHandshakeContext shc = (ServerHandshakeContext) context;
	ClientHelloMessage clientHello = (ClientHelloMessage) message;

	// negotiate the cipher suite.
	CipherSuite cipherSuite =
	T13ServerHelloProducer.chooseCipherSuite(shc, clientHello);
	if (cipherSuite == null) {
	shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
	"no cipher suites in common for hello retry request");
	return null; // make the compiler happy
	}

	ServerHelloMessage hhrm = new ServerHelloMessage(shc,
	ProtocolVersion.TLS12, // use legacy version
	clientHello.sessionId, // echo back
	cipherSuite,
	RandomCookie.hrrRandom,
	clientHello
	);

	shc.negotiatedCipherSuite = cipherSuite;
	shc.handshakeHash.determine(
	shc.negotiatedProtocol, shc.negotiatedCipherSuite);

	// Produce extensions for HelloRetryRequest handshake message.
	SSLExtension[] serverHelloExtensions =
	shc.sslConfig.getEnabledExtensions(
	SSLHandshake.HELLO_RETRY_REQUEST, shc.negotiatedProtocol);
	hhrm.extensions.produce(shc, serverHelloExtensions);
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine(
	"Produced HelloRetryRequest handshake message", hhrm);
	}

	// Output the handshake message.
	hhrm.write(shc.handshakeOutput);
	shc.handshakeOutput.flush();

	// Stateless, shall we clean up the handshake context as well?
	shc.handshakeHash.finish(); // forgot about the handshake hash
	shc.handshakeExtensions.clear();

	// What's the expected response?
	shc.handshakeConsumers.put(
	SSLHandshake.CLIENT_HELLO.id, SSLHandshake.CLIENT_HELLO);

	// The handshake message has been delivered.
	return null;
	}
	}

	/**
	* The "HelloRetryRequest" handshake message reproducer.
	*/
	private static final
	class T13HelloRetryRequestReproducer implements HandshakeProducer {
	// Prevent instantiation of this class.
	private T13HelloRetryRequestReproducer() {
	// blank
	}

	@Override
	public byte[] produce(ConnectionContext context,
	HandshakeMessage message) throws IOException {
	ServerHandshakeContext shc = (ServerHandshakeContext) context;
	ClientHelloMessage clientHello = (ClientHelloMessage) message;

	// negotiate the cipher suite.
	CipherSuite cipherSuite = shc.negotiatedCipherSuite;
	ServerHelloMessage hhrm = new ServerHelloMessage(shc,
	ProtocolVersion.TLS12, // use legacy version
	clientHello.sessionId, // echo back
	cipherSuite,
	RandomCookie.hrrRandom,
	clientHello
	);

	// Produce extensions for HelloRetryRequest handshake message.
	SSLExtension[] serverHelloExtensions =
	shc.sslConfig.getEnabledExtensions(
	SSLHandshake.MESSAGE_HASH, shc.negotiatedProtocol);
	hhrm.extensions.produce(shc, serverHelloExtensions);
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine(
	"Reproduced HelloRetryRequest handshake message", hhrm);
	}

	HandshakeOutStream hos = new HandshakeOutStream(null);
	hhrm.write(hos);

	return hos.toByteArray();
	}
	}

	/**
	* The "ServerHello" handshake message consumer.
	*/
	private static final
	class ServerHelloConsumer implements SSLConsumer {
	// Prevent instantiation of this class.
	private ServerHelloConsumer() {
	// blank
	}

	@Override
	public void consume(ConnectionContext context,
	ByteBuffer message) throws IOException {
	// The consuming happens in client side only.
	ClientHandshakeContext chc = (ClientHandshakeContext)context;

	// clean up this consumer
	chc.handshakeConsumers.remove(SSLHandshake.SERVER_HELLO.id);
	if (!chc.handshakeConsumers.isEmpty()) {
	// DTLS 1.0/1.2
	chc.handshakeConsumers.remove(
	SSLHandshake.HELLO_VERIFY_REQUEST.id);
	}
	if (!chc.handshakeConsumers.isEmpty()) {
	chc.conContext.fatal(Alert.UNEXPECTED_MESSAGE,
	"No more message expected before ServerHello is processed");
	}

	ServerHelloMessage shm = new ServerHelloMessage(chc, message);
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine("Consuming ServerHello handshake message", shm);
	}

	if (shm.serverRandom.isHelloRetryRequest()) {
	onHelloRetryRequest(chc, shm);
	} else {
	onServerHello(chc, shm);
	}
	}

	private void onHelloRetryRequest(ClientHandshakeContext chc,
	ServerHelloMessage helloRetryRequest) throws IOException {
	// Negotiate protocol version.
	//
	// Check and launch SupportedVersions.
	SSLExtension[] extTypes = new SSLExtension[] {
	SSLExtension.HRR_SUPPORTED_VERSIONS
	};
	helloRetryRequest.extensions.consumeOnLoad(chc, extTypes);

	ProtocolVersion serverVersion;
	SHSupportedVersionsSpec svs =
	(SHSupportedVersionsSpec)chc.handshakeExtensions.get(
	SSLExtension.HRR_SUPPORTED_VERSIONS);
	if (svs != null) {
	serverVersion = // could be null
	ProtocolVersion.valueOf(svs.selectedVersion);
	} else {
	serverVersion = helloRetryRequest.serverVersion;
	}

	if (!chc.activeProtocols.contains(serverVersion)) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"The server selected protocol version " + serverVersion +
	" is not accepted by client preferences " +
	chc.activeProtocols);
	}

	if (!serverVersion.useTLS13PlusSpec()) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"Unexpected HelloRetryRequest for " + serverVersion.name);
	}

	chc.negotiatedProtocol = serverVersion;
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine(
	"Negotiated protocol version: " + serverVersion.name);
	}

	// TLS 1.3 key share extension may have produced client
	// possessions for TLS 1.3 key exchanges.
	//
	// Clean up before producing new client key share possessions.
	chc.handshakePossessions.clear();

	if (serverVersion.isDTLS) {
	d13HrrHandshakeConsumer.consume(chc, helloRetryRequest);
	} else {
	t13HrrHandshakeConsumer.consume(chc, helloRetryRequest);
	}
	}

	private void onServerHello(ClientHandshakeContext chc,
	ServerHelloMessage serverHello) throws IOException {
	// Negotiate protocol version.
	//
	// Check and launch SupportedVersions.
	SSLExtension[] extTypes = new SSLExtension[] {
	SSLExtension.SH_SUPPORTED_VERSIONS
	};
	serverHello.extensions.consumeOnLoad(chc, extTypes);

	ProtocolVersion serverVersion;
	SHSupportedVersionsSpec svs =
	(SHSupportedVersionsSpec)chc.handshakeExtensions.get(
	SSLExtension.SH_SUPPORTED_VERSIONS);
	if (svs != null) {
	serverVersion = // could be null
	ProtocolVersion.valueOf(svs.selectedVersion);
	} else {
	serverVersion = serverHello.serverVersion;
	}

	if (!chc.activeProtocols.contains(serverVersion)) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"The server selected protocol version " + serverVersion +
	" is not accepted by client preferences " +
	chc.activeProtocols);
	}

	chc.negotiatedProtocol = serverVersion;
	if (!chc.conContext.isNegotiated) {
	chc.conContext.protocolVersion = chc.negotiatedProtocol;
	chc.conContext.outputRecord.setVersion(chc.negotiatedProtocol);
	}
	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine(
	"Negotiated protocol version: " + serverVersion.name);
	}

	if (serverHello.serverRandom.isVersionDowngrade(chc)) {
	chc.conContext.fatal(Alert.ILLEGAL_PARAMETER,
	"A potential protocol version downgrade attack");
	}

	// Consume the handshake message for the specific protocol version.
	if (serverVersion.isDTLS) {
	if (serverVersion.useTLS13PlusSpec()) {
	d13HandshakeConsumer.consume(chc, serverHello);
	} else {
	// TLS 1.3 key share extension may have produced client
	// possessions for TLS 1.3 key exchanges.
	chc.handshakePossessions.clear();

	d12HandshakeConsumer.consume(chc, serverHello);
	}
	} else {
	if (serverVersion.useTLS13PlusSpec()) {
	t13HandshakeConsumer.consume(chc, serverHello);
	} else {
	// TLS 1.3 key share extension may have produced client
	// possessions for TLS 1.3 key exchanges.
	chc.handshakePossessions.clear();

	t12HandshakeConsumer.consume(chc, serverHello);
	}
	}
	}
	}

	private static final
	class T12ServerHelloConsumer implements HandshakeConsumer {
	// Prevent instantiation of this class.
	private T12ServerHelloConsumer() {
	// blank
	}

	@Override
	public void consume(ConnectionContext context,
	HandshakeMessage message) throws IOException {
	// The consuming happens in client side only.
	ClientHandshakeContext chc = (ClientHandshakeContext)context;
	ServerHelloMessage serverHello = (ServerHelloMessage)message;
	if (!chc.isNegotiable(serverHello.serverVersion)) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"Server chose " + serverHello.serverVersion +
	", but that protocol version is not enabled or " +
	"not supported by the client.");
	}

	// chc.negotiatedProtocol = serverHello.serverVersion;
	chc.negotiatedCipherSuite = serverHello.cipherSuite;
	chc.handshakeHash.determine(
	chc.negotiatedProtocol, chc.negotiatedCipherSuite);
	chc.serverHelloRandom = serverHello.serverRandom;
	if (chc.negotiatedCipherSuite.keyExchange == null) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"TLS 1.2 or prior version does not support the " +
	"server cipher suite: " + chc.negotiatedCipherSuite.name);
	}

	//
	// validate
	//

	// Check and launch the "renegotiation_info" extension.
	SSLExtension[] extTypes = new SSLExtension[] {
	SSLExtension.SH_RENEGOTIATION_INFO
	};
	serverHello.extensions.consumeOnLoad(chc, extTypes);

	// Is it session resuming?
	if (chc.resumingSession != null) {
	// we tried to resume, let's see what the server decided
	if (serverHello.sessionId.equals(
	chc.resumingSession.getSessionId())) {
	// server resumed the session, let's make sure everything
	// checks out

	// Verify that the session ciphers are unchanged.
	CipherSuite sessionSuite = chc.resumingSession.getSuite();
	if (chc.negotiatedCipherSuite != sessionSuite) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"Server returned wrong cipher suite for session");
	}

	// verify protocol version match
	ProtocolVersion sessionVersion =
	chc.resumingSession.getProtocolVersion();
	if (chc.negotiatedProtocol != sessionVersion) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"Server resumed with wrong protocol version");
	}

	// looks fine; resume it.
	chc.isResumption = true;
	chc.resumingSession.setAsSessionResumption(true);
	chc.handshakeSession = chc.resumingSession;
	} else {
	// we wanted to resume, but the server refused
	//
	// Invalidate the session for initial handshake in case
	// of reusing next time.
	if (chc.resumingSession != null) {
	chc.resumingSession.invalidate();
	chc.resumingSession = null;
	}
	chc.isResumption = false;
	if (!chc.sslConfig.enableSessionCreation) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"New session creation is disabled");
	}
	}
	}

	// Check and launch ClientHello extensions.
	extTypes = chc.sslConfig.getEnabledExtensions(
	SSLHandshake.SERVER_HELLO);
	serverHello.extensions.consumeOnLoad(chc, extTypes);

	if (!chc.isResumption) {
	if (chc.resumingSession != null) {
	// in case the resumption happens next time.
	chc.resumingSession.invalidate();
	chc.resumingSession = null;
	}

	if (!chc.sslConfig.enableSessionCreation) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"New session creation is disabled");
	}
	chc.handshakeSession = new SSLSessionImpl(chc,
	chc.negotiatedCipherSuite,
	serverHello.sessionId);
	chc.handshakeSession.setMaximumPacketSize(
	chc.sslConfig.maximumPacketSize);
	}

	//
	// update
	//
	serverHello.extensions.consumeOnTrade(chc, extTypes);

	// update the consumers and producers
	if (chc.isResumption) {
	SSLTrafficKeyDerivation kdg =
	SSLTrafficKeyDerivation.valueOf(chc.negotiatedProtocol);
	if (kdg == null) {
	// unlikely
	chc.conContext.fatal(Alert.INTERNAL_ERROR,
	"Not supported key derivation: " +
	chc.negotiatedProtocol);
	} else {
	chc.handshakeKeyDerivation = kdg.createKeyDerivation(
	chc, chc.resumingSession.getMasterSecret());
	}

	chc.conContext.consumers.putIfAbsent(
	ContentType.CHANGE_CIPHER_SPEC.id,
	ChangeCipherSpec.t10Consumer);
	chc.handshakeConsumers.put(
	SSLHandshake.FINISHED.id,
	SSLHandshake.FINISHED);
	} else {
	SSLKeyExchange ke = SSLKeyExchange.valueOf(
	chc.negotiatedCipherSuite.keyExchange,
	chc.negotiatedProtocol);
	chc.handshakeKeyExchange = ke;
	if (ke != null) {
	for (SSLHandshake handshake :
	ke.getRelatedHandshakers(chc)) {
	chc.handshakeConsumers.put(handshake.id, handshake);
	}
	}

	chc.handshakeConsumers.put(SSLHandshake.SERVER_HELLO_DONE.id,
	SSLHandshake.SERVER_HELLO_DONE);
	}

	//
	// produce
	//
	// Need no new handshake message producers here.
	}
	}

	private static void setUpPskKD(HandshakeContext hc,
	SecretKey psk) throws SSLHandshakeException {

	if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
	SSLLogger.fine("Using PSK to derive early secret");
	}

	try {
	CipherSuite.HashAlg hashAlg = hc.negotiatedCipherSuite.hashAlg;
	HKDF hkdf = new HKDF(hashAlg.name);
	byte[] zeros = new byte[hashAlg.hashLength];
	SecretKey earlySecret = hkdf.extract(zeros, psk, "TlsEarlySecret");
	hc.handshakeKeyDerivation =
	new SSLSecretDerivation(hc, earlySecret);
	} catch (GeneralSecurityException gse) {
	throw (SSLHandshakeException) new SSLHandshakeException(
	"Could not generate secret").initCause(gse);
	}
	}

	private static final
	class T13ServerHelloConsumer implements HandshakeConsumer {
	// Prevent instantiation of this class.
	private T13ServerHelloConsumer() {
	// blank
	}

	@Override
	public void consume(ConnectionContext context,
	HandshakeMessage message) throws IOException {
	// The consuming happens in client side only.
	ClientHandshakeContext chc = (ClientHandshakeContext)context;
	ServerHelloMessage serverHello = (ServerHelloMessage)message;
	if (serverHello.serverVersion != ProtocolVersion.TLS12) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"The ServerHello.legacy_version field is not TLS 1.2");
	}

	chc.negotiatedCipherSuite = serverHello.cipherSuite;
	chc.handshakeHash.determine(
	chc.negotiatedProtocol, chc.negotiatedCipherSuite);
	chc.serverHelloRandom = serverHello.serverRandom;

	//
	// validate
	//

	// Check and launch ServerHello extensions.
	SSLExtension[] extTypes = chc.sslConfig.getEnabledExtensions(
	SSLHandshake.SERVER_HELLO);
	serverHello.extensions.consumeOnLoad(chc, extTypes);
	if (!chc.isResumption) {
	if (chc.resumingSession != null) {
	// in case the resumption happens next time.
	chc.resumingSession.invalidate();
	chc.resumingSession = null;
	}

	if (!chc.sslConfig.enableSessionCreation) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"New session creation is disabled");
	}
	chc.handshakeSession = new SSLSessionImpl(chc,
	chc.negotiatedCipherSuite,
	serverHello.sessionId);
	chc.handshakeSession.setMaximumPacketSize(
	chc.sslConfig.maximumPacketSize);
	} else {
	// The PSK is consumed to allow it to be deleted
	Optional<SecretKey> psk =
	chc.resumingSession.consumePreSharedKey();
	if(!psk.isPresent()) {
	chc.conContext.fatal(Alert.INTERNAL_ERROR,
	"No PSK available. Unable to resume.");
	}

	chc.handshakeSession = chc.resumingSession;

	setUpPskKD(chc, psk.get());
	}

	//
	// update
	//
	serverHello.extensions.consumeOnTrade(chc, extTypes);

	// Change client/server handshake traffic secrets.
	// Refresh handshake hash
	chc.handshakeHash.update();

	SSLKeyExchange ke = chc.handshakeKeyExchange;
	if (ke == null) {
	// unlikely
	chc.conContext.fatal(Alert.INTERNAL_ERROR,
	"Not negotiated key shares");
	return; // make the compiler happy
	}

	SSLKeyDerivation handshakeKD = ke.createKeyDerivation(chc);
	SecretKey handshakeSecret = handshakeKD.deriveKey(
	"TlsHandshakeSecret", null);
	SSLTrafficKeyDerivation kdg =
	SSLTrafficKeyDerivation.valueOf(chc.negotiatedProtocol);
	if (kdg == null) {
	// unlikely
	chc.conContext.fatal(Alert.INTERNAL_ERROR,
	"Not supported key derivation: " +
	chc.negotiatedProtocol);
	return; // make the compiler happy
	}

	SSLKeyDerivation secretKD =
	new SSLSecretDerivation(chc, handshakeSecret);

	// update the handshake traffic read keys.
	SecretKey readSecret = secretKD.deriveKey(
	"TlsServerHandshakeTrafficSecret", null);

	SSLKeyDerivation readKD =
	kdg.createKeyDerivation(chc, readSecret);
	SecretKey readKey = readKD.deriveKey(
	"TlsKey", null);
	SecretKey readIvSecret = readKD.deriveKey(
	"TlsIv", null);
	IvParameterSpec readIv =
	new IvParameterSpec(readIvSecret.getEncoded());
	SSLReadCipher readCipher;
	try {
	readCipher =
	chc.negotiatedCipherSuite.bulkCipher.createReadCipher(
	Authenticator.valueOf(chc.negotiatedProtocol),
	chc.negotiatedProtocol, readKey, readIv,
	chc.sslContext.getSecureRandom());
	} catch (GeneralSecurityException gse) {
	// unlikely
	chc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
	"Missing cipher algorithm", gse);
	return; // make the compiler happy
	}

	chc.baseReadSecret = readSecret;
	chc.conContext.inputRecord.changeReadCiphers(readCipher);

	// update the handshake traffic write keys.
	SecretKey writeSecret = secretKD.deriveKey(
	"TlsClientHandshakeTrafficSecret", null);
	SSLKeyDerivation writeKD =
	kdg.createKeyDerivation(chc, writeSecret);
	SecretKey writeKey = writeKD.deriveKey(
	"TlsKey", null);
	SecretKey writeIvSecret = writeKD.deriveKey(
	"TlsIv", null);
	IvParameterSpec writeIv =
	new IvParameterSpec(writeIvSecret.getEncoded());
	SSLWriteCipher writeCipher;
	try {
	writeCipher =
	chc.negotiatedCipherSuite.bulkCipher.createWriteCipher(
	Authenticator.valueOf(chc.negotiatedProtocol),
	chc.negotiatedProtocol, writeKey, writeIv,
	chc.sslContext.getSecureRandom());
	} catch (GeneralSecurityException gse) {
	// unlikely
	chc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
	"Missing cipher algorithm", gse);
	return; // make the compiler happy
	}

	chc.baseWriteSecret = writeSecret;
	chc.conContext.outputRecord.changeWriteCiphers(
	writeCipher, (serverHello.sessionId.length() != 0));

	// Should use resumption_master_secret for TLS 1.3.
	// chc.handshakeSession.setMasterSecret(masterSecret);

	// Update the context for master key derivation.
	chc.handshakeKeyDerivation = secretKD;

	// update the consumers and producers
	//
	// The server sends a dummy change_cipher_spec record immediately
	// after its first handshake message. This may either be after a
	// ServerHello or a HelloRetryRequest.
	chc.conContext.consumers.putIfAbsent(
	ContentType.CHANGE_CIPHER_SPEC.id,
	ChangeCipherSpec.t13Consumer);

	chc.handshakeConsumers.put(
	SSLHandshake.ENCRYPTED_EXTENSIONS.id,
	SSLHandshake.ENCRYPTED_EXTENSIONS);

	// Support cert authentication only, when not PSK.
	chc.handshakeConsumers.put(
	SSLHandshake.CERTIFICATE_REQUEST.id,
	SSLHandshake.CERTIFICATE_REQUEST);
	chc.handshakeConsumers.put(
	SSLHandshake.CERTIFICATE.id,
	SSLHandshake.CERTIFICATE);
	chc.handshakeConsumers.put(
	SSLHandshake.CERTIFICATE_VERIFY.id,
	SSLHandshake.CERTIFICATE_VERIFY);

	chc.handshakeConsumers.put(
	SSLHandshake.FINISHED.id,
	SSLHandshake.FINISHED);

	//
	// produce
	//
	// Need no new handshake message producers here.
	}
	}

	private static final
	class T13HelloRetryRequestConsumer implements HandshakeConsumer {
	// Prevent instantiation of this class.
	private T13HelloRetryRequestConsumer() {
	// blank
	}

	@Override
	public void consume(ConnectionContext context,
	HandshakeMessage message) throws IOException {
	// The consuming happens in client side only.
	ClientHandshakeContext chc = (ClientHandshakeContext)context;
	ServerHelloMessage helloRetryRequest = (ServerHelloMessage)message;
	if (helloRetryRequest.serverVersion != ProtocolVersion.TLS12) {
	chc.conContext.fatal(Alert.PROTOCOL_VERSION,
	"The HelloRetryRequest.legacy_version is not TLS 1.2");
	}

	chc.negotiatedCipherSuite = helloRetryRequest.cipherSuite;

	//
	// validate
	//

	// Check and launch ClientHello extensions.
	SSLExtension[] extTypes = chc.sslConfig.getEnabledExtensions(
	SSLHandshake.HELLO_RETRY_REQUEST);
	helloRetryRequest.extensions.consumeOnLoad(chc, extTypes);

	//
	// update
	//
	helloRetryRequest.extensions.consumeOnTrade(chc, extTypes);

	// Change client/server handshake traffic secrets.
	// Refresh handshake hash
	chc.handshakeHash.finish(); // reset the handshake hash

	// calculate the transcript hash of the 1st ClientHello message
	HandshakeOutStream hos = new HandshakeOutStream(null);
	try {
	chc.initialClientHelloMsg.write(hos);
	} catch (IOException ioe) {
	// unlikely
	chc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
	"Failed to construct message hash", ioe);
	}
	chc.handshakeHash.deliver(hos.toByteArray());
	chc.handshakeHash.determine(
	chc.negotiatedProtocol, chc.negotiatedCipherSuite);
	byte[] clientHelloHash = chc.handshakeHash.digest();

	// calculate the message_hash
	//
	// Transcript-Hash(ClientHello1, HelloRetryRequest, ... Mn) =
	// Hash(message_hash \|\| /* Handshake type */
	// 00 00 Hash.length \|\| /* Handshake message length (bytes) */
	// Hash(ClientHello1) \|\| /* Hash of ClientHello1 */
	// HelloRetryRequest \|\| ... \|\| Mn)
	int hashLen = chc.negotiatedCipherSuite.hashAlg.hashLength;
	byte[] hashedClientHello = new byte[4 + hashLen];
	hashedClientHello[0] = SSLHandshake.MESSAGE_HASH.id;
	hashedClientHello[1] = (byte)0x00;
	hashedClientHello[2] = (byte)0x00;
	hashedClientHello[3] = (byte)(hashLen & 0xFF);
	System.arraycopy(clientHelloHash, 0,
	hashedClientHello, 4, hashLen);

	chc.handshakeHash.finish(); // reset the handshake hash
	chc.handshakeHash.deliver(hashedClientHello);

	int hrrBodyLen = helloRetryRequest.handshakeRecord.remaining();
	byte[] hrrMessage = new byte[4 + hrrBodyLen];
	hrrMessage[0] = SSLHandshake.HELLO_RETRY_REQUEST.id;
	hrrMessage[1] = (byte)((hrrBodyLen >> 16) & 0xFF);
	hrrMessage[2] = (byte)((hrrBodyLen >> 8) & 0xFF);
	hrrMessage[3] = (byte)(hrrBodyLen & 0xFF);

	ByteBuffer hrrBody = helloRetryRequest.handshakeRecord.duplicate();
	hrrBody.get(hrrMessage, 4, hrrBodyLen);

	chc.handshakeHash.receive(hrrMessage);

	// Update the initial ClientHello handshake message.
	chc.initialClientHelloMsg.extensions.reproduce(chc,
	new SSLExtension[] {
	SSLExtension.CH_COOKIE,
	SSLExtension.CH_KEY_SHARE,
	SSLExtension.CH_PRE_SHARED_KEY
	});

	//
	// produce response handshake message
	//
	SSLHandshake.CLIENT_HELLO.produce(context, helloRetryRequest);
	}
	}
	}

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