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	/*
	* 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.nio.ByteBuffer;
	import java.security.AccessController;
	import java.security.GeneralSecurityException;
	import java.security.InvalidAlgorithmParameterException;
	import java.security.InvalidKeyException;
	import java.security.Key;
	import java.security.PrivilegedAction;
	import java.security.SecureRandom;
	import java.security.Security;
	import java.security.spec.AlgorithmParameterSpec;
	import java.util.AbstractMap.SimpleImmutableEntry;
	import java.util.Arrays;
	import java.util.HashMap;
	import java.util.Map;
	import javax.crypto.BadPaddingException;
	import javax.crypto.Cipher;
	import javax.crypto.IllegalBlockSizeException;
	import javax.crypto.SecretKey;
	import javax.crypto.ShortBufferException;
	import javax.crypto.spec.GCMParameterSpec;
	import javax.crypto.spec.IvParameterSpec;
	import sun.security.ssl.Authenticator.MAC;
	import static sun.security.ssl.CipherType.*;
	import static sun.security.ssl.JsseJce.*;

	enum SSLCipher {
	// exportable ciphers
	@SuppressWarnings({"unchecked", "rawtypes"})
	B_NULL("NULL", NULL_CIPHER, 0, 0, 0, 0, true, true,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new NullReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_NONE
	),
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new NullReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_13
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new NullWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_NONE
	),
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new NullWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_13
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_RC4_40(CIPHER_RC4, STREAM_CIPHER, 5, 16, 0, 0, true, true,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new StreamReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new StreamWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_RC2_40("RC2", BLOCK_CIPHER, 5, 16, 8, 0, false, true,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new StreamReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new StreamWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_DES_40(CIPHER_DES, BLOCK_CIPHER, 5, 8, 8, 0, true, true,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T10BlockReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T10BlockWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	)
	})),

	// domestic strength ciphers
	@SuppressWarnings({"unchecked", "rawtypes"})
	B_RC4_128(CIPHER_RC4, STREAM_CIPHER, 16, 16, 0, 0, true, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new StreamReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_12
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new StreamWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_12
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_DES(CIPHER_DES, BLOCK_CIPHER, 8, 8, 8, 0, true, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T10BlockReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	),
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T11BlockReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_11
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T10BlockWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	),
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T11BlockWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_11
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_3DES(CIPHER_3DES, BLOCK_CIPHER, 24, 24, 8, 0, true, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T10BlockReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	),
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T11BlockReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_11_12
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T10BlockWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	),
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T11BlockWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_11_12
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_IDEA("IDEA", BLOCK_CIPHER, 16, 16, 8, 0, false, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	null,
	ProtocolVersion.PROTOCOLS_TO_12
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	null,
	ProtocolVersion.PROTOCOLS_TO_12
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_AES_128(CIPHER_AES, BLOCK_CIPHER, 16, 16, 16, 0, true, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T10BlockReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	),
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T11BlockReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_11_12
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T10BlockWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	),
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T11BlockWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_11_12
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_AES_256(CIPHER_AES, BLOCK_CIPHER, 32, 32, 16, 0, true, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T10BlockReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	),
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T11BlockReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_11_12
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T10BlockWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_TO_10
	),
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T11BlockWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_11_12
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_AES_128_GCM(CIPHER_AES_GCM, AEAD_CIPHER, 16, 16, 12, 4, true, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T12GcmReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_12
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T12GcmWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_12
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_AES_256_GCM(CIPHER_AES_GCM, AEAD_CIPHER, 32, 32, 12, 4, true, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T12GcmReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_12
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T12GcmWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_12
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_AES_128_GCM_IV(CIPHER_AES_GCM, AEAD_CIPHER, 16, 16, 12, 0, true, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T13GcmReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_13
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T13GcmWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_13
	)
	})),

	@SuppressWarnings({"unchecked", "rawtypes"})
	B_AES_256_GCM_IV(CIPHER_AES_GCM, AEAD_CIPHER, 32, 32, 12, 0, true, false,
	(Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<ReadCipherGenerator, ProtocolVersion[]>(
	new T13GcmReadCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_13
	)
	}),
	(Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[])(new Map.Entry[] {
	new SimpleImmutableEntry<WriteCipherGenerator, ProtocolVersion[]>(
	new T13GcmWriteCipherGenerator(),
	ProtocolVersion.PROTOCOLS_OF_13
	)
	}));

	// descriptive name including key size, e.g. AES/128
	final String description;

	// JCE cipher transformation string, e.g. AES/CBC/NoPadding
	final String transformation;

	// algorithm name, e.g. AES
	final String algorithm;

	// supported and compile time enabled. Also see isAvailable()
	final boolean allowed;

	// number of bytes of entropy in the key
	final int keySize;

	// length of the actual cipher key in bytes.
	// for non-exportable ciphers, this is the same as keySize
	final int expandedKeySize;

	// size of the IV
	final int ivSize;

	// size of fixed IV
	//
	// record_iv_length = ivSize - fixedIvSize
	final int fixedIvSize;

	// exportable under 512/40 bit rules
	final boolean exportable;

	// Is the cipher algorithm of Cipher Block Chaining (CBC) mode?
	final CipherType cipherType;

	// size of the authentication tag, only applicable to cipher suites in
	// Galois Counter Mode (GCM)
	//
	// As far as we know, all supported GCM cipher suites use 128-bits
	// authentication tags.
	final int tagSize = 16;

	// runtime availability
	private final boolean isAvailable;

	private final Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[] readCipherGenerators;
	private final Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[] writeCipherGenerators;

	// Map of Ciphers listed in jdk.tls.keyLimits
	private static final HashMap<String, Long> cipherLimits = new HashMap<>();

	// Keywords found on the jdk.tls.keyLimits security property.
	final static String tag[] = {"KEYUPDATE"};

	static {
	final long max = 4611686018427387904L; // 2^62
	String prop = AccessController.doPrivileged(
	new PrivilegedAction<String>() {
	@Override
	public String run() {
	return Security.getProperty("jdk.tls.keyLimits");
	}
	});

	if (prop != null) {
	String propvalue[] = prop.split(",");

	for (String entry : propvalue) {
	int index;
	// If this is not a UsageLimit, goto to next entry.
	String values[] = entry.trim().toUpperCase().split(" ");

	if (values[1].contains(tag[0])) {
	index = 0;
	} else {
	if (SSLLogger.isOn && SSLLogger.isOn("ssl")) {
	SSLLogger.fine("jdk.tls.keyLimits: Unknown action: " +
	entry);
	}
	continue;
	}

	long size;
	int i = values[2].indexOf("^");
	try {
	if (i >= 0) {
	size = (long) Math.pow(2,
	Integer.parseInt(values[2].substring(i + 1)));
	} else {
	size = Long.parseLong(values[2]);
	}
	if (size < 1 \|\| size > max) {
	throw new NumberFormatException(
	"Length exceeded limits");
	}
	} catch (NumberFormatException e) {
	if (SSLLogger.isOn && SSLLogger.isOn("ssl")) {
	SSLLogger.fine("jdk.tls.keyLimits: " + e.getMessage() +
	": " + entry);
	}
	continue;
	}
	if (SSLLogger.isOn && SSLLogger.isOn("ssl")) {
	SSLLogger.fine("jdk.tls.keyLimits: entry = " + entry +
	". " + values[0] + ":" + tag[index] + " = " + size);
	}
	cipherLimits.put(values[0] + ":" + tag[index], size);
	}
	}
	}

	private SSLCipher(String transformation,
	CipherType cipherType, int keySize,
	int expandedKeySize, int ivSize,
	int fixedIvSize, boolean allowed, boolean exportable,
	Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]>[] readCipherGenerators,
	Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]>[] writeCipherGenerators) {
	this.transformation = transformation;
	String[] splits = transformation.split("/");
	this.algorithm = splits[0];
	this.cipherType = cipherType;
	this.description = this.algorithm + "/" + (keySize << 3);
	this.keySize = keySize;
	this.ivSize = ivSize;
	this.fixedIvSize = fixedIvSize;
	this.allowed = allowed;

	this.expandedKeySize = expandedKeySize;
	this.exportable = exportable;

	// availability of this bulk cipher
	//
	// We assume all supported ciphers are always available since they are
	// shipped with the SunJCE provider. However, AES/256 is unavailable
	// when the default JCE policy jurisdiction files are installed because
	// of key length restrictions.
	this.isAvailable = allowed && isUnlimited(keySize, transformation);

	this.readCipherGenerators = readCipherGenerators;
	this.writeCipherGenerators = writeCipherGenerators;
	}

	SSLReadCipher createReadCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion,
	SecretKey key, IvParameterSpec iv,
	SecureRandom random) throws GeneralSecurityException {
	if (readCipherGenerators.length == 0) {
	return null;
	}

	ReadCipherGenerator rcg = null;
	for (Map.Entry<ReadCipherGenerator,
	ProtocolVersion[]> me : readCipherGenerators) {
	for (ProtocolVersion pv : me.getValue()) {
	if (protocolVersion == pv) {
	rcg = me.getKey();
	}
	}
	}

	if (rcg != null) {
	return rcg.createCipher(this, authenticator,
	protocolVersion, transformation, key, iv, random);
	}
	return null;
	}

	SSLWriteCipher createWriteCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion,
	SecretKey key, IvParameterSpec iv,
	SecureRandom random) throws GeneralSecurityException {
	if (readCipherGenerators.length == 0) {
	return null;
	}

	WriteCipherGenerator rcg = null;
	for (Map.Entry<WriteCipherGenerator,
	ProtocolVersion[]> me : writeCipherGenerators) {
	for (ProtocolVersion pv : me.getValue()) {
	if (protocolVersion == pv) {
	rcg = me.getKey();
	}
	}
	}

	if (rcg != null) {
	return rcg.createCipher(this, authenticator,
	protocolVersion, transformation, key, iv, random);
	}
	return null;
	}

	/**
	* Test if this bulk cipher is available. For use by CipherSuite.
	*/
	boolean isAvailable() {
	return this.isAvailable;
	}

	private static boolean isUnlimited(int keySize, String transformation) {
	int keySizeInBits = keySize * 8;
	if (keySizeInBits > 128) { // need the JCE unlimited
	// strength jurisdiction policy
	try {
	if (Cipher.getMaxAllowedKeyLength(
	transformation) < keySizeInBits) {
	return false;
	}
	} catch (Exception e) {
	return false;
	}
	}

	return true;
	}

	@Override
	public String toString() {
	return description;
	}

	interface ReadCipherGenerator {
	SSLReadCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException;
	}

	abstract static class SSLReadCipher {
	final Authenticator authenticator;
	final ProtocolVersion protocolVersion;
	boolean keyLimitEnabled = false;
	long keyLimitCountdown = 0;
	SecretKey baseSecret;

	SSLReadCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion) {
	this.authenticator = authenticator;
	this.protocolVersion = protocolVersion;
	}

	static final SSLReadCipher nullTlsReadCipher() {
	try {
	return B_NULL.createReadCipher(
	Authenticator.nullTlsMac(),
	ProtocolVersion.NONE, null, null, null);
	} catch (GeneralSecurityException gse) {
	// unlikely
	throw new RuntimeException("Cannot create NULL SSLCipher", gse);
	}
	}

	static final SSLReadCipher nullDTlsReadCipher() {
	try {
	return B_NULL.createReadCipher(
	Authenticator.nullDtlsMac(),
	ProtocolVersion.NONE, null, null, null);
	} catch (GeneralSecurityException gse) {
	// unlikely
	throw new RuntimeException("Cannot create NULL SSLCipher", gse);
	}
	}

	abstract Plaintext decrypt(byte contentType, ByteBuffer bb,
	byte[] sequence) throws GeneralSecurityException;

	void dispose() {
	// blank
	}

	abstract int estimateFragmentSize(int packetSize, int headerSize);

	boolean isNullCipher() {
	return false;
	}

	/**
	* Check if processed bytes have reached the key usage limit.
	* If key usage limit is not be monitored, return false.
	*/
	public boolean atKeyLimit() {
	if (keyLimitCountdown >= 0) {
	return false;
	}

	// Turn off limit checking as KeyUpdate will be occurring
	keyLimitEnabled = false;
	return true;
	}
	}

	interface WriteCipherGenerator {
	SSLWriteCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException;
	}

	abstract static class SSLWriteCipher {
	final Authenticator authenticator;
	final ProtocolVersion protocolVersion;
	boolean keyLimitEnabled = false;
	long keyLimitCountdown = 0;
	SecretKey baseSecret;

	SSLWriteCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion) {
	this.authenticator = authenticator;
	this.protocolVersion = protocolVersion;
	}

	abstract int encrypt(byte contentType, ByteBuffer bb);

	static final SSLWriteCipher nullTlsWriteCipher() {
	try {
	return B_NULL.createWriteCipher(
	Authenticator.nullTlsMac(),
	ProtocolVersion.NONE, null, null, null);
	} catch (GeneralSecurityException gse) {
	// unlikely
	throw new RuntimeException(
	"Cannot create NULL SSL write Cipher", gse);
	}
	}

	static final SSLWriteCipher nullDTlsWriteCipher() {
	try {
	return B_NULL.createWriteCipher(
	Authenticator.nullDtlsMac(),
	ProtocolVersion.NONE, null, null, null);
	} catch (GeneralSecurityException gse) {
	// unlikely
	throw new RuntimeException(
	"Cannot create NULL SSL write Cipher", gse);
	}
	}

	void dispose() {
	// blank
	}

	abstract int getExplicitNonceSize();
	abstract int calculateFragmentSize(int packetLimit, int headerSize);
	abstract int calculatePacketSize(int fragmentSize, int headerSize);

	boolean isCBCMode() {
	return false;
	}

	boolean isNullCipher() {
	return false;
	}

	/**
	* Check if processed bytes have reached the key usage limit.
	* If key usage limit is not be monitored, return false.
	*/
	public boolean atKeyLimit() {
	if (keyLimitCountdown >= 0) {
	return false;
	}

	// Turn off limit checking as KeyUpdate will be occurring
	keyLimitEnabled = false;
	return true;
	}
	}

	private static final
	class NullReadCipherGenerator implements ReadCipherGenerator {
	@Override
	public SSLReadCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new NullReadCipher(authenticator, protocolVersion);
	}

	static final class NullReadCipher extends SSLReadCipher {
	NullReadCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion) {
	super(authenticator, protocolVersion);
	}

	@Override
	public Plaintext decrypt(byte contentType, ByteBuffer bb,
	byte[] sequence) throws GeneralSecurityException {
	MAC signer = (MAC)authenticator;
	if (signer.macAlg().size != 0) {
	checkStreamMac(signer, bb, contentType, sequence);
	} else {
	authenticator.increaseSequenceNumber();
	}

	return new Plaintext(contentType,
	ProtocolVersion.NONE.major, ProtocolVersion.NONE.minor,
	-1, -1L, bb.slice());
	}

	@Override
	int estimateFragmentSize(int packetSize, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	return packetSize - headerSize - macLen;
	}

	@Override
	boolean isNullCipher() {
	return true;
	}
	}
	}

	private static final
	class NullWriteCipherGenerator implements WriteCipherGenerator {
	@Override
	public SSLWriteCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new NullWriteCipher(authenticator, protocolVersion);
	}

	static final class NullWriteCipher extends SSLWriteCipher {
	NullWriteCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion) {
	super(authenticator, protocolVersion);
	}

	@Override
	public int encrypt(byte contentType, ByteBuffer bb) {
	// add message authentication code
	MAC signer = (MAC)authenticator;
	if (signer.macAlg().size != 0) {
	addMac(signer, bb, contentType);
	} else {
	authenticator.increaseSequenceNumber();
	}

	int len = bb.remaining();
	bb.position(bb.limit());
	return len;
	}


	@Override
	int getExplicitNonceSize() {
	return 0;
	}

	@Override
	int calculateFragmentSize(int packetLimit, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	return packetLimit - headerSize - macLen;
	}

	@Override
	int calculatePacketSize(int fragmentSize, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	return fragmentSize + headerSize + macLen;
	}

	@Override
	boolean isNullCipher() {
	return true;
	}
	}
	}

	private static final
	class StreamReadCipherGenerator implements ReadCipherGenerator {
	@Override
	public SSLReadCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new StreamReadCipher(authenticator, protocolVersion,
	algorithm, key, params, random);
	}

	static final class StreamReadCipher extends SSLReadCipher {
	private final Cipher cipher;

	StreamReadCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	cipher.init(Cipher.DECRYPT_MODE, key, params, random);
	}

	@Override
	public Plaintext decrypt(byte contentType, ByteBuffer bb,
	byte[] sequence) throws GeneralSecurityException {
	int len = bb.remaining();
	int pos = bb.position();
	ByteBuffer dup = bb.duplicate();
	try {
	if (len != cipher.update(dup, bb)) {
	// catch BouncyCastle buffering error
	throw new RuntimeException(
	"Unexpected number of plaintext bytes");
	}
	if (bb.position() != dup.position()) {
	throw new RuntimeException(
	"Unexpected ByteBuffer position");
	}
	} catch (ShortBufferException sbe) {
	// catch BouncyCastle buffering error
	throw new RuntimeException("Cipher buffering error in " +
	"JCE provider " + cipher.getProvider().getName(), sbe);
	}
	bb.position(pos);
	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.fine(
	"Plaintext after DECRYPTION", bb.duplicate());
	}

	MAC signer = (MAC)authenticator;
	if (signer.macAlg().size != 0) {
	checkStreamMac(signer, bb, contentType, sequence);
	} else {
	authenticator.increaseSequenceNumber();
	}

	return new Plaintext(contentType,
	ProtocolVersion.NONE.major, ProtocolVersion.NONE.minor,
	-1, -1L, bb.slice());
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int estimateFragmentSize(int packetSize, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	return packetSize - headerSize - macLen;
	}
	}
	}

	private static final
	class StreamWriteCipherGenerator implements WriteCipherGenerator {
	@Override
	public SSLWriteCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new StreamWriteCipher(authenticator,
	protocolVersion, algorithm, key, params, random);
	}

	static final class StreamWriteCipher extends SSLWriteCipher {
	private final Cipher cipher;

	StreamWriteCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	cipher.init(Cipher.ENCRYPT_MODE, key, params, random);
	}

	@Override
	public int encrypt(byte contentType, ByteBuffer bb) {
	// add message authentication code
	MAC signer = (MAC)authenticator;
	if (signer.macAlg().size != 0) {
	addMac(signer, bb, contentType);
	} else {
	authenticator.increaseSequenceNumber();
	}

	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.finest(
	"Padded plaintext before ENCRYPTION", bb.duplicate());
	}

	int len = bb.remaining();
	ByteBuffer dup = bb.duplicate();
	try {
	if (len != cipher.update(dup, bb)) {
	// catch BouncyCastle buffering error
	throw new RuntimeException(
	"Unexpected number of plaintext bytes");
	}
	if (bb.position() != dup.position()) {
	throw new RuntimeException(
	"Unexpected ByteBuffer position");
	}
	} catch (ShortBufferException sbe) {
	// catch BouncyCastle buffering error
	throw new RuntimeException("Cipher buffering error in " +
	"JCE provider " + cipher.getProvider().getName(), sbe);
	}

	return len;
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int getExplicitNonceSize() {
	return 0;
	}

	@Override
	int calculateFragmentSize(int packetLimit, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	return packetLimit - headerSize - macLen;
	}

	@Override
	int calculatePacketSize(int fragmentSize, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	return fragmentSize + headerSize + macLen;
	}
	}
	}

	private static final
	class T10BlockReadCipherGenerator implements ReadCipherGenerator {
	@Override
	public SSLReadCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new BlockReadCipher(authenticator,
	protocolVersion, algorithm, key, params, random);
	}

	static final class BlockReadCipher extends SSLReadCipher {
	private final Cipher cipher;

	BlockReadCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	cipher.init(Cipher.DECRYPT_MODE, key, params, random);
	}

	@Override
	public Plaintext decrypt(byte contentType, ByteBuffer bb,
	byte[] sequence) throws GeneralSecurityException {
	BadPaddingException reservedBPE = null;

	// sanity check length of the ciphertext
	MAC signer = (MAC)authenticator;
	int cipheredLength = bb.remaining();
	int tagLen = signer.macAlg().size;
	if (tagLen != 0) {
	if (!sanityCheck(tagLen, bb.remaining())) {
	reservedBPE = new BadPaddingException(
	"ciphertext sanity check failed");
	}
	}
	// decryption
	int len = bb.remaining();
	int pos = bb.position();
	ByteBuffer dup = bb.duplicate();
	try {
	if (len != cipher.update(dup, bb)) {
	// catch BouncyCastle buffering error
	throw new RuntimeException(
	"Unexpected number of plaintext bytes");
	}

	if (bb.position() != dup.position()) {
	throw new RuntimeException(
	"Unexpected ByteBuffer position");
	}
	} catch (ShortBufferException sbe) {
	// catch BouncyCastle buffering error
	throw new RuntimeException("Cipher buffering error in " +
	"JCE provider " + cipher.getProvider().getName(), sbe);
	}

	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.fine(
	"Padded plaintext after DECRYPTION",
	bb.duplicate().position(pos));
	}

	// remove the block padding
	int blockSize = cipher.getBlockSize();
	bb.position(pos);
	try {
	removePadding(bb, tagLen, blockSize, protocolVersion);
	} catch (BadPaddingException bpe) {
	if (reservedBPE == null) {
	reservedBPE = bpe;
	}
	}

	// Requires message authentication code for null, stream and
	// block cipher suites.
	try {
	if (tagLen != 0) {
	checkCBCMac(signer, bb,
	contentType, cipheredLength, sequence);
	} else {
	authenticator.increaseSequenceNumber();
	}
	} catch (BadPaddingException bpe) {
	if (reservedBPE == null) {
	reservedBPE = bpe;
	}
	}

	// Is it a failover?
	if (reservedBPE != null) {
	throw reservedBPE;
	}

	return new Plaintext(contentType,
	ProtocolVersion.NONE.major, ProtocolVersion.NONE.minor,
	-1, -1L, bb.slice());
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int estimateFragmentSize(int packetSize, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;

	// No padding for a maximum fragment.
	//
	// 1 byte padding length field: 0x00
	return packetSize - headerSize - macLen - 1;
	}

	/**
	* Sanity check the length of a fragment before decryption.
	*
	* In CBC mode, check that the fragment length is one or multiple
	* times of the block size of the cipher suite, and is at least
	* one (one is the smallest size of padding in CBC mode) bigger
	* than the tag size of the MAC algorithm except the explicit IV
	* size for TLS 1.1 or later.
	*
	* In non-CBC mode, check that the fragment length is not less than
	* the tag size of the MAC algorithm.
	*
	* @return true if the length of a fragment matches above
	* requirements
	*/
	private boolean sanityCheck(int tagLen, int fragmentLen) {
	int blockSize = cipher.getBlockSize();
	if ((fragmentLen % blockSize) == 0) {
	int minimal = tagLen + 1;
	minimal = (minimal >= blockSize) ? minimal : blockSize;

	return (fragmentLen >= minimal);
	}

	return false;
	}
	}
	}

	private static final
	class T10BlockWriteCipherGenerator implements WriteCipherGenerator {
	@Override
	public SSLWriteCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new BlockWriteCipher(authenticator,
	protocolVersion, algorithm, key, params, random);
	}

	static final class BlockWriteCipher extends SSLWriteCipher {
	private final Cipher cipher;

	BlockWriteCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	cipher.init(Cipher.ENCRYPT_MODE, key, params, random);
	}

	@Override
	public int encrypt(byte contentType, ByteBuffer bb) {
	int pos = bb.position();

	// add message authentication code
	MAC signer = (MAC)authenticator;
	if (signer.macAlg().size != 0) {
	addMac(signer, bb, contentType);
	} else {
	authenticator.increaseSequenceNumber();
	}

	int blockSize = cipher.getBlockSize();
	int len = addPadding(bb, blockSize);
	bb.position(pos);

	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.fine(
	"Padded plaintext before ENCRYPTION",
	bb.duplicate());
	}

	ByteBuffer dup = bb.duplicate();
	try {
	if (len != cipher.update(dup, bb)) {
	// catch BouncyCastle buffering error
	throw new RuntimeException(
	"Unexpected number of plaintext bytes");
	}

	if (bb.position() != dup.position()) {
	throw new RuntimeException(
	"Unexpected ByteBuffer position");
	}
	} catch (ShortBufferException sbe) {
	// catch BouncyCastle buffering error
	throw new RuntimeException("Cipher buffering error in " +
	"JCE provider " + cipher.getProvider().getName(), sbe);
	}

	return len;
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int getExplicitNonceSize() {
	return 0;
	}

	@Override
	int calculateFragmentSize(int packetLimit, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	int blockSize = cipher.getBlockSize();
	int fragLen = packetLimit - headerSize;
	fragLen -= (fragLen % blockSize); // cannot hold a block
	// No padding for a maximum fragment.
	fragLen -= 1; // 1 byte padding length field: 0x00
	fragLen -= macLen;
	return fragLen;
	}

	@Override
	int calculatePacketSize(int fragmentSize, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	int blockSize = cipher.getBlockSize();
	int paddedLen = fragmentSize + macLen + 1;
	if ((paddedLen % blockSize) != 0) {
	paddedLen += blockSize - 1;
	paddedLen -= paddedLen % blockSize;
	}

	return headerSize + paddedLen;
	}

	@Override
	boolean isCBCMode() {
	return true;
	}
	}
	}

	// For TLS 1.1 and 1.2
	private static final
	class T11BlockReadCipherGenerator implements ReadCipherGenerator {
	@Override
	public SSLReadCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator, ProtocolVersion protocolVersion,
	String algorithm, Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new BlockReadCipher(authenticator, protocolVersion,
	sslCipher, algorithm, key, params, random);
	}

	static final class BlockReadCipher extends SSLReadCipher {
	private final Cipher cipher;

	BlockReadCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion,
	SSLCipher sslCipher, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	if (params == null) {
	params = new IvParameterSpec(new byte[sslCipher.ivSize]);
	}
	cipher.init(Cipher.DECRYPT_MODE, key, params, random);
	}

	@Override
	public Plaintext decrypt(byte contentType, ByteBuffer bb,
	byte[] sequence) throws GeneralSecurityException {
	BadPaddingException reservedBPE = null;

	// sanity check length of the ciphertext
	MAC signer = (MAC)authenticator;
	int cipheredLength = bb.remaining();
	int tagLen = signer.macAlg().size;
	if (tagLen != 0) {
	if (!sanityCheck(tagLen, bb.remaining())) {
	reservedBPE = new BadPaddingException(
	"ciphertext sanity check failed");
	}
	}

	// decryption
	int len = bb.remaining();
	int pos = bb.position();
	ByteBuffer dup = bb.duplicate();
	try {
	if (len != cipher.update(dup, bb)) {
	// catch BouncyCastle buffering error
	throw new RuntimeException(
	"Unexpected number of plaintext bytes");
	}

	if (bb.position() != dup.position()) {
	throw new RuntimeException(
	"Unexpected ByteBuffer position");
	}
	} catch (ShortBufferException sbe) {
	// catch BouncyCastle buffering error
	throw new RuntimeException("Cipher buffering error in " +
	"JCE provider " + cipher.getProvider().getName(), sbe);
	}

	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.fine(
	"Padded plaintext after DECRYPTION",
	bb.duplicate().position(pos));
	}

	// Ignore the explicit nonce.
	bb.position(pos + cipher.getBlockSize());
	pos = bb.position();

	// remove the block padding
	int blockSize = cipher.getBlockSize();
	bb.position(pos);
	try {
	removePadding(bb, tagLen, blockSize, protocolVersion);
	} catch (BadPaddingException bpe) {
	if (reservedBPE == null) {
	reservedBPE = bpe;
	}
	}

	// Requires message authentication code for null, stream and
	// block cipher suites.
	try {
	if (tagLen != 0) {
	checkCBCMac(signer, bb,
	contentType, cipheredLength, sequence);
	} else {
	authenticator.increaseSequenceNumber();
	}
	} catch (BadPaddingException bpe) {
	if (reservedBPE == null) {
	reservedBPE = bpe;
	}
	}

	// Is it a failover?
	if (reservedBPE != null) {
	throw reservedBPE;
	}

	return new Plaintext(contentType,
	ProtocolVersion.NONE.major, ProtocolVersion.NONE.minor,
	-1, -1L, bb.slice());
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int estimateFragmentSize(int packetSize, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;

	// No padding for a maximum fragment.
	//
	// 1 byte padding length field: 0x00
	int nonceSize = cipher.getBlockSize();
	return packetSize - headerSize - nonceSize - macLen - 1;
	}

	/**
	* Sanity check the length of a fragment before decryption.
	*
	* In CBC mode, check that the fragment length is one or multiple
	* times of the block size of the cipher suite, and is at least
	* one (one is the smallest size of padding in CBC mode) bigger
	* than the tag size of the MAC algorithm except the explicit IV
	* size for TLS 1.1 or later.
	*
	* In non-CBC mode, check that the fragment length is not less than
	* the tag size of the MAC algorithm.
	*
	* @return true if the length of a fragment matches above
	* requirements
	*/
	private boolean sanityCheck(int tagLen, int fragmentLen) {
	int blockSize = cipher.getBlockSize();
	if ((fragmentLen % blockSize) == 0) {
	int minimal = tagLen + 1;
	minimal = (minimal >= blockSize) ? minimal : blockSize;
	minimal += blockSize;

	return (fragmentLen >= minimal);
	}

	return false;
	}
	}
	}

	// For TLS 1.1 and 1.2
	private static final
	class T11BlockWriteCipherGenerator implements WriteCipherGenerator {
	@Override
	public SSLWriteCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator, ProtocolVersion protocolVersion,
	String algorithm, Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new BlockWriteCipher(authenticator, protocolVersion,
	sslCipher, algorithm, key, params, random);
	}

	static final class BlockWriteCipher extends SSLWriteCipher {
	private final Cipher cipher;
	private final SecureRandom random;

	BlockWriteCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion,
	SSLCipher sslCipher, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	this.random = random;
	if (params == null) {
	params = new IvParameterSpec(new byte[sslCipher.ivSize]);
	}
	cipher.init(Cipher.ENCRYPT_MODE, key, params, random);
	}

	@Override
	public int encrypt(byte contentType, ByteBuffer bb) {
	// To be unique and aware of overflow-wrap, sequence number
	// is used as the nonce_explicit of block cipher suites.
	int pos = bb.position();

	// add message authentication code
	MAC signer = (MAC)authenticator;
	if (signer.macAlg().size != 0) {
	addMac(signer, bb, contentType);
	} else {
	authenticator.increaseSequenceNumber();
	}

	// DON'T WORRY, the nonce spaces are considered already.
	byte[] nonce = new byte[cipher.getBlockSize()];
	random.nextBytes(nonce);
	pos = pos - nonce.length;
	bb.position(pos);
	bb.put(nonce);
	bb.position(pos);

	int blockSize = cipher.getBlockSize();
	int len = addPadding(bb, blockSize);
	bb.position(pos);

	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.fine(
	"Padded plaintext before ENCRYPTION",
	bb.duplicate());
	}

	ByteBuffer dup = bb.duplicate();
	try {
	if (len != cipher.update(dup, bb)) {
	// catch BouncyCastle buffering error
	throw new RuntimeException(
	"Unexpected number of plaintext bytes");
	}

	if (bb.position() != dup.position()) {
	throw new RuntimeException(
	"Unexpected ByteBuffer position");
	}
	} catch (ShortBufferException sbe) {
	// catch BouncyCastle buffering error
	throw new RuntimeException("Cipher buffering error in " +
	"JCE provider " + cipher.getProvider().getName(), sbe);
	}

	return len;
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int getExplicitNonceSize() {
	return cipher.getBlockSize();
	}

	@Override
	int calculateFragmentSize(int packetLimit, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	int blockSize = cipher.getBlockSize();
	int fragLen = packetLimit - headerSize - blockSize;
	fragLen -= (fragLen % blockSize); // cannot hold a block
	// No padding for a maximum fragment.
	fragLen -= 1; // 1 byte padding length field: 0x00
	fragLen -= macLen;
	return fragLen;
	}

	@Override
	int calculatePacketSize(int fragmentSize, int headerSize) {
	int macLen = ((MAC)authenticator).macAlg().size;
	int blockSize = cipher.getBlockSize();
	int paddedLen = fragmentSize + macLen + 1;
	if ((paddedLen % blockSize) != 0) {
	paddedLen += blockSize - 1;
	paddedLen -= paddedLen % blockSize;
	}

	return headerSize + blockSize + paddedLen;
	}

	@Override
	boolean isCBCMode() {
	return true;
	}
	}
	}

	private static final
	class T12GcmReadCipherGenerator implements ReadCipherGenerator {
	@Override
	public SSLReadCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new GcmReadCipher(authenticator, protocolVersion, sslCipher,
	algorithm, key, params, random);
	}

	static final class GcmReadCipher extends SSLReadCipher {
	private final Cipher cipher;
	private final int tagSize;
	private final Key key;
	private final byte[] fixedIv;
	private final int recordIvSize;
	private final SecureRandom random;

	GcmReadCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion,
	SSLCipher sslCipher, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	this.tagSize = sslCipher.tagSize;
	this.key = key;
	this.fixedIv = ((IvParameterSpec)params).getIV();
	this.recordIvSize = sslCipher.ivSize - sslCipher.fixedIvSize;
	this.random = random;

	// DON'T initialize the cipher for AEAD!
	}

	@Override
	public Plaintext decrypt(byte contentType, ByteBuffer bb,
	byte[] sequence) throws GeneralSecurityException {
	if (bb.remaining() < (recordIvSize + tagSize)) {
	throw new BadPaddingException(
	"Insufficient buffer remaining for AEAD cipher " +
	"fragment (" + bb.remaining() + "). Needs to be " +
	"more than or equal to IV size (" + recordIvSize +
	") + tag size (" + tagSize + ")");
	}

	// initialize the AEAD cipher for the unique IV
	byte[] iv = Arrays.copyOf(fixedIv,
	fixedIv.length + recordIvSize);
	bb.get(iv, fixedIv.length, recordIvSize);
	GCMParameterSpec spec = new GCMParameterSpec(tagSize * 8, iv);
	try {
	cipher.init(Cipher.DECRYPT_MODE, key, spec, random);
	} catch (InvalidKeyException \|
	InvalidAlgorithmParameterException ikae) {
	// unlikely to happen
	throw new RuntimeException(
	"invalid key or spec in GCM mode", ikae);
	}

	// update the additional authentication data
	byte[] aad = authenticator.acquireAuthenticationBytes(
	contentType, bb.remaining() - tagSize,
	sequence);
	cipher.updateAAD(aad);

	// DON'T decrypt the nonce_explicit for AEAD mode. The buffer
	// position has moved out of the nonce_explicit range.
	int len, pos = bb.position();
	ByteBuffer dup = bb.duplicate();
	try {
	len = cipher.doFinal(dup, bb);
	} catch (IllegalBlockSizeException ibse) {
	// unlikely to happen
	throw new RuntimeException(
	"Cipher error in AEAD mode \"" + ibse.getMessage() +
	" \"in JCE provider " + cipher.getProvider().getName());
	} catch (ShortBufferException sbe) {
	// catch BouncyCastle buffering error
	throw new RuntimeException("Cipher buffering error in " +
	"JCE provider " + cipher.getProvider().getName(), sbe);
	}
	// reset the limit to the end of the decrypted data
	bb.position(pos);
	bb.limit(pos + len);

	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.fine(
	"Plaintext after DECRYPTION", bb.duplicate());
	}

	return new Plaintext(contentType,
	ProtocolVersion.NONE.major, ProtocolVersion.NONE.minor,
	-1, -1L, bb.slice());
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int estimateFragmentSize(int packetSize, int headerSize) {
	return packetSize - headerSize - recordIvSize - tagSize;
	}
	}
	}

	private static final
	class T12GcmWriteCipherGenerator implements WriteCipherGenerator {
	@Override
	public SSLWriteCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator,
	ProtocolVersion protocolVersion, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new GcmWriteCipher(authenticator, protocolVersion, sslCipher,
	algorithm, key, params, random);
	}

	private static final class GcmWriteCipher extends SSLWriteCipher {
	private final Cipher cipher;
	private final int tagSize;
	private final Key key;
	private final byte[] fixedIv;
	private final int recordIvSize;
	private final SecureRandom random;

	GcmWriteCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion,
	SSLCipher sslCipher, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	this.tagSize = sslCipher.tagSize;
	this.key = key;
	this.fixedIv = ((IvParameterSpec)params).getIV();
	this.recordIvSize = sslCipher.ivSize - sslCipher.fixedIvSize;
	this.random = random;

	// DON'T initialize the cipher for AEAD!
	}

	@Override
	public int encrypt(byte contentType,
	ByteBuffer bb) {
	// To be unique and aware of overflow-wrap, sequence number
	// is used as the nonce_explicit of AEAD cipher suites.
	byte[] nonce = authenticator.sequenceNumber();

	// initialize the AEAD cipher for the unique IV
	byte[] iv = Arrays.copyOf(fixedIv,
	fixedIv.length + nonce.length);
	System.arraycopy(nonce, 0, iv, fixedIv.length, nonce.length);

	GCMParameterSpec spec = new GCMParameterSpec(tagSize * 8, iv);
	try {
	cipher.init(Cipher.ENCRYPT_MODE, key, spec, random);
	} catch (InvalidKeyException \|
	InvalidAlgorithmParameterException ikae) {
	// unlikely to happen
	throw new RuntimeException(
	"invalid key or spec in GCM mode", ikae);
	}

	// Update the additional authentication data, using the
	// implicit sequence number of the authenticator.
	byte[] aad = authenticator.acquireAuthenticationBytes(
	contentType, bb.remaining(), null);
	cipher.updateAAD(aad);

	// DON'T WORRY, the nonce spaces are considered already.
	bb.position(bb.position() - nonce.length);
	bb.put(nonce);

	// DON'T encrypt the nonce for AEAD mode.
	int len, pos = bb.position();
	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.fine(
	"Plaintext before ENCRYPTION",
	bb.duplicate());
	}

	ByteBuffer dup = bb.duplicate();
	int outputSize = cipher.getOutputSize(dup.remaining());
	if (outputSize > bb.remaining()) {
	// Need to expand the limit of the output buffer for
	// the authentication tag.
	//
	// DON'T worry about the buffer's capacity, we have
	// reserved space for the authentication tag.
	bb.limit(pos + outputSize);
	}

	try {
	len = cipher.doFinal(dup, bb);
	} catch (IllegalBlockSizeException \|
	BadPaddingException \| ShortBufferException ibse) {
	// unlikely to happen
	throw new RuntimeException(
	"Cipher error in AEAD mode in JCE provider " +
	cipher.getProvider().getName(), ibse);
	}

	if (len != outputSize) {
	throw new RuntimeException(
	"Cipher buffering error in JCE provider " +
	cipher.getProvider().getName());
	}

	return len + nonce.length;
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int getExplicitNonceSize() {
	return recordIvSize;
	}

	@Override
	int calculateFragmentSize(int packetLimit, int headerSize) {
	return packetLimit - headerSize - recordIvSize - tagSize;
	}

	@Override
	int calculatePacketSize(int fragmentSize, int headerSize) {
	return fragmentSize + headerSize + recordIvSize + tagSize;
	}
	}
	}

	private static final
	class T13GcmReadCipherGenerator implements ReadCipherGenerator {

	@Override
	public SSLReadCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator, ProtocolVersion protocolVersion,
	String algorithm, Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new GcmReadCipher(authenticator, protocolVersion, sslCipher,
	algorithm, key, params, random);
	}

	static final class GcmReadCipher extends SSLReadCipher {
	private final Cipher cipher;
	private final int tagSize;
	private final Key key;
	private final byte[] iv;
	private final SecureRandom random;

	GcmReadCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion,
	SSLCipher sslCipher, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	this.tagSize = sslCipher.tagSize;
	this.key = key;
	this.iv = ((IvParameterSpec)params).getIV();
	this.random = random;

	keyLimitCountdown = cipherLimits.getOrDefault(
	algorithm.toUpperCase() + ":" + tag[0], 0L);
	if (SSLLogger.isOn && SSLLogger.isOn("ssl")) {
	SSLLogger.fine("KeyLimit read side: algorithm = " +
	algorithm.toUpperCase() + ":" + tag[0] +
	"\ncountdown value = " + keyLimitCountdown);
	}
	if (keyLimitCountdown > 0) {
	keyLimitEnabled = true;
	}
	// DON'T initialize the cipher for AEAD!
	}

	@Override
	public Plaintext decrypt(byte contentType, ByteBuffer bb,
	byte[] sequence) throws GeneralSecurityException {
	// An implementation may receive an unencrypted record of type
	// change_cipher_spec consisting of the single byte value 0x01
	// at any time after the first ClientHello message has been
	// sent or received and before the peer's Finished message has
	// been received and MUST simply drop it without further
	// processing.
	if (contentType == ContentType.CHANGE_CIPHER_SPEC.id) {
	return new Plaintext(contentType,
	ProtocolVersion.NONE.major, ProtocolVersion.NONE.minor,
	-1, -1L, bb.slice());
	}

	if (bb.remaining() <= tagSize) {
	throw new BadPaddingException(
	"Insufficient buffer remaining for AEAD cipher " +
	"fragment (" + bb.remaining() + "). Needs to be " +
	"more than tag size (" + tagSize + ")");
	}

	byte[] sn = sequence;
	if (sn == null) {
	sn = authenticator.sequenceNumber();
	}
	byte[] nonce = iv.clone();
	int offset = nonce.length - sn.length;
	for (int i = 0; i < sn.length; i++) {
	nonce[offset + i] ^= sn[i];
	}

	// initialize the AEAD cipher for the unique IV
	GCMParameterSpec spec =
	new GCMParameterSpec(tagSize * 8, nonce);
	try {
	cipher.init(Cipher.DECRYPT_MODE, key, spec, random);
	} catch (InvalidKeyException \|
	InvalidAlgorithmParameterException ikae) {
	// unlikely to happen
	throw new RuntimeException(
	"invalid key or spec in GCM mode", ikae);
	}

	// Update the additional authentication data, using the
	// implicit sequence number of the authenticator.
	byte[] aad = authenticator.acquireAuthenticationBytes(
	contentType, bb.remaining(), sn);
	cipher.updateAAD(aad);

	int len, pos = bb.position();
	ByteBuffer dup = bb.duplicate();
	try {
	len = cipher.doFinal(dup, bb);
	} catch (IllegalBlockSizeException ibse) {
	// unlikely to happen
	throw new RuntimeException(
	"Cipher error in AEAD mode \"" + ibse.getMessage() +
	" \"in JCE provider " + cipher.getProvider().getName());
	} catch (ShortBufferException sbe) {
	// catch BouncyCastle buffering error
	throw new RuntimeException("Cipher buffering error in " +
	"JCE provider " + cipher.getProvider().getName(), sbe);
	}
	// reset the limit to the end of the decrypted data
	bb.position(pos);
	bb.limit(pos + len);

	// remove inner plaintext padding
	int i = bb.limit() - 1;
	for (; i > 0 && bb.get(i) == 0; i--) {
	// blank
	}
	if (i < (pos + 1)) {
	throw new BadPaddingException(
	"Incorrect inner plaintext: no content type");
	}
	contentType = bb.get(i);
	bb.limit(i);

	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.fine(
	"Plaintext after DECRYPTION", bb.duplicate());
	}
	if (keyLimitEnabled) {
	keyLimitCountdown -= len;
	}

	return new Plaintext(contentType,
	ProtocolVersion.NONE.major, ProtocolVersion.NONE.minor,
	-1, -1L, bb.slice());
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int estimateFragmentSize(int packetSize, int headerSize) {
	return packetSize - headerSize - tagSize;
	}
	}
	}

	private static final
	class T13GcmWriteCipherGenerator implements WriteCipherGenerator {
	@Override
	public SSLWriteCipher createCipher(SSLCipher sslCipher,
	Authenticator authenticator, ProtocolVersion protocolVersion,
	String algorithm, Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	return new GcmWriteCipher(authenticator, protocolVersion, sslCipher,
	algorithm, key, params, random);
	}

	private static final class GcmWriteCipher extends SSLWriteCipher {
	private final Cipher cipher;
	private final int tagSize;
	private final Key key;
	private final byte[] iv;
	private final SecureRandom random;

	GcmWriteCipher(Authenticator authenticator,
	ProtocolVersion protocolVersion,
	SSLCipher sslCipher, String algorithm,
	Key key, AlgorithmParameterSpec params,
	SecureRandom random) throws GeneralSecurityException {
	super(authenticator, protocolVersion);
	this.cipher = JsseJce.getCipher(algorithm);
	this.tagSize = sslCipher.tagSize;
	this.key = key;
	this.iv = ((IvParameterSpec)params).getIV();
	this.random = random;

	keyLimitCountdown = cipherLimits.getOrDefault(
	algorithm.toUpperCase() + ":" + tag[0], 0L);
	if (SSLLogger.isOn && SSLLogger.isOn("ssl")) {
	SSLLogger.fine("KeyLimit write side: algorithm = "
	+ algorithm.toUpperCase() + ":" + tag[0] +
	"\ncountdown value = " + keyLimitCountdown);
	}
	if (keyLimitCountdown > 0) {
	keyLimitEnabled = true;
	}

	// DON'T initialize the cipher for AEAD!
	}

	@Override
	public int encrypt(byte contentType,
	ByteBuffer bb) {
	byte[] sn = authenticator.sequenceNumber();
	byte[] nonce = iv.clone();
	int offset = nonce.length - sn.length;
	for (int i = 0; i < sn.length; i++) {
	nonce[offset + i] ^= sn[i];
	}

	// initialize the AEAD cipher for the unique IV
	GCMParameterSpec spec =
	new GCMParameterSpec(tagSize * 8, nonce);
	try {
	cipher.init(Cipher.ENCRYPT_MODE, key, spec, random);
	} catch (InvalidKeyException \|
	InvalidAlgorithmParameterException ikae) {
	// unlikely to happen
	throw new RuntimeException(
	"invalid key or spec in GCM mode", ikae);
	}

	// Update the additional authentication data, using the
	// implicit sequence number of the authenticator.
	int outputSize = cipher.getOutputSize(bb.remaining());
	byte[] aad = authenticator.acquireAuthenticationBytes(
	contentType, outputSize, sn);
	cipher.updateAAD(aad);

	int len, pos = bb.position();
	if (SSLLogger.isOn && SSLLogger.isOn("plaintext")) {
	SSLLogger.fine(
	"Plaintext before ENCRYPTION",
	bb.duplicate());
	}

	ByteBuffer dup = bb.duplicate();
	if (outputSize > bb.remaining()) {
	// Need to expand the limit of the output buffer for
	// the authentication tag.
	//
	// DON'T worry about the buffer's capacity, we have
	// reserved space for the authentication tag.
	bb.limit(pos + outputSize);
	}

	try {
	len = cipher.doFinal(dup, bb);
	} catch (IllegalBlockSizeException \|
	BadPaddingException \| ShortBufferException ibse) {
	// unlikely to happen
	throw new RuntimeException(
	"Cipher error in AEAD mode in JCE provider " +
	cipher.getProvider().getName(), ibse);
	}

	if (len != outputSize) {
	throw new RuntimeException(
	"Cipher buffering error in JCE provider " +
	cipher.getProvider().getName());
	}

	if (keyLimitEnabled) {
	keyLimitCountdown -= len;
	}
	return len;
	}

	@Override
	void dispose() {
	if (cipher != null) {
	try {
	cipher.doFinal();
	} catch (Exception e) {
	// swallow all types of exceptions.
	}
	}
	}

	@Override
	int getExplicitNonceSize() {
	return 0;
	}

	@Override
	int calculateFragmentSize(int packetLimit, int headerSize) {
	return packetLimit - headerSize - tagSize;
	}

	@Override
	int calculatePacketSize(int fragmentSize, int headerSize) {
	return fragmentSize + headerSize + tagSize;
	}
	}
	}

	private static void addMac(MAC signer,
	ByteBuffer destination, byte contentType) {
	if (signer.macAlg().size != 0) {
	int dstContent = destination.position();
	byte[] hash = signer.compute(contentType, destination, false);

	/*
	* position was advanced to limit in MAC compute above.
	*
	* Mark next area as writable (above layers should have
	* established that we have plenty of room), then write
	* out the hash.
	*/
	destination.limit(destination.limit() + hash.length);
	destination.put(hash);

	// reset the position and limit
	destination.position(dstContent);
	}
	}

	// for null and stream cipher
	private static void checkStreamMac(MAC signer, ByteBuffer bb,
	byte contentType, byte[] sequence) throws BadPaddingException {
	int tagLen = signer.macAlg().size;

	// Requires message authentication code for null, stream and
	// block cipher suites.
	if (tagLen != 0) {
	int contentLen = bb.remaining() - tagLen;
	if (contentLen < 0) {
	throw new BadPaddingException("bad record");
	}

	// Run MAC computation and comparison on the payload.
	//
	// MAC data would be stripped off during the check.
	if (checkMacTags(contentType, bb, signer, sequence, false)) {
	throw new BadPaddingException("bad record MAC");
	}
	}
	}

	// for CBC cipher
	private static void checkCBCMac(MAC signer, ByteBuffer bb,
	byte contentType, int cipheredLength,
	byte[] sequence) throws BadPaddingException {
	BadPaddingException reservedBPE = null;
	int tagLen = signer.macAlg().size;
	int pos = bb.position();

	if (tagLen != 0) {
	int contentLen = bb.remaining() - tagLen;
	if (contentLen < 0) {
	reservedBPE = new BadPaddingException("bad record");

	// set offset of the dummy MAC
	contentLen = cipheredLength - tagLen;
	bb.limit(pos + cipheredLength);
	}

	// Run MAC computation and comparison on the payload.
	//
	// MAC data would be stripped off during the check.
	if (checkMacTags(contentType, bb, signer, sequence, false)) {
	if (reservedBPE == null) {
	reservedBPE =
	new BadPaddingException("bad record MAC");
	}
	}

	// Run MAC computation and comparison on the remainder.
	int remainingLen = calculateRemainingLen(
	signer, cipheredLength, contentLen);

	// NOTE: remainingLen may be bigger (less than 1 block of the
	// hash algorithm of the MAC) than the cipheredLength.
	//
	// Is it possible to use a static buffer, rather than allocate
	// it dynamically?
	remainingLen += signer.macAlg().size;
	ByteBuffer temporary = ByteBuffer.allocate(remainingLen);

	// Won't need to worry about the result on the remainder. And
	// then we won't need to worry about what's actual data to
	// check MAC tag on. We start the check from the header of the
	// buffer so that we don't need to construct a new byte buffer.
	checkMacTags(contentType, temporary, signer, sequence, true);
	}

	// Is it a failover?
	if (reservedBPE != null) {
	throw reservedBPE;
	}
	}

	/*
	* Run MAC computation and comparison
	*/
	private static boolean checkMacTags(byte contentType, ByteBuffer bb,
	MAC signer, byte[] sequence, boolean isSimulated) {
	int tagLen = signer.macAlg().size;
	int position = bb.position();
	int lim = bb.limit();
	int macOffset = lim - tagLen;

	bb.limit(macOffset);
	byte[] hash = signer.compute(contentType, bb, sequence, isSimulated);
	if (hash == null \|\| tagLen != hash.length) {
	// Something is wrong with MAC implementation.
	throw new RuntimeException("Internal MAC error");
	}

	bb.position(macOffset);
	bb.limit(lim);
	try {
	int[] results = compareMacTags(bb, hash);
	return (results[0] != 0);
	} finally {
	// reset to the data
	bb.position(position);
	bb.limit(macOffset);
	}
	}

	/*
	* A constant-time comparison of the MAC tags.
	*
	* Please DON'T change the content of the ByteBuffer parameter!
	*/
	private static int[] compareMacTags(ByteBuffer bb, byte[] tag) {
	// An array of hits is used to prevent Hotspot optimization for
	// the purpose of a constant-time check.
	int[] results = {0, 0}; // {missed #, matched #}

	// The caller ensures there are enough bytes available in the buffer.
	// So we won't need to check the remaining of the buffer.
	for (byte t : tag) {
	if (bb.get() != t) {
	results[0]++; // mismatched bytes
	} else {
	results[1]++; // matched bytes
	}
	}

	return results;
	}

	/*
	* Calculate the length of a dummy buffer to run MAC computation
	* and comparison on the remainder.
	*
	* The caller MUST ensure that the fullLen is not less than usedLen.
	*/
	private static int calculateRemainingLen(
	MAC signer, int fullLen, int usedLen) {

	int blockLen = signer.macAlg().hashBlockSize;
	int minimalPaddingLen = signer.macAlg().minimalPaddingSize;

	// (blockLen - minimalPaddingLen) is the maximum message size of
	// the last block of hash function operation. See FIPS 180-4, or
	// MD5 specification.
	fullLen += 13 - (blockLen - minimalPaddingLen);
	usedLen += 13 - (blockLen - minimalPaddingLen);

	// Note: fullLen is always not less than usedLen, and blockLen
	// is always bigger than minimalPaddingLen, so we don't worry
	// about negative values. 0x01 is added to the result to ensure
	// that the return value is positive. The extra one byte does
	// not impact the overall MAC compression function evaluations.
	return 0x01 + (int)(Math.ceil(fullLen/(1.0d * blockLen)) -
	Math.ceil(usedLen/(1.0d * blockLen))) * blockLen;
	}

	private static int addPadding(ByteBuffer bb, int blockSize) {

	int len = bb.remaining();
	int offset = bb.position();

	int newlen = len + 1;
	byte pad;
	int i;

	if ((newlen % blockSize) != 0) {
	newlen += blockSize - 1;
	newlen -= newlen % blockSize;
	}
	pad = (byte) (newlen - len);

	/*
	* Update the limit to what will be padded.
	*/
	bb.limit(newlen + offset);

	/*
	* TLS version of the padding works for both SSLv3 and TLSv1
	*/
	for (i = 0, offset += len; i < pad; i++) {
	bb.put(offset++, (byte) (pad - 1));
	}

	bb.position(offset);
	bb.limit(offset);

	return newlen;
	}

	private static int removePadding(ByteBuffer bb,
	int tagLen, int blockSize,
	ProtocolVersion protocolVersion) throws BadPaddingException {
	int len = bb.remaining();
	int offset = bb.position();

	// last byte is length byte (i.e. actual padding length - 1)
	int padOffset = offset + len - 1;
	int padLen = bb.get(padOffset) & 0xFF;

	int newLen = len - (padLen + 1);
	if ((newLen - tagLen) < 0) {
	// If the buffer is not long enough to contain the padding plus
	// a MAC tag, do a dummy constant-time padding check.
	//
	// Note that it is a dummy check, so we won't care about what is
	// the actual padding data.
	checkPadding(bb.duplicate(), (byte)(padLen & 0xFF));

	throw new BadPaddingException("Invalid Padding length: " + padLen);
	}

	// The padding data should be filled with the padding length value.
	int[] results = checkPadding(
	bb.duplicate().position(offset + newLen),
	(byte)(padLen & 0xFF));
	if (protocolVersion.useTLS10PlusSpec()) {
	if (results[0] != 0) { // padding data has invalid bytes
	throw new BadPaddingException("Invalid TLS padding data");
	}
	} else { // SSLv3
	// SSLv3 requires 0 <= length byte < block size
	// some implementations do 1 <= length byte <= block size,
	// so accept that as well
	// v3 does not require any particular value for the other bytes
	if (padLen > blockSize) {
	throw new BadPaddingException("Padding length (" +
	padLen + ") of SSLv3 message should not be bigger " +
	"than the block size (" + blockSize + ")");
	}
	}

	// Reset buffer limit to remove padding.
	bb.limit(offset + newLen);

	return newLen;
	}

	/*
	* A constant-time check of the padding.
	*
	* NOTE that we are checking both the padding and the padLen bytes here.
	*
	* The caller MUST ensure that the bb parameter has remaining.
	*/
	private static int[] checkPadding(ByteBuffer bb, byte pad) {
	if (!bb.hasRemaining()) {
	throw new RuntimeException("hasRemaining() must be positive");
	}

	// An array of hits is used to prevent Hotspot optimization for
	// the purpose of a constant-time check.
	int[] results = {0, 0}; // {missed #, matched #}
	bb.mark();
	for (int i = 0; i <= 256; bb.reset()) {
	for (; bb.hasRemaining() && i <= 256; i++) {
	if (bb.get() != pad) {
	results[0]++; // mismatched padding data
	} else {
	results[1]++; // matched padding data
	}
	}
	}

	return results;
	}
	}

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