/*
* Copyright 2011 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.handler.ssl;
import static io.netty.channel.Channels.*;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.Executor;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.regex.Pattern;
import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLEngineResult;
import javax.net.ssl.SSLEngineResult.HandshakeStatus;
import javax.net.ssl.SSLEngineResult.Status;
import javax.net.ssl.SSLException;
import io.netty.buffer.ChannelBuffer;
import io.netty.buffer.ChannelBuffers;
import io.netty.channel.Channel;
import io.netty.channel.ChannelDownstreamHandler;
import io.netty.channel.ChannelEvent;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelStateEvent;
import io.netty.channel.Channels;
import io.netty.channel.DownstreamMessageEvent;
import io.netty.channel.ExceptionEvent;
import io.netty.channel.LifeCycleAwareChannelHandler;
import io.netty.channel.MessageEvent;
import io.netty.handler.codec.frame.FrameDecoder;
import io.netty.logging.InternalLogger;
import io.netty.logging.InternalLoggerFactory;
import io.netty.util.internal.NonReentrantLock;
import io.netty.util.internal.QueueFactory;
/**
* Adds <a href="http://en.wikipedia.org/wiki/Transport_Layer_Security">SSL
* · TLS</a> and StartTLS support to a {@link Channel}. Please refer
* to the <strong>"SecureChat"</strong> example in the distribution or the web
* site for the detailed usage.
*
* <h3>Beginning the handshake</h3>
* <p>
* You must make sure not to write a message while the
* {@linkplain #handshake() handshake} is in progress unless you are
* renegotiating. You will be notified by the {@link ChannelFuture} which is
* returned by the {@link #handshake()} method when the handshake
* process succeeds or fails.
*
* <h3>Handshake</h3>
* <p>
* If {@link #isIssueHandshake()} is {@code false}
* (default) you will need to take care of calling {@link #handshake()} by your own. In most situations were {@link SslHandler} is used in 'client mode'
* you want to issue a handshake once the connection was established. if {@link #setIssueHandshake(boolean)} is set to <code>true</code> you don't need to
* worry about this as the {@link SslHandler} will take care of it.
* <p>
*
* <h3>Renegotiation</h3>
* <p>
* If {@link #isEnableRenegotiation() enableRenegotiation} is {@code true}
* (default) and the initial handshake has been done successfully, you can call
* {@link #handshake()} to trigger the renegotiation.
* <p>
* If {@link #isEnableRenegotiation() enableRenegotiation} is {@code false},
* an attempt to trigger renegotiation will result in the connection closure.
* <p>
* Please note that TLS renegotiation had a security issue before. If your
* runtime environment did not fix it, please make sure to disable TLS
* renegotiation by calling {@link #setEnableRenegotiation(boolean)} with
* {@code false}. For more information, please refer to the following documents:
* <ul>
* <li><a href="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3555">CVE-2009-3555</a></li>
* <li><a href="http://www.ietf.org/rfc/rfc5746.txt">RFC5746</a></li>
* <li><a href="http://www.oracle.com/technetwork/java/javase/documentation/tlsreadme2-176330.html">Phased Approach to Fixing the TLS Renegotiation Issue</a></li>
* </ul>
*
* <h3>Closing the session</h3>
* <p>
* To close the SSL session, the {@link #close()} method should be
* called to send the {@code close_notify} message to the remote peer. One
* exception is when you close the {@link Channel} - {@link SslHandler}
* intercepts the close request and send the {@code close_notify} message
* before the channel closure automatically. Once the SSL session is closed,
* it is not reusable, and consequently you should create a new
* {@link SslHandler} with a new {@link SSLEngine} as explained in the
* following section.
*
* <h3>Restarting the session</h3>
* <p>
* To restart the SSL session, you must remove the existing closed
* {@link SslHandler} from the {@link ChannelPipeline}, insert a new
* {@link SslHandler} with a new {@link SSLEngine} into the pipeline,
* and start the handshake process as described in the first section.
*
* <h3>Implementing StartTLS</h3>
* <p>
* <a href="http://en.wikipedia.org/wiki/STARTTLS">StartTLS</a> is the
* communication pattern that secures the wire in the middle of the plaintext
* connection. Please note that it is different from SSL · TLS, that
* secures the wire from the beginning of the connection. Typically, StartTLS
* is composed of three steps:
* <ol>
* <li>Client sends a StartTLS request to server.</li>
* <li>Server sends a StartTLS response to client.</li>
* <li>Client begins SSL handshake.</li>
* </ol>
* If you implement a server, you need to:
* <ol>
* <li>create a new {@link SslHandler} instance with {@code startTls} flag set
* to {@code true},</li>
* <li>insert the {@link SslHandler} to the {@link ChannelPipeline}, and</li>
* <li>write a StartTLS response.</li>
* </ol>
* Please note that you must insert {@link SslHandler} <em>before</em> sending
* the StartTLS response. Otherwise the client can send begin SSL handshake
* before {@link SslHandler} is inserted to the {@link ChannelPipeline}, causing
* data corruption.
* <p>
* The client-side implementation is much simpler.
* <ol>
* <li>Write a StartTLS request,</li>
* <li>wait for the StartTLS response,</li>
* <li>create a new {@link SslHandler} instance with {@code startTls} flag set
* to {@code false},</li>
* <li>insert the {@link SslHandler} to the {@link ChannelPipeline}, and</li>
* <li>Initiate SSL handshake by calling {@link SslHandler#handshake()}.</li>
* </ol>
* @apiviz.landmark
* @apiviz.uses io.netty.handler.ssl.SslBufferPool
*/
public class SslHandler extends FrameDecoder
implements ChannelDownstreamHandler,
LifeCycleAwareChannelHandler {
private static final InternalLogger logger =
InternalLoggerFactory.getInstance(SslHandler.class);
private static final ByteBuffer EMPTY_BUFFER = ByteBuffer.allocate(0);
private static final Pattern IGNORABLE_ERROR_MESSAGE = Pattern.compile(
"^.*(?:connection.*reset|connection.*closed|broken.*pipe).*$",
Pattern.CASE_INSENSITIVE);
private static SslBufferPool defaultBufferPool;
/**
* Returns the default {@link SslBufferPool} used when no pool is
* specified in the constructor.
*/
public static synchronized SslBufferPool getDefaultBufferPool() {
if (defaultBufferPool == null) {
defaultBufferPool = new SslBufferPool();
}
return defaultBufferPool;
}
private volatile ChannelHandlerContext ctx;
private final SSLEngine engine;
private final SslBufferPool bufferPool;
private final Executor delegatedTaskExecutor;
private final boolean startTls;
private volatile boolean enableRenegotiation = true;
final Object handshakeLock = new Object();
private boolean handshaking;
private volatile boolean handshaken;
private volatile ChannelFuture handshakeFuture;
private final AtomicBoolean sentFirstMessage = new AtomicBoolean();
private final AtomicBoolean sentCloseNotify = new AtomicBoolean();
int ignoreClosedChannelException;
final Object ignoreClosedChannelExceptionLock = new Object();
private final Queue<PendingWrite> pendingUnencryptedWrites = new LinkedList<PendingWrite>();
private final Queue<MessageEvent> pendingEncryptedWrites = QueueFactory.createQueue(MessageEvent.class);
private final NonReentrantLock pendingEncryptedWritesLock = new NonReentrantLock();
private volatile boolean issueHandshake;
private static final ChannelFutureListener HANDSHAKE_LISTENER = new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (!future.isSuccess()) {
Channels.fireExceptionCaught(future.getChannel(), future.getCause());
}
}
};
/**
* Creates a new instance.
*
* @param engine the {@link SSLEngine} this handler will use
*/
public SslHandler(SSLEngine engine) {
this(engine, getDefaultBufferPool(), ImmediateExecutor.INSTANCE);
}
/**
* Creates a new instance.
*
* @param engine the {@link SSLEngine} this handler will use
* @param bufferPool the {@link SslBufferPool} where this handler will
* acquire the buffers required by the {@link SSLEngine}
*/
public SslHandler(SSLEngine engine, SslBufferPool bufferPool) {
this(engine, bufferPool, ImmediateExecutor.INSTANCE);
}
/**
* Creates a new instance.
*
* @param engine the {@link SSLEngine} this handler will use
* @param startTls {@code true} if the first write request shouldn't be
* encrypted by the {@link SSLEngine}
*/
public SslHandler(SSLEngine engine, boolean startTls) {
this(engine, getDefaultBufferPool(), startTls);
}
/**
* Creates a new instance.
*
* @param engine the {@link SSLEngine} this handler will use
* @param bufferPool the {@link SslBufferPool} where this handler will
* acquire the buffers required by the {@link SSLEngine}
* @param startTls {@code true} if the first write request shouldn't be
* encrypted by the {@link SSLEngine}
*/
public SslHandler(SSLEngine engine, SslBufferPool bufferPool, boolean startTls) {
this(engine, bufferPool, startTls, ImmediateExecutor.INSTANCE);
}
/**
* Creates a new instance.
*
* @param engine
* the {@link SSLEngine} this handler will use
* @param delegatedTaskExecutor
* the {@link Executor} which will execute the delegated task
* that {@link SSLEngine#getDelegatedTask()} will return
*/
public SslHandler(SSLEngine engine, Executor delegatedTaskExecutor) {
this(engine, getDefaultBufferPool(), delegatedTaskExecutor);
}
/**
* Creates a new instance.
*
* @param engine
* the {@link SSLEngine} this handler will use
* @param bufferPool
* the {@link SslBufferPool} where this handler will acquire
* the buffers required by the {@link SSLEngine}
* @param delegatedTaskExecutor
* the {@link Executor} which will execute the delegated task
* that {@link SSLEngine#getDelegatedTask()} will return
*/
public SslHandler(SSLEngine engine, SslBufferPool bufferPool, Executor delegatedTaskExecutor) {
this(engine, bufferPool, false, delegatedTaskExecutor);
}
/**
* Creates a new instance.
*
* @param engine
* the {@link SSLEngine} this handler will use
* @param startTls
* {@code true} if the first write request shouldn't be encrypted
* by the {@link SSLEngine}
* @param delegatedTaskExecutor
* the {@link Executor} which will execute the delegated task
* that {@link SSLEngine#getDelegatedTask()} will return
*/
public SslHandler(SSLEngine engine, boolean startTls, Executor delegatedTaskExecutor) {
this(engine, getDefaultBufferPool(), startTls, delegatedTaskExecutor);
}
/**
* Creates a new instance.
*
* @param engine
* the {@link SSLEngine} this handler will use
* @param bufferPool
* the {@link SslBufferPool} where this handler will acquire
* the buffers required by the {@link SSLEngine}
* @param startTls
* {@code true} if the first write request shouldn't be encrypted
* by the {@link SSLEngine}
* @param delegatedTaskExecutor
* the {@link Executor} which will execute the delegated task
* that {@link SSLEngine#getDelegatedTask()} will return
*/
public SslHandler(SSLEngine engine, SslBufferPool bufferPool, boolean startTls, Executor delegatedTaskExecutor) {
if (engine == null) {
throw new NullPointerException("engine");
}
if (bufferPool == null) {
throw new NullPointerException("bufferPool");
}
if (delegatedTaskExecutor == null) {
throw new NullPointerException("delegatedTaskExecutor");
}
this.engine = engine;
this.bufferPool = bufferPool;
this.delegatedTaskExecutor = delegatedTaskExecutor;
this.startTls = startTls;
}
/**
* Returns the {@link SSLEngine} which is used by this handler.
*/
public SSLEngine getEngine() {
return engine;
}
/**
* Starts an SSL / TLS handshake for the specified channel.
*
* @return a {@link ChannelFuture} which is notified when the handshake
* succeeds or fails.
*/
public ChannelFuture handshake() {
if (handshaken && !isEnableRenegotiation()) {
throw new IllegalStateException("renegotiation disabled");
}
ChannelHandlerContext ctx = this.ctx;
Channel channel = ctx.getChannel();
ChannelFuture handshakeFuture;
Exception exception = null;
synchronized (handshakeLock) {
if (handshaking) {
return this.handshakeFuture;
} else {
handshaking = true;
try {
engine.beginHandshake();
runDelegatedTasks();
handshakeFuture = this.handshakeFuture = future(channel);
} catch (Exception e) {
handshakeFuture = this.handshakeFuture = failedFuture(channel, e);
exception = e;
}
}
}
if (exception == null) { // Began handshake successfully.
try {
wrapNonAppData(ctx, channel);
} catch (SSLException e) {
fireExceptionCaught(ctx, e);
handshakeFuture.setFailure(e);
}
} else { // Failed to initiate handshake.
fireExceptionCaught(ctx, exception);
}
return handshakeFuture;
}
/**
* Sends an SSL {@code close_notify} message to the specified channel and
* destroys the underlying {@link SSLEngine}.
*/
public ChannelFuture close() {
ChannelHandlerContext ctx = this.ctx;
Channel channel = ctx.getChannel();
try {
engine.closeOutbound();
return wrapNonAppData(ctx, channel);
} catch (SSLException e) {
fireExceptionCaught(ctx, e);
return failedFuture(channel, e);
}
}
/**
* Returns {@code true} if and only if TLS renegotiation is enabled.
*/
public boolean isEnableRenegotiation() {
return enableRenegotiation;
}
/**
* Enables or disables TLS renegotiation.
*/
public void setEnableRenegotiation(boolean enableRenegotiation) {
this.enableRenegotiation = enableRenegotiation;
}
/**
* Enables or disables the automatic handshake once the {@link Channel} is connected. The value will only have affect if its set before the
* {@link Channel} is connected.
*/
public void setIssueHandshake(boolean issueHandshake) {
this.issueHandshake = issueHandshake;
}
/**
* Returns <code>true</code> if the automatic handshake is enabled
*/
public boolean isIssueHandshake() {
return issueHandshake;
}
@Override
public void handleDownstream(
final ChannelHandlerContext context, final ChannelEvent evt) throws Exception {
if (evt instanceof ChannelStateEvent) {
ChannelStateEvent e = (ChannelStateEvent) evt;
switch (e.getState()) {
case OPEN:
case CONNECTED:
case BOUND:
if (Boolean.FALSE.equals(e.getValue()) || e.getValue() == null) {
closeOutboundAndChannel(context, e);
return;
}
}
}
if (!(evt instanceof MessageEvent)) {
context.sendDownstream(evt);
return;
}
MessageEvent e = (MessageEvent) evt;
if (!(e.getMessage() instanceof ChannelBuffer)) {
context.sendDownstream(evt);
return;
}
// Do not encrypt the first write request if this handler is
// created with startTLS flag turned on.
if (startTls && sentFirstMessage.compareAndSet(false, true)) {
context.sendDownstream(evt);
return;
}
// Otherwise, all messages are encrypted.
ChannelBuffer msg = (ChannelBuffer) e.getMessage();
PendingWrite pendingWrite;
if (msg.readable()) {
pendingWrite = new PendingWrite(evt.getFuture(), msg.toByteBuffer(msg.readerIndex(), msg.readableBytes()));
} else {
pendingWrite = new PendingWrite(evt.getFuture(), null);
}
synchronized (pendingUnencryptedWrites) {
boolean offered = pendingUnencryptedWrites.offer(pendingWrite);
assert offered;
}
wrap(context, evt.getChannel());
}
@Override
public void channelDisconnected(ChannelHandlerContext ctx,
ChannelStateEvent e) throws Exception {
// Make sure the handshake future is notified when a connection has
// been closed during handshake.
synchronized (handshakeLock) {
if (handshaking) {
handshakeFuture.setFailure(new ClosedChannelException());
}
}
try {
super.channelDisconnected(ctx, e);
} finally {
unwrap(ctx, e.getChannel(), ChannelBuffers.EMPTY_BUFFER, 0, 0);
engine.closeOutbound();
if (!sentCloseNotify.get() && handshaken) {
try {
engine.closeInbound();
} catch (SSLException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Failed to clean up SSLEngine.", ex);
}
}
}
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e)
throws Exception {
Throwable cause = e.getCause();
if (cause instanceof IOException) {
if (cause instanceof ClosedChannelException) {
synchronized (ignoreClosedChannelExceptionLock) {
if (ignoreClosedChannelException > 0) {
ignoreClosedChannelException --;
if (logger.isDebugEnabled()) {
logger.debug(
"Swallowing an exception raised while " +
"writing non-app data", cause);
}
return;
}
}
} else if (engine.isOutboundDone()) {
String message = String.valueOf(cause.getMessage()).toLowerCase();
if (IGNORABLE_ERROR_MESSAGE.matcher(message).matches()) {
// It is safe to ignore the 'connection reset by peer' or
// 'broken pipe' error after sending closure_notify.
if (logger.isDebugEnabled()) {
logger.debug(
"Swallowing a 'connection reset by peer / " +
"broken pipe' error occurred while writing " +
"'closure_notify'", cause);
}
// Close the connection explicitly just in case the transport
// did not close the connection automatically.
Channels.close(ctx, succeededFuture(e.getChannel()));
return;
}
}
}
ctx.sendUpstream(e);
}
@Override
protected Object decode(
final ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception {
if (buffer.readableBytes() < 5) {
return null;
}
int packetLength = 0;
// SSLv3 or TLS - Check ContentType
boolean tls;
switch (buffer.getUnsignedByte(buffer.readerIndex())) {
case 20: // change_cipher_spec
case 21: // alert
case 22: // handshake
case 23: // application_data
tls = true;
break;
default:
// SSLv2 or bad data
tls = false;
}
if (tls) {
// SSLv3 or TLS - Check ProtocolVersion
int majorVersion = buffer.getUnsignedByte(buffer.readerIndex() + 1);
if (majorVersion >= 3 && majorVersion < 10) {
// SSLv3 or TLS
packetLength = (getShort(buffer, buffer.readerIndex() + 3) & 0xFFFF) + 5;
if (packetLength <= 5) {
// Neither SSLv2 or TLSv1 (i.e. SSLv2 or bad data)
tls = false;
}
} else {
// Neither SSLv2 or TLSv1 (i.e. SSLv2 or bad data)
tls = false;
}
}
if (!tls) {
// SSLv2 or bad data - Check the version
boolean sslv2 = true;
int headerLength = (buffer.getUnsignedByte(
buffer.readerIndex()) & 0x80) != 0 ? 2 : 3;
int majorVersion = buffer.getUnsignedByte(
buffer.readerIndex() + headerLength + 1);
if (majorVersion >= 2 && majorVersion < 10) {
// SSLv2
if (headerLength == 2) {
packetLength = (getShort(buffer, buffer.readerIndex()) & 0x7FFF) + 2;
} else {
packetLength = (getShort(buffer, buffer.readerIndex()) & 0x3FFF) + 3;
}
if (packetLength <= headerLength) {
sslv2 = false;
}
} else {
sslv2 = false;
}
if (!sslv2) {
// Bad data - discard the buffer and raise an exception.
SSLException e = new SSLException(
"not an SSL/TLS record: " + ChannelBuffers.hexDump(buffer));
buffer.skipBytes(buffer.readableBytes());
throw e;
}
}
assert packetLength > 0;
if (buffer.readableBytes() < packetLength) {
return null;
}
// We advance the buffer's readerIndex before calling unwrap() because
// unwrap() can trigger FrameDecoder call decode(), this method, recursively.
// The recursive call results in decoding the same packet twice if
// the readerIndex is advanced *after* decode().
//
// Here's an example:
// 1) An SSL packet is received from the wire.
// 2) SslHandler.decode() deciphers the packet and calls the user code.
// 3) The user closes the channel in the same thread.
// 4) The same thread triggers a channelDisconnected() event.
// 5) FrameDecoder.cleanup() is called, and it calls SslHandler.decode().
// 6) SslHandler.decode() will feed the same packet with what was
// deciphered at the step 2 again if the readerIndex was not advanced
// before calling the user code.
final int packetOffset = buffer.readerIndex();
buffer.skipBytes(packetLength);
return unwrap(ctx, channel, buffer, packetOffset, packetLength);
}
/**
* Reads a big-endian short integer from the buffer. Please note that we do not use
* {@link ChannelBuffer#getShort(int)} because it might be a little-endian buffer.
*/
private static short getShort(ChannelBuffer buf, int offset) {
return (short) (buf.getByte(offset) << 8 | buf.getByte(offset + 1) & 0xFF);
}
private ChannelFuture wrap(ChannelHandlerContext context, Channel channel)
throws SSLException {
ChannelFuture future = null;
ChannelBuffer msg;
ByteBuffer outNetBuf = bufferPool.acquire();
boolean success = true;
boolean offered = false;
boolean needsUnwrap = false;
try {
loop:
for (;;) {
// Acquire a lock to make sure unencrypted data is polled
// in order and their encrypted counterpart is offered in
// order.
synchronized (pendingUnencryptedWrites) {
PendingWrite pendingWrite = pendingUnencryptedWrites.peek();
if (pendingWrite == null) {
break;
}
ByteBuffer outAppBuf = pendingWrite.outAppBuf;
if (outAppBuf == null) {
// A write request with an empty buffer
pendingUnencryptedWrites.remove();
offerEncryptedWriteRequest(
new DownstreamMessageEvent(
channel, pendingWrite.future,
ChannelBuffers.EMPTY_BUFFER,
channel.getRemoteAddress()));
offered = true;
} else {
SSLEngineResult result = null;
try {
synchronized (handshakeLock) {
result = engine.wrap(outAppBuf, outNetBuf);
}
} finally {
if (!outAppBuf.hasRemaining()) {
pendingUnencryptedWrites.remove();
}
}
if (result.bytesProduced() > 0) {
outNetBuf.flip();
msg = ChannelBuffers.buffer(outNetBuf.remaining());
msg.writeBytes(outNetBuf.array(), 0, msg.capacity());
outNetBuf.clear();
if (pendingWrite.outAppBuf.hasRemaining()) {
// pendingWrite's future shouldn't be notified if
// only partial data is written.
future = succeededFuture(channel);
} else {
future = pendingWrite.future;
}
MessageEvent encryptedWrite = new DownstreamMessageEvent(
channel, future, msg, channel.getRemoteAddress());
offerEncryptedWriteRequest(encryptedWrite);
offered = true;
} else if (result.getStatus() == Status.CLOSED) {
// SSLEngine has been closed already.
// Any further write attempts should be denied.
success = false;
break;
} else {
final HandshakeStatus handshakeStatus = result.getHandshakeStatus();
handleRenegotiation(handshakeStatus);
switch (handshakeStatus) {
case NEED_WRAP:
if (outAppBuf.hasRemaining()) {
break;
} else {
break loop;
}
case NEED_UNWRAP:
needsUnwrap = true;
break loop;
case NEED_TASK:
runDelegatedTasks();
break;
case FINISHED:
case NOT_HANDSHAKING:
if (handshakeStatus == HandshakeStatus.FINISHED) {
setHandshakeSuccess(channel);
}
if (result.getStatus() == Status.CLOSED) {
success = false;
}
break loop;
default:
throw new IllegalStateException(
"Unknown handshake status: " +
handshakeStatus);
}
}
}
}
}
} catch (SSLException e) {
success = false;
setHandshakeFailure(channel, e);
throw e;
} finally {
bufferPool.release(outNetBuf);
if (offered) {
flushPendingEncryptedWrites(context);
}
if (!success) {
IllegalStateException cause =
new IllegalStateException("SSLEngine already closed");
// Mark all remaining pending writes as failure if anything
// wrong happened before the write requests are wrapped.
// Please note that we do not call setFailure while a lock is
// acquired, to avoid a potential dead lock.
for (;;) {
PendingWrite pendingWrite;
synchronized (pendingUnencryptedWrites) {
pendingWrite = pendingUnencryptedWrites.poll();
if (pendingWrite == null) {
break;
}
}
pendingWrite.future.setFailure(cause);
}
}
}
if (needsUnwrap) {
unwrap(context, channel, ChannelBuffers.EMPTY_BUFFER, 0, 0);
}
if (future == null) {
future = succeededFuture(channel);
}
return future;
}
private void offerEncryptedWriteRequest(MessageEvent encryptedWrite) {
final boolean locked = pendingEncryptedWritesLock.tryLock();
try {
pendingEncryptedWrites.offer(encryptedWrite);
} finally {
if (locked) {
pendingEncryptedWritesLock.unlock();
}
}
}
private void flushPendingEncryptedWrites(ChannelHandlerContext ctx) {
// Avoid possible dead lock and data integrity issue
// which is caused by cross communication between more than one channel
// in the same VM.
if (!pendingEncryptedWritesLock.tryLock()) {
return;
}
try {
MessageEvent e;
while ((e = pendingEncryptedWrites.poll()) != null) {
ctx.sendDownstream(e);
}
} finally {
pendingEncryptedWritesLock.unlock();
}
}
private ChannelFuture wrapNonAppData(ChannelHandlerContext ctx, Channel channel) throws SSLException {
ChannelFuture future = null;
ByteBuffer outNetBuf = bufferPool.acquire();
SSLEngineResult result;
try {
for (;;) {
synchronized (handshakeLock) {
result = engine.wrap(EMPTY_BUFFER, outNetBuf);
}
if (result.bytesProduced() > 0) {
outNetBuf.flip();
ChannelBuffer msg = ChannelBuffers.buffer(outNetBuf.remaining());
msg.writeBytes(outNetBuf.array(), 0, msg.capacity());
outNetBuf.clear();
future = future(channel);
future.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future)
throws Exception {
if (future.getCause() instanceof ClosedChannelException) {
synchronized (ignoreClosedChannelExceptionLock) {
ignoreClosedChannelException ++;
}
}
}
});
write(ctx, future, msg);
}
final HandshakeStatus handshakeStatus = result.getHandshakeStatus();
handleRenegotiation(handshakeStatus);
switch (handshakeStatus) {
case FINISHED:
setHandshakeSuccess(channel);
runDelegatedTasks();
break;
case NEED_TASK:
runDelegatedTasks();
break;
case NEED_UNWRAP:
if (!Thread.holdsLock(handshakeLock)) {
// unwrap shouldn't be called when this method was
// called by unwrap - unwrap will keep running after
// this method returns.
unwrap(ctx, channel, ChannelBuffers.EMPTY_BUFFER, 0, 0);
}
break;
case NOT_HANDSHAKING:
case NEED_WRAP:
break;
default:
throw new IllegalStateException(
"Unexpected handshake status: " + handshakeStatus);
}
if (result.bytesProduced() == 0) {
break;
}
}
} catch (SSLException e) {
setHandshakeFailure(channel, e);
throw e;
} finally {
bufferPool.release(outNetBuf);
}
if (future == null) {
future = succeededFuture(channel);
}
return future;
}
private ChannelBuffer unwrap(
ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer, int offset, int length) throws SSLException {
ByteBuffer inNetBuf = buffer.toByteBuffer(offset, length);
ByteBuffer outAppBuf = bufferPool.acquire();
try {
boolean needsWrap = false;
loop:
for (;;) {
SSLEngineResult result;
boolean needsHandshake = false;
synchronized (handshakeLock) {
if (!handshaken && !handshaking &&
!engine.getUseClientMode() &&
!engine.isInboundDone() && !engine.isOutboundDone()) {
needsHandshake = true;
}
}
if (needsHandshake) {
handshake();
}
synchronized (handshakeLock) {
result = engine.unwrap(inNetBuf, outAppBuf);
}
final HandshakeStatus handshakeStatus = result.getHandshakeStatus();
handleRenegotiation(handshakeStatus);
switch (handshakeStatus) {
case NEED_UNWRAP:
if (inNetBuf.hasRemaining() && !engine.isInboundDone()) {
break;
} else {
break loop;
}
case NEED_WRAP:
wrapNonAppData(ctx, channel);
break;
case NEED_TASK:
runDelegatedTasks();
break;
case FINISHED:
setHandshakeSuccess(channel);
needsWrap = true;
break loop;
case NOT_HANDSHAKING:
needsWrap = true;
break loop;
default:
throw new IllegalStateException(
"Unknown handshake status: " + handshakeStatus);
}
}
if (needsWrap) {
// wrap() acquires pendingUnencryptedWrites first and then
// handshakeLock. If handshakeLock is already hold by the
// current thread, calling wrap() will lead to a dead lock
// i.e. pendingUnencryptedWrites -> handshakeLock vs.
// handshakeLock -> pendingUnencryptedLock -> handshakeLock
//
// There is also a same issue between pendingEncryptedWrites
// and pendingUnencryptedWrites.
if (!Thread.holdsLock(handshakeLock) &&
!pendingEncryptedWritesLock.isHeldByCurrentThread()) {
wrap(ctx, channel);
}
}
outAppBuf.flip();
if (outAppBuf.hasRemaining()) {
ChannelBuffer frame = ChannelBuffers.buffer(outAppBuf.remaining());
frame.writeBytes(outAppBuf.array(), 0, frame.capacity());
return frame;
} else {
return null;
}
} catch (SSLException e) {
setHandshakeFailure(channel, e);
throw e;
} finally {
bufferPool.release(outAppBuf);
}
}
private void handleRenegotiation(HandshakeStatus handshakeStatus) {
if (handshakeStatus == HandshakeStatus.NOT_HANDSHAKING ||
handshakeStatus == HandshakeStatus.FINISHED) {
// Not handshaking
return;
}
if (!handshaken) {
// Not renegotiation
return;
}
final boolean renegotiate;
synchronized (handshakeLock) {
if (handshaking) {
// Renegotiation in progress or failed already.
// i.e. Renegotiation check has been done already below.
return;
}
if (engine.isInboundDone() || engine.isOutboundDone()) {
// Not handshaking but closing.
return;
}
if (isEnableRenegotiation()) {
// Continue renegotiation.
renegotiate = true;
} else {
// Do not renegotiate.
renegotiate = false;
// Prevent reentrance of this method.
handshaking = true;
}
}
if (renegotiate) {
// Renegotiate.
handshake();
} else {
// Raise an exception.
fireExceptionCaught(
ctx, new SSLException(
"renegotiation attempted by peer; " +
"closing the connection"));
// Close the connection to stop renegotiation.
Channels.close(ctx, succeededFuture(ctx.getChannel()));
}
}
private void runDelegatedTasks() {
for (;;) {
final Runnable task;
synchronized (handshakeLock) {
task = engine.getDelegatedTask();
}
if (task == null) {
break;
}
delegatedTaskExecutor.execute(new Runnable() {
@Override
public void run() {
synchronized (handshakeLock) {
task.run();
}
}
});
}
}
private void setHandshakeSuccess(Channel channel) {
synchronized (handshakeLock) {
handshaking = false;
handshaken = true;
if (handshakeFuture == null) {
handshakeFuture = future(channel);
}
}
handshakeFuture.setSuccess();
}
private void setHandshakeFailure(Channel channel, SSLException cause) {
synchronized (handshakeLock) {
if (!handshaking) {
return;
}
handshaking = false;
handshaken = false;
if (handshakeFuture == null) {
handshakeFuture = future(channel);
}
// Release all resources such as internal buffers that SSLEngine
// is managing.
engine.closeOutbound();
try {
engine.closeInbound();
} catch (SSLException e) {
if (logger.isDebugEnabled()) {
logger.debug(
"SSLEngine.closeInbound() raised an exception after " +
"a handshake failure.", e);
}
}
}
handshakeFuture.setFailure(cause);
}
private void closeOutboundAndChannel(
final ChannelHandlerContext context, final ChannelStateEvent e) {
if (!e.getChannel().isConnected()) {
context.sendDownstream(e);
return;
}
boolean success = false;
try {
try {
unwrap(context, e.getChannel(), ChannelBuffers.EMPTY_BUFFER, 0, 0);
} catch (SSLException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Failed to unwrap before sending a close_notify message", ex);
}
}
if (!engine.isInboundDone()) {
if (sentCloseNotify.compareAndSet(false, true)) {
engine.closeOutbound();
try {
ChannelFuture closeNotifyFuture = wrapNonAppData(context, e.getChannel());
closeNotifyFuture.addListener(
new ClosingChannelFutureListener(context, e));
success = true;
} catch (SSLException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Failed to encode a close_notify message", ex);
}
}
}
} else {
success = true;
}
} finally {
if (!success) {
context.sendDownstream(e);
}
}
}
private static final class PendingWrite {
final ChannelFuture future;
final ByteBuffer outAppBuf;
PendingWrite(ChannelFuture future, ByteBuffer outAppBuf) {
this.future = future;
this.outAppBuf = outAppBuf;
}
}
private static final class ClosingChannelFutureListener implements ChannelFutureListener {
private final ChannelHandlerContext context;
private final ChannelStateEvent e;
ClosingChannelFutureListener(
ChannelHandlerContext context, ChannelStateEvent e) {
this.context = context;
this.e = e;
}
@Override
public void operationComplete(ChannelFuture closeNotifyFuture) throws Exception {
if (!(closeNotifyFuture.getCause() instanceof ClosedChannelException)) {
Channels.close(context, e.getFuture());
} else {
e.getFuture().setSuccess();
}
}
}
@Override
public void beforeAdd(ChannelHandlerContext ctx) throws Exception {
this.ctx = ctx;
}
@Override
public void afterAdd(ChannelHandlerContext ctx) throws Exception {
// Unused
}
@Override
public void beforeRemove(ChannelHandlerContext ctx) throws Exception {
// Unused
}
@Override
public void afterRemove(ChannelHandlerContext ctx) throws Exception {
// Unused
}
/**
* Calls {@link #handshake()} once the {@link Channel} is connected
*/
@Override
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
if (issueHandshake) {
// issue and handshake and add a listener to it which will fire an exception event if an exception was thrown
// while doing the handshake
handshake().addListener(HANDSHAKE_LISTENER);
}
super.channelConnected(ctx, e);
}
}