/*
* Copyright 2012 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 io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.CompositeByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandler;
import io.netty.channel.ChannelOutboundHandler;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelPromise;
import io.netty.channel.PendingWriteQueue;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.util.concurrent.DefaultPromise;
import io.netty.util.concurrent.EventExecutor;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.FutureListener;
import io.netty.util.concurrent.ImmediateExecutor;
import io.netty.util.concurrent.Promise;
import io.netty.util.internal.EmptyArrays;
import io.netty.util.internal.OneTimeTask;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
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 java.io.IOException;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.DatagramChannel;
import java.nio.channels.SocketChannel;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executor;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;
/**
* 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 handshake is in progress unless you are
* renegotiating. You will be notified by the {@link Future} which is
* returned by the {@link #handshakeFuture()} method when the handshake
* process succeeds or fails.
* <p>
* Beside using the handshake {@link ChannelFuture} to get notified about the completation of the handshake it's
* also possible to detect it by implement the
* {@link ChannelInboundHandler#userEventTriggered(ChannelHandlerContext, Object)}
* method and check for a {@link SslHandshakeCompletionEvent}.
*
* <h3>Handshake</h3>
* <p>
* The handshake will be automaticly issued for you once the {@link Channel} is active and
* {@link SSLEngine#getUseClientMode()} returns {@code true}.
* So no need to bother with it by your self.
*
* <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.</li>
* </ol>
*
* <h3>Known issues</h3>
* <p>
* Because of a known issue with the current implementation of the SslEngine that comes
* with Java it may be possible that you see blocked IO-Threads while a full GC is done.
* <p>
* So if you are affected you can workaround this problem by adjust the cache settings
* like shown below:
*
* <pre>
* SslContext context = ...;
* context.getServerSessionContext().setSessionCacheSize(someSaneSize);
* context.getServerSessionContext().setSessionTime(someSameTimeout);
* </pre>
* <p>
* What values to use here depends on the nature of your application and should be set
* based on monitoring and debugging of it.
* For more details see
* <a href="https://github.com/netty/netty/issues/832">#832</a> in our issue tracker.
*/
public class SslHandler extends ByteToMessageDecoder implements ChannelOutboundHandler {
private static final InternalLogger logger =
InternalLoggerFactory.getInstance(SslHandler.class);
private static final Pattern IGNORABLE_CLASS_IN_STACK = Pattern.compile(
"^.*(?:Socket|Datagram|Sctp|Udt)Channel.*$");
private static final Pattern IGNORABLE_ERROR_MESSAGE = Pattern.compile(
"^.*(?:connection.*(?:reset|closed|abort|broken)|broken.*pipe).*$", Pattern.CASE_INSENSITIVE);
/**
* Used in {@link #unwrapNonAppData(ChannelHandlerContext)} as input for
* {@link #unwrap(ChannelHandlerContext, ByteBuf, int, int)}. Using this static instance reduce object
* creation as {@link Unpooled#EMPTY_BUFFER#nioBuffer()} creates a new {@link ByteBuffer} everytime.
*/
private static final SSLException SSLENGINE_CLOSED = new SSLException("SSLEngine closed already");
private static final SSLException HANDSHAKE_TIMED_OUT = new SSLException("handshake timed out");
private static final ClosedChannelException CHANNEL_CLOSED = new ClosedChannelException();
static {
SSLENGINE_CLOSED.setStackTrace(EmptyArrays.EMPTY_STACK_TRACE);
HANDSHAKE_TIMED_OUT.setStackTrace(EmptyArrays.EMPTY_STACK_TRACE);
CHANNEL_CLOSED.setStackTrace(EmptyArrays.EMPTY_STACK_TRACE);
}
private volatile ChannelHandlerContext ctx;
private final SSLEngine engine;
private final int maxPacketBufferSize;
private final Executor delegatedTaskExecutor;
/**
* Used if {@link SSLEngine#wrap(ByteBuffer[], ByteBuffer)} and {@link SSLEngine#unwrap(ByteBuffer, ByteBuffer[])}
* should be called with a {@link ByteBuf} that is only backed by one {@link ByteBuffer} to reduce the object
* creation.
*/
private final ByteBuffer[] singleBuffer = new ByteBuffer[1];
// BEGIN Platform-dependent flags
/**
* {@code true} if and only if {@link SSLEngine} expects a direct buffer.
*/
private final boolean wantsDirectBuffer;
/**
* {@code true} if and only if {@link SSLEngine#wrap(ByteBuffer, ByteBuffer)} requires the output buffer
* to be always as large as {@link #maxPacketBufferSize} even if the input buffer contains small amount of data.
* <p>
* If this flag is {@code false}, we allocate a smaller output buffer.
* </p>
*/
private final boolean wantsLargeOutboundNetworkBuffer;
/**
* {@code true} if and only if {@link SSLEngine#unwrap(ByteBuffer, ByteBuffer)} expects a heap buffer rather than
* a direct buffer. For an unknown reason, JDK8 SSLEngine causes JVM to crash when its cipher suite uses Galois
* Counter Mode (GCM).
*/
private boolean wantsInboundHeapBuffer;
// END Platform-dependent flags
private final boolean startTls;
private boolean sentFirstMessage;
private boolean flushedBeforeHandshake;
private boolean readDuringHandshake;
private PendingWriteQueue pendingUnencryptedWrites;
private Promise<Channel> handshakePromise = new LazyChannelPromise();
private final LazyChannelPromise sslCloseFuture = new LazyChannelPromise();
/**
* Set by wrap*() methods when something is produced.
* {@link #channelReadComplete(ChannelHandlerContext)} will check this flag, clear it, and call ctx.flush().
*/
private boolean needsFlush;
private int packetLength;
private volatile long handshakeTimeoutMillis = 10000;
private volatile long closeNotifyTimeoutMillis = 3000;
/**
* Creates a new instance.
*
* @param engine the {@link SSLEngine} this handler will use
*/
public SslHandler(SSLEngine engine) {
this(engine, false);
}
/**
* 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}
*/
@SuppressWarnings("deprecation")
public SslHandler(SSLEngine engine, boolean startTls) {
this(engine, startTls, ImmediateExecutor.INSTANCE);
}
/**
* @deprecated Use {@link #SslHandler(SSLEngine)} instead.
*/
@Deprecated
public SslHandler(SSLEngine engine, Executor delegatedTaskExecutor) {
this(engine, false, delegatedTaskExecutor);
}
/**
* @deprecated Use {@link #SslHandler(SSLEngine, boolean)} instead.
*/
@Deprecated
public SslHandler(SSLEngine engine, boolean startTls, Executor delegatedTaskExecutor) {
if (engine == null) {
throw new NullPointerException("engine");
}
if (delegatedTaskExecutor == null) {
throw new NullPointerException("delegatedTaskExecutor");
}
this.engine = engine;
this.delegatedTaskExecutor = delegatedTaskExecutor;
this.startTls = startTls;
maxPacketBufferSize = engine.getSession().getPacketBufferSize();
boolean opensslEngine = engine instanceof OpenSslEngine;
wantsDirectBuffer = opensslEngine;
wantsLargeOutboundNetworkBuffer = !opensslEngine;
/**
* When using JDK {@link SSLEngine}, we use {@link #MERGE_CUMULATOR} because it works only with
* one {@link ByteBuffer}.
*
* When using {@link OpenSslEngine}, we can use {@link #COMPOSITE_CUMULATOR} because it has
* {@link OpenSslEngine#unwrap(ByteBuffer[], ByteBuffer[])} which works with multiple {@link ByteBuffer}s
* and which does not need to do extra memory copies.
*/
setCumulator(opensslEngine ? COMPOSITE_CUMULATOR : MERGE_CUMULATOR);
}
public long getHandshakeTimeoutMillis() {
return handshakeTimeoutMillis;
}
public void setHandshakeTimeout(long handshakeTimeout, TimeUnit unit) {
if (unit == null) {
throw new NullPointerException("unit");
}
setHandshakeTimeoutMillis(unit.toMillis(handshakeTimeout));
}
public void setHandshakeTimeoutMillis(long handshakeTimeoutMillis) {
if (handshakeTimeoutMillis < 0) {
throw new IllegalArgumentException(
"handshakeTimeoutMillis: " + handshakeTimeoutMillis + " (expected: >= 0)");
}
this.handshakeTimeoutMillis = handshakeTimeoutMillis;
}
public long getCloseNotifyTimeoutMillis() {
return closeNotifyTimeoutMillis;
}
public void setCloseNotifyTimeout(long closeNotifyTimeout, TimeUnit unit) {
if (unit == null) {
throw new NullPointerException("unit");
}
setCloseNotifyTimeoutMillis(unit.toMillis(closeNotifyTimeout));
}
public void setCloseNotifyTimeoutMillis(long closeNotifyTimeoutMillis) {
if (closeNotifyTimeoutMillis < 0) {
throw new IllegalArgumentException(
"closeNotifyTimeoutMillis: " + closeNotifyTimeoutMillis + " (expected: >= 0)");
}
this.closeNotifyTimeoutMillis = closeNotifyTimeoutMillis;
}
/**
* Returns the {@link SSLEngine} which is used by this handler.
*/
public SSLEngine engine() {
return engine;
}
/**
* Returns a {@link Future} that will get notified once the current TLS handshake completes.
*
* @return the {@link Future} for the iniital TLS handshake if {@link #renegotiate()} was not invoked.
* The {@link Future} for the most recent {@linkplain #renegotiate() TLS renegotiation} otherwise.
*/
public Future<Channel> handshakeFuture() {
return handshakePromise;
}
/**
* Sends an SSL {@code close_notify} message to the specified channel and
* destroys the underlying {@link SSLEngine}.
*/
public ChannelFuture close() {
return close(ctx.newPromise());
}
/**
* See {@link #close()}
*/
public ChannelFuture close(final ChannelPromise future) {
final ChannelHandlerContext ctx = this.ctx;
ctx.executor().execute(new Runnable() {
@Override
public void run() {
engine.closeOutbound();
try {
write(ctx, Unpooled.EMPTY_BUFFER, future);
flush(ctx);
} catch (Exception e) {
if (!future.tryFailure(e)) {
logger.warn("{} flush() raised a masked exception.", ctx.channel(), e);
}
}
}
});
return future;
}
/**
* Return the {@link Future} that will get notified if the inbound of the {@link SSLEngine} is closed.
*
* This method will return the same {@link Future} all the time.
*
* @see SSLEngine
*/
public Future<Channel> sslCloseFuture() {
return sslCloseFuture;
}
@Override
public void handlerRemoved0(ChannelHandlerContext ctx) throws Exception {
if (!pendingUnencryptedWrites.isEmpty()) {
// Check if queue is not empty first because create a new ChannelException is expensive
pendingUnencryptedWrites.removeAndFailAll(new ChannelException("Pending write on removal of SslHandler"));
}
}
@Override
public void bind(ChannelHandlerContext ctx, SocketAddress localAddress, ChannelPromise promise) throws Exception {
ctx.bind(localAddress, promise);
}
@Override
public void connect(ChannelHandlerContext ctx, SocketAddress remoteAddress, SocketAddress localAddress,
ChannelPromise promise) throws Exception {
ctx.connect(remoteAddress, localAddress, promise);
}
@Override
public void deregister(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
ctx.deregister(promise);
}
@Override
public void disconnect(final ChannelHandlerContext ctx,
final ChannelPromise promise) throws Exception {
closeOutboundAndChannel(ctx, promise, true);
}
@Override
public void close(final ChannelHandlerContext ctx,
final ChannelPromise promise) throws Exception {
closeOutboundAndChannel(ctx, promise, false);
}
@Override
public void read(ChannelHandlerContext ctx) throws Exception {
if (!handshakePromise.isDone()) {
readDuringHandshake = true;
}
ctx.read();
}
@Override
public void write(final ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
pendingUnencryptedWrites.add(msg, promise);
}
@Override
public void flush(ChannelHandlerContext ctx) throws Exception {
// Do not encrypt the first write request if this handler is
// created with startTLS flag turned on.
if (startTls && !sentFirstMessage) {
sentFirstMessage = true;
pendingUnencryptedWrites.removeAndWriteAll();
ctx.flush();
return;
}
if (pendingUnencryptedWrites.isEmpty()) {
// It's important to NOT use a voidPromise here as the user
// may want to add a ChannelFutureListener to the ChannelPromise later.
//
// See https://github.com/netty/netty/issues/3364
pendingUnencryptedWrites.add(Unpooled.EMPTY_BUFFER, ctx.newPromise());
}
if (!handshakePromise.isDone()) {
flushedBeforeHandshake = true;
}
wrap(ctx, false);
ctx.flush();
}
private void wrap(ChannelHandlerContext ctx, boolean inUnwrap) throws SSLException {
ByteBuf out = null;
ChannelPromise promise = null;
ByteBufAllocator alloc = ctx.alloc();
try {
for (;;) {
Object msg = pendingUnencryptedWrites.current();
if (msg == null) {
break;
}
if (!(msg instanceof ByteBuf)) {
pendingUnencryptedWrites.removeAndWrite();
continue;
}
ByteBuf buf = (ByteBuf) msg;
if (out == null) {
out = allocateOutNetBuf(ctx, buf.readableBytes());
}
SSLEngineResult result = wrap(alloc, engine, buf, out);
if (!buf.isReadable()) {
promise = pendingUnencryptedWrites.remove();
} else {
promise = null;
}
if (result.getStatus() == Status.CLOSED) {
// SSLEngine has been closed already.
// Any further write attempts should be denied.
pendingUnencryptedWrites.removeAndFailAll(SSLENGINE_CLOSED);
return;
} else {
switch (result.getHandshakeStatus()) {
case NEED_TASK:
runDelegatedTasks();
break;
case FINISHED:
setHandshakeSuccess();
// deliberate fall-through
case NOT_HANDSHAKING:
setHandshakeSuccessIfStillHandshaking();
// deliberate fall-through
case NEED_WRAP:
finishWrap(ctx, out, promise, inUnwrap);
promise = null;
out = null;
break;
case NEED_UNWRAP:
return;
default:
throw new IllegalStateException(
"Unknown handshake status: " + result.getHandshakeStatus());
}
}
}
} catch (SSLException e) {
setHandshakeFailure(ctx, e);
throw e;
} finally {
finishWrap(ctx, out, promise, inUnwrap);
}
}
private void finishWrap(ChannelHandlerContext ctx, ByteBuf out, ChannelPromise promise, boolean inUnwrap) {
if (out == null) {
out = Unpooled.EMPTY_BUFFER;
} else if (!out.isReadable()) {
out.release();
out = Unpooled.EMPTY_BUFFER;
}
if (promise != null) {
ctx.write(out, promise);
} else {
ctx.write(out);
}
if (inUnwrap) {
needsFlush = true;
}
}
private void wrapNonAppData(ChannelHandlerContext ctx, boolean inUnwrap) throws SSLException {
ByteBuf out = null;
ByteBufAllocator alloc = ctx.alloc();
try {
for (;;) {
if (out == null) {
out = allocateOutNetBuf(ctx, 0);
}
SSLEngineResult result = wrap(alloc, engine, Unpooled.EMPTY_BUFFER, out);
if (result.bytesProduced() > 0) {
ctx.write(out);
if (inUnwrap) {
needsFlush = true;
}
out = null;
}
switch (result.getHandshakeStatus()) {
case FINISHED:
setHandshakeSuccess();
break;
case NEED_TASK:
runDelegatedTasks();
break;
case NEED_UNWRAP:
if (!inUnwrap) {
unwrapNonAppData(ctx);
}
break;
case NEED_WRAP:
break;
case NOT_HANDSHAKING:
setHandshakeSuccessIfStillHandshaking();
// Workaround for TLS False Start problem reported at:
// https://github.com/netty/netty/issues/1108#issuecomment-14266970
if (!inUnwrap) {
unwrapNonAppData(ctx);
}
break;
default:
throw new IllegalStateException("Unknown handshake status: " + result.getHandshakeStatus());
}
if (result.bytesProduced() == 0) {
break;
}
}
} catch (SSLException e) {
setHandshakeFailure(ctx, e);
throw e;
} finally {
if (out != null) {
out.release();
}
}
}
private SSLEngineResult wrap(ByteBufAllocator alloc, SSLEngine engine, ByteBuf in, ByteBuf out)
throws SSLException {
ByteBuf newDirectIn = null;
try {
int readerIndex = in.readerIndex();
int readableBytes = in.readableBytes();
// We will call SslEngine.wrap(ByteBuffer[], ByteBuffer) to allow efficient handling of
// CompositeByteBuf without force an extra memory copy when CompositeByteBuffer.nioBuffer() is called.
final ByteBuffer[] in0;
if (in.isDirect() || !wantsDirectBuffer) {
// As CompositeByteBuf.nioBufferCount() can be expensive (as it needs to check all composed ByteBuf
// to calculate the count) we will just assume a CompositeByteBuf contains more then 1 ByteBuf.
// The worst that can happen is that we allocate an extra ByteBuffer[] in CompositeByteBuf.nioBuffers()
// which is better then walking the composed ByteBuf in most cases.
if (!(in instanceof CompositeByteBuf) && in.nioBufferCount() == 1) {
in0 = singleBuffer;
// We know its only backed by 1 ByteBuffer so use internalNioBuffer to keep object allocation
// to a minimum.
in0[0] = in.internalNioBuffer(readerIndex, readableBytes);
} else {
in0 = in.nioBuffers();
}
} else {
// We could even go further here and check if its a CompositeByteBuf and if so try to decompose it and
// only replace the ByteBuffer that are not direct. At the moment we just will replace the whole
// CompositeByteBuf to keep the complexity to a minimum
newDirectIn = alloc.directBuffer(readableBytes);
newDirectIn.writeBytes(in, readerIndex, readableBytes);
in0 = singleBuffer;
in0[0] = newDirectIn.internalNioBuffer(0, readableBytes);
}
for (;;) {
ByteBuffer out0 = out.nioBuffer(out.writerIndex(), out.writableBytes());
SSLEngineResult result = engine.wrap(in0, out0);
in.skipBytes(result.bytesConsumed());
out.writerIndex(out.writerIndex() + result.bytesProduced());
switch (result.getStatus()) {
case BUFFER_OVERFLOW:
out.ensureWritable(maxPacketBufferSize);
break;
default:
return result;
}
}
} finally {
// Null out to allow GC of ByteBuffer
singleBuffer[0] = null;
if (newDirectIn != null) {
newDirectIn.release();
}
}
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
// Make sure to release SSLEngine,
// and notify the handshake future if the connection has been closed during handshake.
setHandshakeFailure(ctx, CHANNEL_CLOSED);
super.channelInactive(ctx);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
if (ignoreException(cause)) {
// It is safe to ignore the 'connection reset by peer' or
// 'broken pipe' error after sending close_notify.
if (logger.isDebugEnabled()) {
logger.debug(
"{} Swallowing a harmless 'connection reset by peer / broken pipe' error that occurred " +
"while writing close_notify in response to the peer's close_notify", ctx.channel(), cause);
}
// Close the connection explicitly just in case the transport
// did not close the connection automatically.
if (ctx.channel().isActive()) {
ctx.close();
}
} else {
ctx.fireExceptionCaught(cause);
}
}
/**
* Checks if the given {@link Throwable} can be ignore and just "swallowed"
*
* When an ssl connection is closed a close_notify message is sent.
* After that the peer also sends close_notify however, it's not mandatory to receive
* the close_notify. The party who sent the initial close_notify can close the connection immediately
* then the peer will get connection reset error.
*
*/
private boolean ignoreException(Throwable t) {
if (!(t instanceof SSLException) && t instanceof IOException && sslCloseFuture.isDone()) {
String message = String.valueOf(t.getMessage()).toLowerCase();
// first try to match connection reset / broke peer based on the regex. This is the fastest way
// but may fail on different jdk impls or OS's
if (IGNORABLE_ERROR_MESSAGE.matcher(message).matches()) {
return true;
}
// Inspect the StackTraceElements to see if it was a connection reset / broken pipe or not
StackTraceElement[] elements = t.getStackTrace();
for (StackTraceElement element: elements) {
String classname = element.getClassName();
String methodname = element.getMethodName();
// skip all classes that belong to the io.netty package
if (classname.startsWith("io.netty.")) {
continue;
}
// check if the method name is read if not skip it
if (!"read".equals(methodname)) {
continue;
}
// This will also match against SocketInputStream which is used by openjdk 7 and maybe
// also others
if (IGNORABLE_CLASS_IN_STACK.matcher(classname).matches()) {
return true;
}
try {
// No match by now.. Try to load the class via classloader and inspect it.
// This is mainly done as other JDK implementations may differ in name of
// the impl.
Class<?> clazz = PlatformDependent.getClassLoader(getClass()).loadClass(classname);
if (SocketChannel.class.isAssignableFrom(clazz)
|| DatagramChannel.class.isAssignableFrom(clazz)) {
return true;
}
// also match against SctpChannel via String matching as it may not present.
if (PlatformDependent.javaVersion() >= 7
&& "com.sun.nio.sctp.SctpChannel".equals(clazz.getSuperclass().getName())) {
return true;
}
} catch (ClassNotFoundException e) {
// This should not happen just ignore
}
}
}
return false;
}
/**
* Returns {@code true} if the given {@link ByteBuf} is encrypted. Be aware that this method
* will not increase the readerIndex of the given {@link ByteBuf}.
*
* @param buffer
* The {@link ByteBuf} to read from. Be aware that it must have at least 5 bytes to read,
* otherwise it will throw an {@link IllegalArgumentException}.
* @return encrypted
* {@code true} if the {@link ByteBuf} is encrypted, {@code false} otherwise.
* @throws IllegalArgumentException
* Is thrown if the given {@link ByteBuf} has not at least 5 bytes to read.
*/
public static boolean isEncrypted(ByteBuf buffer) {
if (buffer.readableBytes() < 5) {
throw new IllegalArgumentException("buffer must have at least 5 readable bytes");
}
return getEncryptedPacketLength(buffer, buffer.readerIndex()) != -1;
}
/**
* Return how much bytes can be read out of the encrypted data. Be aware that this method will not increase
* the readerIndex of the given {@link ByteBuf}.
*
* @param buffer
* The {@link ByteBuf} to read from. Be aware that it must have at least 5 bytes to read,
* otherwise it will throw an {@link IllegalArgumentException}.
* @return length
* The length of the encrypted packet that is included in the buffer. This will
* return {@code -1} if the given {@link ByteBuf} is not encrypted at all.
* @throws IllegalArgumentException
* Is thrown if the given {@link ByteBuf} has not at least 5 bytes to read.
*/
private static int getEncryptedPacketLength(ByteBuf buffer, int offset) {
int packetLength = 0;
// SSLv3 or TLS - Check ContentType
boolean tls;
switch (buffer.getUnsignedByte(offset)) {
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(offset + 1);
if (majorVersion == 3) {
// SSLv3 or TLS
packetLength = buffer.getUnsignedShort(offset + 3) + 5;
if (packetLength <= 5) {
// Neither SSLv3 or TLSv1 (i.e. SSLv2 or bad data)
tls = false;
}
} else {
// Neither SSLv3 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(offset) & 0x80) != 0 ? 2 : 3;
int majorVersion = buffer.getUnsignedByte(offset + headerLength + 1);
if (majorVersion == 2 || majorVersion == 3) {
// SSLv2
if (headerLength == 2) {
packetLength = (buffer.getShort(offset) & 0x7FFF) + 2;
} else {
packetLength = (buffer.getShort(offset) & 0x3FFF) + 3;
}
if (packetLength <= headerLength) {
sslv2 = false;
}
} else {
sslv2 = false;
}
if (!sslv2) {
return -1;
}
}
return packetLength;
}
@Override
protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws SSLException {
final int startOffset = in.readerIndex();
final int endOffset = in.writerIndex();
int offset = startOffset;
int totalLength = 0;
// If we calculated the length of the current SSL record before, use that information.
if (packetLength > 0) {
if (endOffset - startOffset < packetLength) {
return;
} else {
offset += packetLength;
totalLength = packetLength;
packetLength = 0;
}
}
boolean nonSslRecord = false;
while (totalLength < OpenSslEngine.MAX_ENCRYPTED_PACKET_LENGTH) {
final int readableBytes = endOffset - offset;
if (readableBytes < 5) {
break;
}
final int packetLength = getEncryptedPacketLength(in, offset);
if (packetLength == -1) {
nonSslRecord = true;
break;
}
assert packetLength > 0;
if (packetLength > readableBytes) {
// wait until the whole packet can be read
this.packetLength = packetLength;
break;
}
int newTotalLength = totalLength + packetLength;
if (newTotalLength > OpenSslEngine.MAX_ENCRYPTED_PACKET_LENGTH) {
// Don't read too much.
break;
}
// We have a whole packet.
// Increment the offset to handle the next packet.
offset += packetLength;
totalLength = newTotalLength;
}
if (totalLength > 0) {
// The buffer contains one or more full SSL records.
// Slice out the whole packet so unwrap will only be called with complete packets.
// Also directly reset the packetLength. This is needed as unwrap(..) may trigger
// decode(...) again via:
// 1) unwrap(..) is called
// 2) wrap(...) is called from within unwrap(...)
// 3) wrap(...) calls unwrapLater(...)
// 4) unwrapLater(...) calls decode(...)
//
// See https://github.com/netty/netty/issues/1534
in.skipBytes(totalLength);
// If SSLEngine expects a heap buffer for unwrapping, do the conversion.
if (in.isDirect() && wantsInboundHeapBuffer) {
ByteBuf copy = ctx.alloc().heapBuffer(totalLength);
try {
copy.writeBytes(in, startOffset, totalLength);
unwrap(ctx, copy, 0, totalLength);
} finally {
copy.release();
}
} else {
unwrap(ctx, in, startOffset, totalLength);
}
}
if (nonSslRecord) {
// Not an SSL/TLS packet
NotSslRecordException e = new NotSslRecordException(
"not an SSL/TLS record: " + ByteBufUtil.hexDump(in));
in.skipBytes(in.readableBytes());
ctx.fireExceptionCaught(e);
setHandshakeFailure(ctx, e);
}
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
if (needsFlush) {
needsFlush = false;
ctx.flush();
}
// If handshake is not finished yet, we need more data.
if (!handshakePromise.isDone() && !ctx.channel().config().isAutoRead()) {
ctx.read();
}
super.channelReadComplete(ctx);
}
/**
* Calls {@link SSLEngine#unwrap(ByteBuffer, ByteBuffer)} with an empty buffer to handle handshakes, etc.
*/
private void unwrapNonAppData(ChannelHandlerContext ctx) throws SSLException {
unwrap(ctx, Unpooled.EMPTY_BUFFER, 0, 0);
}
/**
* Unwraps inbound SSL records.
*/
private void unwrap(
ChannelHandlerContext ctx, ByteBuf packet, int offset, int length) throws SSLException {
boolean wrapLater = false;
boolean notifyClosure = false;
ByteBuf decodeOut = allocate(ctx, length);
try {
for (;;) {
final SSLEngineResult result = unwrap(engine, packet, offset, length, decodeOut);
final Status status = result.getStatus();
final HandshakeStatus handshakeStatus = result.getHandshakeStatus();
final int produced = result.bytesProduced();
final int consumed = result.bytesConsumed();
// Update indexes for the next iteration
offset += consumed;
length -= consumed;
if (status == Status.CLOSED) {
// notify about the CLOSED state of the SSLEngine. See #137
notifyClosure = true;
}
switch (handshakeStatus) {
case NEED_UNWRAP:
break;
case NEED_WRAP:
wrapNonAppData(ctx, true);
break;
case NEED_TASK:
runDelegatedTasks();
break;
case FINISHED:
setHandshakeSuccess();
wrapLater = true;
continue;
case NOT_HANDSHAKING:
if (setHandshakeSuccessIfStillHandshaking()) {
wrapLater = true;
continue;
}
if (flushedBeforeHandshake) {
// We need to call wrap(...) in case there was a flush done before the handshake completed.
//
// See https://github.com/netty/netty/pull/2437
flushedBeforeHandshake = false;
wrapLater = true;
}
break;
default:
throw new IllegalStateException("unknown handshake status: " + handshakeStatus);
}
if (status == Status.BUFFER_UNDERFLOW || consumed == 0 && produced == 0) {
break;
}
}
if (wrapLater) {
wrap(ctx, true);
}
if (notifyClosure) {
sslCloseFuture.trySuccess(ctx.channel());
}
} catch (SSLException e) {
setHandshakeFailure(ctx, e);
throw e;
} finally {
if (decodeOut.isReadable()) {
ctx.fireChannelRead(decodeOut);
} else {
decodeOut.release();
}
}
}
private SSLEngineResult unwrap(
SSLEngine engine, ByteBuf in, int readerIndex, int len, ByteBuf out) throws SSLException {
int nioBufferCount = in.nioBufferCount();
if (engine instanceof OpenSslEngine && nioBufferCount > 1) {
/**
* If {@link OpenSslEngine} is in use,
* we can use a special {@link OpenSslEngine#unwrap(ByteBuffer[], ByteBuffer[])} method
* that accepts multiple {@link ByteBuffer}s without additional memory copies.
*/
OpenSslEngine opensslEngine = (OpenSslEngine) engine;
int overflows = 0;
ByteBuffer[] in0 = in.nioBuffers(readerIndex, len);
try {
for (;;) {
int writerIndex = out.writerIndex();
int writableBytes = out.writableBytes();
ByteBuffer out0;
if (out.nioBufferCount() == 1) {
out0 = out.internalNioBuffer(writerIndex, writableBytes);
} else {
out0 = out.nioBuffer(writerIndex, writableBytes);
}
singleBuffer[0] = out0;
SSLEngineResult result = opensslEngine.unwrap(in0, singleBuffer);
out.writerIndex(out.writerIndex() + result.bytesProduced());
switch (result.getStatus()) {
case BUFFER_OVERFLOW:
int max = engine.getSession().getApplicationBufferSize();
switch (overflows ++) {
case 0:
out.ensureWritable(Math.min(max, in.readableBytes()));
break;
default:
out.ensureWritable(max);
}
break;
default:
return result;
}
}
} finally {
singleBuffer[0] = null;
}
} else {
int overflows = 0;
ByteBuffer in0;
if (nioBufferCount == 1) {
// Use internalNioBuffer to reduce object creation.
in0 = in.internalNioBuffer(readerIndex, len);
} else {
// This should never be true as this is only the case when OpenSslEngine is used, anyway lets
// guard against it.
in0 = in.nioBuffer(readerIndex, len);
}
for (;;) {
int writerIndex = out.writerIndex();
int writableBytes = out.writableBytes();
ByteBuffer out0;
if (out.nioBufferCount() == 1) {
out0 = out.internalNioBuffer(writerIndex, writableBytes);
} else {
out0 = out.nioBuffer(writerIndex, writableBytes);
}
SSLEngineResult result = engine.unwrap(in0, out0);
out.writerIndex(out.writerIndex() + result.bytesProduced());
switch (result.getStatus()) {
case BUFFER_OVERFLOW:
int max = engine.getSession().getApplicationBufferSize();
switch (overflows ++) {
case 0:
out.ensureWritable(Math.min(max, in.readableBytes()));
break;
default:
out.ensureWritable(max);
}
break;
default:
return result;
}
}
}
}
/**
* Fetches all delegated tasks from the {@link SSLEngine} and runs them via the {@link #delegatedTaskExecutor}.
* If the {@link #delegatedTaskExecutor} is {@link ImmediateExecutor}, just call {@link Runnable#run()} directly
* instead of using {@link Executor#execute(Runnable)}. Otherwise, run the tasks via
* the {@link #delegatedTaskExecutor} and wait until the tasks are finished.
*/
private void runDelegatedTasks() {
if (delegatedTaskExecutor == ImmediateExecutor.INSTANCE) {
for (;;) {
Runnable task = engine.getDelegatedTask();
if (task == null) {
break;
}
task.run();
}
} else {
final List<Runnable> tasks = new ArrayList<Runnable>(2);
for (;;) {
final Runnable task = engine.getDelegatedTask();
if (task == null) {
break;
}
tasks.add(task);
}
if (tasks.isEmpty()) {
return;
}
final CountDownLatch latch = new CountDownLatch(1);
delegatedTaskExecutor.execute(new Runnable() {
@Override
public void run() {
try {
for (Runnable task: tasks) {
task.run();
}
} catch (Exception e) {
ctx.fireExceptionCaught(e);
} finally {
latch.countDown();
}
}
});
boolean interrupted = false;
while (latch.getCount() != 0) {
try {
latch.await();
} catch (InterruptedException e) {
// Interrupt later.
interrupted = true;
}
}
if (interrupted) {
Thread.currentThread().interrupt();
}
}
}
/**
* Works around some Android {@link SSLEngine} implementations that skip {@link HandshakeStatus#FINISHED} and
* go straight into {@link HandshakeStatus#NOT_HANDSHAKING} when handshake is finished.
*
* @return {@code true} if and only if the workaround has been applied and thus {@link #handshakeFuture} has been
* marked as success by this method
*/
private boolean setHandshakeSuccessIfStillHandshaking() {
if (!handshakePromise.isDone()) {
setHandshakeSuccess();
return true;
}
return false;
}
/**
* Notify all the handshake futures about the successfully handshake
*/
private void setHandshakeSuccess() {
// Work around the JVM crash which occurs when a cipher suite with GCM enabled.
final String cipherSuite = String.valueOf(engine.getSession().getCipherSuite());
if (!wantsDirectBuffer && (cipherSuite.contains("_GCM_") || cipherSuite.contains("-GCM-"))) {
wantsInboundHeapBuffer = true;
}
handshakePromise.trySuccess(ctx.channel());
if (logger.isDebugEnabled()) {
logger.debug("{} HANDSHAKEN: {}", ctx.channel(), engine.getSession().getCipherSuite());
}
ctx.fireUserEventTriggered(SslHandshakeCompletionEvent.SUCCESS);
if (readDuringHandshake && !ctx.channel().config().isAutoRead()) {
readDuringHandshake = false;
ctx.read();
}
}
/**
* Notify all the handshake futures about the failure during the handshake.
*/
private void setHandshakeFailure(ChannelHandlerContext ctx, Throwable cause) {
// Release all resources such as internal buffers that SSLEngine
// is managing.
engine.closeOutbound();
try {
engine.closeInbound();
} catch (SSLException e) {
// only log in debug mode as it most likely harmless and latest chrome still trigger
// this all the time.
//
// See https://github.com/netty/netty/issues/1340
String msg = e.getMessage();
if (msg == null || !msg.contains("possible truncation attack")) {
logger.debug("{} SSLEngine.closeInbound() raised an exception.", ctx.channel(), e);
}
}
notifyHandshakeFailure(cause);
pendingUnencryptedWrites.removeAndFailAll(cause);
}
private void notifyHandshakeFailure(Throwable cause) {
if (handshakePromise.tryFailure(cause)) {
ctx.fireUserEventTriggered(new SslHandshakeCompletionEvent(cause));
ctx.close();
}
}
private void closeOutboundAndChannel(
final ChannelHandlerContext ctx, final ChannelPromise promise, boolean disconnect) throws Exception {
if (!ctx.channel().isActive()) {
if (disconnect) {
ctx.disconnect(promise);
} else {
ctx.close(promise);
}
return;
}
engine.closeOutbound();
ChannelPromise closeNotifyFuture = ctx.newPromise();
write(ctx, Unpooled.EMPTY_BUFFER, closeNotifyFuture);
flush(ctx);
safeClose(ctx, closeNotifyFuture, promise);
}
@Override
public void handlerAdded(final ChannelHandlerContext ctx) throws Exception {
this.ctx = ctx;
pendingUnencryptedWrites = new PendingWriteQueue(ctx);
if (ctx.channel().isActive() && engine.getUseClientMode()) {
// Begin the initial handshake.
// channelActive() event has been fired already, which means this.channelActive() will
// not be invoked. We have to initialize here instead.
handshake(null);
} else {
// channelActive() event has not been fired yet. this.channelOpen() will be invoked
// and initialization will occur there.
}
}
/**
* Performs TLS renegotiation.
*/
public Future<Channel> renegotiate() {
ChannelHandlerContext ctx = this.ctx;
if (ctx == null) {
throw new IllegalStateException();
}
return renegotiate(ctx.executor().<Channel>newPromise());
}
/**
* Performs TLS renegotiation.
*/
public Future<Channel> renegotiate(final Promise<Channel> promise) {
if (promise == null) {
throw new NullPointerException("promise");
}
ChannelHandlerContext ctx = this.ctx;
if (ctx == null) {
throw new IllegalStateException();
}
EventExecutor executor = ctx.executor();
if (!executor.inEventLoop()) {
executor.execute(new OneTimeTask() {
@Override
public void run() {
handshake(promise);
}
});
return promise;
}
handshake(promise);
return promise;
}
/**
* Performs TLS (re)negotiation.
*
* @param newHandshakePromise if {@code null}, use the existing {@link #handshakePromise},
* assuming that the current negotiation has not been finished.
* Currently, {@code null} is expected only for the initial handshake.
*/
private void handshake(final Promise<Channel> newHandshakePromise) {
final Promise<Channel> p;
if (newHandshakePromise != null) {
final Promise<Channel> oldHandshakePromise = handshakePromise;
if (!oldHandshakePromise.isDone()) {
// There's no need to handshake because handshake is in progress already.
// Merge the new promise into the old one.
oldHandshakePromise.addListener(new FutureListener<Channel>() {
@Override
public void operationComplete(Future<Channel> future) throws Exception {
if (future.isSuccess()) {
newHandshakePromise.setSuccess(future.getNow());
} else {
newHandshakePromise.setFailure(future.cause());
}
}
});
return;
}
handshakePromise = p = newHandshakePromise;
} else {
// Forced to reuse the old handshake.
p = handshakePromise;
assert !p.isDone();
}
// Begin handshake.
final ChannelHandlerContext ctx = this.ctx;
try {
engine.beginHandshake();
wrapNonAppData(ctx, false);
ctx.flush();
} catch (Exception e) {
notifyHandshakeFailure(e);
}
// Set timeout if necessary.
final long handshakeTimeoutMillis = this.handshakeTimeoutMillis;
if (handshakeTimeoutMillis <= 0 || p.isDone()) {
return;
}
final ScheduledFuture<?> timeoutFuture = ctx.executor().schedule(new Runnable() {
@Override
public void run() {
if (p.isDone()) {
return;
}
notifyHandshakeFailure(HANDSHAKE_TIMED_OUT);
}
}, handshakeTimeoutMillis, TimeUnit.MILLISECONDS);
// Cancel the handshake timeout when handshake is finished.
p.addListener(new FutureListener<Channel>() {
@Override
public void operationComplete(Future<Channel> f) throws Exception {
timeoutFuture.cancel(false);
}
});
}
/**
* Issues an initial TLS handshake once connected when used in client-mode
*/
@Override
public void channelActive(final ChannelHandlerContext ctx) throws Exception {
if (!startTls && engine.getUseClientMode()) {
// Begin the initial handshake
handshake(null);
}
ctx.fireChannelActive();
}
private void safeClose(
final ChannelHandlerContext ctx, ChannelFuture flushFuture,
final ChannelPromise promise) {
if (!ctx.channel().isActive()) {
ctx.close(promise);
return;
}
final ScheduledFuture<?> timeoutFuture;
if (closeNotifyTimeoutMillis > 0) {
// Force-close the connection if close_notify is not fully sent in time.
timeoutFuture = ctx.executor().schedule(new Runnable() {
@Override
public void run() {
logger.warn("{} Last write attempt timed out; force-closing the connection.", ctx.channel());
ctx.close(promise);
}
}, closeNotifyTimeoutMillis, TimeUnit.MILLISECONDS);
} else {
timeoutFuture = null;
}
// Close the connection if close_notify is sent in time.
flushFuture.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture f)
throws Exception {
if (timeoutFuture != null) {
timeoutFuture.cancel(false);
}
// Trigger the close in all cases to make sure the promise is notified
// See https://github.com/netty/netty/issues/2358
ctx.close(promise);
}
});
}
/**
* Always prefer a direct buffer when it's pooled, so that we reduce the number of memory copies
* in {@link OpenSslEngine}.
*/
private ByteBuf allocate(ChannelHandlerContext ctx, int capacity) {
ByteBufAllocator alloc = ctx.alloc();
if (wantsDirectBuffer) {
return alloc.directBuffer(capacity);
} else {
return alloc.buffer(capacity);
}
}
/**
* Allocates an outbound network buffer for {@link SSLEngine#wrap(ByteBuffer, ByteBuffer)} which can encrypt
* the specified amount of pending bytes.
*/
private ByteBuf allocateOutNetBuf(ChannelHandlerContext ctx, int pendingBytes) {
if (wantsLargeOutboundNetworkBuffer) {
return allocate(ctx, maxPacketBufferSize);
} else {
return allocate(ctx, Math.min(
pendingBytes + OpenSslEngine.MAX_ENCRYPTION_OVERHEAD_LENGTH,
maxPacketBufferSize));
}
}
private final class LazyChannelPromise extends DefaultPromise<Channel> {
@Override
protected EventExecutor executor() {
if (ctx == null) {
throw new IllegalStateException();
}
return ctx.executor();
}
}
}