SslHandler.setHandshakeTimeout*(...) should also been enforced on the server side.

Motivation:

We should also enforce the handshake timeout on the server-side to allow closing connections which will not finish the handshake in an expected amount of time.

Modifications:

- Enforce the timeout on the server and client side
- Add unit test.

Result:

Fixes [#7230].

handler/src/main/java/io/netty/handler/ssl/SslHandler.java

@@ -1536,11 +1536,15 @@ public class SslHandler extends ByteToMessageDecoder implements ChannelOutboundH
     public void handlerAdded(final ChannelHandlerContext ctx) throws Exception {
         this.ctx = ctx;
 
-        if (ctx.channel().isActive() && engine.getUseClientMode()) {
+        if (ctx.channel().isActive()) {
-            // Begin the initial handshake.
+            if (engine.getUseClientMode()) {
-            // channelActive() event has been fired already, which means this.channelActive() will
+                // Begin the initial handshake.
-            // not be invoked. We have to initialize here instead.
+                // channelActive() event has been fired already, which means this.channelActive() will
-            handshake(null);
+                // not be invoked. We have to initialize here instead.
+                handshake(null);
+            } else {
+                applyHandshakeTimeout(null);
+            }
         } else {
             // channelActive() event has not been fired yet.  this.channelOpen() will be invoked
             // and initialization will occur there.
@@ -1635,17 +1639,21 @@ public class SslHandler extends ByteToMessageDecoder implements ChannelOutboundH
         } finally {
            forceFlush(ctx);
         }
+        applyHandshakeTimeout(p);
+    }
 
+    private void applyHandshakeTimeout(Promise<Channel> p) {
+        final Promise<Channel> promise = p == null ? handshakePromise : p;
         // Set timeout if necessary.
         final long handshakeTimeoutMillis = this.handshakeTimeoutMillis;
-        if (handshakeTimeoutMillis <= 0 || p.isDone()) {
+        if (handshakeTimeoutMillis <= 0 || promise.isDone()) {
             return;
         }
 
         final ScheduledFuture<?> timeoutFuture = ctx.executor().schedule(new Runnable() {
             @Override
             public void run() {
-                if (p.isDone()) {
+                if (promise.isDone()) {
                     return;
                 }
                 notifyHandshakeFailure(HANDSHAKE_TIMED_OUT);
@@ -1653,7 +1661,7 @@ public class SslHandler extends ByteToMessageDecoder implements ChannelOutboundH
         }, handshakeTimeoutMillis, TimeUnit.MILLISECONDS);
 
         // Cancel the handshake timeout when handshake is finished.
-        p.addListener(new FutureListener<Channel>() {
+        promise.addListener(new FutureListener<Channel>() {
             @Override
             public void operationComplete(Future<Channel> f) throws Exception {
                 timeoutFuture.cancel(false);
@@ -1671,9 +1679,13 @@ public class SslHandler extends ByteToMessageDecoder implements ChannelOutboundH
      */
     @Override
     public void channelActive(final ChannelHandlerContext ctx) throws Exception {
-        if (!startTls && engine.getUseClientMode()) {
+        if (!startTls) {
-            // Begin the initial handshake
+            if (engine.getUseClientMode()) {
-            handshake(null);
+                // Begin the initial handshake.
+                handshake(null);
+            } else {
+                applyHandshakeTimeout(null);
+            }
         }
         ctx.fireChannelActive();
     }

handler/src/test/java/io/netty/handler/ssl/SslHandlerTest.java

@@ -85,6 +85,36 @@ import static org.junit.Assume.assumeTrue;
 
 public class SslHandlerTest {
 
+    @Test(expected = SSLException.class, timeout = 3000)
+    public void testClientHandshakeTimeout() throws Exception {
+        testHandshakeTimeout(true);
+    }
+
+    @Test(expected = SSLException.class, timeout = 3000)
+    public void testServerHandshakeTimeout() throws Exception {
+        testHandshakeTimeout(false);
+    }
+
+    private static void testHandshakeTimeout(boolean client) throws Exception {
+        SSLEngine engine = SSLContext.getDefault().createSSLEngine();
+        engine.setUseClientMode(client);
+        SslHandler handler = new SslHandler(engine);
+        handler.setHandshakeTimeoutMillis(1);
+
+        EmbeddedChannel ch = new EmbeddedChannel(handler);
+        try {
+            while (!handler.handshakeFuture().isDone()) {
+                Thread.sleep(10);
+                // We need to run all pending tasks as the handshake timeout is scheduled on the EventLoop.
+                ch.runPendingTasks();
+            }
+
+            handler.handshakeFuture().syncUninterruptibly();
+        } finally {
+            ch.finishAndReleaseAll();
+        }
+    }
+
     @Test
     public void testTruncatedPacket() throws Exception {
         SSLEngine engine = SSLContext.getDefault().createSSLEngine();