OF-2738: Include SNI when setting up outbound server-to-server connec…

…tion

When setting up an outbound server-to-server connection, Openfire should send along an indication to what domain name it is attempting to connect. This will help the recipient server to process the connection for the correct vhost when that server is hosting multipe XMPP domains on the same server (ejabberd allows for this, for example).

xmppserver/src/main/java/org/jivesoftware/openfire/nio/NettyConnection.java

@@ -348,14 +348,19 @@ public void startTLS(boolean clientMode, boolean directTLS) throws Exception {
 
         final EncryptionArtifactFactory factory = new EncryptionArtifactFactory( configuration );
 
-        final SslContext sslContext;
+        final SslHandler sslHandler;
         if (clientMode) {
-            sslContext = factory.createClientModeSslContext();
+            final SslContext sslContext = factory.createClientModeSslContext();
+
+            // OF-2738: Send along the XMPP domain that's needed for SNI
+            final NettyOutboundConnectionHandler handler = channelHandlerContext.channel().pipeline().get(NettyOutboundConnectionHandler.class);
+
+            sslHandler = sslContext.newHandler(channelHandlerContext.alloc(), handler.getDomainPair().getRemote(), handler.getPort());
         } else {
-            sslContext = factory.createServerModeSslContext(directTLS);
+            final SslContext sslContext = factory.createServerModeSslContext(directTLS);
+            sslHandler = sslContext.newHandler(channelHandlerContext.alloc());
         }
 
-        final SslHandler sslHandler = sslContext.newHandler(channelHandlerContext.alloc());
         channelHandlerContext.pipeline().addFirst(SSL_HANDLER_NAME, sslHandler);
 
         if ( !clientMode && !directTLS ) {

xmppserver/src/main/java/org/jivesoftware/openfire/nio/NettyOutboundConnectionHandler.java

@@ -212,6 +212,16 @@ private boolean connectionConfigDoesNotRequireTls() {
         return this.configuration.getTlsPolicy() != Connection.TLSPolicy.required;
     }
 
+    public DomainPair getDomainPair()
+    {
+        return domainPair;
+    }
+
+    public int getPort()
+    {
+        return port;
+    }
+
     @Override
     public String toString()
     {