OF-2534: Support inline XEP-0198 <enable/> in SASL2 Bind2 requests

xmppserver/src/main/java/org/jivesoftware/openfire/SessionManager.java

@@ -38,6 +38,8 @@
 import org.jivesoftware.openfire.session.*;
 import org.jivesoftware.openfire.spi.BasicStreamIDFactory;
 import org.jivesoftware.openfire.spi.ConnectionType;
+import org.jivesoftware.openfire.handler.Bind2StreamManagementHandler;
+import org.jivesoftware.openfire.net.Bind2Request;
 import org.jivesoftware.openfire.streammanagement.TerminationDelegate;
 import org.jivesoftware.util.*;
 import org.jivesoftware.util.cache.*;
@@ -270,6 +272,7 @@ public class SessionManager extends BasicModule implements ClusterEventListener
     private RoutingTable routingTable;
 
     private StreamIDFactory streamIDFactory;
+    private Bind2StreamManagementHandler bind2StreamManagementHandler;
 
     /**
      * Returns the instance of <CODE>SessionManagerImpl</CODE> being used by the XMPPServer.
@@ -1897,10 +1900,15 @@ private Message createServerMessage(String subject, String body) {
     }
 
     @Override
-    public void start() throws IllegalStateException {
+    public synchronized void start() throws IllegalStateException {
         super.start();
         localSessionManager.start();
 
+        // Register the XEP-0198 Stream Management handler for SASL2 Bind2 inline feature processing.
+        final Bind2StreamManagementHandler localHandler = new Bind2StreamManagementHandler();
+        Bind2Request.registerElementHandler(localHandler);
+        bind2StreamManagementHandler = localHandler; // Only dereference any previous handler after registration succeeds, otherwise that previous handler can never be removed again.
+
         // Run through the server sessions every 10% of the time of the maximum time that a session is allowed to be
         // detached, or every 3 minutes if the max time is outside the default boundaries.
         // TODO Reschedule task if getSessionDetachTime value changes.
@@ -1915,8 +1923,14 @@ public void start() throws IllegalStateException {
     }
 
     @Override
-    public void stop() {
+    public synchronized void stop() {
         Log.debug("SessionManager: Stopping server");
+
+        if (bind2StreamManagementHandler != null) {
+            Bind2Request.unregisterElementHandler(bind2StreamManagementHandler);
+            bind2StreamManagementHandler = null;
+        }
+
         // Stop threads that are sending packets to remote servers
         OutgoingSessionPromise.getInstance().shutdown();
         if (JiveGlobals.getBooleanProperty("shutdownMessage.enabled")) {

xmppserver/src/main/java/org/jivesoftware/openfire/handler/Bind2StreamManagementHandler.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2026 Ignite Realtime Foundation. All rights reserved.
+ *
+ * Licensed 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 org.jivesoftware.openfire.handler;
+
+import org.dom4j.Element;
+import org.jivesoftware.openfire.net.Bind2InlineHandler;
+import org.jivesoftware.openfire.session.LocalClientSession;
+import org.jivesoftware.openfire.streammanagement.StreamManagementException;
+import org.jivesoftware.openfire.streammanagement.StreamManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.xmpp.packet.PacketError;
+
+/**
+ * A {@link Bind2InlineHandler} that processes XEP-0198 Stream Management {@code <enable/>} elements
+ * sent inline within a SASL2 Bind2 request (XEP-0388 / XEP-0386).
+ *
+ * <p>When a client includes an {@code <enable/>} element in the {@code urn:xmpp:sm:3} namespace
+ * inside its Bind2 {@code <bind/>} element, this handler delegates to the session's
+ * {@link StreamManager} to enable stream management (and optionally resumption) immediately
+ * after resource binding, without requiring a separate round-trip.</p>
+ *
+ * <p>The {@code <enabled/>} response from the server is added as a child of the {@code <bound/>}
+ * element in the SASL2 {@code <success/>} stanza.</p>
+ *
+ * @see <a href="https://xmpp.org/extensions/xep-0198.html">XEP-0198: Stream Management</a>
+ * @see <a href="https://xmpp.org/extensions/xep-0388.html">XEP-0388: Extensible SASL Profile</a>
+ */
+public class Bind2StreamManagementHandler implements Bind2InlineHandler {
+
+    private static final Logger Log = LoggerFactory.getLogger(Bind2StreamManagementHandler.class);
+
+    @Override
+    public String getNamespace() {
+        return StreamManager.NAMESPACE_V3;
+    }
+
+    @Override
+    public boolean isEnabled() {
+        return StreamManager.isStreamManagementActive();
+    }
+
+    /**
+     * Handles an {@code <enable/>} element from a Bind2 inline feature request by enabling
+     * XEP-0198 stream management on the session. The {@code <enabled/>} response element
+     * produced by the stream manager is added as a child of the provided {@code bound} element.
+     *
+     * <p>Only {@code <enable/>} elements are processed; any other element name is ignored.</p>
+     *
+     * @param session the client session on which stream management should be enabled
+     * @param bound   the {@code <bound/>} element to which the {@code <enabled/>} response is added
+     * @param element the inline element from the Bind2 request (expected to be {@code <enable/>})
+     * @return {@code true} if the element was an {@code <enable/>} and was processed;
+     *         {@code false} if the element was not an {@code <enable/>} or processing failed
+     */
+    @Override
+    public boolean handleElement(LocalClientSession session, Element bound, Element element) {
+        if (!"enable".equals(element.getName())) {
+            Log.debug("Received unexpected element '{}'; ignoring.", element.getName());
+            return false;
+        }
+        final String resumeAttr = element.attributeValue("resume");
+        final boolean resume = "true".equalsIgnoreCase(resumeAttr) || "1".equals(resumeAttr) || "yes".equalsIgnoreCase(resumeAttr);
+        bound.add(session.getStreamManager().enableAndBuildElement(getNamespace(), resume));
+        return true;
+    }
+
+    /**
+     * Adds the {@code <failed/>} element that XEP-0198 § 9.1.1 requires inside {@code <bound/>} when stream
+     * management could not be enabled.
+     *
+     * The condition is taken from the failure itself where one is available. A handler that declined the request
+     * without failing did so because the element was not an {@code <enable/>}, which is a malformed request.
+     */
+    @Override
+    public void handleFailure(LocalClientSession session, Element bound, Element element, Exception cause) {
+        final PacketError.Condition condition;
+        if (cause instanceof StreamManagementException sme) {
+            condition = sme.getCondition();
+        } else if (cause == null) {
+            condition = PacketError.Condition.bad_request;
+        } else {
+            condition = PacketError.Condition.internal_server_error;
+        }
+        bound.addElement("failed", StreamManager.NAMESPACE_V3)
+            .addElement(condition.toXMPP(), "urn:ietf:params:xml:ns:xmpp-stanzas");
+    }
+}