Add wolfjsse.autoSNI Security property

README.md

@@ -531,6 +531,12 @@ are enabled in different ways depending on the JDK implementation. For
 Oracle/OpenJDK and variants, this System property enables session tickets and
 was added in Java 13. Should be set to "true" to enable.
 
+**wolfjsse.autoSNI (boolean)** - Controls automatic Server Name Indication (SNI)
+extension setting based on hostname or peer address. When set to "true", enables
+legacy behavior where SNI is automatically configured from hostname/peer information
+even without explicit SSLParameters configuration. Default value is "false", where
+SNI is only set when explicitly configured through SSLParameters.
+
 If there are other System properties you would like to use with wolfJSSE,
 please contact [email protected].
 

src/java/com/wolfssl/provider/jsse/WolfSSLEngineHelper.java

@@ -876,7 +876,6 @@ private static boolean checkBooleanProperty(String prop,
      * what String.
      */
     private void setLocalServerNames() {
-
         /* Do not add SNI if system property has been set to false */
         boolean enableSNI =
             checkBooleanProperty("jsse.enableSNIExtension", true);
@@ -886,6 +885,13 @@ private void setLocalServerNames() {
         boolean trustNameService =
             checkBooleanProperty("jdk.tls.trustNameService", false);
 
+        /*
+         * Check if automatic SNI setting is enabled via Security property.
+         * This allows users to enable legacy hostname-based SNI behavior
+         * through java.security configuration rather than JVM arguments. */
+        boolean autoSNI = "true".equalsIgnoreCase(
+            Security.getProperty("wolfjsse.autoSNI"));
+
         if (!enableSNI) {
             WolfSSLDebug.log(getClass(), WolfSSLDebug.INFO,
                 "jsse.enableSNIExtension property set to false, " +
@@ -904,8 +910,7 @@ else if (this.clientMode) {
                 if (sni != null) {
                     this.ssl.useSNI((byte)sni.getType(), sni.getEncoded());
                 }
-
-            } else {
+            } else if (autoSNI) {
                 if (this.peerAddr != null && trustNameService) {
                     WolfSSLDebug.log(getClass(), WolfSSLDebug.INFO,
                         "setting SNI extension with " +
@@ -914,8 +919,7 @@ else if (this.clientMode) {
 
                     this.ssl.useSNI((byte)0,
                         this.peerAddr.getHostName().getBytes());
-                }
-                else if (this.hostname != null) {
+                } else if (this.hostname != null) {
                     if (peerAddr != null) {
                         WolfSSLDebug.log(getClass(), WolfSSLDebug.INFO,
                             "jdk.tls.trustNameService not set to true, " +
@@ -930,12 +934,13 @@ else if (this.hostname != null) {
                             "hostname: " + this.hostname);
                     }
                     this.ssl.useSNI((byte)0, this.hostname.getBytes());
-
-                }
-                else {
+                } else {
                     WolfSSLDebug.log(getClass(), WolfSSLDebug.INFO,
                         "hostname and peerAddr are null, not setting SNI");
                 }
+            } else {
+                WolfSSLDebug.log(getClass(), WolfSSLDebug.INFO,
+                    "No SNI configured through SSLParameters, not setting SNI");
             }
         }
     }

src/test/com/wolfssl/provider/jsse/test/WolfSSLSocketTest.java

@@ -3287,6 +3287,102 @@ public Void call() throws Exception {
 
         System.out.println("\t... passed");
     }
+    @Test
+    public void testAutoSNIProperty() throws Exception {
+        System.out.print("\tTesting autoSNI property");
+
+        /* Save original Security property value */
+        String originalProp = Security.getProperty("wolfjsse.autoSNI");
+
+        try {
+            /* Test with autoSNI enabled */
+            Security.setProperty("wolfjsse.autoSNI", "true");
+
+            /* Create new CTX */
+            this.ctx = tf.createSSLContext("TLS", ctxProvider);
+
+            /* Create SSLServerSocket first to get ephemeral port */
+            SSLServerSocket ss = (SSLServerSocket)ctx.getServerSocketFactory()
+                .createServerSocket(0);
+
+            /* Set up test arguments without explicit SNI configuration.
+            * With autoSNI=true, SNI should be automatically set based on hostname */
+            TestArgs sArgs = new TestArgs(null,
+                            null, true,
+                            true,
+                            true,
+                            null);
+            TestArgs cArgs = new TestArgs(null,
+                            null,
+                            false,
+                            false,
+                            true,
+                            null);
+
+            CountDownLatch sDoneLatch = new CountDownLatch(1);
+            CountDownLatch cDoneLatch = new CountDownLatch(1);
+
+            TestServer server = new TestServer(this.ctx, ss, sArgs, 1, sDoneLatch);
+            server.start();
+
+            TestClient client = new TestClient(this.ctx, ss.getLocalPort(), cArgs,
+                cDoneLatch);
+            client.start();
+
+            cDoneLatch.await();
+            sDoneLatch.await();
+
+            Exception srvException = server.getException();
+            if (srvException != null) {
+                throw srvException;
+            }
+
+            Exception cliException = client.getException();
+            if (cliException != null) {
+                throw cliException;
+            }
+
+            /* Test with autoSNI disabled */
+            Security.setProperty("wolfjsse.autoSNI", "false");
+
+            ss = (SSLServerSocket)ctx.getServerSocketFactory()
+                .createServerSocket(0);
+
+            sDoneLatch = new CountDownLatch(1);
+            cDoneLatch = new CountDownLatch(1);
+
+            server = new TestServer(this.ctx, ss, sArgs,
+                            1, sDoneLatch);
+            server.start();
+
+            client = new TestClient(this.ctx, ss.getLocalPort(), cArgs,
+                cDoneLatch);
+            client.start();
+
+            cDoneLatch.await();
+            sDoneLatch.await();
+
+            srvException = server.getException();
+            if (srvException != null) {
+                throw srvException;
+            }
+
+            cliException = client.getException();
+            if (cliException != null) {
+                throw cliException;
+            }
+
+            System.out.println("\t\t... passed");
+
+        } finally {
+            /* Restore original property value */
+            if (originalProp != null) {
+                Security.setProperty("wolfjsse.autoSNI", originalProp);
+            } else {
+                Security.setProperty("wolfjsse.autoSNI", "true");
+            }
+        }
+    }
 
     /**
      * Inner class used to hold configuration options for