Issue #4385 - Limit new UnsupportedOperationException to direct SslContextFactory usage

jetty-util/src/main/java/org/eclipse/jetty/util/ssl/SslContextFactory.java

@@ -1249,10 +1249,17 @@ protected KeyManager[] getKeyManagers(KeyStore keyStore) throws Exception
                 // Is SNI needed to select a certificate?
                 if (!_certWilds.isEmpty() || _certHosts.size() > 1 || (_certHosts.size() == 1 && _aliasX509.size() > 1))
                 {
-                    for (int idx = 0; idx < managers.length; idx++)
+                    if (this instanceof SslContextFactory.Server)
                     {
-                        if (managers[idx] instanceof X509ExtendedKeyManager)
-                            managers[idx] = newSniX509ExtendedKeyManager((X509ExtendedKeyManager)managers[idx]);
+                        for (int idx = 0; idx < managers.length; idx++)
+                        {
+                            if (managers[idx] instanceof X509ExtendedKeyManager)
+                                managers[idx] = newSniX509ExtendedKeyManager((X509ExtendedKeyManager)managers[idx]);
+                        }
+                    }
+                    else
+                    {
+                        LOG.warn("Unable to support SNI on {} (expecting {})", this.getClass().getName(), SslContextFactory.Server.class.getName());
                     }
                 }
             }
@@ -1270,7 +1277,7 @@ protected KeyManager[] getKeyManagers(KeyStore keyStore) throws Exception
     @Deprecated
     protected X509ExtendedKeyManager newSniX509ExtendedKeyManager(X509ExtendedKeyManager keyManager)
     {
-        throw new UnsupportedOperationException("X509ExtendedKeyManager only supported on Server");
+        throw new UnsupportedOperationException("X509ExtendedKeyManager only supported on " + SslContextFactory.Server.class.getName());
     }
 
     protected TrustManager[] getTrustManagers(KeyStore trustStore, Collection<? extends CRL> crls) throws Exception

jetty-util/src/test/java/org/eclipse/jetty/util/ssl/X509Test.java

@@ -18,10 +18,13 @@
 
 package org.eclipse.jetty.util.ssl;
 
+import java.nio.file.Path;
 import java.security.cert.X509Certificate;
 import javax.net.ssl.KeyManager;
 import javax.net.ssl.X509ExtendedKeyManager;
 
+import org.eclipse.jetty.toolchain.test.MavenTestingUtils;
+import org.eclipse.jetty.util.resource.PathResource;
 import org.eclipse.jetty.util.resource.Resource;
 import org.junit.jupiter.api.Test;
 
@@ -162,16 +165,27 @@ public void testSniX509ExtendedKeyManager_BaseClass() throws Exception
         SslContextFactory baseSsl = new SslContextFactory();
         X509ExtendedKeyManager x509ExtendedKeyManager = getX509ExtendedKeyManager(baseSsl);
         UnsupportedOperationException npe = assertThrows(UnsupportedOperationException.class, () -> baseSsl.newSniX509ExtendedKeyManager(x509ExtendedKeyManager));
-        assertThat("UnsupportedOperationException.message", npe.getMessage(), containsString("X509ExtendedKeyManager only supported on Server"));
+        assertThat("UnsupportedOperationException.message", npe.getMessage(), containsString("X509ExtendedKeyManager only supported on " + SslContextFactory.Server.class.getName()));
+    }
+
+    @Test
+    public void testSniX509ExtendedKeyManager_BaseClass_Start() throws Exception
+    {
+        SslContextFactory baseSsl = new SslContextFactory();
+        Path keystorePath = MavenTestingUtils.getTestResourcePathFile("keystore_sni.p12");
+        baseSsl.setKeyStoreResource(new PathResource(keystorePath));
+        baseSsl.setKeyStorePassword("OBF:1vny1zlo1x8e1vnw1vn61x8g1zlu1vn4");
+        baseSsl.setKeyManagerPassword("OBF:1u2u1wml1z7s1z7a1wnl1u2g");
+        baseSsl.start(); // should not throw an exception
     }
 
     @Test
     public void testSniX509ExtendedKeyManager_ClientClass() throws Exception
     {
         SslContextFactory clientSsl = new SslContextFactory.Client();
         X509ExtendedKeyManager x509ExtendedKeyManager = getX509ExtendedKeyManager(clientSsl);
-        UnsupportedOperationException re = assertThrows(UnsupportedOperationException.class, () -> clientSsl.newSniX509ExtendedKeyManager(x509ExtendedKeyManager));
-        assertThat("UnsupportedOperationException.message", re.getMessage(), containsString("X509ExtendedKeyManager only supported on Server"));
+        X509ExtendedKeyManager sniX509ExtendedKeyManager = clientSsl.newSniX509ExtendedKeyManager(x509ExtendedKeyManager);
+        assertThat("SNI X509 ExtendedKeyManager is undefined in Client mode", sniX509ExtendedKeyManager, is(x509ExtendedKeyManager));
     }
 
     @Test