8217633: Configurable extensions with system properties

Reviewed-by: rhalade, jnimeh

Author: XueleiFan

src/java.base/share/classes/sun/security/ssl/SSLExtension.java

@@ -28,10 +28,9 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.text.MessageFormat;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.LinkedList;
-import java.util.Locale;
+import java.util.*;
+
+import sun.security.action.GetPropertyAction;
 import sun.security.ssl.SSLHandshake.HandshakeMessage;
 import sun.security.util.HexDumpEncoder;
 
@@ -648,8 +647,8 @@ void absentOnTrade(ConnectionContext context,
     }
 
     public boolean isAvailable(ProtocolVersion protocolVersion) {
-        for (int i = 0; i < supportedProtocols.length; i++) {
-            if (supportedProtocols[i] == protocolVersion) {
+        for (ProtocolVersion supportedProtocol : supportedProtocols) {
+            if (supportedProtocol == protocolVersion) {
                 return true;
             }
         }
@@ -713,18 +712,23 @@ static final class ClientExtensions {
         static final Collection<SSLExtension> defaults;
 
         static {
+            Collection<String> clientDisabledExtensions =
+                    getDisabledExtensions("jdk.tls.client.disableExtensions");
             Collection<SSLExtension> extensions = new LinkedList<>();
             for (SSLExtension extension : SSLExtension.values()) {
-                if (extension.handshakeType != SSLHandshake.NOT_APPLICABLE) {
+                if (extension.handshakeType != SSLHandshake.NOT_APPLICABLE &&
+                        !clientDisabledExtensions.contains(extension.name)) {
                     extensions.add(extension);
                 }
             }
 
-            // Switch off SNI extention?
-            boolean enableExtension =
-                Utilities.getBooleanProperty("jsse.enableSNIExtension", true);
-            if (!enableExtension) {
-                extensions.remove(CH_SERVER_NAME);
+            // Switch off SNI extension?
+            if (extensions.contains(CH_SERVER_NAME)) {
+                boolean enableExtension = Utilities.getBooleanProperty(
+                        "jsse.enableSNIExtension", true);
+                if (!enableExtension) {
+                    extensions.remove(CH_SERVER_NAME);
+                }
             }
 
             // To switch off the max_fragment_length extension.
@@ -735,13 +739,15 @@ static final class ClientExtensions {
             // the two properties set to true, the extension is switch on.
             // We may remove the "jsse.enableMFLExtension" property in the
             // future.  Please don't continue to use the misspelling property.
-            enableExtension =
-                Utilities.getBooleanProperty(
-                        "jsse.enableMFLNExtension", false) ||
-                Utilities.getBooleanProperty(
-                        "jsse.enableMFLExtension", false);
-            if (!enableExtension) {
-                extensions.remove(CH_MAX_FRAGMENT_LENGTH);
+            if (extensions.contains(CH_MAX_FRAGMENT_LENGTH)) {
+                boolean enableExtension =
+                        Utilities.getBooleanProperty(
+                                "jsse.enableMFLNExtension", false) ||
+                        Utilities.getBooleanProperty(
+                                "jsse.enableMFLExtension", false);
+                if (!enableExtension) {
+                    extensions.remove(CH_MAX_FRAGMENT_LENGTH);
+                }
             }
 
             // To switch on certificate_authorities extension in ClientHello.
@@ -782,10 +788,12 @@ static final class ClientExtensions {
             // lot in practice.  When there is a need to use this extension
             // in ClientHello handshake message, please take care of the
             // potential compatibility and interoperability issues above.
-            enableExtension = Utilities.getBooleanProperty(
-                    "jdk.tls.client.enableCAExtension", false);
-            if (!enableExtension) {
-                extensions.remove(CH_CERTIFICATE_AUTHORITIES);
+            if (extensions.contains(CH_CERTIFICATE_AUTHORITIES)) {
+                boolean enableExtension = Utilities.getBooleanProperty(
+                        "jdk.tls.client.enableCAExtension", false);
+                if (!enableExtension) {
+                    extensions.remove(CH_CERTIFICATE_AUTHORITIES);
+                }
             }
 
             defaults = Collections.unmodifiableCollection(extensions);
@@ -797,14 +805,51 @@ static final class ServerExtensions {
         static final Collection<SSLExtension> defaults;
 
         static {
+            Collection<String> serverDisabledExtensions =
+                    getDisabledExtensions("jdk.tls.server.disableExtensions");
             Collection<SSLExtension> extensions = new LinkedList<>();
             for (SSLExtension extension : SSLExtension.values()) {
-                if (extension.handshakeType != SSLHandshake.NOT_APPLICABLE) {
+                if (extension.handshakeType != SSLHandshake.NOT_APPLICABLE &&
+                        !serverDisabledExtensions.contains(extension.name)) {
                     extensions.add(extension);
                 }
             }
 
             defaults = Collections.unmodifiableCollection(extensions);
         }
     }
+
+    // Get disabled extensions, which could be customized with System Properties.
+    private static Collection<String> getDisabledExtensions(
+                String propertyName) {
+        String property = GetPropertyAction.privilegedGetProperty(propertyName);
+        if (SSLLogger.isOn && SSLLogger.isOn("ssl,sslctx")) {
+            SSLLogger.fine(
+                    "System property " + propertyName + " is set to '" +
+                            property + "'");
+        }
+        if (property != null && !property.isEmpty()) {
+            // remove double quote marks from beginning/end of the property
+            if (property.length() > 1 && property.charAt(0) == '"' &&
+                    property.charAt(property.length() - 1) == '"') {
+                property = property.substring(1, property.length() - 1);
+            }
+        }
+
+        if (property != null && !property.isEmpty()) {
+            String[] extensionNames = property.split(",");
+            Collection<String> extensions =
+                    new ArrayList<>(extensionNames.length);
+            for (String extension : extensionNames) {
+                extension = extension.trim();
+                if (!extension.isEmpty()) {
+                    extensions.add(extension);
+                }
+            }
+
+            return extensions;
+        }
+
+        return Collections.emptyList();
+    }
 }

test/jdk/sun/security/ssl/SSLSocketImpl/DisableExtensions.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8217633
+ * @library /javax/net/ssl/templates
+ * @summary Configurable extensions with system properties
+ * @run main/othervm DisableExtensions supported_versions TLSv1.3 fail
+ * @run main/othervm DisableExtensions supported_versions TLSv1.2
+ */
+
+import javax.net.ssl.SSLSocket;
+import javax.net.ssl.SSLException;
+
+public class DisableExtensions extends SSLSocketTemplate {
+
+    private final String[] protocols;
+
+    public DisableExtensions(String[] protocols) {
+        this.protocols = protocols;
+    }
+
+    @Override
+    protected void configureClientSocket(SSLSocket socket) {
+        socket.setEnabledProtocols(protocols);
+    }
+
+    // Run the test case.
+    //
+    // Check that the extension could be disabled, and the impact may be
+    // different for different protocols.
+    public static void main(String[] args) throws Exception {
+        System.setProperty("jdk.tls.client.disableExtensions", args[0]);
+
+        boolean shouldSuccess = (args.length != 3);
+
+        try {
+            (new DisableExtensions(new String[] {args[1]})).run();
+        } catch (SSLException | IllegalStateException ssle) {
+            if (shouldSuccess) {
+                throw new RuntimeException(
+                        "The extension " + args[0] + " is disabled");
+            }
+
+            return;
+        }
+
+        if (!shouldSuccess) {
+            throw new RuntimeException(
+                    "The extension " + args[0] +
+                    " should be disabled and the connection should fail");
+        }
+    }
+}