Remove java.xml from system modules

docs/changelog/133671.yaml

@@ -0,0 +1,5 @@
+pr: 133671
+summary: Remove `java.xml` from system modules
+area: Infra/Core
+type: bug
+issues: []

libs/entitlement/qa/entitlement-test-plugin/src/main/java/org/elasticsearch/entitlement/qa/test/FileCheckActions.java

@@ -13,6 +13,7 @@
 import org.elasticsearch.core.SuppressForbidden;
 import org.elasticsearch.entitlement.qa.entitled.EntitledActions;
 import org.elasticsearch.env.Environment;
+import org.xml.sax.helpers.DefaultHandler;
 
 import java.io.File;
 import java.io.FileDescriptor;
@@ -39,6 +40,7 @@
 import java.util.zip.ZipFile;
 
 import javax.imageio.stream.FileImageInputStream;
+import javax.xml.parsers.SAXParserFactory;
 
 import static java.nio.charset.Charset.defaultCharset;
 import static java.nio.file.StandardOpenOption.CREATE;
@@ -610,5 +612,12 @@ static void javaDesktopFileAccess() throws Exception {
         new FileImageInputStream(file.toFile()).close();
     }
 
+    @EntitlementTest(expectedAccess = ALWAYS_DENIED)
+    static void javaXmlFileRequest() throws Exception {
+        // java.xml is part of the jdk, but not a system module. this checks it can't access files
+        var saxParser = SAXParserFactory.newInstance().newSAXParser();
+        saxParser.parse(readFile().toFile(), new DefaultHandler());
+    }
+
     private FileCheckActions() {}
 }

libs/entitlement/qa/entitlement-test-plugin/src/main/java/org/elasticsearch/entitlement/qa/test/JvmActions.java

@@ -18,6 +18,9 @@
 import java.util.Locale;
 import java.util.TimeZone;
 
+import javax.xml.parsers.SAXParserFactory;
+
+import static org.elasticsearch.entitlement.qa.test.EntitlementTest.ExpectedAccess.ALWAYS_ALLOWED;
 import static org.elasticsearch.entitlement.qa.test.EntitlementTest.ExpectedAccess.ALWAYS_DENIED;
 import static org.elasticsearch.entitlement.qa.test.EntitlementTest.ExpectedAccess.PLUGINS;
 
@@ -80,5 +83,12 @@ static void createLogManager() {
         Thread.setDefaultUncaughtExceptionHandler(Thread.getDefaultUncaughtExceptionHandler());
     }
 
+    @EntitlementTest(expectedAccess = ALWAYS_ALLOWED)
+    static void useJavaXmlParser() {
+        // java.xml is part of the jdk, but not a system module. this checks it's actually usable
+        // as it needs to read classes from the jdk which is not generally allowed
+        SAXParserFactory.newInstance();
+    }
+
     private JvmActions() {}
 }

libs/entitlement/qa/entitlement-test-plugin/src/main/java/org/elasticsearch/entitlement/qa/test/NetworkAccessCheckActions.java

@@ -10,6 +10,7 @@
 package org.elasticsearch.entitlement.qa.test;
 
 import org.elasticsearch.core.SuppressForbidden;
+import org.xml.sax.helpers.DefaultHandler;
 
 import java.io.IOException;
 import java.net.DatagramPacket;
@@ -46,6 +47,7 @@
 
 import javax.net.ssl.HttpsURLConnection;
 import javax.net.ssl.SSLContext;
+import javax.xml.parsers.SAXParserFactory;
 
 import static org.elasticsearch.entitlement.qa.test.EntitlementTest.ExpectedAccess.ALWAYS_DENIED;
 import static org.elasticsearch.entitlement.qa.test.EntitlementTest.ExpectedAccess.PLUGINS;
@@ -434,5 +436,12 @@ static void receiveDatagramSocket() throws IOException {
         }
     }
 
+    @EntitlementTest(expectedAccess = ALWAYS_DENIED)
+    static void javaXmlNetworkRequest() throws Exception {
+        // java.xml is part of the jdk, but not a system module. this checks it can't access the network
+        var saxParser = SAXParserFactory.newInstance().newSAXParser();
+        saxParser.parse("http://127.0.0.1/foo.json", new DefaultHandler());
+    }
+
     private NetworkAccessCheckActions() {}
 }

libs/entitlement/src/main/java/org/elasticsearch/entitlement/bootstrap/HardcodedEntitlements.java

@@ -21,6 +21,7 @@
 import org.elasticsearch.entitlement.runtime.policy.entitlements.LoadNativeLibrariesEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.ManageThreadsEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.OutboundNetworkEntitlement;
+import org.elasticsearch.entitlement.runtime.policy.entitlements.ReadJdkImageEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.ReadStoreAttributesEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.SetHttpsConnectionPropertiesEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.WriteSystemPropertiesEntitlement;
@@ -114,6 +115,21 @@ private static List<Scope> createServerEntitlements(Path pidFile) {
                 )
             ),
             new Scope("java.desktop", List.of(new LoadNativeLibrariesEntitlement())),
+            new Scope(
+                "java.xml",
+                List.of(
+                    new ReadJdkImageEntitlement(),
+                    // java.xml does some reflective stuff that reads calling jars, so allow reading the codebases
+                    // of any code in the system so that they can all use java.xml
+                    new FilesEntitlement(
+                        List.of(
+                            FilesEntitlement.FileData.ofBaseDirPath(LIB, READ),
+                            FilesEntitlement.FileData.ofBaseDirPath(MODULES, READ),
+                            FilesEntitlement.FileData.ofBaseDirPath(PLUGINS, READ)
+                        )
+                    )
+                )
+            ),
             new Scope("org.apache.httpcomponents.httpclient", List.of(new OutboundNetworkEntitlement())),
             new Scope(
                 "org.apache.lucene.core",

libs/entitlement/src/main/java/org/elasticsearch/entitlement/runtime/policy/PolicyCheckerImpl.java

@@ -21,6 +21,7 @@
 import org.elasticsearch.entitlement.runtime.policy.entitlements.LoadNativeLibrariesEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.ManageThreadsEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.OutboundNetworkEntitlement;
+import org.elasticsearch.entitlement.runtime.policy.entitlements.ReadJdkImageEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.ReadStoreAttributesEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.SetHttpsConnectionPropertiesEntitlement;
 import org.elasticsearch.entitlement.runtime.policy.entitlements.WriteSystemPropertiesEntitlement;
@@ -490,6 +491,8 @@ public void checkEntitlementForUrl(Class<?> callerClass, URL url) {
             if (jarFileUrl == null || handleNetworkOrFileUrlCheck(callerClass, jarFileUrl) == false) {
                 checkUnsupportedURLProtocolConnection(callerClass, "jar with unsupported inner protocol");
             }
+        } else if (isJrtUrl(url)) {
+            checkEntitlementPresent(callerClass, ReadJdkImageEntitlement.class);
         } else {
             checkUnsupportedURLProtocolConnection(callerClass, url.getProtocol());
         }
@@ -560,6 +563,10 @@ private static boolean isJarUrl(java.net.URL url) {
         return "jar".equals(url.getProtocol());
     }
 
+    private static boolean isJrtUrl(java.net.URL url) {
+        return "jrt".equals(url.getProtocol());
+    }
+
     // We have to use class names for sun.net.www classes as java.base does not export them
     private static final List<String> ADDITIONAL_NETWORK_URL_CONNECT_CLASS_NAMES = List.of(
         "sun.net.www.protocol.ftp.FtpURLConnection",

libs/entitlement/src/main/java/org/elasticsearch/entitlement/runtime/policy/PolicyManager.java

@@ -54,7 +54,7 @@ public class PolicyManager {
      */
     static final Logger generalLogger = LogManager.getLogger(PolicyManager.class);
 
-    static final Set<String> MODULES_EXCLUDED_FROM_SYSTEM_MODULES = Set.of("java.desktop");
+    static final Set<String> MODULES_EXCLUDED_FROM_SYSTEM_MODULES = Set.of("java.desktop", "java.xml");
 
     /**
      * Identifies a particular entitlement {@link Scope} within a {@link Policy}.

libs/entitlement/src/main/java/org/elasticsearch/entitlement/runtime/policy/entitlements/ReadJdkImageEntitlement.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+package org.elasticsearch.entitlement.runtime.policy.entitlements;
+
+/**
+ * Internal entitlement to read code from the jdk.
+ *
+ * Concretely this means the code can open jrt urls. Since the java
+ * runtime images (jrt) are read only, this implicitly only allows
+ * reading those urls.
+ */
+public class ReadJdkImageEntitlement implements Entitlement {}