/*
 * Copyright (c) 1999, 2018, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.
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package com.sun.jndi.ldap;

import jdk.internal.access.SharedSecrets;

import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.AccessControlContext;
import java.security.AccessController;
import java.security.PrivilegedAction;

public final class VersionHelper {

    private static final VersionHelper helper = new VersionHelper();

    
Determines whether classes may be loaded from an arbitrary URL code base.
/** * Determines whether classes may be loaded from an arbitrary URL code base. */
private static final boolean trustURLCodebase; static { // System property to control whether classes may be loaded from an // arbitrary URL code base PrivilegedAction<String> act = () -> System.getProperty("com.sun.jndi.ldap.object.trustURLCodebase", "false"); String trust = AccessController.doPrivileged(act); trustURLCodebase = "true".equalsIgnoreCase(trust); } private VersionHelper() { } static VersionHelper getVersionHelper() { return helper; } ClassLoader getURLClassLoader(String[] url) throws MalformedURLException { ClassLoader parent = getContextClassLoader(); /* * Classes may only be loaded from an arbitrary URL code base when * the system property com.sun.jndi.ldap.object.trustURLCodebase * has been set to "true". */ if (url != null && trustURLCodebase) { return URLClassLoader.newInstance(getUrlArray(url), parent); } else { return parent; } } Class<?> loadClass(String className) throws ClassNotFoundException { return Class.forName(className, true, getContextClassLoader()); } Thread createThread(Runnable r) { AccessControlContext acc = AccessController.getContext(); // 4290486: doPrivileged is needed to create a thread in // an environment that restricts "modifyThreadGroup". PrivilegedAction<Thread> act = () -> SharedSecrets.getJavaLangAccess().newThreadWithAcc(r, acc); return AccessController.doPrivileged(act); } private ClassLoader getContextClassLoader() { PrivilegedAction<ClassLoader> act = Thread.currentThread()::getContextClassLoader; return AccessController.doPrivileged(act); } private static URL[] getUrlArray(String[] url) throws MalformedURLException { URL[] urlArray = new URL[url.length]; for (int i = 0; i < urlArray.length; i++) { urlArray[i] = new URL(url[i]); } return urlArray; } }