/*
* Copyright (c) 1995, 2006, 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.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package sun.applet;
import java.io.File;
import java.io.FilePermission;
import java.io.IOException;
import java.io.FileDescriptor;
import java.net.URL;
import java.net.URLClassLoader;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.net.SocketPermission;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.HashSet;
import java.util.StringTokenizer;
import java.security.*;
import java.lang.reflect.*;
import sun.awt.AWTSecurityManager;
import sun.awt.AppContext;
import sun.security.provider.*;
import sun.security.util.SecurityConstants;
/**
* This class defines an applet security policy
*
*/
public
class AppletSecurity extends AWTSecurityManager {
private AppContext mainAppContext;
//URLClassLoader.acc
private static Field facc = null;
//AccessControlContext.context;
private static Field fcontext = null;
static {
try {
facc = URLClassLoader.class.getDeclaredField("acc");
facc.setAccessible(true);
fcontext = AccessControlContext.class.getDeclaredField("context");
fcontext.setAccessible(true);
} catch (NoSuchFieldException e) {
throw new UnsupportedOperationException(e);
}
}
/**
* Construct and initialize.
*/
public AppletSecurity() {
reset();
mainAppContext = AppContext.getAppContext();
}
// Cache to store known restricted packages
private HashSet restrictedPackages = new HashSet();
/**
* Reset from Properties
*/
public void reset()
{
// Clear cache
restrictedPackages.clear();
AccessController.doPrivileged(new PrivilegedAction() {
public Object run()
{
// Enumerate system properties
Enumeration e = System.getProperties().propertyNames();
while (e.hasMoreElements())
{
String name = (String) e.nextElement();
if (name != null && name.startsWith("package.restrict.access."))
{
String value = System.getProperty(name);
if (value != null && value.equalsIgnoreCase("true"))
{
String pkg = name.substring(24);
// Cache restricted packages
restrictedPackages.add(pkg);
}
}
}
return null;
}
});
}
/**
* get the current (first) instance of an AppletClassLoader on the stack.
*/
private AppletClassLoader currentAppletClassLoader()
{
// try currentClassLoader first
ClassLoader loader = currentClassLoader();
if ((loader == null) || (loader instanceof AppletClassLoader))
return (AppletClassLoader)loader;
// if that fails, get all the classes on the stack and check them.
Class[] context = getClassContext();
for (int i = 0; i < context.length; i++) {
loader = context[i].getClassLoader();
if (loader instanceof AppletClassLoader)
return (AppletClassLoader)loader;
}
/*
* fix bug # 6433620 the logic here is : try to find URLClassLoader from
* class context, check its AccessControlContext to see if
* AppletClassLoader is in stack when it's created. for this kind of
* URLClassLoader, return the AppContext assocated with the
* AppletClassLoader.
*/
for (int i = 0; i < context.length; i++) {
final ClassLoader currentLoader = context[i].getClassLoader();
if (currentLoader instanceof URLClassLoader) {
loader = (ClassLoader) AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
AccessControlContext acc = null;
ProtectionDomain[] pds = null;
try {
acc = (AccessControlContext) facc.get(currentLoader);
if (acc == null) {
return null;
}
pds = (ProtectionDomain[]) fcontext.get(acc);
if (pds == null) {
return null;
}
} catch (Exception e) {
throw new UnsupportedOperationException(e);
}
for (int i=0; i<pds.length; i++) {
ClassLoader cl = pds[i].getClassLoader();
if (cl instanceof AppletClassLoader) {
return cl;
}
}
return null;
}
});
if (loader != null) {
return (AppletClassLoader) loader;
}
}
}
// if that fails, try the context class loader
loader = Thread.currentThread().getContextClassLoader();
if (loader instanceof AppletClassLoader)
return (AppletClassLoader)loader;
// no AppletClassLoaders on the stack
return (AppletClassLoader)null;
}
/**
* Returns true if this threadgroup is in the applet's own thread
* group. This will return false if there is no current class
* loader.
*/
protected boolean inThreadGroup(ThreadGroup g) {
if (currentAppletClassLoader() == null)
return false;
else
return getThreadGroup().parentOf(g);
}
/**
* Returns true of the threadgroup of thread is in the applet's
* own threadgroup.
*/
protected boolean inThreadGroup(Thread thread) {
return inThreadGroup(thread.getThreadGroup());
}
/**
* Applets are not allowed to manipulate threads outside
* applet thread groups. However a terminated thread no longer belongs
* to any group.
*/
public void checkAccess(Thread t) {
/* When multiple applets is reloaded simultaneously, there will be
* multiple invocations to this method from plugin's SecurityManager.
* This method should not be synchronized to avoid deadlock when
* a page with multiple applets is reloaded
*/
if ((t.getState() != Thread.State.TERMINATED) && !inThreadGroup(t)) {
checkPermission(SecurityConstants.MODIFY_THREAD_PERMISSION);
}
}
private boolean inThreadGroupCheck = false;
/**
* Applets are not allowed to manipulate thread groups outside
* applet thread groups.
*/
public synchronized void checkAccess(ThreadGroup g) {
if (inThreadGroupCheck) {
// if we are in a recursive check, it is because
// inThreadGroup is calling appletLoader.getThreadGroup
// in that case, only do the super check, as appletLoader
// has a begin/endPrivileged
checkPermission(SecurityConstants.MODIFY_THREADGROUP_PERMISSION);
} else {
try {
inThreadGroupCheck = true;
if (!inThreadGroup(g)) {
checkPermission(SecurityConstants.MODIFY_THREADGROUP_PERMISSION);
}
} finally {
inThreadGroupCheck = false;
}
}
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to access the package specified by
* the argument.
* <p>
* This method is used by the <code>loadClass</code> method of class
* loaders.
* <p>
* The <code>checkPackageAccess</code> method for class
* <code>SecurityManager</code> calls
* <code>checkPermission</code> with the
* <code>RuntimePermission("accessClassInPackage."+pkg)</code>
* permission.
*
* @param pkg the package name.
* @exception SecurityException if the caller does not have
* permission to access the specified package.
* @see java.lang.ClassLoader#loadClass(java.lang.String, boolean)
*/
public void checkPackageAccess(final String pkgname) {
// first see if the VM-wide policy allows access to this package
super.checkPackageAccess(pkgname);
// now check the list of restricted packages
for (Iterator iter = restrictedPackages.iterator(); iter.hasNext();)
{
String pkg = (String) iter.next();
// Prevent matching "sun" and "sunir" even if they
// starts with similar beginning characters
//
if (pkgname.equals(pkg) || pkgname.startsWith(pkg + "."))
{
checkPermission(new java.lang.RuntimePermission
("accessClassInPackage." + pkgname));
}
}
}
/**
* Tests if a client can get access to the AWT event queue.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>AWTPermission("accessEventQueue")</code> permission.
*
* @since JDK1.1
* @exception SecurityException if the caller does not have
* permission to accesss the AWT event queue.
*/
public void checkAwtEventQueueAccess() {
AppContext appContext = AppContext.getAppContext();
AppletClassLoader appletClassLoader = currentAppletClassLoader();
if ((appContext == mainAppContext) && (appletClassLoader != null)) {
// If we're about to allow access to the main EventQueue,
// and anything untrusted is on the class context stack,
// disallow access.
super.checkAwtEventQueueAccess();
}
} // checkAwtEventQueueAccess()
/**
* Returns the thread group of the applet. We consult the classloader
* if there is one.
*/
public ThreadGroup getThreadGroup() {
/* If any applet code is on the execution stack, we return
that applet's ThreadGroup. Otherwise, we use the default
behavior. */
AppletClassLoader appletLoader = currentAppletClassLoader();
ThreadGroup loaderGroup = (appletLoader == null) ? null
: appletLoader.getThreadGroup();
if (loaderGroup != null) {
return loaderGroup;
} else {
return super.getThreadGroup();
}
} // getThreadGroup()
/**
* Get the AppContext corresponding to the current context.
* The default implementation returns null, but this method
* may be overridden by various SecurityManagers
* (e.g. AppletSecurity) to index AppContext objects by the
* calling context.
*
* @return the AppContext corresponding to the current context.
* @see sun.awt.AppContext
* @see java.lang.SecurityManager
* @since JDK1.2.1
*/
public AppContext getAppContext() {
AppletClassLoader appletLoader = currentAppletClassLoader();
if (appletLoader == null) {
return null;
} else {
AppContext context = appletLoader.getAppContext();
// context == null when some thread in applet thread group
// has not been destroyed in AppContext.dispose()
if (context == null) {
throw new SecurityException("Applet classloader has invalid AppContext");
}
return context;
}
}
} // class AppletSecurity