author | xuelei |
Sat, 15 Mar 2008 13:43:05 -0400 | |
changeset 97 | 5c029f131927 |
parent 2 | 90ce3da70b43 |
child 476 | b23646c026ed |
permissions | -rw-r--r-- |
2 | 1 |
/* |
97
5c029f131927
6648816: REGRESSION: setting -Djava.security.debug=failure result in NPE in ACC
xuelei
parents:
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diff
changeset
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* Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Sun designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Sun in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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* CA 95054 USA or visit www.sun.com if you need additional information or |
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* have any questions. |
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*/ |
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package java.security; |
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import java.util.ArrayList; |
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import java.util.List; |
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import sun.security.util.Debug; |
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import sun.security.util.SecurityConstants; |
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/** |
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* An AccessControlContext is used to make system resource access decisions |
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* based on the context it encapsulates. |
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* |
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* <p>More specifically, it encapsulates a context and |
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* has a single method, <code>checkPermission</code>, |
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* that is equivalent to the <code>checkPermission</code> method |
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* in the AccessController class, with one difference: The AccessControlContext |
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* <code>checkPermission</code> method makes access decisions based on the |
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* context it encapsulates, |
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* rather than that of the current execution thread. |
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* |
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* <p>Thus, the purpose of AccessControlContext is for those situations where |
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* a security check that should be made within a given context |
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* actually needs to be done from within a |
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* <i>different</i> context (for example, from within a worker thread). |
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* |
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* <p> An AccessControlContext is created by calling the |
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* <code>AccessController.getContext</code> method. |
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* The <code>getContext</code> method takes a "snapshot" |
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* of the current calling context, and places |
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* it in an AccessControlContext object, which it returns. A sample call is |
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* the following: |
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* |
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* <pre> |
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* AccessControlContext acc = AccessController.getContext() |
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* </pre> |
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* |
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* <p> |
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* Code within a different context can subsequently call the |
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* <code>checkPermission</code> method on the |
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* previously-saved AccessControlContext object. A sample call is the |
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* following: |
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* |
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* <pre> |
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* acc.checkPermission(permission) |
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* </pre> |
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* |
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* @see AccessController |
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* |
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* @author Roland Schemers |
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*/ |
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public final class AccessControlContext { |
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private ProtectionDomain context[]; |
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private boolean isPrivileged; |
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// Note: This field is directly used by the virtual machine |
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// native codes. Don't touch it. |
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private AccessControlContext privilegedContext; |
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private DomainCombiner combiner = null; |
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private static boolean debugInit = false; |
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private static Debug debug = null; |
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static Debug getDebug() |
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{ |
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if (debugInit) |
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return debug; |
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else { |
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if (Policy.isSet()) { |
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debug = Debug.getInstance("access"); |
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debugInit = true; |
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} |
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return debug; |
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} |
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} |
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/** |
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* Create an AccessControlContext with the given set of ProtectionDomains. |
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* Context must not be null. Duplicate domains will be removed from the |
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* context. |
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* |
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* @param context the ProtectionDomains associated with this context. |
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* The non-duplicate domains are copied from the array. Subsequent |
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* changes to the array will not affect this AccessControlContext. |
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*/ |
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public AccessControlContext(ProtectionDomain context[]) |
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{ |
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if (context.length == 0) { |
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this.context = null; |
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} else if (context.length == 1) { |
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if (context[0] != null) { |
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this.context = context.clone(); |
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} else { |
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this.context = null; |
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} |
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} else { |
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List<ProtectionDomain> v = new ArrayList<ProtectionDomain>(context.length); |
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for (int i =0; i< context.length; i++) { |
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if ((context[i] != null) && (!v.contains(context[i]))) |
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v.add(context[i]); |
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} |
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this.context = new ProtectionDomain[v.size()]; |
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this.context = v.toArray(this.context); |
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} |
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} |
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/** |
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* Create a new <code>AccessControlContext</code> with the given |
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* <code>AccessControlContext</code> and <code>DomainCombiner</code>. |
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* This constructor associates the provided |
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* <code>DomainCombiner</code> with the provided |
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* <code>AccessControlContext</code>. |
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* |
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* <p> |
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* |
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* @param acc the <code>AccessControlContext</code> associated |
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* with the provided <code>DomainCombiner</code>. |
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* |
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* @param combiner the <code>DomainCombiner</code> to be associated |
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* with the provided <code>AccessControlContext</code>. |
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* |
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* @exception NullPointerException if the provided |
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* <code>context</code> is <code>null</code>. |
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* |
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* @exception SecurityException if a security manager is installed and the |
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* caller does not have the "createAccessControlContext" |
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* {@link SecurityPermission} |
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* @since 1.3 |
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*/ |
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public AccessControlContext(AccessControlContext acc, |
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DomainCombiner combiner) { |
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SecurityManager sm = System.getSecurityManager(); |
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if (sm != null) { |
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sm.checkPermission(SecurityConstants.CREATE_ACC_PERMISSION); |
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} |
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this.context = acc.context; |
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// we do not need to run the combine method on the |
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// provided ACC. it was already "combined" when the |
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// context was originally retrieved. |
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// |
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// at this point in time, we simply throw away the old |
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// combiner and use the newly provided one. |
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this.combiner = combiner; |
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} |
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/** |
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* package private for AccessController |
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*/ |
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AccessControlContext(ProtectionDomain context[], DomainCombiner combiner) { |
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if (context != null) { |
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this.context = context.clone(); |
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} |
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this.combiner = combiner; |
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} |
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/** |
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* package private constructor for AccessController.getContext() |
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*/ |
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AccessControlContext(ProtectionDomain context[], |
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boolean isPrivileged) |
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{ |
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this.context = context; |
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this.isPrivileged = isPrivileged; |
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} |
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/** |
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* Returns true if this context is privileged. |
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*/ |
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boolean isPrivileged() |
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{ |
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return isPrivileged; |
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} |
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/** |
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* get the assigned combiner from the privileged or inherited context |
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*/ |
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DomainCombiner getAssignedCombiner() { |
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AccessControlContext acc; |
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if (isPrivileged) { |
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acc = privilegedContext; |
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} else { |
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acc = AccessController.getInheritedAccessControlContext(); |
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} |
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if (acc != null) { |
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return acc.combiner; |
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} |
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return null; |
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} |
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/** |
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* Get the <code>DomainCombiner</code> associated with this |
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* <code>AccessControlContext</code>. |
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* |
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* <p> |
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* |
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* @return the <code>DomainCombiner</code> associated with this |
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* <code>AccessControlContext</code>, or <code>null</code> |
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* if there is none. |
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* |
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* @exception SecurityException if a security manager is installed and |
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* the caller does not have the "getDomainCombiner" |
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* {@link SecurityPermission} |
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* @since 1.3 |
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*/ |
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public DomainCombiner getDomainCombiner() { |
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SecurityManager sm = System.getSecurityManager(); |
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if (sm != null) { |
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sm.checkPermission(SecurityConstants.GET_COMBINER_PERMISSION); |
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} |
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return combiner; |
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} |
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/** |
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* Determines whether the access request indicated by the |
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* specified permission should be allowed or denied, based on |
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* the security policy currently in effect, and the context in |
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* this object. The request is allowed only if every ProtectionDomain |
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* in the context implies the permission. Otherwise the request is |
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* denied. |
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* |
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* <p> |
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* This method quietly returns if the access request |
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* is permitted, or throws a suitable AccessControlException otherwise. |
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* |
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* @param perm the requested permission. |
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* |
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* @exception AccessControlException if the specified permission |
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* is not permitted, based on the current security policy and the |
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* context encapsulated by this object. |
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* @exception NullPointerException if the permission to check for is null. |
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*/ |
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public void checkPermission(Permission perm) |
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throws AccessControlException |
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{ |
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boolean dumpDebug = false; |
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if (perm == null) { |
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throw new NullPointerException("permission can't be null"); |
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} |
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if (getDebug() != null) { |
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// If "codebase" is not specified, we dump the info by default. |
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dumpDebug = !Debug.isOn("codebase="); |
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if (!dumpDebug) { |
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// If "codebase" is specified, only dump if the specified code |
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// value is in the stack. |
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for (int i = 0; context != null && i < context.length; i++) { |
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if (context[i].getCodeSource() != null && |
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context[i].getCodeSource().getLocation() != null && |
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Debug.isOn("codebase=" + context[i].getCodeSource().getLocation().toString())) { |
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dumpDebug = true; |
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break; |
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} |
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} |
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} |
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dumpDebug &= !Debug.isOn("permission=") || |
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Debug.isOn("permission=" + perm.getClass().getCanonicalName()); |
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if (dumpDebug && Debug.isOn("stack")) { |
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Thread.currentThread().dumpStack(); |
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} |
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if (dumpDebug && Debug.isOn("domain")) { |
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if (context == null) { |
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debug.println("domain (context is null)"); |
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} else { |
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for (int i=0; i< context.length; i++) { |
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debug.println("domain "+i+" "+context[i]); |
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} |
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} |
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} |
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} |
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/* |
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* iterate through the ProtectionDomains in the context. |
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* Stop at the first one that doesn't allow the |
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* requested permission (throwing an exception). |
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* |
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*/ |
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311 |
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/* if ctxt is null, all we had on the stack were system domains, |
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or the first domain was a Privileged system domain. This |
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is to make the common case for system code very fast */ |
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315 |
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316 |
if (context == null) |
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return; |
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318 |
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for (int i=0; i< context.length; i++) { |
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if (context[i] != null && !context[i].implies(perm)) { |
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if (dumpDebug) { |
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debug.println("access denied " + perm); |
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} |
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||
97
5c029f131927
6648816: REGRESSION: setting -Djava.security.debug=failure result in NPE in ACC
xuelei
parents:
2
diff
changeset
|
325 |
if (Debug.isOn("failure") && debug != null) { |
2 | 326 |
// Want to make sure this is always displayed for failure, |
327 |
// but do not want to display again if already displayed |
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// above. |
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if (!dumpDebug) { |
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debug.println("access denied " + perm); |
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} |
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Thread.currentThread().dumpStack(); |
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final ProtectionDomain pd = context[i]; |
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final Debug db = debug; |
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AccessController.doPrivileged (new PrivilegedAction<Void>() { |
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336 |
public Void run() { |
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db.println("domain that failed "+pd); |
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return null; |
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} |
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340 |
}); |
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341 |
} |
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342 |
throw new AccessControlException("access denied "+perm, perm); |
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343 |
} |
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344 |
} |
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345 |
||
346 |
// allow if all of them allowed access |
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347 |
if (dumpDebug) { |
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348 |
debug.println("access allowed "+perm); |
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349 |
} |
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350 |
||
351 |
return; |
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352 |
} |
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353 |
||
354 |
/** |
|
355 |
* Take the stack-based context (this) and combine it with the |
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356 |
* privileged or inherited context, if need be. |
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*/ |
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358 |
AccessControlContext optimize() { |
|
359 |
// the assigned (privileged or inherited) context |
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360 |
AccessControlContext acc; |
|
361 |
if (isPrivileged) { |
|
362 |
acc = privilegedContext; |
|
363 |
} else { |
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364 |
acc = AccessController.getInheritedAccessControlContext(); |
|
365 |
} |
|
366 |
||
367 |
// this.context could be null if only system code is on the stack; |
|
368 |
// in that case, ignore the stack context |
|
369 |
boolean skipStack = (context == null); |
|
370 |
||
371 |
// acc.context could be null if only system code was involved; |
|
372 |
// in that case, ignore the assigned context |
|
373 |
boolean skipAssigned = (acc == null || acc.context == null); |
|
374 |
||
375 |
if (acc != null && acc.combiner != null) { |
|
376 |
// let the assigned acc's combiner do its thing |
|
377 |
return goCombiner(context, acc); |
|
378 |
} |
|
379 |
||
380 |
// optimization: if neither have contexts; return acc if possible |
|
381 |
// rather than this, because acc might have a combiner |
|
382 |
if (skipAssigned && skipStack) { |
|
383 |
return this; |
|
384 |
} |
|
385 |
||
386 |
// optimization: if there is no stack context; there is no reason |
|
387 |
// to compress the assigned context, it already is compressed |
|
388 |
if (skipStack) { |
|
389 |
return acc; |
|
390 |
} |
|
391 |
||
392 |
int slen = context.length; |
|
393 |
||
394 |
// optimization: if there is no assigned context and the stack length |
|
395 |
// is less then or equal to two; there is no reason to compress the |
|
396 |
// stack context, it already is |
|
397 |
if (skipAssigned && slen <= 2) { |
|
398 |
return this; |
|
399 |
} |
|
400 |
||
401 |
// optimization: if there is a single stack domain and that domain |
|
402 |
// is already in the assigned context; no need to combine |
|
403 |
if ((slen == 1) && (context[0] == acc.context[0])) { |
|
404 |
return acc; |
|
405 |
} |
|
406 |
||
407 |
int n = (skipAssigned) ? 0 : acc.context.length; |
|
408 |
||
409 |
// now we combine both of them, and create a new context |
|
410 |
ProtectionDomain pd[] = new ProtectionDomain[slen + n]; |
|
411 |
||
412 |
// first copy in the assigned context domains, no need to compress |
|
413 |
if (!skipAssigned) { |
|
414 |
System.arraycopy(acc.context, 0, pd, 0, n); |
|
415 |
} |
|
416 |
||
417 |
// now add the stack context domains, discarding nulls and duplicates |
|
418 |
outer: |
|
419 |
for (int i = 0; i < context.length; i++) { |
|
420 |
ProtectionDomain sd = context[i]; |
|
421 |
if (sd != null) { |
|
422 |
for (int j = 0; j < n; j++) { |
|
423 |
if (sd == pd[j]) { |
|
424 |
continue outer; |
|
425 |
} |
|
426 |
} |
|
427 |
pd[n++] = sd; |
|
428 |
} |
|
429 |
} |
|
430 |
||
431 |
// if length isn't equal, we need to shorten the array |
|
432 |
if (n != pd.length) { |
|
433 |
// optimization: if we didn't really combine anything |
|
434 |
if (!skipAssigned && n == acc.context.length) { |
|
435 |
return acc; |
|
436 |
} else if (skipAssigned && n == slen) { |
|
437 |
return this; |
|
438 |
} |
|
439 |
ProtectionDomain tmp[] = new ProtectionDomain[n]; |
|
440 |
System.arraycopy(pd, 0, tmp, 0, n); |
|
441 |
pd = tmp; |
|
442 |
} |
|
443 |
||
444 |
// return new AccessControlContext(pd, false); |
|
445 |
||
446 |
// Reuse existing ACC |
|
447 |
||
448 |
this.context = pd; |
|
449 |
this.combiner = null; |
|
450 |
this.isPrivileged = false; |
|
451 |
||
452 |
return this; |
|
453 |
} |
|
454 |
||
455 |
private AccessControlContext goCombiner(ProtectionDomain[] current, |
|
456 |
AccessControlContext assigned) { |
|
457 |
||
458 |
// the assigned ACC's combiner is not null -- |
|
459 |
// let the combiner do its thing |
|
460 |
||
461 |
// XXX we could add optimizations to 'current' here ... |
|
462 |
||
463 |
if (getDebug() != null) { |
|
464 |
debug.println("AccessControlContext invoking the Combiner"); |
|
465 |
} |
|
466 |
||
467 |
// No need to clone current and assigned.context |
|
468 |
// combine() will not update them |
|
469 |
ProtectionDomain[] combinedPds = assigned.combiner.combine( |
|
470 |
current, assigned.context); |
|
471 |
||
472 |
// return new AccessControlContext(combinedPds, assigned.combiner); |
|
473 |
||
474 |
// Reuse existing ACC |
|
475 |
this.context = combinedPds; |
|
476 |
this.combiner = assigned.combiner; |
|
477 |
this.isPrivileged = false; |
|
478 |
||
479 |
return this; |
|
480 |
} |
|
481 |
||
482 |
/** |
|
483 |
* Checks two AccessControlContext objects for equality. |
|
484 |
* Checks that <i>obj</i> is |
|
485 |
* an AccessControlContext and has the same set of ProtectionDomains |
|
486 |
* as this context. |
|
487 |
* <P> |
|
488 |
* @param obj the object we are testing for equality with this object. |
|
489 |
* @return true if <i>obj</i> is an AccessControlContext, and has the |
|
490 |
* same set of ProtectionDomains as this context, false otherwise. |
|
491 |
*/ |
|
492 |
public boolean equals(Object obj) { |
|
493 |
if (obj == this) |
|
494 |
return true; |
|
495 |
||
496 |
if (! (obj instanceof AccessControlContext)) |
|
497 |
return false; |
|
498 |
||
499 |
AccessControlContext that = (AccessControlContext) obj; |
|
500 |
||
501 |
||
502 |
if (context == null) { |
|
503 |
return (that.context == null); |
|
504 |
} |
|
505 |
||
506 |
if (that.context == null) |
|
507 |
return false; |
|
508 |
||
509 |
if (!(this.containsAllPDs(that) && that.containsAllPDs(this))) |
|
510 |
return false; |
|
511 |
||
512 |
if (this.combiner == null) |
|
513 |
return (that.combiner == null); |
|
514 |
||
515 |
if (that.combiner == null) |
|
516 |
return false; |
|
517 |
||
518 |
if (!this.combiner.equals(that.combiner)) |
|
519 |
return false; |
|
520 |
||
521 |
return true; |
|
522 |
} |
|
523 |
||
524 |
private boolean containsAllPDs(AccessControlContext that) { |
|
525 |
boolean match = false; |
|
526 |
// |
|
527 |
// ProtectionDomains within an ACC currently cannot be null |
|
528 |
// and this is enforced by the constructor and the various |
|
529 |
// optimize methods. However, historically this logic made attempts |
|
530 |
// to support the notion of a null PD and therefore this logic continues |
|
531 |
// to support that notion. |
|
532 |
ProtectionDomain thisPd; |
|
533 |
for (int i = 0; i < context.length; i++) { |
|
534 |
match = false; |
|
535 |
if ((thisPd = context[i]) == null) { |
|
536 |
for (int j = 0; (j < that.context.length) && !match; j++) { |
|
537 |
match = (that.context[j] == null); |
|
538 |
} |
|
539 |
} else { |
|
540 |
Class thisPdClass = thisPd.getClass(); |
|
541 |
ProtectionDomain thatPd; |
|
542 |
for (int j = 0; (j < that.context.length) && !match; j++) { |
|
543 |
thatPd = that.context[j]; |
|
544 |
||
545 |
// Class check required to avoid PD exposure (4285406) |
|
546 |
match = (thatPd != null && |
|
547 |
thisPdClass == thatPd.getClass() && thisPd.equals(thatPd)); |
|
548 |
} |
|
549 |
} |
|
550 |
if (!match) return false; |
|
551 |
} |
|
552 |
return match; |
|
553 |
} |
|
554 |
/** |
|
555 |
* Returns the hash code value for this context. The hash code |
|
556 |
* is computed by exclusive or-ing the hash code of all the protection |
|
557 |
* domains in the context together. |
|
558 |
* |
|
559 |
* @return a hash code value for this context. |
|
560 |
*/ |
|
561 |
||
562 |
public int hashCode() { |
|
563 |
int hashCode = 0; |
|
564 |
||
565 |
if (context == null) |
|
566 |
return hashCode; |
|
567 |
||
568 |
for (int i =0; i < context.length; i++) { |
|
569 |
if (context[i] != null) |
|
570 |
hashCode ^= context[i].hashCode(); |
|
571 |
} |
|
572 |
return hashCode; |
|
573 |
} |
|
574 |
} |