--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/java/security/AccessControlContext.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,940 @@
+/*
+ * Copyright (c) 1997, 2013, 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
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.security;
+
+import java.util.ArrayList;
+import java.util.List;
+import sun.security.util.Debug;
+import sun.security.util.SecurityConstants;
+
+
+/**
+ * An AccessControlContext is used to make system resource access decisions
+ * based on the context it encapsulates.
+ *
+ * <p>More specifically, it encapsulates a context and
+ * has a single method, {@code checkPermission},
+ * that is equivalent to the {@code checkPermission} method
+ * in the AccessController class, with one difference: The AccessControlContext
+ * {@code checkPermission} method makes access decisions based on the
+ * context it encapsulates,
+ * rather than that of the current execution thread.
+ *
+ * <p>Thus, the purpose of AccessControlContext is for those situations where
+ * a security check that should be made within a given context
+ * actually needs to be done from within a
+ * <i>different</i> context (for example, from within a worker thread).
+ *
+ * <p> An AccessControlContext is created by calling the
+ * {@code AccessController.getContext} method.
+ * The {@code getContext} method takes a "snapshot"
+ * of the current calling context, and places
+ * it in an AccessControlContext object, which it returns. A sample call is
+ * the following:
+ *
+ * <pre>
+ * AccessControlContext acc = AccessController.getContext()
+ * </pre>
+ *
+ * <p>
+ * Code within a different context can subsequently call the
+ * {@code checkPermission} method on the
+ * previously-saved AccessControlContext object. A sample call is the
+ * following:
+ *
+ * <pre>
+ * acc.checkPermission(permission)
+ * </pre>
+ *
+ * @see AccessController
+ *
+ * @author Roland Schemers
+ */
+
+public final class AccessControlContext {
+
+ private ProtectionDomain context[];
+ // isPrivileged and isAuthorized are referenced by the VM - do not remove
+ // or change their names
+ private boolean isPrivileged;
+ private boolean isAuthorized = false;
+
+ // Note: This field is directly used by the virtual machine
+ // native codes. Don't touch it.
+ private AccessControlContext privilegedContext;
+
+ private DomainCombiner combiner = null;
+
+ // limited privilege scope
+ private Permission permissions[];
+ private AccessControlContext parent;
+ private boolean isWrapped;
+
+ // is constrained by limited privilege scope?
+ private boolean isLimited;
+ private ProtectionDomain limitedContext[];
+
+ private static boolean debugInit = false;
+ private static Debug debug = null;
+
+ static Debug getDebug()
+ {
+ if (debugInit)
+ return debug;
+ else {
+ if (Policy.isSet()) {
+ debug = Debug.getInstance("access");
+ debugInit = true;
+ }
+ return debug;
+ }
+ }
+
+ /**
+ * Create an AccessControlContext with the given array of ProtectionDomains.
+ * Context must not be null. Duplicate domains will be removed from the
+ * context.
+ *
+ * @param context the ProtectionDomains associated with this context.
+ * The non-duplicate domains are copied from the array. Subsequent
+ * changes to the array will not affect this AccessControlContext.
+ * @throws NullPointerException if {@code context} is {@code null}
+ */
+ public AccessControlContext(ProtectionDomain context[])
+ {
+ if (context.length == 0) {
+ this.context = null;
+ } else if (context.length == 1) {
+ if (context[0] != null) {
+ this.context = context.clone();
+ } else {
+ this.context = null;
+ }
+ } else {
+ List<ProtectionDomain> v = new ArrayList<>(context.length);
+ for (int i =0; i< context.length; i++) {
+ if ((context[i] != null) && (!v.contains(context[i])))
+ v.add(context[i]);
+ }
+ if (!v.isEmpty()) {
+ this.context = new ProtectionDomain[v.size()];
+ this.context = v.toArray(this.context);
+ }
+ }
+ }
+
+ /**
+ * Create a new {@code AccessControlContext} with the given
+ * {@code AccessControlContext} and {@code DomainCombiner}.
+ * This constructor associates the provided
+ * {@code DomainCombiner} with the provided
+ * {@code AccessControlContext}.
+ *
+ * <p>
+ *
+ * @param acc the {@code AccessControlContext} associated
+ * with the provided {@code DomainCombiner}.
+ *
+ * @param combiner the {@code DomainCombiner} to be associated
+ * with the provided {@code AccessControlContext}.
+ *
+ * @exception NullPointerException if the provided
+ * {@code context} is {@code null}.
+ *
+ * @exception SecurityException if a security manager is installed and the
+ * caller does not have the "createAccessControlContext"
+ * {@link SecurityPermission}
+ * @since 1.3
+ */
+ public AccessControlContext(AccessControlContext acc,
+ DomainCombiner combiner) {
+
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(SecurityConstants.CREATE_ACC_PERMISSION);
+ this.isAuthorized = true;
+ }
+
+ this.context = acc.context;
+
+ // we do not need to run the combine method on the
+ // provided ACC. it was already "combined" when the
+ // context was originally retrieved.
+ //
+ // at this point in time, we simply throw away the old
+ // combiner and use the newly provided one.
+ this.combiner = combiner;
+ }
+
+ /**
+ * package private for AccessController
+ *
+ * This "argument wrapper" context will be passed as the actual context
+ * parameter on an internal doPrivileged() call used in the implementation.
+ */
+ AccessControlContext(ProtectionDomain caller, DomainCombiner combiner,
+ AccessControlContext parent, AccessControlContext context,
+ Permission[] perms)
+ {
+ /*
+ * Combine the domains from the doPrivileged() context into our
+ * wrapper context, if necessary.
+ */
+ ProtectionDomain[] callerPDs = null;
+ if (caller != null) {
+ callerPDs = new ProtectionDomain[] { caller };
+ }
+ if (context != null) {
+ if (combiner != null) {
+ this.context = combiner.combine(callerPDs, context.context);
+ } else {
+ this.context = combine(callerPDs, context.context);
+ }
+ } else {
+ /*
+ * Call combiner even if there is seemingly nothing to combine.
+ */
+ if (combiner != null) {
+ this.context = combiner.combine(callerPDs, null);
+ } else {
+ this.context = combine(callerPDs, null);
+ }
+ }
+ this.combiner = combiner;
+
+ Permission[] tmp = null;
+ if (perms != null) {
+ tmp = new Permission[perms.length];
+ for (int i=0; i < perms.length; i++) {
+ if (perms[i] == null) {
+ throw new NullPointerException("permission can't be null");
+ }
+
+ /*
+ * An AllPermission argument is equivalent to calling
+ * doPrivileged() without any limit permissions.
+ */
+ if (perms[i].getClass() == AllPermission.class) {
+ parent = null;
+ }
+ tmp[i] = perms[i];
+ }
+ }
+
+ /*
+ * For a doPrivileged() with limited privilege scope, initialize
+ * the relevant fields.
+ *
+ * The limitedContext field contains the union of all domains which
+ * are enclosed by this limited privilege scope. In other words,
+ * it contains all of the domains which could potentially be checked
+ * if none of the limiting permissions implied a requested permission.
+ */
+ if (parent != null) {
+ this.limitedContext = combine(parent.context, parent.limitedContext);
+ this.isLimited = true;
+ this.isWrapped = true;
+ this.permissions = tmp;
+ this.parent = parent;
+ this.privilegedContext = context; // used in checkPermission2()
+ }
+ this.isAuthorized = true;
+ }
+
+
+ /**
+ * package private constructor for AccessController.getContext()
+ */
+
+ AccessControlContext(ProtectionDomain context[],
+ boolean isPrivileged)
+ {
+ this.context = context;
+ this.isPrivileged = isPrivileged;
+ this.isAuthorized = true;
+ }
+
+ /**
+ * Constructor for JavaSecurityAccess.doIntersectionPrivilege()
+ */
+ AccessControlContext(ProtectionDomain[] context,
+ AccessControlContext privilegedContext)
+ {
+ this.context = context;
+ this.privilegedContext = privilegedContext;
+ this.isPrivileged = true;
+ }
+
+ /**
+ * Returns this context's context.
+ */
+ ProtectionDomain[] getContext() {
+ return context;
+ }
+
+ /**
+ * Returns true if this context is privileged.
+ */
+ boolean isPrivileged()
+ {
+ return isPrivileged;
+ }
+
+ /**
+ * get the assigned combiner from the privileged or inherited context
+ */
+ DomainCombiner getAssignedCombiner() {
+ AccessControlContext acc;
+ if (isPrivileged) {
+ acc = privilegedContext;
+ } else {
+ acc = AccessController.getInheritedAccessControlContext();
+ }
+ if (acc != null) {
+ return acc.combiner;
+ }
+ return null;
+ }
+
+ /**
+ * Get the {@code DomainCombiner} associated with this
+ * {@code AccessControlContext}.
+ *
+ * <p>
+ *
+ * @return the {@code DomainCombiner} associated with this
+ * {@code AccessControlContext}, or {@code null}
+ * if there is none.
+ *
+ * @exception SecurityException if a security manager is installed and
+ * the caller does not have the "getDomainCombiner"
+ * {@link SecurityPermission}
+ * @since 1.3
+ */
+ public DomainCombiner getDomainCombiner() {
+
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(SecurityConstants.GET_COMBINER_PERMISSION);
+ }
+ return getCombiner();
+ }
+
+ /**
+ * package private for AccessController
+ */
+ DomainCombiner getCombiner() {
+ return combiner;
+ }
+
+ boolean isAuthorized() {
+ return isAuthorized;
+ }
+
+ /**
+ * Determines whether the access request indicated by the
+ * specified permission should be allowed or denied, based on
+ * the security policy currently in effect, and the context in
+ * this object. The request is allowed only if every ProtectionDomain
+ * in the context implies the permission. Otherwise the request is
+ * denied.
+ *
+ * <p>
+ * This method quietly returns if the access request
+ * is permitted, or throws a suitable AccessControlException otherwise.
+ *
+ * @param perm the requested permission.
+ *
+ * @exception AccessControlException if the specified permission
+ * is not permitted, based on the current security policy and the
+ * context encapsulated by this object.
+ * @exception NullPointerException if the permission to check for is null.
+ */
+ public void checkPermission(Permission perm)
+ throws AccessControlException
+ {
+ boolean dumpDebug = false;
+
+ if (perm == null) {
+ throw new NullPointerException("permission can't be null");
+ }
+ if (getDebug() != null) {
+ // If "codebase" is not specified, we dump the info by default.
+ dumpDebug = !Debug.isOn("codebase=");
+ if (!dumpDebug) {
+ // If "codebase" is specified, only dump if the specified code
+ // value is in the stack.
+ for (int i = 0; context != null && i < context.length; i++) {
+ if (context[i].getCodeSource() != null &&
+ context[i].getCodeSource().getLocation() != null &&
+ Debug.isOn("codebase=" + context[i].getCodeSource().getLocation().toString())) {
+ dumpDebug = true;
+ break;
+ }
+ }
+ }
+
+ dumpDebug &= !Debug.isOn("permission=") ||
+ Debug.isOn("permission=" + perm.getClass().getCanonicalName());
+
+ if (dumpDebug && Debug.isOn("stack")) {
+ Thread.dumpStack();
+ }
+
+ if (dumpDebug && Debug.isOn("domain")) {
+ if (context == null) {
+ debug.println("domain (context is null)");
+ } else {
+ for (int i=0; i< context.length; i++) {
+ debug.println("domain "+i+" "+context[i]);
+ }
+ }
+ }
+ }
+
+ /*
+ * iterate through the ProtectionDomains in the context.
+ * Stop at the first one that doesn't allow the
+ * requested permission (throwing an exception).
+ *
+ */
+
+ /* if ctxt is null, all we had on the stack were system domains,
+ or the first domain was a Privileged system domain. This
+ is to make the common case for system code very fast */
+
+ if (context == null) {
+ checkPermission2(perm);
+ return;
+ }
+
+ for (int i=0; i< context.length; i++) {
+ if (context[i] != null && !context[i].implies(perm)) {
+ if (dumpDebug) {
+ debug.println("access denied " + perm);
+ }
+
+ if (Debug.isOn("failure") && debug != null) {
+ // Want to make sure this is always displayed for failure,
+ // but do not want to display again if already displayed
+ // above.
+ if (!dumpDebug) {
+ debug.println("access denied " + perm);
+ }
+ Thread.dumpStack();
+ final ProtectionDomain pd = context[i];
+ final Debug db = debug;
+ AccessController.doPrivileged (new PrivilegedAction<Void>() {
+ public Void run() {
+ db.println("domain that failed "+pd);
+ return null;
+ }
+ });
+ }
+ throw new AccessControlException("access denied "+perm, perm);
+ }
+ }
+
+ // allow if all of them allowed access
+ if (dumpDebug) {
+ debug.println("access allowed "+perm);
+ }
+
+ checkPermission2(perm);
+ }
+
+ /*
+ * Check the domains associated with the limited privilege scope.
+ */
+ private void checkPermission2(Permission perm) {
+ if (!isLimited) {
+ return;
+ }
+
+ /*
+ * Check the doPrivileged() context parameter, if present.
+ */
+ if (privilegedContext != null) {
+ privilegedContext.checkPermission2(perm);
+ }
+
+ /*
+ * Ignore the limited permissions and parent fields of a wrapper
+ * context since they were already carried down into the unwrapped
+ * context.
+ */
+ if (isWrapped) {
+ return;
+ }
+
+ /*
+ * Try to match any limited privilege scope.
+ */
+ if (permissions != null) {
+ Class<?> permClass = perm.getClass();
+ for (int i=0; i < permissions.length; i++) {
+ Permission limit = permissions[i];
+ if (limit.getClass().equals(permClass) && limit.implies(perm)) {
+ return;
+ }
+ }
+ }
+
+ /*
+ * Check the limited privilege scope up the call stack or the inherited
+ * parent thread call stack of this ACC.
+ */
+ if (parent != null) {
+ /*
+ * As an optimization, if the parent context is the inherited call
+ * stack context from a parent thread then checking the protection
+ * domains of the parent context is redundant since they have
+ * already been merged into the child thread's context by
+ * optimize(). When parent is set to an inherited context this
+ * context was not directly created by a limited scope
+ * doPrivileged() and it does not have its own limited permissions.
+ */
+ if (permissions == null) {
+ parent.checkPermission2(perm);
+ } else {
+ parent.checkPermission(perm);
+ }
+ }
+ }
+
+ /**
+ * Take the stack-based context (this) and combine it with the
+ * privileged or inherited context, if need be. Any limited
+ * privilege scope is flagged regardless of whether the assigned
+ * context comes from an immediately enclosing limited doPrivileged().
+ * The limited privilege scope can indirectly flow from the inherited
+ * parent thread or an assigned context previously captured by getContext().
+ */
+ AccessControlContext optimize() {
+ // the assigned (privileged or inherited) context
+ AccessControlContext acc;
+ DomainCombiner combiner = null;
+ AccessControlContext parent = null;
+ Permission[] permissions = null;
+
+ if (isPrivileged) {
+ acc = privilegedContext;
+ if (acc != null) {
+ /*
+ * If the context is from a limited scope doPrivileged() then
+ * copy the permissions and parent fields out of the wrapper
+ * context that was created to hold them.
+ */
+ if (acc.isWrapped) {
+ permissions = acc.permissions;
+ parent = acc.parent;
+ }
+ }
+ } else {
+ acc = AccessController.getInheritedAccessControlContext();
+ if (acc != null) {
+ /*
+ * If the inherited context is constrained by a limited scope
+ * doPrivileged() then set it as our parent so we will process
+ * the non-domain-related state.
+ */
+ if (acc.isLimited) {
+ parent = acc;
+ }
+ }
+ }
+
+ // this.context could be null if only system code is on the stack;
+ // in that case, ignore the stack context
+ boolean skipStack = (context == null);
+
+ // acc.context could be null if only system code was involved;
+ // in that case, ignore the assigned context
+ boolean skipAssigned = (acc == null || acc.context == null);
+ ProtectionDomain[] assigned = (skipAssigned) ? null : acc.context;
+ ProtectionDomain[] pd;
+
+ // if there is no enclosing limited privilege scope on the stack or
+ // inherited from a parent thread
+ boolean skipLimited = ((acc == null || !acc.isWrapped) && parent == null);
+
+ if (acc != null && acc.combiner != null) {
+ // let the assigned acc's combiner do its thing
+ if (getDebug() != null) {
+ debug.println("AccessControlContext invoking the Combiner");
+ }
+
+ // No need to clone current and assigned.context
+ // combine() will not update them
+ combiner = acc.combiner;
+ pd = combiner.combine(context, assigned);
+ } else {
+ if (skipStack) {
+ if (skipAssigned) {
+ calculateFields(acc, parent, permissions);
+ return this;
+ } else if (skipLimited) {
+ return acc;
+ }
+ } else if (assigned != null) {
+ if (skipLimited) {
+ // optimization: if there is a single stack domain and
+ // that domain is already in the assigned context; no
+ // need to combine
+ if (context.length == 1 && context[0] == assigned[0]) {
+ return acc;
+ }
+ }
+ }
+
+ pd = combine(context, assigned);
+ if (skipLimited && !skipAssigned && pd == assigned) {
+ return acc;
+ } else if (skipAssigned && pd == context) {
+ calculateFields(acc, parent, permissions);
+ return this;
+ }
+ }
+
+ // Reuse existing ACC
+ this.context = pd;
+ this.combiner = combiner;
+ this.isPrivileged = false;
+
+ calculateFields(acc, parent, permissions);
+ return this;
+ }
+
+
+ /*
+ * Combine the current (stack) and assigned domains.
+ */
+ private static ProtectionDomain[] combine(ProtectionDomain[]current,
+ ProtectionDomain[] assigned) {
+
+ // current could be null if only system code is on the stack;
+ // in that case, ignore the stack context
+ boolean skipStack = (current == null);
+
+ // assigned could be null if only system code was involved;
+ // in that case, ignore the assigned context
+ boolean skipAssigned = (assigned == null);
+
+ int slen = (skipStack) ? 0 : current.length;
+
+ // optimization: if there is no assigned context and the stack length
+ // is less then or equal to two; there is no reason to compress the
+ // stack context, it already is
+ if (skipAssigned && slen <= 2) {
+ return current;
+ }
+
+ int n = (skipAssigned) ? 0 : assigned.length;
+
+ // now we combine both of them, and create a new context
+ ProtectionDomain pd[] = new ProtectionDomain[slen + n];
+
+ // first copy in the assigned context domains, no need to compress
+ if (!skipAssigned) {
+ System.arraycopy(assigned, 0, pd, 0, n);
+ }
+
+ // now add the stack context domains, discarding nulls and duplicates
+ outer:
+ for (int i = 0; i < slen; i++) {
+ ProtectionDomain sd = current[i];
+ if (sd != null) {
+ for (int j = 0; j < n; j++) {
+ if (sd == pd[j]) {
+ continue outer;
+ }
+ }
+ pd[n++] = sd;
+ }
+ }
+
+ // if length isn't equal, we need to shorten the array
+ if (n != pd.length) {
+ // optimization: if we didn't really combine anything
+ if (!skipAssigned && n == assigned.length) {
+ return assigned;
+ } else if (skipAssigned && n == slen) {
+ return current;
+ }
+ ProtectionDomain tmp[] = new ProtectionDomain[n];
+ System.arraycopy(pd, 0, tmp, 0, n);
+ pd = tmp;
+ }
+
+ return pd;
+ }
+
+
+ /*
+ * Calculate the additional domains that could potentially be reached via
+ * limited privilege scope. Mark the context as being subject to limited
+ * privilege scope unless the reachable domains (if any) are already
+ * contained in this domain context (in which case any limited
+ * privilege scope checking would be redundant).
+ */
+ private void calculateFields(AccessControlContext assigned,
+ AccessControlContext parent, Permission[] permissions)
+ {
+ ProtectionDomain[] parentLimit = null;
+ ProtectionDomain[] assignedLimit = null;
+ ProtectionDomain[] newLimit;
+
+ parentLimit = (parent != null)? parent.limitedContext: null;
+ assignedLimit = (assigned != null)? assigned.limitedContext: null;
+ newLimit = combine(parentLimit, assignedLimit);
+ if (newLimit != null) {
+ if (context == null || !containsAllPDs(newLimit, context)) {
+ this.limitedContext = newLimit;
+ this.permissions = permissions;
+ this.parent = parent;
+ this.isLimited = true;
+ }
+ }
+ }
+
+
+ /**
+ * Checks two AccessControlContext objects for equality.
+ * Checks that <i>obj</i> is
+ * an AccessControlContext and has the same set of ProtectionDomains
+ * as this context.
+ * <P>
+ * @param obj the object we are testing for equality with this object.
+ * @return true if <i>obj</i> is an AccessControlContext, and has the
+ * same set of ProtectionDomains as this context, false otherwise.
+ */
+ public boolean equals(Object obj) {
+ if (obj == this)
+ return true;
+
+ if (! (obj instanceof AccessControlContext))
+ return false;
+
+ AccessControlContext that = (AccessControlContext) obj;
+
+ if (!equalContext(that))
+ return false;
+
+ if (!equalLimitedContext(that))
+ return false;
+
+ return true;
+ }
+
+ /*
+ * Compare for equality based on state that is free of limited
+ * privilege complications.
+ */
+ private boolean equalContext(AccessControlContext that) {
+ if (!equalPDs(this.context, that.context))
+ return false;
+
+ if (this.combiner == null && that.combiner != null)
+ return false;
+
+ if (this.combiner != null && !this.combiner.equals(that.combiner))
+ return false;
+
+ return true;
+ }
+
+ private boolean equalPDs(ProtectionDomain[] a, ProtectionDomain[] b) {
+ if (a == null) {
+ return (b == null);
+ }
+
+ if (b == null)
+ return false;
+
+ if (!(containsAllPDs(a, b) && containsAllPDs(b, a)))
+ return false;
+
+ return true;
+ }
+
+ /*
+ * Compare for equality based on state that is captured during a
+ * call to AccessController.getContext() when a limited privilege
+ * scope is in effect.
+ */
+ private boolean equalLimitedContext(AccessControlContext that) {
+ if (that == null)
+ return false;
+
+ /*
+ * If neither instance has limited privilege scope then we're done.
+ */
+ if (!this.isLimited && !that.isLimited)
+ return true;
+
+ /*
+ * If only one instance has limited privilege scope then we're done.
+ */
+ if (!(this.isLimited && that.isLimited))
+ return false;
+
+ /*
+ * Wrapped instances should never escape outside the implementation
+ * this class and AccessController so this will probably never happen
+ * but it only makes any sense to compare if they both have the same
+ * isWrapped state.
+ */
+ if ((this.isWrapped && !that.isWrapped) ||
+ (!this.isWrapped && that.isWrapped)) {
+ return false;
+ }
+
+ if (this.permissions == null && that.permissions != null)
+ return false;
+
+ if (this.permissions != null && that.permissions == null)
+ return false;
+
+ if (!(this.containsAllLimits(that) && that.containsAllLimits(this)))
+ return false;
+
+ /*
+ * Skip through any wrapped contexts.
+ */
+ AccessControlContext thisNextPC = getNextPC(this);
+ AccessControlContext thatNextPC = getNextPC(that);
+
+ /*
+ * The protection domains and combiner of a privilegedContext are
+ * not relevant because they have already been included in the context
+ * of this instance by optimize() so we only care about any limited
+ * privilege state they may have.
+ */
+ if (thisNextPC == null && thatNextPC != null && thatNextPC.isLimited)
+ return false;
+
+ if (thisNextPC != null && !thisNextPC.equalLimitedContext(thatNextPC))
+ return false;
+
+ if (this.parent == null && that.parent != null)
+ return false;
+
+ if (this.parent != null && !this.parent.equals(that.parent))
+ return false;
+
+ return true;
+ }
+
+ /*
+ * Follow the privilegedContext link making our best effort to skip
+ * through any wrapper contexts.
+ */
+ private static AccessControlContext getNextPC(AccessControlContext acc) {
+ while (acc != null && acc.privilegedContext != null) {
+ acc = acc.privilegedContext;
+ if (!acc.isWrapped)
+ return acc;
+ }
+ return null;
+ }
+
+ private static boolean containsAllPDs(ProtectionDomain[] thisContext,
+ ProtectionDomain[] thatContext) {
+ boolean match = false;
+
+ //
+ // ProtectionDomains within an ACC currently cannot be null
+ // and this is enforced by the constructor and the various
+ // optimize methods. However, historically this logic made attempts
+ // to support the notion of a null PD and therefore this logic continues
+ // to support that notion.
+ ProtectionDomain thisPd;
+ for (int i = 0; i < thisContext.length; i++) {
+ match = false;
+ if ((thisPd = thisContext[i]) == null) {
+ for (int j = 0; (j < thatContext.length) && !match; j++) {
+ match = (thatContext[j] == null);
+ }
+ } else {
+ Class<?> thisPdClass = thisPd.getClass();
+ ProtectionDomain thatPd;
+ for (int j = 0; (j < thatContext.length) && !match; j++) {
+ thatPd = thatContext[j];
+
+ // Class check required to avoid PD exposure (4285406)
+ match = (thatPd != null &&
+ thisPdClass == thatPd.getClass() && thisPd.equals(thatPd));
+ }
+ }
+ if (!match) return false;
+ }
+ return match;
+ }
+
+ private boolean containsAllLimits(AccessControlContext that) {
+ boolean match = false;
+ Permission thisPerm;
+
+ if (this.permissions == null && that.permissions == null)
+ return true;
+
+ for (int i = 0; i < this.permissions.length; i++) {
+ Permission limit = this.permissions[i];
+ Class <?> limitClass = limit.getClass();
+ match = false;
+ for (int j = 0; (j < that.permissions.length) && !match; j++) {
+ Permission perm = that.permissions[j];
+ match = (limitClass.equals(perm.getClass()) &&
+ limit.equals(perm));
+ }
+ if (!match) return false;
+ }
+ return match;
+ }
+
+
+ /**
+ * Returns the hash code value for this context. The hash code
+ * is computed by exclusive or-ing the hash code of all the protection
+ * domains in the context together.
+ *
+ * @return a hash code value for this context.
+ */
+
+ public int hashCode() {
+ int hashCode = 0;
+
+ if (context == null)
+ return hashCode;
+
+ for (int i =0; i < context.length; i++) {
+ if (context[i] != null)
+ hashCode ^= context[i].hashCode();
+ }
+
+ return hashCode;
+ }
+}