-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathAccessControlContext.java
More file actions
940 lines (825 loc) · 30.6 KB
/
AccessControlContext.java
File metadata and controls
940 lines (825 loc) · 30.6 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
/*
* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*/
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;
}
}