1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
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20 *
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22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26
27 package java.security;
28
29 import java.util.Enumeration;
30 import java.util.WeakHashMap;
31 import java.util.concurrent.atomic.AtomicReference;
32 import sun.security.jca.GetInstance;
33 import sun.security.util.Debug;
34 import sun.security.util.SecurityConstants;
35
36
37 /**
38 * A Policy object is responsible for determining whether code executing
39 * in the Java runtime environment has permission to perform a
40 * security-sensitive operation.
41 *
42 * <p> There is only one Policy object installed in the runtime at any
43 * given time. A Policy object can be installed by calling the
44 * {@code setPolicy} method. The installed Policy object can be
45 * obtained by calling the {@code getPolicy} method.
46 *
47 * <p> If no Policy object has been installed in the runtime, a call to
48 * {@code getPolicy} installs an instance of the default Policy
49 * implementation (a default subclass implementation of this abstract class).
50 * The default Policy implementation can be changed by setting the value
51 * of the {@code policy.provider} security property to the fully qualified
52 * name of the desired Policy subclass implementation. The system class loader
53 * is used to load this class.
54 *
55 * <p> Application code can directly subclass Policy to provide a custom
56 * implementation. In addition, an instance of a Policy object can be
57 * constructed by invoking one of the {@code getInstance} factory methods
58 * with a standard type. The default policy type is "JavaPolicy".
59 *
60 * <p> Once a Policy instance has been installed (either by default, or by
61 * calling {@code setPolicy}), the Java runtime invokes its
62 * {@code implies} method when it needs to
63 * determine whether executing code (encapsulated in a ProtectionDomain)
64 * can perform SecurityManager-protected operations. How a Policy object
65 * retrieves its policy data is up to the Policy implementation itself.
66 * The policy data may be stored, for example, in a flat ASCII file,
67 * in a serialized binary file of the Policy class, or in a database.
68 *
69 * <p> The {@code refresh} method causes the policy object to
70 * refresh/reload its data. This operation is implementation-dependent.
71 * For example, if the policy object stores its data in configuration files,
72 * calling {@code refresh} will cause it to re-read the configuration
73 * policy files. If a refresh operation is not supported, this method does
74 * nothing. Note that refreshed policy may not have an effect on classes
75 * in a particular ProtectionDomain. This is dependent on the Policy
76 * provider's implementation of the {@code implies}
77 * method and its PermissionCollection caching strategy.
78 *
79 * @author Roland Schemers
80 * @author Gary Ellison
81 * @see java.security.Provider
82 * @see java.security.ProtectionDomain
83 * @see java.security.Permission
84 * @see java.security.Security security properties
85 */
86
87 public abstract class Policy {
88
89 /**
90 * A read-only empty PermissionCollection instance.
91 * @since 1.6
92 */
93 public static final PermissionCollection UNSUPPORTED_EMPTY_COLLECTION =
94 new UnsupportedEmptyCollection();
95
96 // Information about the system-wide policy.
97 private static class PolicyInfo {
98 // the system-wide policy
99 final Policy policy;
100 // a flag indicating if the system-wide policy has been initialized
101 final boolean initialized;
102
103 PolicyInfo(Policy policy, boolean initialized) {
104 this.policy = policy;
105 this.initialized = initialized;
106 }
107 }
108
109 // PolicyInfo is stored in an AtomicReference
110 private static AtomicReference<PolicyInfo> policy =
111 new AtomicReference<>(new PolicyInfo(null, false));
112
113 private static final Debug debug = Debug.getInstance("policy");
114
115 // Default policy provider
116 private static final String DEFAULT_POLICY =
117 "sun.security.provider.PolicyFile";
118
119 // Cache mapping ProtectionDomain.Key to PermissionCollection
120 private WeakHashMap<ProtectionDomain.Key, PermissionCollection> pdMapping;
121
122 /** package private for AccessControlContext and ProtectionDomain */
123 static boolean isSet()
124 {
125 PolicyInfo pi = policy.get();
126 return pi.policy != null && pi.initialized == true;
127 }
128
129 private static void checkPermission(String type) {
130 SecurityManager sm = System.getSecurityManager();
131 if (sm != null) {
132 sm.checkPermission(new SecurityPermission("createPolicy." + type));
133 }
134 }
135
136 /**
137 * Returns the installed Policy object. This value should not be cached,
138 * as it may be changed by a call to {@code setPolicy}.
139 * This method first calls
140 * {@code SecurityManager.checkPermission} with a
141 * {@code SecurityPermission("getPolicy")} permission
142 * to ensure it's ok to get the Policy object.
143 *
144 * @return the installed Policy.
145 *
146 * @throws SecurityException
147 * if a security manager exists and its
148 * {@code checkPermission} method doesn't allow
149 * getting the Policy object.
150 *
151 * @see SecurityManager#checkPermission(Permission)
152 * @see #setPolicy(java.security.Policy)
153 */
154 public static Policy getPolicy()
155 {
156 SecurityManager sm = System.getSecurityManager();
157 if (sm != null)
158 sm.checkPermission(SecurityConstants.GET_POLICY_PERMISSION);
159 return getPolicyNoCheck();
160 }
161
162 /**
163 * Returns the installed Policy object, skipping the security check.
164 * Used by ProtectionDomain and getPolicy.
165 *
166 * @return the installed Policy.
167 */
168 static Policy getPolicyNoCheck()
169 {
170 PolicyInfo pi = policy.get();
171 // Use double-check idiom to avoid locking if system-wide policy is
172 // already initialized
173 if (pi.initialized == false || pi.policy == null) {
174 synchronized (Policy.class) {
175 PolicyInfo pinfo = policy.get();
176 if (pinfo.policy == null) {
177 return loadPolicyProvider();
178 }
179 return pinfo.policy;
180 }
181 }
182 return pi.policy;
183 }
184
185 /**
186 * Loads and instantiates a Policy implementation specified by the
187 * policy.provider security property. Note that this method should only
188 * be called by getPolicyNoCheck and from within a synchronized block with
189 * an intrinsic lock on the Policy.class.
190 */
191 private static Policy loadPolicyProvider() {
192 String policyProvider =
193 AccessController.doPrivileged(new PrivilegedAction<>() {
194 @Override
195 public String run() {
196 return Security.getProperty("policy.provider");
197 }
198 });
199
200 /*
201 * If policy.provider is not set or is set to the default provider,
202 * simply instantiate it and return.
203 */
204 if (policyProvider == null || policyProvider.isEmpty() ||
205 policyProvider.equals(DEFAULT_POLICY))
206 {
207 Policy polFile = new sun.security.provider.PolicyFile();
208 policy.set(new PolicyInfo(polFile, true));
209 return polFile;
210 }
211
212 /*
213 * Locate, load, and instantiate the policy.provider impl using
214 * the system class loader. While doing so, install the bootstrap
215 * provider to avoid potential recursion.
216 */
217 Policy polFile = new sun.security.provider.PolicyFile();
218 policy.set(new PolicyInfo(polFile, false));
219
220 Policy pol = AccessController.doPrivileged(new PrivilegedAction<>() {
221 @Override
222 public Policy run() {
223 try {
224 ClassLoader scl = ClassLoader.getSystemClassLoader();
225 @SuppressWarnings("deprecation")
226 Object o = Class.forName(policyProvider, true, scl).newInstance();
227 return (Policy)o;
228 } catch (Exception e) {
229 if (debug != null) {
230 debug.println("policy provider " + policyProvider +
231 " not available");
232 e.printStackTrace();
233 }
234 return null;
235 }
236 }
237 });
238
239 if (pol == null) {
240 // Fallback and use the system default implementation
241 if (debug != null) {
242 debug.println("using " + DEFAULT_POLICY);
243 }
244 pol = polFile;
245 }
246 policy.set(new PolicyInfo(pol, true));
247 return pol;
248 }
249
250 /**
251 * Sets the system-wide Policy object. This method first calls
252 * {@code SecurityManager.checkPermission} with a
253 * {@code SecurityPermission("setPolicy")}
254 * permission to ensure it's ok to set the Policy.
255 *
256 * @param p the new system Policy object.
257 *
258 * @throws SecurityException
259 * if a security manager exists and its
260 * {@code checkPermission} method doesn't allow
261 * setting the Policy.
262 *
263 * @see SecurityManager#checkPermission(Permission)
264 * @see #getPolicy()
265 *
266 */
267 public static void setPolicy(Policy p)
268 {
269 SecurityManager sm = System.getSecurityManager();
270 if (sm != null) sm.checkPermission(
271 new SecurityPermission("setPolicy"));
272 if (p != null) {
273 initPolicy(p);
274 }
275 synchronized (Policy.class) {
276 policy.set(new PolicyInfo(p, p != null));
277 }
278 }
279
280 /**
281 * Initialize superclass state such that a legacy provider can
282 * handle queries for itself.
283 *
284 * @since 1.4
285 */
286 private static void initPolicy (final Policy p) {
287 /*
288 * A policy provider not on the bootclasspath could trigger
289 * security checks fulfilling a call to either Policy.implies
290 * or Policy.getPermissions. If this does occur the provider
291 * must be able to answer for it's own ProtectionDomain
292 * without triggering additional security checks, otherwise
293 * the policy implementation will end up in an infinite
294 * recursion.
295 *
296 * To mitigate this, the provider can collect it's own
297 * ProtectionDomain and associate a PermissionCollection while
298 * it is being installed. The currently installed policy
299 * provider (if there is one) will handle calls to
300 * Policy.implies or Policy.getPermissions during this
301 * process.
302 *
303 * This Policy superclass caches away the ProtectionDomain and
304 * statically binds permissions so that legacy Policy
305 * implementations will continue to function.
306 */
307
308 ProtectionDomain policyDomain =
309 AccessController.doPrivileged(new PrivilegedAction<>() {
310 public ProtectionDomain run() {
311 return p.getClass().getProtectionDomain();
312 }
313 });
314
315 /*
316 * Collect the permissions granted to this protection domain
317 * so that the provider can be security checked while processing
318 * calls to Policy.implies or Policy.getPermissions.
319 */
320 PermissionCollection policyPerms = null;
321 synchronized (p) {
322 if (p.pdMapping == null) {
323 p.pdMapping = new WeakHashMap<>();
324 }
325 }
326
327 if (policyDomain.getCodeSource() != null) {
328 Policy pol = policy.get().policy;
329 if (pol != null) {
330 policyPerms = pol.getPermissions(policyDomain);
331 }
332
333 if (policyPerms == null) { // assume it has all
334 policyPerms = new Permissions();
335 policyPerms.add(SecurityConstants.ALL_PERMISSION);
336 }
337
338 synchronized (p.pdMapping) {
339 // cache of pd to permissions
340 p.pdMapping.put(policyDomain.key, policyPerms);
341 }
342 }
343 return;
344 }
345
346
347 /**
348 * Returns a Policy object of the specified type.
349 *
350 * <p> This method traverses the list of registered security providers,
351 * starting with the most preferred Provider.
352 * A new Policy object encapsulating the
353 * PolicySpi implementation from the first
354 * Provider that supports the specified type is returned.
355 *
356 * <p> Note that the list of registered providers may be retrieved via
357 * the {@link Security#getProviders() Security.getProviders()} method.
358 *
359 * @implNote
360 * The JDK Reference Implementation additionally uses the
361 * {@code jdk.security.provider.preferred}
362 * {@link Security#getProperty(String) Security} property to determine
363 * the preferred provider order for the specified algorithm. This
364 * may be different than the order of providers returned by
365 * {@link Security#getProviders() Security.getProviders()}.
366 *
367 * @param type the specified Policy type. See the Policy section in the
368 * <a href=
369 * "{@docRoot}/../technotes/guides/security/StandardNames.html#Policy">
370 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
371 * for a list of standard Policy types.
372 *
373 * @param params parameters for the Policy, which may be null.
374 *
375 * @return the new Policy object.
376 *
377 * @exception SecurityException if the caller does not have permission
378 * to get a Policy instance for the specified type.
379 *
380 * @exception NullPointerException if the specified type is null.
381 *
382 * @exception IllegalArgumentException if the specified parameters
383 * are not understood by the PolicySpi implementation
384 * from the selected Provider.
385 *
386 * @exception NoSuchAlgorithmException if no Provider supports a PolicySpi
387 * implementation for the specified type.
388 *
389 * @see Provider
390 * @since 1.6
391 */
392 public static Policy getInstance(String type, Policy.Parameters params)
393 throws NoSuchAlgorithmException {
394
395 checkPermission(type);
396 try {
397 GetInstance.Instance instance = GetInstance.getInstance("Policy",
398 PolicySpi.class,
399 type,
400 params);
401 return new PolicyDelegate((PolicySpi)instance.impl,
402 instance.provider,
403 type,
404 params);
405 } catch (NoSuchAlgorithmException nsae) {
406 return handleException(nsae);
407 }
408 }
409
410 /**
411 * Returns a Policy object of the specified type.
412 *
413 * <p> A new Policy object encapsulating the
414 * PolicySpi implementation from the specified provider
415 * is returned. The specified provider must be registered
416 * in the provider list.
417 *
418 * <p> Note that the list of registered providers may be retrieved via
419 * the {@link Security#getProviders() Security.getProviders()} method.
420 *
421 * @param type the specified Policy type. See the Policy section in the
422 * <a href=
423 * "{@docRoot}/../technotes/guides/security/StandardNames.html#Policy">
424 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
425 * for a list of standard Policy types.
426 *
427 * @param params parameters for the Policy, which may be null.
428 *
429 * @param provider the provider.
430 *
431 * @return the new Policy object.
432 *
433 * @exception SecurityException if the caller does not have permission
434 * to get a Policy instance for the specified type.
435 *
436 * @exception NullPointerException if the specified type is null.
437 *
438 * @exception IllegalArgumentException if the specified provider
439 * is null or empty,
440 * or if the specified parameters are not understood by
441 * the PolicySpi implementation from the specified provider.
442 *
443 * @exception NoSuchProviderException if the specified provider is not
444 * registered in the security provider list.
445 *
446 * @exception NoSuchAlgorithmException if the specified provider does not
447 * support a PolicySpi implementation for the specified type.
448 *
449 * @see Provider
450 * @since 1.6
451 */
452 public static Policy getInstance(String type,
453 Policy.Parameters params,
454 String provider)
455 throws NoSuchProviderException, NoSuchAlgorithmException {
456
457 if (provider == null || provider.length() == 0) {
458 throw new IllegalArgumentException("missing provider");
459 }
460
461 checkPermission(type);
462 try {
463 GetInstance.Instance instance = GetInstance.getInstance("Policy",
464 PolicySpi.class,
465 type,
466 params,
467 provider);
468 return new PolicyDelegate((PolicySpi)instance.impl,
469 instance.provider,
470 type,
471 params);
472 } catch (NoSuchAlgorithmException nsae) {
473 return handleException(nsae);
474 }
475 }
476
477 /**
478 * Returns a Policy object of the specified type.
479 *
480 * <p> A new Policy object encapsulating the
481 * PolicySpi implementation from the specified Provider
482 * object is returned. Note that the specified Provider object
483 * does not have to be registered in the provider list.
484 *
485 * @param type the specified Policy type. See the Policy section in the
486 * <a href=
487 * "{@docRoot}/../technotes/guides/security/StandardNames.html#Policy">
488 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
489 * for a list of standard Policy types.
490 *
491 * @param params parameters for the Policy, which may be null.
492 *
493 * @param provider the Provider.
494 *
495 * @return the new Policy object.
496 *
497 * @exception SecurityException if the caller does not have permission
498 * to get a Policy instance for the specified type.
499 *
500 * @exception NullPointerException if the specified type is null.
501 *
502 * @exception IllegalArgumentException if the specified Provider is null,
503 * or if the specified parameters are not understood by
504 * the PolicySpi implementation from the specified Provider.
505 *
506 * @exception NoSuchAlgorithmException if the specified Provider does not
507 * support a PolicySpi implementation for the specified type.
508 *
509 * @see Provider
510 * @since 1.6
511 */
512 public static Policy getInstance(String type,
513 Policy.Parameters params,
514 Provider provider)
515 throws NoSuchAlgorithmException {
516
517 if (provider == null) {
518 throw new IllegalArgumentException("missing provider");
519 }
520
521 checkPermission(type);
522 try {
523 GetInstance.Instance instance = GetInstance.getInstance("Policy",
524 PolicySpi.class,
525 type,
526 params,
527 provider);
528 return new PolicyDelegate((PolicySpi)instance.impl,
529 instance.provider,
530 type,
531 params);
532 } catch (NoSuchAlgorithmException nsae) {
533 return handleException(nsae);
534 }
535 }
536
537 private static Policy handleException(NoSuchAlgorithmException nsae)
538 throws NoSuchAlgorithmException {
539 Throwable cause = nsae.getCause();
540 if (cause instanceof IllegalArgumentException) {
541 throw (IllegalArgumentException)cause;
542 }
543 throw nsae;
544 }
545
546 /**
547 * Return the Provider of this Policy.
548 *
549 * <p> This Policy instance will only have a Provider if it
550 * was obtained via a call to {@code Policy.getInstance}.
551 * Otherwise this method returns null.
552 *
553 * @return the Provider of this Policy, or null.
554 *
555 * @since 1.6
556 */
557 public Provider getProvider() {
558 return null;
559 }
560
561 /**
562 * Return the type of this Policy.
563 *
564 * <p> This Policy instance will only have a type if it
565 * was obtained via a call to {@code Policy.getInstance}.
566 * Otherwise this method returns null.
567 *
568 * @return the type of this Policy, or null.
569 *
570 * @since 1.6
571 */
572 public String getType() {
573 return null;
574 }
575
576 /**
577 * Return Policy parameters.
578 *
579 * <p> This Policy instance will only have parameters if it
580 * was obtained via a call to {@code Policy.getInstance}.
581 * Otherwise this method returns null.
582 *
583 * @return Policy parameters, or null.
584 *
585 * @since 1.6
586 */
587 public Policy.Parameters getParameters() {
588 return null;
589 }
590
591 /**
592 * Return a PermissionCollection object containing the set of
593 * permissions granted to the specified CodeSource.
594 *
595 * <p> Applications are discouraged from calling this method
596 * since this operation may not be supported by all policy implementations.
597 * Applications should solely rely on the {@code implies} method
598 * to perform policy checks. If an application absolutely must call
599 * a getPermissions method, it should call
600 * {@code getPermissions(ProtectionDomain)}.
601 *
602 * <p> The default implementation of this method returns
603 * Policy.UNSUPPORTED_EMPTY_COLLECTION. This method can be
604 * overridden if the policy implementation can return a set of
605 * permissions granted to a CodeSource.
606 *
607 * @param codesource the CodeSource to which the returned
608 * PermissionCollection has been granted.
609 *
610 * @return a set of permissions granted to the specified CodeSource.
611 * If this operation is supported, the returned
612 * set of permissions must be a new mutable instance
613 * and it must support heterogeneous Permission types.
614 * If this operation is not supported,
615 * Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
616 */
617 public PermissionCollection getPermissions(CodeSource codesource) {
618 return Policy.UNSUPPORTED_EMPTY_COLLECTION;
619 }
620
621 /**
622 * Return a PermissionCollection object containing the set of
623 * permissions granted to the specified ProtectionDomain.
624 *
625 * <p> Applications are discouraged from calling this method
626 * since this operation may not be supported by all policy implementations.
627 * Applications should rely on the {@code implies} method
628 * to perform policy checks.
629 *
630 * <p> The default implementation of this method first retrieves
631 * the permissions returned via {@code getPermissions(CodeSource)}
632 * (the CodeSource is taken from the specified ProtectionDomain),
633 * as well as the permissions located inside the specified ProtectionDomain.
634 * All of these permissions are then combined and returned in a new
635 * PermissionCollection object. If {@code getPermissions(CodeSource)}
636 * returns Policy.UNSUPPORTED_EMPTY_COLLECTION, then this method
637 * returns the permissions contained inside the specified ProtectionDomain
638 * in a new PermissionCollection object.
639 *
640 * <p> This method can be overridden if the policy implementation
641 * supports returning a set of permissions granted to a ProtectionDomain.
642 *
643 * @param domain the ProtectionDomain to which the returned
644 * PermissionCollection has been granted.
645 *
646 * @return a set of permissions granted to the specified ProtectionDomain.
647 * If this operation is supported, the returned
648 * set of permissions must be a new mutable instance
649 * and it must support heterogeneous Permission types.
650 * If this operation is not supported,
651 * Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
652 *
653 * @since 1.4
654 */
655 public PermissionCollection getPermissions(ProtectionDomain domain) {
656 PermissionCollection pc = null;
657
658 if (domain == null)
659 return new Permissions();
660
661 if (pdMapping == null) {
662 initPolicy(this);
663 }
664
665 synchronized (pdMapping) {
666 pc = pdMapping.get(domain.key);
667 }
668
669 if (pc != null) {
670 Permissions perms = new Permissions();
671 synchronized (pc) {
672 for (Enumeration<Permission> e = pc.elements() ; e.hasMoreElements() ;) {
673 perms.add(e.nextElement());
674 }
675 }
676 return perms;
677 }
678
679 pc = getPermissions(domain.getCodeSource());
680 if (pc == null || pc == UNSUPPORTED_EMPTY_COLLECTION) {
681 pc = new Permissions();
682 }
683
684 addStaticPerms(pc, domain.getPermissions());
685 return pc;
686 }
687
688 /**
689 * add static permissions to provided permission collection
690 */
691 private void addStaticPerms(PermissionCollection perms,
692 PermissionCollection statics) {
693 if (statics != null) {
694 synchronized (statics) {
695 Enumeration<Permission> e = statics.elements();
696 while (e.hasMoreElements()) {
697 perms.add(e.nextElement());
698 }
699 }
700 }
701 }
702
703 /**
704 * Evaluates the global policy for the permissions granted to
705 * the ProtectionDomain and tests whether the permission is
706 * granted.
707 *
708 * @param domain the ProtectionDomain to test
709 * @param permission the Permission object to be tested for implication.
710 *
711 * @return true if "permission" is a proper subset of a permission
712 * granted to this ProtectionDomain.
713 *
714 * @see java.security.ProtectionDomain
715 * @since 1.4
716 */
717 public boolean implies(ProtectionDomain domain, Permission permission) {
718 PermissionCollection pc;
719
720 if (pdMapping == null) {
721 initPolicy(this);
722 }
723
724 synchronized (pdMapping) {
725 pc = pdMapping.get(domain.key);
726 }
727
728 if (pc != null) {
729 return pc.implies(permission);
730 }
731
732 pc = getPermissions(domain);
733 if (pc == null) {
734 return false;
735 }
736
737 synchronized (pdMapping) {
738 // cache it
739 pdMapping.put(domain.key, pc);
740 }
741
742 return pc.implies(permission);
743 }
744
745 /**
746 * Refreshes/reloads the policy configuration. The behavior of this method
747 * depends on the implementation. For example, calling {@code refresh}
748 * on a file-based policy will cause the file to be re-read.
749 *
750 * <p> The default implementation of this method does nothing.
751 * This method should be overridden if a refresh operation is supported
752 * by the policy implementation.
753 */
754 public void refresh() { }
755
756 /**
757 * This subclass is returned by the getInstance calls. All Policy calls
758 * are delegated to the underlying PolicySpi.
759 */
760 private static class PolicyDelegate extends Policy {
761
762 private PolicySpi spi;
763 private Provider p;
764 private String type;
765 private Policy.Parameters params;
766
767 private PolicyDelegate(PolicySpi spi, Provider p,
768 String type, Policy.Parameters params) {
769 this.spi = spi;
770 this.p = p;
771 this.type = type;
772 this.params = params;
773 }
774
775 @Override public String getType() { return type; }
776
777 @Override public Policy.Parameters getParameters() { return params; }
778
779 @Override public Provider getProvider() { return p; }
780
781 @Override
782 public PermissionCollection getPermissions(CodeSource codesource) {
783 return spi.engineGetPermissions(codesource);
784 }
785 @Override
786 public PermissionCollection getPermissions(ProtectionDomain domain) {
787 return spi.engineGetPermissions(domain);
788 }
789 @Override
790 public boolean implies(ProtectionDomain domain, Permission perm) {
791 return spi.engineImplies(domain, perm);
792 }
793 @Override
794 public void refresh() {
795 spi.engineRefresh();
796 }
797 }
798
799 /**
800 * This represents a marker interface for Policy parameters.
801 *
802 * @since 1.6
803 */
804 public static interface Parameters { }
805
806 /**
807 * This class represents a read-only empty PermissionCollection object that
808 * is returned from the {@code getPermissions(CodeSource)} and
809 * {@code getPermissions(ProtectionDomain)}
810 * methods in the Policy class when those operations are not
811 * supported by the Policy implementation.
812 */
813 private static class UnsupportedEmptyCollection
814 extends PermissionCollection {
815
816 private static final long serialVersionUID = -8492269157353014774L;
817
818 private Permissions perms;
819
820 /**
821 * Create a read-only empty PermissionCollection object.
822 */
823 public UnsupportedEmptyCollection() {
824 this.perms = new Permissions();
825 perms.setReadOnly();
826 }
827
828 /**
829 * Adds a permission object to the current collection of permission
830 * objects.
831 *
832 * @param permission the Permission object to add.
833 *
834 * @exception SecurityException - if this PermissionCollection object
835 * has been marked readonly
836 */
837 @Override public void add(Permission permission) {
838 perms.add(permission);
839 }
840
841 /**
842 * Checks to see if the specified permission is implied by the
843 * collection of Permission objects held in this PermissionCollection.
844 *
845 * @param permission the Permission object to compare.
846 *
847 * @return true if "permission" is implied by the permissions in
848 * the collection, false if not.
849 */
850 @Override public boolean implies(Permission permission) {
851 return perms.implies(permission);
852 }
853
854 /**
855 * Returns an enumeration of all the Permission objects in the
856 * collection.
857 *
858 * @return an enumeration of all the Permissions.
859 */
860 @Override public Enumeration<Permission> elements() {
861 return perms.elements();
862 }
863 }
864 }