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 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 Class<?> c = Class.forName(policyProvider, true, scl);
226 return (Policy)c.newInstance();
227 } catch (Exception e) {
228 if (debug != null) {
229 debug.println("policy provider " + policyProvider +
230 " not available");
231 e.printStackTrace();
232 }
233 return null;
234 }
235 }
236 });
237
238 if (pol == null) {
239 // Fallback and use the system default implementation
240 if (debug != null) {
241 debug.println("using " + DEFAULT_POLICY);
242 }
243 pol = polFile;
244 }
245 policy.set(new PolicyInfo(pol, true));
246 return pol;
247 }
248
249 /**
250 * Sets the system-wide Policy object. This method first calls
251 * {@code SecurityManager.checkPermission} with a
252 * {@code SecurityPermission("setPolicy")}
253 * permission to ensure it's ok to set the Policy.
254 *
255 * @param p the new system Policy object.
256 *
257 * @throws SecurityException
258 * if a security manager exists and its
259 * {@code checkPermission} method doesn't allow
260 * setting the Policy.
261 *
262 * @see SecurityManager#checkPermission(Permission)
263 * @see #getPolicy()
264 *
265 */
266 public static void setPolicy(Policy p)
267 {
268 SecurityManager sm = System.getSecurityManager();
269 if (sm != null) sm.checkPermission(
270 new SecurityPermission("setPolicy"));
271 if (p != null) {
272 initPolicy(p);
273 }
274 synchronized (Policy.class) {
275 policy.set(new PolicyInfo(p, p != null));
276 }
277 }
278
279 /**
280 * Initialize superclass state such that a legacy provider can
281 * handle queries for itself.
282 *
283 * @since 1.4
284 */
285 private static void initPolicy (final Policy p) {
286 /*
287 * A policy provider not on the bootclasspath could trigger
288 * security checks fulfilling a call to either Policy.implies
289 * or Policy.getPermissions. If this does occur the provider
290 * must be able to answer for it's own ProtectionDomain
291 * without triggering additional security checks, otherwise
292 * the policy implementation will end up in an infinite
293 * recursion.
294 *
295 * To mitigate this, the provider can collect it's own
296 * ProtectionDomain and associate a PermissionCollection while
297 * it is being installed. The currently installed policy
298 * provider (if there is one) will handle calls to
299 * Policy.implies or Policy.getPermissions during this
300 * process.
301 *
302 * This Policy superclass caches away the ProtectionDomain and
303 * statically binds permissions so that legacy Policy
304 * implementations will continue to function.
305 */
306
307 ProtectionDomain policyDomain =
308 AccessController.doPrivileged(new PrivilegedAction<>() {
309 public ProtectionDomain run() {
310 return p.getClass().getProtectionDomain();
311 }
312 });
313
314 /*
315 * Collect the permissions granted to this protection domain
316 * so that the provider can be security checked while processing
317 * calls to Policy.implies or Policy.getPermissions.
318 */
319 PermissionCollection policyPerms = null;
320 synchronized (p) {
321 if (p.pdMapping == null) {
322 p.pdMapping = new WeakHashMap<>();
323 }
324 }
325
326 if (policyDomain.getCodeSource() != null) {
327 Policy pol = policy.get().policy;
328 if (pol != null) {
329 policyPerms = pol.getPermissions(policyDomain);
330 }
331
332 if (policyPerms == null) { // assume it has all
333 policyPerms = new Permissions();
334 policyPerms.add(SecurityConstants.ALL_PERMISSION);
335 }
336
337 synchronized (p.pdMapping) {
338 // cache of pd to permissions
339 p.pdMapping.put(policyDomain.key, policyPerms);
340 }
341 }
342 return;
343 }
344
345
346 /**
347 * Returns a Policy object of the specified type.
348 *
349 * <p> This method traverses the list of registered security providers,
350 * starting with the most preferred Provider.
351 * A new Policy object encapsulating the
352 * PolicySpi implementation from the first
353 * Provider that supports the specified type is returned.
354 *
355 * <p> Note that the list of registered providers may be retrieved via
356 * the {@link Security#getProviders() Security.getProviders()} method.
357 *
358 * @implNote
359 * The JDK Reference Implementation additionally uses the
360 * {@code jdk.security.provider.preferred}
361 * {@link Security#getProperty(String) Security} property to determine
362 * the preferred provider order for the specified algorithm. This
363 * may be different than the order of providers returned by
364 * {@link Security#getProviders() Security.getProviders()}.
365 *
366 * @param type the specified Policy type. See the Policy section in the
367 * <a href=
368 * "{@docRoot}/../technotes/guides/security/StandardNames.html#Policy">
369 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
370 * for a list of standard Policy types.
371 *
372 * @param params parameters for the Policy, which may be null.
373 *
374 * @return the new Policy object.
375 *
376 * @exception SecurityException if the caller does not have permission
377 * to get a Policy instance for the specified type.
378 *
379 * @exception NullPointerException if the specified type is null.
380 *
381 * @exception IllegalArgumentException if the specified parameters
382 * are not understood by the PolicySpi implementation
383 * from the selected Provider.
384 *
385 * @exception NoSuchAlgorithmException if no Provider supports a PolicySpi
386 * implementation for the specified type.
387 *
388 * @see Provider
389 * @since 1.6
390 */
391 public static Policy getInstance(String type, Policy.Parameters params)
392 throws NoSuchAlgorithmException {
393
394 checkPermission(type);
395 try {
396 GetInstance.Instance instance = GetInstance.getInstance("Policy",
397 PolicySpi.class,
398 type,
399 params);
400 return new PolicyDelegate((PolicySpi)instance.impl,
401 instance.provider,
402 type,
403 params);
404 } catch (NoSuchAlgorithmException nsae) {
405 return handleException(nsae);
406 }
407 }
408
409 /**
410 * Returns a Policy object of the specified type.
411 *
412 * <p> A new Policy object encapsulating the
413 * PolicySpi implementation from the specified provider
414 * is returned. The specified provider must be registered
415 * in the provider list.
416 *
417 * <p> Note that the list of registered providers may be retrieved via
418 * the {@link Security#getProviders() Security.getProviders()} method.
419 *
420 * @param type the specified Policy type. See the Policy section in the
421 * <a href=
422 * "{@docRoot}/../technotes/guides/security/StandardNames.html#Policy">
423 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
424 * for a list of standard Policy types.
425 *
426 * @param params parameters for the Policy, which may be null.
427 *
428 * @param provider the provider.
429 *
430 * @return the new Policy object.
431 *
432 * @exception SecurityException if the caller does not have permission
433 * to get a Policy instance for the specified type.
434 *
435 * @exception NullPointerException if the specified type is null.
436 *
437 * @exception IllegalArgumentException if the specified provider
438 * is null or empty,
439 * or if the specified parameters are not understood by
440 * the PolicySpi implementation from the specified provider.
441 *
442 * @exception NoSuchProviderException if the specified provider is not
443 * registered in the security provider list.
444 *
445 * @exception NoSuchAlgorithmException if the specified provider does not
446 * support a PolicySpi implementation for the specified type.
447 *
448 * @see Provider
449 * @since 1.6
450 */
451 public static Policy getInstance(String type,
452 Policy.Parameters params,
453 String provider)
454 throws NoSuchProviderException, NoSuchAlgorithmException {
455
456 if (provider == null || provider.length() == 0) {
457 throw new IllegalArgumentException("missing provider");
458 }
459
460 checkPermission(type);
461 try {
462 GetInstance.Instance instance = GetInstance.getInstance("Policy",
463 PolicySpi.class,
464 type,
465 params,
466 provider);
467 return new PolicyDelegate((PolicySpi)instance.impl,
468 instance.provider,
469 type,
470 params);
471 } catch (NoSuchAlgorithmException nsae) {
472 return handleException(nsae);
473 }
474 }
475
476 /**
477 * Returns a Policy object of the specified type.
478 *
479 * <p> A new Policy object encapsulating the
480 * PolicySpi implementation from the specified Provider
481 * object is returned. Note that the specified Provider object
482 * does not have to be registered in the provider list.
483 *
484 * @param type the specified Policy type. See the Policy section in the
485 * <a href=
486 * "{@docRoot}/../technotes/guides/security/StandardNames.html#Policy">
487 * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
488 * for a list of standard Policy types.
489 *
490 * @param params parameters for the Policy, which may be null.
491 *
492 * @param provider the Provider.
493 *
494 * @return the new Policy object.
495 *
496 * @exception SecurityException if the caller does not have permission
497 * to get a Policy instance for the specified type.
498 *
499 * @exception NullPointerException if the specified type is null.
500 *
501 * @exception IllegalArgumentException if the specified Provider is null,
502 * or if the specified parameters are not understood by
503 * the PolicySpi implementation from the specified Provider.
504 *
505 * @exception NoSuchAlgorithmException if the specified Provider does not
506 * support a PolicySpi implementation for the specified type.
507 *
508 * @see Provider
509 * @since 1.6
510 */
511 public static Policy getInstance(String type,
512 Policy.Parameters params,
513 Provider provider)
514 throws NoSuchAlgorithmException {
515
516 if (provider == null) {
517 throw new IllegalArgumentException("missing provider");
518 }
519
520 checkPermission(type);
521 try {
522 GetInstance.Instance instance = GetInstance.getInstance("Policy",
523 PolicySpi.class,
524 type,
525 params,
526 provider);
527 return new PolicyDelegate((PolicySpi)instance.impl,
528 instance.provider,
529 type,
530 params);
531 } catch (NoSuchAlgorithmException nsae) {
532 return handleException(nsae);
533 }
534 }
535
536 private static Policy handleException(NoSuchAlgorithmException nsae)
537 throws NoSuchAlgorithmException {
538 Throwable cause = nsae.getCause();
539 if (cause instanceof IllegalArgumentException) {
540 throw (IllegalArgumentException)cause;
541 }
542 throw nsae;
543 }
544
545 /**
546 * Return the Provider of this Policy.
547 *
548 * <p> This Policy instance will only have a Provider if it
549 * was obtained via a call to {@code Policy.getInstance}.
550 * Otherwise this method returns null.
551 *
552 * @return the Provider of this Policy, or null.
553 *
554 * @since 1.6
555 */
556 public Provider getProvider() {
557 return null;
558 }
559
560 /**
561 * Return the type of this Policy.
562 *
563 * <p> This Policy instance will only have a type if it
564 * was obtained via a call to {@code Policy.getInstance}.
565 * Otherwise this method returns null.
566 *
567 * @return the type of this Policy, or null.
568 *
569 * @since 1.6
570 */
571 public String getType() {
572 return null;
573 }
574
575 /**
576 * Return Policy parameters.
577 *
578 * <p> This Policy instance will only have parameters if it
579 * was obtained via a call to {@code Policy.getInstance}.
580 * Otherwise this method returns null.
581 *
582 * @return Policy parameters, or null.
583 *
584 * @since 1.6
585 */
586 public Policy.Parameters getParameters() {
587 return null;
588 }
589
590 /**
591 * Return a PermissionCollection object containing the set of
592 * permissions granted to the specified CodeSource.
593 *
594 * <p> Applications are discouraged from calling this method
595 * since this operation may not be supported by all policy implementations.
596 * Applications should solely rely on the {@code implies} method
597 * to perform policy checks. If an application absolutely must call
598 * a getPermissions method, it should call
599 * {@code getPermissions(ProtectionDomain)}.
600 *
601 * <p> The default implementation of this method returns
602 * Policy.UNSUPPORTED_EMPTY_COLLECTION. This method can be
603 * overridden if the policy implementation can return a set of
604 * permissions granted to a CodeSource.
605 *
606 * @param codesource the CodeSource to which the returned
607 * PermissionCollection has been granted.
608 *
609 * @return a set of permissions granted to the specified CodeSource.
610 * If this operation is supported, the returned
611 * set of permissions must be a new mutable instance
612 * and it must support heterogeneous Permission types.
613 * If this operation is not supported,
614 * Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
615 */
616 public PermissionCollection getPermissions(CodeSource codesource) {
617 return Policy.UNSUPPORTED_EMPTY_COLLECTION;
618 }
619
620 /**
621 * Return a PermissionCollection object containing the set of
622 * permissions granted to the specified ProtectionDomain.
623 *
624 * <p> Applications are discouraged from calling this method
625 * since this operation may not be supported by all policy implementations.
626 * Applications should rely on the {@code implies} method
627 * to perform policy checks.
628 *
629 * <p> The default implementation of this method first retrieves
630 * the permissions returned via {@code getPermissions(CodeSource)}
631 * (the CodeSource is taken from the specified ProtectionDomain),
632 * as well as the permissions located inside the specified ProtectionDomain.
633 * All of these permissions are then combined and returned in a new
634 * PermissionCollection object. If {@code getPermissions(CodeSource)}
635 * returns Policy.UNSUPPORTED_EMPTY_COLLECTION, then this method
636 * returns the permissions contained inside the specified ProtectionDomain
637 * in a new PermissionCollection object.
638 *
639 * <p> This method can be overridden if the policy implementation
640 * supports returning a set of permissions granted to a ProtectionDomain.
641 *
642 * @param domain the ProtectionDomain to which the returned
643 * PermissionCollection has been granted.
644 *
645 * @return a set of permissions granted to the specified ProtectionDomain.
646 * If this operation is supported, the returned
647 * set of permissions must be a new mutable instance
648 * and it must support heterogeneous Permission types.
649 * If this operation is not supported,
650 * Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
651 *
652 * @since 1.4
653 */
654 public PermissionCollection getPermissions(ProtectionDomain domain) {
655 PermissionCollection pc = null;
656
657 if (domain == null)
658 return new Permissions();
659
660 if (pdMapping == null) {
661 initPolicy(this);
662 }
663
664 synchronized (pdMapping) {
665 pc = pdMapping.get(domain.key);
666 }
667
668 if (pc != null) {
669 Permissions perms = new Permissions();
670 synchronized (pc) {
671 for (Enumeration<Permission> e = pc.elements() ; e.hasMoreElements() ;) {
672 perms.add(e.nextElement());
673 }
674 }
675 return perms;
676 }
677
678 pc = getPermissions(domain.getCodeSource());
679 if (pc == null || pc == UNSUPPORTED_EMPTY_COLLECTION) {
680 pc = new Permissions();
681 }
682
683 addStaticPerms(pc, domain.getPermissions());
684 return pc;
685 }
686
687 /**
688 * add static permissions to provided permission collection
689 */
690 private void addStaticPerms(PermissionCollection perms,
691 PermissionCollection statics) {
692 if (statics != null) {
693 synchronized (statics) {
694 Enumeration<Permission> e = statics.elements();
695 while (e.hasMoreElements()) {
696 perms.add(e.nextElement());
697 }
698 }
699 }
700 }
701
702 /**
703 * Evaluates the global policy for the permissions granted to
704 * the ProtectionDomain and tests whether the permission is
705 * granted.
706 *
707 * @param domain the ProtectionDomain to test
708 * @param permission the Permission object to be tested for implication.
709 *
710 * @return true if "permission" is a proper subset of a permission
711 * granted to this ProtectionDomain.
712 *
713 * @see java.security.ProtectionDomain
714 * @since 1.4
715 */
716 public boolean implies(ProtectionDomain domain, Permission permission) {
717 PermissionCollection pc;
718
719 if (pdMapping == null) {
720 initPolicy(this);
721 }
722
723 synchronized (pdMapping) {
724 pc = pdMapping.get(domain.key);
725 }
726
727 if (pc != null) {
728 return pc.implies(permission);
729 }
730
731 pc = getPermissions(domain);
732 if (pc == null) {
733 return false;
734 }
735
736 synchronized (pdMapping) {
737 // cache it
738 pdMapping.put(domain.key, pc);
739 }
740
741 return pc.implies(permission);
742 }
743
744 /**
745 * Refreshes/reloads the policy configuration. The behavior of this method
746 * depends on the implementation. For example, calling {@code refresh}
747 * on a file-based policy will cause the file to be re-read.
748 *
749 * <p> The default implementation of this method does nothing.
750 * This method should be overridden if a refresh operation is supported
751 * by the policy implementation.
752 */
753 public void refresh() { }
754
755 /**
756 * This subclass is returned by the getInstance calls. All Policy calls
757 * are delegated to the underlying PolicySpi.
758 */
759 private static class PolicyDelegate extends Policy {
760
761 private PolicySpi spi;
762 private Provider p;
763 private String type;
764 private Policy.Parameters params;
765
766 private PolicyDelegate(PolicySpi spi, Provider p,
767 String type, Policy.Parameters params) {
768 this.spi = spi;
769 this.p = p;
770 this.type = type;
771 this.params = params;
772 }
773
774 @Override public String getType() { return type; }
775
776 @Override public Policy.Parameters getParameters() { return params; }
777
778 @Override public Provider getProvider() { return p; }
779
780 @Override
781 public PermissionCollection getPermissions(CodeSource codesource) {
782 return spi.engineGetPermissions(codesource);
783 }
784 @Override
785 public PermissionCollection getPermissions(ProtectionDomain domain) {
786 return spi.engineGetPermissions(domain);
787 }
788 @Override
789 public boolean implies(ProtectionDomain domain, Permission perm) {
790 return spi.engineImplies(domain, perm);
791 }
792 @Override
793 public void refresh() {
794 spi.engineRefresh();
795 }
796 }
797
798 /**
799 * This represents a marker interface for Policy parameters.
800 *
801 * @since 1.6
802 */
803 public static interface Parameters { }
804
805 /**
806 * This class represents a read-only empty PermissionCollection object that
807 * is returned from the {@code getPermissions(CodeSource)} and
808 * {@code getPermissions(ProtectionDomain)}
809 * methods in the Policy class when those operations are not
810 * supported by the Policy implementation.
811 */
812 private static class UnsupportedEmptyCollection
813 extends PermissionCollection {
814
815 private static final long serialVersionUID = -8492269157353014774L;
816
817 private Permissions perms;
818
819 /**
820 * Create a read-only empty PermissionCollection object.
821 */
822 public UnsupportedEmptyCollection() {
823 this.perms = new Permissions();
824 perms.setReadOnly();
825 }
826
827 /**
828 * Adds a permission object to the current collection of permission
829 * objects.
830 *
831 * @param permission the Permission object to add.
832 *
833 * @exception SecurityException - if this PermissionCollection object
834 * has been marked readonly
835 */
836 @Override public void add(Permission permission) {
837 perms.add(permission);
838 }
839
840 /**
841 * Checks to see if the specified permission is implied by the
842 * collection of Permission objects held in this PermissionCollection.
843 *
844 * @param permission the Permission object to compare.
845 *
846 * @return true if "permission" is implied by the permissions in
847 * the collection, false if not.
848 */
849 @Override public boolean implies(Permission permission) {
850 return perms.implies(permission);
851 }
852
853 /**
854 * Returns an enumeration of all the Permission objects in the
855 * collection.
856 *
857 * @return an enumeration of all the Permissions.
858 */
859 @Override public Enumeration<Permission> elements() {
860 return perms.elements();
861 }
862 }
863 }