| /* Policy.java --- Policy Manager Class |
| Copyright (C) 1999 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package java.security; |
| |
| /** |
| Policy is an abstract class for managing the system security |
| policy for the Java application environment. It specifies |
| which permissions are available for code from various |
| sources. The security policy is represented through a |
| subclass of Policy. |
| |
| Only one Policy is in effect at any time. ProtectionDomain |
| initializes itself with information from this class on the |
| set of permssions to grant. |
| |
| The location for the actual Policy could be anywhere in any |
| form because it depends on the Policy implementation. The |
| default system is in a flat ASCII file or it could be in a |
| database. |
| |
| The current installed Policy can be accessed with getPolicy |
| and changed with setPolicy if the code has the correct |
| permissions. |
| |
| The refresh method causes the Policy class to refresh/reload |
| its configuration. The method used to refresh depends on the |
| Policy implementation. |
| |
| When a protection domain initializes its permissions it uses |
| code like: |
| <code> |
| policy = Policy.getPolicy(); |
| permissionCollection perms = policy.getPermissions(MyCodeSource) |
| </code> |
| The protection domain passes the Policy handler a CodeSource |
| object which contains the codebase URL and public key. The |
| Policy implementation then returns the proper set of |
| permissions for the CodeSource. |
| |
| The default Policy implementation can be changed by setting |
| the "policy.provider" security provider in java.security |
| to the correct Policy implementation class. |
| |
| @author Mark Benvenuto |
| |
| @since JDK 1.2 |
| */ |
| public abstract class Policy |
| { |
| // FIXME: The class name of the Policy provider should really be sourced |
| // from the "java.security" configuration file. For now, just hard-code |
| // a stub implementation. |
| static private Policy currentPolicy = null; |
| static |
| { |
| String pp = System.getProperty ("policy.provider"); |
| if (pp != null) |
| try |
| { |
| currentPolicy = (Policy)Class.forName(pp).newInstance(); |
| } |
| catch (Exception _) |
| { |
| currentPolicy = null; |
| } |
| if (currentPolicy == null) |
| currentPolicy = new gnu.java.security.provider.DefaultPolicy(); |
| } |
| |
| /** |
| Constructs a new Policy class. |
| */ |
| public Policy() |
| { |
| } |
| |
| /** |
| Gets the currently installed Policy handler. The value should |
| not be cached as it can be changed by setPolicy. This |
| function first calls <code>SecurityManager.checkPermission</code> |
| with <code>SecurityPermission("getPolicy")</code> to check |
| if the caller has Permission to get the current Policy. |
| |
| @return the current Policy |
| |
| @throws SecurityException if the security manager exists |
| the caller does not have permission to |
| <code>getPolicy</code>. |
| */ |
| public static Policy getPolicy() |
| { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) |
| sm.checkPermission(new SecurityPermission("getPolicy")); |
| |
| return currentPolicy; |
| } |
| |
| /** |
| Sets the currently installed Policy handler. This |
| function first calls <code>SecurityManager.checkPermission</code> |
| with <code>SecurityPermission("setPolicy")</code> to check |
| if the caller has Permission to get the current Policy. |
| |
| @param policy the new Policy to use |
| |
| @throws SecurityException if the security manager exists |
| the caller does not have permission to |
| <code>getPolicy</code>. |
| */ |
| public static void setPolicy(Policy policy) |
| { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) |
| sm.checkPermission(new SecurityPermission("setPolicy")); |
| |
| currentPolicy = policy; |
| } |
| |
| |
| /** |
| Evalutes the global policy and returns a set of Permissions |
| allowed for the specified CodeSource. |
| |
| @param codesource The CodeSource to get Permission for |
| |
| @return a set of permissions for codesource specified by |
| the current policy |
| |
| @throws SecurityException if the current thread does not |
| have permission to call <code>getPermissions</code> |
| */ |
| public abstract PermissionCollection getPermissions(CodeSource codesource); |
| |
| /** |
| Refreshes and/or reloads the current Policy. The actual |
| behavior of this method depends on the implementation. |
| */ |
| public abstract void refresh(); |
| } |