1 /*
2 jGuard is a security framework based on top of jaas (java authentication and authorization security).
3 it is written for web applications, to resolve simply, access control problems.
4 version $Name: $
5 http://sourceforge.net/projects/jguard/
6
7 Copyright (C) 2004 Charles GAY
8
9 This library is free software; you can redistribute it and/or
10 modify it under the terms of the GNU Lesser General Public
11 License as published by the Free Software Foundation; either
12 version 2.1 of the License, or (at your option) any later version.
13
14 This library is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 Lesser General Public License for more details.
18
19 You should have received a copy of the GNU Lesser General Public
20 License along with this library; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22
23
24 jGuard project home page:
25 http://sourceforge.net/projects/jguard/
26
27 */
28 package net.sf.jguard.core.authorization.policy;
29
30 import java.security.AccessControlContext;
31 import java.security.AccessControlException;
32 import java.security.AccessController;
33 import java.security.Permission;
34 import java.security.PermissionCollection;
35 import java.security.Policy;
36 import java.security.ProtectionDomain;
37 import java.util.Set;
38
39 import javax.security.auth.Subject;
40
41
42 /**
43 * {@link AccessController} clone used to check permission against an isolated Policy
44 * not tight to the system Policy.
45 * @author <a href="mailto:diabolo512@users.sourceforge.net">Charles Gay</a>
46 * @see java.security.AccessController
47 * @since 1.0
48 */
49 public class LocalAccessController {
50
51 private Policy policy;
52
53 public LocalAccessController(Policy policy){
54 this.policy = policy;
55 }
56
57
58 /**
59 * controls that the provided Subject has got the permission requested
60 * against the Policy.
61 * @param permission to check
62 * @throws AccessControlException when access is denied
63 */
64 public void checkPermission(Permission permission)throws AccessControlException{
65 AccessControlContext acc = AccessController.getContext();
66
67 Subject subject = Subject.getSubject(acc);
68 if(acc==null){
69 //system code is always allowed
70 return;
71 }
72 if(subject==null){
73 //like this class is used in 'local' mode,
74 //the security is not tight with the jvm security
75 //we don't make restrictions when this code can be
76 //avoided easily
77 // to have a more deep security, use the 'jvm' mode
78 return;
79 }
80 if(permission == null){
81 throw new NullPointerException(" permission provided is null ");
82 }
83
84 Set principals = subject.getPrincipals();
85 ProtectionDomain domain = ProtectionDomainUtils.getEmptyProtectionDomain(principals);
86 PermissionCollection permColl = policy.getPermissions(domain);
87 if (!permColl.implies(permission)) {
88 StringBuffer sb = new StringBuffer(" permission ");
89 throw new AccessControlException(sb.append(permission.toString()).append(" is not granted ").toString(),permission);
90 }
91 }
92
93 public Policy getPolicy(){
94 return policy;
95 }
96
97 }