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.authentication.callbacks;
29
30 import java.io.IOException;
31
32 import java.util.List;
33 import javax.security.auth.callback.Callback;
34 import javax.security.auth.callback.CallbackHandler;
35 import javax.security.auth.callback.UnsupportedCallbackException;
36
37 /**
38 * {@link CallbackHandler} implementation which permit directly to assign
39 * the callback to the loginModules. the main purpose to this calbackhandler,
40 * is to 'hook' the CallbackHandler purppose to prevent to grab in the
41 * protocol the required callbacks; it is used when you want to set directly
42 * the credentials for the user. one use case is to create a GUEST user
43 * with some GUEST credentials.
44 * @author <a href="mailto:diabolo512@users.sourceforge.net">Charles Gay</a>
45 *
46 */
47 public class HookCallbackHandler implements CallbackHandler {
48
49 private List<Callback> callbacks;
50
51 public HookCallbackHandler(List<Callback> cbks){
52 this.callbacks = cbks;
53 }
54
55 public void handle(Callback[] callbacksToReplace) throws IOException,
56 UnsupportedCallbackException {
57 for(int i = 0;i<callbacksToReplace.length;i++){
58 Callback cbk = callbacksToReplace[i];
59 callbacksToReplace[i] = replaceCallback(cbk);
60 }
61
62 }
63
64 /**
65 * we try to replace the needed callback by
66 * the one provided in the constructor, if their class are
67 * equals. otherwise, we return the one provided in argument.
68 * @param callbackToReplace
69 * @return
70 */
71 private Callback replaceCallback(Callback callbackToReplace){
72 Class clazz = callbackToReplace.getClass();
73 for(int i=0;i<callbacks.size();i++){
74 Callback cb = callbacks.get(i);
75 if(cb.getClass().equals(clazz)){
76 return cb;
77 }
78 }
79 return callbackToReplace;
80 }
81 }