View Javadoc

1   package org.apache.turbine.modules.actions.sessionvalidator;
2   
3   /*
4    * Copyright 2001-2005 The Apache Software Foundation.
5    *
6    * Licensed under the Apache License, Version 2.0 (the "License")
7    * you may not use this file except in compliance with the License.
8    * You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  import org.apache.commons.configuration.Configuration;
20  
21  import org.apache.commons.lang.StringUtils;
22  
23  import org.apache.commons.logging.Log;
24  import org.apache.commons.logging.LogFactory;
25  
26  import org.apache.turbine.Turbine;
27  import org.apache.turbine.TurbineConstants;
28  
29  import org.apache.turbine.services.security.TurbineSecurity;
30  
31  import org.apache.turbine.util.RunData;
32  import org.apache.turbine.util.TurbineException;
33  
34  /***
35   * SessionValidator that requires login for use with Template Services
36   * like Velocity or WebMacro.
37   *
38   * <br>
39   *
40   * Templating services requires a different Session Validator
41   * because of the way it handles screens.  If you use the WebMacro or
42   * Velocity Service with the DefaultSessionValidator, users will be able to
43   * bypass login by directly addressing the template using
44   * template/index.wm.  This is because the Page class looks for the
45   * keyword "template" in the Path information and if it finds it will
46   * reset the screen using it's lookup mechanism and thereby bypass
47   * Login.
48   *
49   * Note that you will need to set the template.login property to the
50   * login template.
51   *
52   * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
53   * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
54   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
55   * @version $Id: TemplateSecureSessionValidator.java 264148 2005-08-29 14:21:04Z henning $
56   */
57  public class TemplateSecureSessionValidator
58      extends SessionValidator
59  {
60      /*** Logging */
61      private static Log log = LogFactory.getLog(
62              TemplateSecureSessionValidator.class);
63  
64      /***
65       * doPerform is virtually identical to DefaultSessionValidator
66       * except that it calls template methods instead of bare screen
67       * methods. For example, it uses <code>setScreenTemplate</code> to
68       * load the tr.props TEMPLATE_LOGIN instead of the default's
69       * setScreen to TurbineConstants.SCREEN_LOGIN.
70       *
71       * @see DefaultSessionValidator
72       * @param data Turbine information.
73       * @throws TurbineException The anonymous user could not be obtained
74       *         from the security service
75       */
76      public void doPerform(RunData data)
77              throws TurbineException
78      {
79          Configuration conf = Turbine.getConfiguration();
80  
81          // Pull user from session.
82          data.populate();
83  
84          // The user may have not logged in, so create a "guest/anonymous" user.
85          if (data.getUser() == null)
86          {
87              log.debug("Fixing up empty User Object!");
88              data.setUser(TurbineSecurity.getAnonymousUser());
89              data.save();
90          }
91  
92          // This is the secure sessionvalidator, so user must be logged in.
93          if (!data.getUser().hasLoggedIn())
94          {
95              log.debug("User is not logged in!");
96  
97              // only set the message if nothing else has already set it
98              // (e.g. the LogoutUser action).
99              if (StringUtils.isEmpty(data.getMessage()))
100             {
101                 data.setMessage(conf.getString(TurbineConstants.LOGIN_MESSAGE));
102             }
103 
104             // Set the screen template to the login page.
105             String loginTemplate =
106                 conf.getString(TurbineConstants.TEMPLATE_LOGIN);
107 
108             log.debug("Sending User to the Login Screen ("
109                     + loginTemplate + ")");
110             data.getTemplateInfo().setScreenTemplate(loginTemplate);
111 
112             // We're not doing any actions buddy! (except action.login which
113             // will have been performed already)
114             data.setAction(null);
115         }
116 
117         log.debug("Login Check finished!");
118 
119         // Make sure we have some way to return a response.
120         if (!data.hasScreen() && StringUtils.isEmpty(
121                 data.getTemplateInfo().getScreenTemplate()))
122         {
123             String template = conf.getString(
124                     TurbineConstants.TEMPLATE_HOMEPAGE);
125 
126             if (StringUtils.isNotEmpty(template))
127             {
128                 data.getTemplateInfo().setScreenTemplate(template);
129             }
130             else
131             {
132                 data.setScreen(conf.getString(
133                         TurbineConstants.SCREEN_HOMEPAGE));
134             }
135         }
136 
137         // The session_access_counter can be placed as a hidden field in
138         // forms.  This can be used to prevent a user from using the
139         // browsers back button and submitting stale data.
140         // FIXME!! a template needs to be written to use this with templates.
141 
142         if (data.getParameters().containsKey("_session_access_counter")
143                 && !TurbineSecurity.isAnonymousUser(data.getUser()))
144         {
145             // See comments in screens.error.InvalidState.
146             if (data.getParameters().getInt("_session_access_counter")
147                     < (((Integer) data.getUser().getTemp(
148                     "_session_access_counter")).intValue() - 1))
149             {
150                 if (data.getTemplateInfo().getScreenTemplate() != null)
151                 {
152                     data.getUser().setTemp("prev_template",
153                             data.getTemplateInfo().getScreenTemplate()
154                             .replace('/', ','));
155                     data.getTemplateInfo().setScreenTemplate(conf.getString(
156                             TurbineConstants.TEMPLATE_INVALID_STATE));
157                 }
158                 else
159                 {
160                     data.getUser().setTemp("prev_screen",
161                                            data.getScreen().replace('/', ','));
162                     data.setScreen(conf.getString(
163                             TurbineConstants.SCREEN_INVALID_STATE));
164                 }
165                 data.getUser().setTemp("prev_parameters", data.getParameters());
166                 data.setAction("");
167             }
168         }
169 
170         // We do not want to allow both a screen and template parameter.
171         // The template parameter is dominant.
172         if (data.getTemplateInfo().getScreenTemplate() != null)
173         {
174             data.setScreen(null);
175         }
176     }
177 }