PassiveCallbackHandler xref

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1   /* 
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.jetspeed.security.impl;
18  
19  import javax.security.auth.callback.*;
20  
21  /***
22   * <p>PassiveCallbackHandler has constructor that takes
23   * a username and password so its handle() method does
24   * not have to prompt the user for input.</p>
25   * <p>Useful for server-side applications.</p>
26   * 
27   * <p>This code was inspired from an article from:<p>
28   * <ul>
29   *    <li><a href="http://www.javaworld.com/javaworld/jw-09-2002/jw-0913-jaas.html">
30   *    All that JAAS</a></li>
31   * </ul> *
32   * @author <a href="mailto:dlestrat@apache.org">David Le Strat</a>
33   */
34  
35  public class PassiveCallbackHandler implements CallbackHandler
36  {
37  
38      private String username;
39      char[] password;
40  
41      /***
42       * <p>Creates a callback handler with the give username
43       * and password.</p>
44       * @param username The username.
45       * @param password The password.
46       */
47      public PassiveCallbackHandler(String username, String password)
48      {
49          this.username = username;
50          this.password = password.toCharArray();
51      }
52  
53      /***
54       * <p>Handles the specified set of Callbacks. Uses the
55       * username and password that were supplied to our
56       * constructor to popluate the Callbacks.</p>
57       * <p>This class supports NameCallback and PasswordCallback.</p>
58       *
59       * @param   callbacks the callbacks to handle
60       * @throws  IOException if an input or output error occurs.
61       * @throws  UnsupportedCallbackException if the callback is not an
62       *          instance of NameCallback or PasswordCallback
63       */
64      public void handle(Callback[] callbacks) throws java.io.IOException, UnsupportedCallbackException
65      {
66          for (int i = 0; i < callbacks.length; i++)
67          {
68              if (callbacks[i] instanceof NameCallback)
69              {
70                  ((NameCallback) callbacks[i]).setName(username);
71              }
72              else if (callbacks[i] instanceof PasswordCallback)
73              {
74                  ((PasswordCallback) callbacks[i]).setPassword(password);
75              }
76              else
77              {
78                  throw new UnsupportedCallbackException(callbacks[i], "Callback class not supported");
79              }
80          }
81      }
82  
83      /***
84       * <p>Clears out password state.</p>
85       */
86      public void clearPassword()
87      {
88          if (password != null)
89          {
90              for (int i = 0; i < password.length; i++)
91              {
92                  password[i] = ' ';
93              }
94              password = null;
95          }
96      }
97  
98  }