001 /* PasswordCallback.java -- callback for passwords.
002 Copyright (C) 2003, Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.security.auth.callback;
040
041 import java.io.Serializable;
042
043 /**
044 * Underlying security services instantiate and pass a <code>PasswordCallback</code>
045 * to the <code>handle()</code> method of a {@link CallbackHandler} to retrieve
046 * password information.
047 *
048 * @see CallbackHandler,
049 */
050 public class PasswordCallback implements Callback, Serializable
051 {
052
053 // Constants and variables
054 // -------------------------------------------------------------------------
055
056 /**
057 * @serial
058 * @since 1.4
059 */
060 private String prompt;
061
062 /**
063 * @serial
064 * @since 1.4
065 */
066 private boolean echoOn;
067
068 /**
069 * @serial
070 * @since 1.4
071 */
072 private char[] inputPassword;
073
074 // Constructor(s)
075 // -------------------------------------------------------------------------
076
077 /**
078 * Construct a <code>PasswordCallback</code> with a prompt and a boolean
079 * specifying whether the password should be displayed as it is being typed.
080 *
081 * @param prompt the prompt used to request the password.
082 * @param echoOn <code>true</code> if the password should be displayed as it
083 * is being typed.
084 * @throws IllegalArgumentException if <code>prompt</code> is <code>null</code>
085 * or if <code>prompt</code> has a length of <code>0</code>.
086 */
087 public PasswordCallback(String prompt, boolean echoOn)
088 {
089 super();
090
091 setPrompt(prompt);
092 this.echoOn = echoOn;
093 }
094
095 // Class methods
096 // -------------------------------------------------------------------------
097
098 // Instance methods
099 // -------------------------------------------------------------------------
100
101 /**
102 * Get the prompt.
103 *
104 * @return the prompt.
105 */
106 public String getPrompt()
107 {
108 return prompt;
109 }
110
111 /**
112 * Return whether the password should be displayed as it is being typed.
113 *
114 * @return the whether the password should be displayed as it is being typed.
115 */
116 public boolean isEchoOn()
117 {
118 return echoOn;
119 }
120
121 /**
122 * <p>Set the retrieved password.</p>
123 *
124 * <p>This method makes a copy of the input password before storing it.</p>
125 *
126 * @param password the retrieved password, which may be <code>null</code>.
127 * @see #getPassword()
128 */
129 public void setPassword(char[] password)
130 {
131 inputPassword = (password == null ? null : (char[]) password.clone());
132 }
133
134 /**
135 * <p>Get the retrieved password.</p>
136 *
137 * <p>This method returns a copy of the retrieved password.</p>
138 *
139 * @return the retrieved password, which may be <code>null</code>.
140 * @see #setPassword(char[])
141 */
142 public char[] getPassword()
143 {
144 return (inputPassword == null ? null : (char[]) inputPassword.clone());
145 }
146
147 /** Clear the retrieved password. */
148 public void clearPassword()
149 {
150 if (inputPassword != null)
151 {
152 for (int i = 0; i < inputPassword.length; i++)
153 {
154 inputPassword[i] = '\0';
155 }
156 inputPassword = null;
157 }
158 }
159
160 private void setPrompt(String prompt) throws IllegalArgumentException
161 {
162 if ((prompt == null) || (prompt.length() == 0))
163 {
164 throw new IllegalArgumentException("invalid prompt");
165 }
166 this.prompt = prompt;
167 }
168 }