1 /* Authenticator.java -- Abstract class for obtaining authentication info
2 Copyright (C) 1998, 2000, 2003 Free Software Foundation, Inc.
3
4 This file is part of GNU Classpath.
5
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301 USA.
20
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
37
38 package java.net;
39
40
41 /**
42 * This abstract class provides a model for obtaining authentication
43 * information (in the form of a username and password) required by
44 * some network operations (such as hitting a password protected
45 * web site).
46 * <p>
47 * To make use of this feature, a programmer must create a subclass
48 * that knows how to obtain the necessary info. An example
49 * would be a class that popped up a dialog box to prompt the user.
50 * After creating an instance of that subclass, the static
51 * <code>setDefault</code> method of this class is called to set up
52 * that instance as the object to use on subsequent calls to obtain
53 * authorization.
54 *
55 * @since 1.2
56 *
57 * @author Aaron M. Renn (arenn@urbanophile.com)
58 * @status Believed to be JDK 1.4 complete
59 */
60 public abstract class Authenticator
61 {
62 /*
63 * Class Variables
64 */
65
66 /**
67 * This is the default Authenticator object to use for password requests
68 */
69 private static Authenticator defaultAuthenticator;
70
71 /*
72 * Instance Variables
73 */
74
75 /**
76 * The hostname of the site requesting authentication
77 */
78 private String host;
79
80 /**
81 * InternetAddress of the site requesting authentication
82 */
83 private InetAddress addr;
84
85 /**
86 * The port number of the site requesting authentication
87 */
88 private int port;
89
90 /**
91 * The protocol name of the site requesting authentication
92 */
93 private String protocol;
94
95 /**
96 * The prompt to display to the user when requesting authentication info
97 */
98 private String prompt;
99
100 /**
101 * The authentication scheme in use
102 */
103 private String scheme;
104
105 /*
106 * Class Methods
107 */
108
109 /**
110 * This method sets the default <code>Authenticator</code> object (an
111 * instance of a subclass of <code>Authenticator</code>) to use when
112 * prompting the user for
113 * information. Note that this method checks to see if the caller is
114 * allowed to set this value (the "setDefaultAuthenticator" permission)
115 * and throws a <code>SecurityException</code> if it is not.
116 *
117 * @param defAuth The new default <code>Authenticator</code> object to use
118 *
119 * @exception SecurityException If the caller does not have permission
120 * to perform this operation
121 */
122 public static void setDefault(Authenticator defAuth)
123 {
124 SecurityManager sm = System.getSecurityManager();
125 if (sm != null)
126 sm.checkPermission(new NetPermission("setDefaultAuthenticator"));
127
128 defaultAuthenticator = defAuth;
129 }
130
131 /**
132 * This method is called whenever a username and password for a given
133 * network operation is required. First, a security check is made to see
134 * if the caller has the "requestPasswordAuthentication"
135 * permission. If not, the method thows an exception. If there is no
136 * default <code>Authenticator</code> object, the method then returns
137 * <code>null</code>. Otherwise, the default authenticators's instance
138 * variables are initialized and it's <code>getPasswordAuthentication</code>
139 * method is called to get the actual authentication information to return.
140 *
141 * @param addr The address requesting authentication
142 * @param port The port requesting authentication
143 * @param protocol The protocol requesting authentication
144 * @param prompt The prompt to display to the user when requesting
145 * authentication info
146 * @param scheme The authentication scheme in use
147 *
148 * @return A <code>PasswordAuthentication</code> object with the user's
149 * authentication info.
150 *
151 * @exception SecurityException If the caller does not have permission to
152 * perform this operation
153 */
154 public static PasswordAuthentication requestPasswordAuthentication(InetAddress addr,
155 int port,
156 String protocol,
157 String prompt,
158 String scheme)
159 throws SecurityException
160 {
161 return requestPasswordAuthentication(null, addr, port, protocol, prompt,
162 scheme);
163 }
164
165 /**
166 * This method is called whenever a username and password for a given
167 * network operation is required. First, a security check is made to see
168 * if the caller has the "requestPasswordAuthentication"
169 * permission. If not, the method thows an exception. If there is no
170 * default <code>Authenticator</code> object, the method then returns
171 * <code>null</code>. Otherwise, the default authenticators's instance
172 * variables are initialized and it's <code>getPasswordAuthentication</code>
173 * method is called to get the actual authentication information to return.
174 * This method is the preferred one as it can be used with hostname
175 * when addr is unknown.
176 *
177 * @param host The hostname requesting authentication
178 * @param addr The address requesting authentication
179 * @param port The port requesting authentication
180 * @param protocol The protocol requesting authentication
181 * @param prompt The prompt to display to the user when requesting
182 * authentication info
183 * @param scheme The authentication scheme in use
184 *
185 * @return A <code>PasswordAuthentication</code> object with the user's
186 * authentication info.
187 *
188 * @exception SecurityException If the caller does not have permission to
189 * perform this operation
190 *
191 * @since 1.4
192 */
193 public static PasswordAuthentication requestPasswordAuthentication(String host,
194 InetAddress addr,
195 int port,
196 String protocol,
197 String prompt,
198 String scheme)
199 throws SecurityException
200 {
201 SecurityManager sm = System.getSecurityManager();
202 if (sm != null)
203 sm.checkPermission(new NetPermission("requestPasswordAuthentication"));
204
205 if (defaultAuthenticator == null)
206 return null;
207
208 defaultAuthenticator.host = host;
209 defaultAuthenticator.addr = addr;
210 defaultAuthenticator.port = port;
211 defaultAuthenticator.protocol = protocol;
212 defaultAuthenticator.prompt = prompt;
213 defaultAuthenticator.scheme = scheme;
214
215 return defaultAuthenticator.getPasswordAuthentication();
216 }
217
218 /*
219 * Constructors
220 */
221
222 /**
223 * Default, no-argument constructor for subclasses to call.
224 */
225 public Authenticator()
226 {
227 }
228
229 /*
230 * Instance Methods
231 */
232
233 /**
234 * This method returns the address of the site that is requesting
235 * authentication.
236 *
237 * @return The requesting site's address
238 */
239 protected final InetAddress getRequestingSite()
240 {
241 return addr;
242 }
243
244 /**
245 * Returns the hostname of the host or proxy requesting authorization,
246 * or <code>null</code> if not available.
247 *
248 * @return The name of the host requesting authentication, or
249 * <code>null</code> if it is not available.
250 *
251 * @since 1.4
252 */
253 protected final String getRequestingHost()
254 {
255 return host;
256 }
257
258 /**
259 * This method returns the port of the site that is requesting
260 * authentication.
261 *
262 * @return The requesting port
263 */
264 protected final int getRequestingPort()
265 {
266 return port;
267 }
268
269 /**
270 * This method returns the requesting protocol of the operation that is
271 * requesting authentication
272 *
273 * @return The requesting protocol
274 */
275 protected final String getRequestingProtocol()
276 {
277 return protocol;
278 }
279
280 /**
281 * Returns the prompt that should be used when requesting authentication
282 * information from the user
283 *
284 * @return The user prompt
285 */
286 protected final String getRequestingPrompt()
287 {
288 return prompt;
289 }
290
291 /**
292 * This method returns the authentication scheme in use
293 *
294 * @return The authentication scheme
295 */
296 protected final String getRequestingScheme()
297 {
298 return scheme;
299 }
300
301 /**
302 * This method is called whenever a request for authentication is made. It
303 * can call the other getXXX methods to determine the information relevant
304 * to this request. Subclasses should override this method, which returns
305 * <code>null</code> by default.
306 *
307 * @return The <code>PasswordAuthentication</code> information
308 */
309 protected PasswordAuthentication getPasswordAuthentication()
310 {
311 return null;
312 }
313 } // class Authenticator
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