/* Authenticator.java -- Abstract class for obtaining authentication info Copyright (C) 1998,2000 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. */ package java.net; /** * Sometimes a network operation (such as hitting a password protected * web site) will require authentication information in the form of a * username and password. This abstract class provides a model for * obtaining that information. *

* To make use of this feature, a programmer must create a subclass of * Authenticator that knows how to obtain the necessary info. An example * would be a class that popped up a dialog box to prompt the user. * After creating an instance of that subclass, the static setDefault * method of this class is called to set up that instance as the object * to use on subsequent calls to obtain authorization. * * @since 1.2 * * @author Aaron M. Renn (arenn@urbanophile.com) */ public abstract class Authenticator { /*************************************************************************/ /* * Class Variables */ /** * This is the default Authenticator object to use for password requests */ private static Authenticator default_authenticator; /*************************************************************************/ /* * Instance Variables */ /** * InternetAddress of the site requesting authentication */ private InetAddress addr; /** * The port number of the site requesting authentication */ private int port; /** * The protocol name of the site requesting authentication */ private String protocol; /** * The prompt to display to the user when requesting authentication info */ private String prompt; /** * The authentication scheme in use */ private String scheme; /*************************************************************************/ /* * Class Methods */ /** * This method sets the default Authenticator object (an * instance of a * subclass of Authenticator) to use when prompting the user for * information. Note that this method checks to see if the caller is * allowed to set this value (the "setDefaultAuthenticator" permission) * and throws a SecurityException if it is not. * * @param def_auth The new default Authenticator object to use * * @exception SecurityException If the caller does not have permission * to perform this operation */ public static void setDefault(Authenticator def_auth) { SecurityManager sm = System.getSecurityManager(); if (sm != null) sm.checkPermission(new NetPermission("setDefaultAuthenticator")); default_authenticator = def_auth; } /*************************************************************************/ /** * This method is called whenever a username and password for a given * network operation is required. First, a security check is made to see * if the caller has the "requestPasswordAuthentication" * permission. If not, the method thows an exception. If there is no * default Authenticator object, the method then returns * null. Otherwise, the default authenticators's instance * variables are initialized and it's getPasswordAuthentication * method is called to get the actual authentication information to return. * * @param addr The address requesting authentication * @param port The port requesting authentication * @param protocol The protocol requesting authentication * @param prompt The prompt to display to the user when requesting authentication info * @param scheme The authentication scheme in use * * @return A PasswordAuthentication object with the user's * authentication info. * * @exception SecurityException If the caller does not have permission to * perform this operation */ public static PasswordAuthentication requestPasswordAuthentication(InetAddress addr, int port, String protocol, String prompt, String scheme) { SecurityManager sm = System.getSecurityManager(); if (sm != null) sm.checkPermission(new NetPermission("requestPasswordAuthentication")); if (default_authenticator == null) return(null); default_authenticator.addr = addr; default_authenticator.port = port; default_authenticator.protocol = protocol; default_authenticator.prompt = prompt; default_authenticator.scheme = scheme; return(default_authenticator.getPasswordAuthentication()); } /*************************************************************************/ /* * Constructors */ /** * Default, no-argument constructor for subclasses to call. */ public Authenticator() { } /*************************************************************************/ /* * Instance Methods */ /** * This method returns the address of the site that is requesting * authentication. * * @return The requesting site */ protected final InetAddress getRequestingSite() { return(addr); } /*************************************************************************/ /** * This method returns the port of the site that is requesting * authentication. * * @return The requesting port */ protected final int getRequestingPort() { return(port); } /*************************************************************************/ /** * This method returns the requesting protocol of the operation that is * requesting authentication * * @return The requesting protocol */ protected final String getRequestingProtocol() { return(protocol); } /*************************************************************************/ /** * Returns the prompt that should be used when requesting authentication * information from the user * * @return The user prompt */ protected final String getRequestingPrompt() { return(prompt); } /*************************************************************************/ /** * This method returns the authentication scheme in use * * @return The authentication scheme */ protected final String getRequestingScheme() { return(scheme); } /*************************************************************************/ /** * This method is called whenever a request for authentication is made. It * can call the other getXXX methods to determine the information relevant * to this request. Subclasses should override this method, which returns * null by default. * * @return The PasswordAuthentication information */ protected PasswordAuthentication getPasswordAuthentication() { return(null); } } // class Authenticator