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Java > Open Source Codes > org > apache > commons > httpclient > auth > AuthChallengeProcessor


1 /*
2  * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/auth/AuthChallengeProcessor.java,v 1.2 2004/04/18 23:51:36 jsdever Exp $
3  * $Revision: 480424 $
4  * $Date: 2006-11-29 05:56:49 +0000 (Wed, 29 Nov 2006) $
5  *
6  * ====================================================================
7  *
8  * Licensed to the Apache Software Foundation (ASF) under one or more
9  * contributor license agreements. See the NOTICE file distributed with
10  * this work for additional information regarding copyright ownership.
11  * The ASF licenses this file to You under the Apache License, Version 2.0
12  * (the "License"); you may not use this file except in compliance with
13  * the License. You may obtain a copy of the License at
14  *
15  * http://www.apache.org/licenses/LICENSE-2.0
16  *
17  * Unless required by applicable law or agreed to in writing, software
18  * distributed under the License is distributed on an "AS IS" BASIS,
19  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20  * See the License for the specific language governing permissions and
21  * limitations under the License.
22  * ====================================================================
23  *
24  * This software consists of voluntary contributions made by many
25  * individuals on behalf of the Apache Software Foundation. For more
26  * information on the Apache Software Foundation, please see
27  * <http://www.apache.org/>.
28  *
29  */
30
31 package org.apache.commons.httpclient.auth;
32
33 import java.util.Collection JavaDoc;
34 import java.util.Iterator JavaDoc;
35 import java.util.Map JavaDoc;
36
37 import org.apache.commons.httpclient.params.HttpParams;
38 import org.apache.commons.logging.Log;
39 import org.apache.commons.logging.LogFactory;
40
41 /**
42  * This class provides utility methods for processing HTTP www and proxy authentication
43  * challenges.
44  *
45  * @author <a HREF="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
46  *
47  * @since 3.0
48  */
49 public final class AuthChallengeProcessor {
50
51     private static final Log LOG = LogFactory.getLog(AuthChallengeProcessor.class);
52
53     private HttpParams params = null;
54     
55     /**
56      * Creates an authentication challenge processor with the given {@link HttpParams HTTP
57      * parameters}
58      *
59      * @param params the {@link HttpParams HTTP parameters} used by this processor
60      */
61     public AuthChallengeProcessor(final HttpParams params) {
62         super();
63         if (params == null) {
64             throw new IllegalArgumentException JavaDoc("Parameter collection may not be null");
65         }
66         this.params = params;
67     }
68
69     /**
70      * Determines the preferred {@link AuthScheme authentication scheme} that can be used
71      * to respond to the given collection of challenges.
72      *
73      * @param challenges the collection of authentication challenges
74      *
75      * @return the preferred {@link AuthScheme authentication scheme}
76      *
77      * @throws AuthChallengeException if the preferred authentication scheme
78      * cannot be determined or is not supported
79      */
80     public AuthScheme selectAuthScheme(final Map JavaDoc challenges) throws AuthChallengeException {
81         if (challenges == null) {
82             throw new IllegalArgumentException JavaDoc("Challenge map may not be null");
83         }
84         Collection JavaDoc authPrefs = (Collection JavaDoc) this.params.getParameter(
85             AuthPolicy.AUTH_SCHEME_PRIORITY);
86         if (authPrefs == null || authPrefs.isEmpty()) {
87             authPrefs = AuthPolicy.getDefaultAuthPrefs();
88         }
89         if (LOG.isDebugEnabled()) {
90             LOG.debug("Supported authentication schemes in the order of preference: "
91                 + authPrefs);
92         }
93         AuthScheme authscheme = null;
94         String JavaDoc challenge = null;
95         Iterator JavaDoc item = authPrefs.iterator();
96         while (item.hasNext()) {
97             String JavaDoc id = (String JavaDoc) item.next();
98             challenge = (String JavaDoc) challenges.get(id.toLowerCase());
99             if (challenge != null) {
100                 if (LOG.isInfoEnabled()) {
101                     LOG.info(id + " authentication scheme selected");
102                 }
103                 try {
104                     authscheme = AuthPolicy.getAuthScheme(id);
105                 } catch (IllegalStateException JavaDoc e) {
106                     throw new AuthChallengeException(e.getMessage());
107                 }
108                 break;
109             } else {
110                 if (LOG.isDebugEnabled()) {
111                     LOG.debug("Challenge for " + id + " authentication scheme not available");
112                     // Try again
113 }
114             }
115         }
116         if (authscheme == null) {
117             // If none selected, something is wrong
118 throw new AuthChallengeException(
119                 "Unable to respond to any of these challenges: "
120                     + challenges);
121         }
122         return authscheme;
123     }
124
125     /**
126      * Processes the given collection of challenges and updates the
127      * {@link AuthState state} of the authentication process.
128      *
129      * @param challenges the collection of authentication challenges
130      *
131      * @return the {@link AuthScheme authentication scheme} used to
132      * process the challenge
133      *
134      * @throws AuthChallengeException if authentication challenges cannot be
135      * successfully processed or the preferred authentication scheme cannot
136      * be determined
137      */
138     public AuthScheme processChallenge(final AuthState state, final Map JavaDoc challenges)
139         throws MalformedChallengeException, AuthenticationException
140     {
141         if (state == null) {
142             throw new IllegalArgumentException JavaDoc("Authentication state may not be null");
143         }
144         if (challenges == null) {
145             throw new IllegalArgumentException JavaDoc("Challenge map may not be null");
146         }
147         
148         if (state.isPreemptive() || state.getAuthScheme() == null) {
149             // Authentication not attempted before
150 state.setAuthScheme(selectAuthScheme(challenges));
151         }
152         AuthScheme authscheme = state.getAuthScheme();
153         String JavaDoc id = authscheme.getSchemeName();
154         if (LOG.isDebugEnabled()) {
155             LOG.debug("Using authentication scheme: " + id);
156         }
157         String JavaDoc challenge = (String JavaDoc) challenges.get(id.toLowerCase());
158         if (challenge == null) {
159             throw new AuthenticationException(id +
160                 " authorization challenge expected, but not found");
161         }
162         authscheme.processChallenge(challenge);
163         LOG.debug("Authorization challenge processed");
164         return authscheme;
165     }
166 }
167
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