/*
* $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 $
* $Revision: 480424 $
* $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
*
* ====================================================================
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.commons.httpclient.auth;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import org.apache.commons.httpclient.params.HttpParams;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* This class provides utility methods for processing HTTP www and proxy authentication
* challenges.
*
* @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
*
* @since 3.0
*/
public final class AuthChallengeProcessor {
private static final Log LOG = LogFactory.getLog(AuthChallengeProcessor.class);
private HttpParams params = null;
/**
* Creates an authentication challenge processor with the given {@link HttpParams HTTP
* parameters}
*
* @param params the {@link HttpParams HTTP parameters} used by this processor
*/
public AuthChallengeProcessor(final HttpParams params) {
super();
if (params == null) {
throw new IllegalArgumentException("Parameter collection may not be null");
}
this.params = params;
}
/**
* Determines the preferred {@link AuthScheme authentication scheme} that can be used
* to respond to the given collection of challenges.
*
* @param challenges the collection of authentication challenges
*
* @return the preferred {@link AuthScheme authentication scheme}
*
* @throws AuthChallengeException if the preferred authentication scheme
* cannot be determined or is not supported
*/
public AuthScheme selectAuthScheme(final Map challenges) throws AuthChallengeException {
if (challenges == null) {
throw new IllegalArgumentException("Challenge map may not be null");
}
Collection authPrefs = (Collection) this.params.getParameter(
AuthPolicy.AUTH_SCHEME_PRIORITY);
if (authPrefs == null || authPrefs.isEmpty()) {
authPrefs = AuthPolicy.getDefaultAuthPrefs();
}
if (LOG.isDebugEnabled()) {
LOG.debug("Supported authentication schemes in the order of preference: "
+ authPrefs);
}
AuthScheme authscheme = null;
String challenge = null;
Iterator item = authPrefs.iterator();
while (item.hasNext()) {
String id = (String) item.next();
challenge = (String) challenges.get(id.toLowerCase());
if (challenge != null) {
if (LOG.isInfoEnabled()) {
LOG.info(id + " authentication scheme selected");
}
try {
authscheme = AuthPolicy.getAuthScheme(id);
} catch (IllegalStateException e) {
throw new AuthChallengeException(e.getMessage());
}
break;
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("Challenge for " + id + " authentication scheme not available");
// Try again
}
}
}
if (authscheme == null) {
// If none selected, something is wrong
throw new AuthChallengeException(
"Unable to respond to any of these challenges: "
+ challenges);
}
return authscheme;
}
/**
* Processes the given collection of challenges and updates the
* {@link AuthState state} of the authentication process.
*
* @param challenges the collection of authentication challenges
*
* @return the {@link AuthScheme authentication scheme} used to
* process the challenge
*
* @throws AuthChallengeException if authentication challenges cannot be
* successfully processed or the preferred authentication scheme cannot
* be determined
*/
public AuthScheme processChallenge(final AuthState state, final Map challenges)
throws MalformedChallengeException, AuthenticationException
{
if (state == null) {
throw new IllegalArgumentException("Authentication state may not be null");
}
if (challenges == null) {
throw new IllegalArgumentException("Challenge map may not be null");
}
if (state.isPreemptive() || state.getAuthScheme() == null) {
// Authentication not attempted before
state.setAuthScheme(selectAuthScheme(challenges));
}
AuthScheme authscheme = state.getAuthScheme();
String id = authscheme.getSchemeName();
if (LOG.isDebugEnabled()) {
LOG.debug("Using authentication scheme: " + id);
}
String challenge = (String) challenges.get(id.toLowerCase());
if (challenge == null) {
throw new AuthenticationException(id +
" authorization challenge expected, but not found");
}
authscheme.processChallenge(challenge);
LOG.debug("Authorization challenge processed");
return authscheme;
}
}