/* * $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;    }}