Java tutorial
/* * $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 com.microsoft.tfs.core.httpclient.auth; import java.util.Collection; import java.util.Iterator; import java.util.Map; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import com.microsoft.tfs.core.httpclient.Credentials; import com.microsoft.tfs.core.httpclient.params.HttpParams; /** * 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; } public AuthScheme selectAuthScheme(final Map challenges) throws AuthChallengeException { return selectAuthScheme(challenges, null); } /** * 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, final Credentials credentials) throws AuthChallengeException { if (challenges == null) { throw new IllegalArgumentException("Challenge map may not be null"); } Collection authPrefs = (Collection) 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; final Iterator item = authPrefs.iterator(); while (item.hasNext()) { final String id = (String) item.next(); challenge = (String) challenges.get(id.toLowerCase()); if (challenge != null) { if (LOG.isDebugEnabled()) { LOG.debug(id + " authentication scheme selected"); } try { final AuthScheme testScheme = AuthPolicy.getAuthScheme(id); // If we were passed credentials, see if the auth scheme // supports them if (credentials == null || testScheme.supportsCredentials(credentials)) { authscheme = testScheme; break; } } catch (final IllegalStateException e) { throw new AuthChallengeException(e.getMessage()); } } 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 { return processChallenge(state, challenges, null); } public AuthScheme processChallenge(final AuthState state, final Map challenges, final Credentials credentials) 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, credentials)); } final AuthScheme authscheme = state.getAuthScheme(); final String id = authscheme.getSchemeName(); if (LOG.isDebugEnabled()) { LOG.debug("Using authentication scheme: " + id); } final 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; } }