/*
* $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpclient/tags/4.0-alpha3/module-client/src/main/java/org/apache/http/impl/client/AbstractAuthenticationHandler.java $
* $Revision: 617207 $
* $Date: 2008-01-31 21:14:12 +0100 (Thu, 31 Jan 2008) $
*
* ====================================================================
* 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.http.impl.client;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.FormattedHeader;
import org.apache.http.Header;
import org.apache.http.HttpResponse;
import org.apache.http.auth.AuthScheme;
import org.apache.http.auth.AuthSchemeRegistry;
import org.apache.http.auth.AuthenticationException;
import org.apache.http.auth.MalformedChallengeException;
import org.apache.http.client.AuthenticationHandler;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.protocol.HTTP;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.CharArrayBuffer;
/**
* @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
*/
public abstract class AbstractAuthenticationHandler implements AuthenticationHandler {
private static final Log LOG = LogFactory.getLog(AbstractAuthenticationHandler.class);
private static List<String> DEFAULT_SCHEME_PRIORITY = Arrays.asList(new String[] {
"digest",
"basic"
});
public AbstractAuthenticationHandler() {
super();
}
protected Map<String, Header> parseChallenges(
final Header[] headers) throws MalformedChallengeException {
Map<String, Header> map = new HashMap<String, Header>(headers.length);
for (int i = 0; i < headers.length; i++) {
Header header = headers[i];
CharArrayBuffer buffer;
int pos;
if (header instanceof FormattedHeader) {
buffer = ((FormattedHeader) header).getBuffer();
pos = ((FormattedHeader) header).getValuePos();
} else {
String s = header.getValue();
if (s == null) {
throw new MalformedChallengeException("Header value is null");
}
buffer = new CharArrayBuffer(s.length());
buffer.append(s);
pos = 0;
}
while (pos < buffer.length() && HTTP.isWhitespace(buffer.charAt(pos))) {
pos++;
}
int beginIndex = pos;
while (pos < buffer.length() && !HTTP.isWhitespace(buffer.charAt(pos))) {
pos++;
}
int endIndex = pos;
String s = buffer.substring(beginIndex, endIndex);
map.put(s.toLowerCase(), header);
}
return map;
}
protected List<String> getAuthPreferences() {
return DEFAULT_SCHEME_PRIORITY;
}
public AuthScheme selectScheme(
final Map<String, Header> challenges,
final HttpResponse response,
final HttpContext context) throws AuthenticationException {
AuthSchemeRegistry registry = (AuthSchemeRegistry) context.getAttribute(
ClientContext.AUTHSCHEME_REGISTRY);
if (registry == null) {
throw new IllegalStateException("AuthScheme registry not set in HTTP context");
}
List<String> authPrefs = getAuthPreferences();
if (LOG.isDebugEnabled()) {
LOG.debug("Supported authentication schemes in the order of preference: "
+ authPrefs);
}
AuthScheme authScheme = null;
for (Iterator<String> it = authPrefs.iterator(); it.hasNext(); ) {
String id = it.next();
Header challenge = challenges.get(id.toLowerCase());
if (challenge != null) {
if (LOG.isDebugEnabled()) {
LOG.debug(id + " authentication scheme selected");
}
try {
authScheme = registry.getAuthScheme(id, response.getParams());
} catch (IllegalStateException e) {
throw new AuthenticationException(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 AuthenticationException(
"Unable to respond to any of these challenges: "
+ challenges);
}
return authScheme;
}
}