/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/auth/AuthScheme.java $
* $Revision: 537144 $
* $Date: 2007-05-11 02:30:13 -0700 (Fri, 11 May 2007) $
*
* ====================================================================
*
* 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.auth;
import org.apache.http.Header;
import org.apache.http.HttpRequest;
/**
* <p>
* This interface represents an abstract challenge-response oriented
* authentication scheme.
* </p>
* <p>
* An authentication scheme should be able to support the following
* functions:
* <ul>
* <li>Parse and process the challenge sent by the targer server
* in response to request for a protected resource
* <li>Provide its textual designation
* <li>Provide its parameters, if available
* <li>Provide the realm this authentication scheme is applicable to,
* if available
* <li>Generate authorization string for the given set of credentials,
* request method and URI as specificed in the HTTP request line
* in response to the actual authorization challenge
* </ul>
* </p>
* <p>
* Authentication schemes may ignore method name and URI parameters
* if they are not relevant for the given authentication mechanism
* </p>
* <p>
* Authentication schemes may be stateful involving a series of
* challenge-response exchanges
* </p>
*
* @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
* @author <a href="mailto:adrian@ephox.com">Adrian Sutton</a>
*
* @since 4.0
*/
public interface AuthScheme {
/**
* Processes the given challenge token. Some authentication schemes
* may involve multiple challenge-response exchanges. Such schemes must be able
* to maintain the state information when dealing with sequential challenges
*
* @param header the challenge header
*/
void processChallenge(final Header header) throws MalformedChallengeException;
/**
* Returns textual designation of the given authentication scheme.
*
* @return the name of the given authentication scheme
*/
String getSchemeName();
/**
* Returns authentication parameter with the given name, if available.
*
* @param name The name of the parameter to be returned
*
* @return the parameter with the given name
*/
String getParameter(final String name);
/**
* Returns authentication realm. If the concept of an authentication
* realm is not applicable to the given authentication scheme, returns
* <code>null</code>.
*
* @return the authentication realm
*/
String getRealm();
/**
* Tests if the authentication scheme is provides authorization on a per
* connection basis instead of usual per request basis
*
* @return <tt>true</tt> if the scheme is connection based, <tt>false</tt>
* if the scheme is request based.
*/
boolean isConnectionBased();
/**
* Authentication process may involve a series of challenge-response exchanges.
* This method tests if the authorization process has been completed, either
* successfully or unsuccessfully, that is, all the required authorization
* challenges have been processed in their entirety.
*
* @return <tt>true</tt> if the authentication process has been completed,
* <tt>false</tt> otherwise.
*/
boolean isComplete();
/**
* Produces an authorization string for the given set of {@link Credentials}.
*
* @param credentials The set of credentials to be used for athentication
* @param request The request being authenticated
* @throws AuthenticationException if authorization string cannot
* be generated due to an authentication failure
*
* @return the authorization string
*/
Header authenticate(Credentials credentials, HttpRequest request)
throws AuthenticationException;
}