/*
* 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.
*/
package org.apache.jackrabbit.oak.security.authentication;
import java.io.IOException;
import java.util.Map;
import javax.jcr.Credentials;
import javax.jcr.GuestCredentials;
import javax.security.auth.Subject;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.UnsupportedCallbackException;
import javax.security.auth.login.LoginException;
import javax.security.auth.spi.LoginModule;
import org.apache.jackrabbit.oak.spi.security.authentication.AbstractLoginModule;
import org.apache.jackrabbit.oak.spi.security.authentication.CredentialsCallback;
import org.apache.jackrabbit.oak.spi.security.principal.EveryonePrincipal;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The {@code GuestLoginModule} is intended to provide backwards compatibility
* with the login handling present in the JCR reference implementation located
* in jackrabbit-core. While the specification claims that {@link javax.jcr.Repository#login}
* with {@code null} Credentials implies that the authentication process is
* handled externally, the default implementation jackrabbit-core treated it
* as 'anonymous' login such as covered by using {@link GuestCredentials}.<p/>
*
* This {@code LoginModule} implementation performs the following tasks upon
* {@link #login()}.
*
* <ol>
* <li>Try to retrieve JCR credentials from the {@link CallbackHandler} using
* the {@link CredentialsCallback}</li>
* <li>In case no credentials could be obtained it pushes a new instance of
* {@link GuestCredentials} to the shared stated. Subsequent login module
* in the authentication process may retrieve the {@link GuestCredentials}
* instead of failing to obtain any credentials.</li>
* </ol>
*
* If this login module pushed {@link GuestLoginModule} to the shared state
* in phase 1 it will add those credentials and the {@link EveryonePrincipal}
* to the subject in phase 2 of the login process. Subsequent login modules
* my choose to provide additional principals/credentials associated with
* a guest login.<p/>
*
* The authentication configuration using this {@code LoginModule} could for
* example look as follows:
*
* <pre>
*
* jackrabbit.oak {
* org.apache.jackrabbit.oak.security.authentication.GuestLoginModule optional;
* org.apache.jackrabbit.oak.security.authentication.LoginModuleImpl required;
* };
*
* </pre>
*
* In this case calling {@link javax.jcr.Repository#login()} would be equivalent
* to {@link javax.jcr.Repository#login(javax.jcr.Credentials) repository.login(new GuestCredentials()}.
*/
public class GuestLoginModule implements LoginModule {
private static final Logger log = LoggerFactory.getLogger(GuestLoginModule.class);
private Subject subject;
private CallbackHandler callbackHandler;
private Map sharedState;
private GuestCredentials guestCredentials;
//--------------------------------------------------------< LoginModule >---
@Override
public void initialize(Subject subject, CallbackHandler callbackHandler, Map<String, ?> sharedState, Map<String, ?> options) {
this.subject = subject;
this.callbackHandler = callbackHandler;
this.sharedState = sharedState;
}
@Override
public boolean login() throws LoginException {
if (callbackHandler != null) {
CredentialsCallback ccb = new CredentialsCallback();
try {
callbackHandler.handle(new Callback[] {ccb});
Credentials credentials = ccb.getCredentials();
if (credentials == null) {
guestCredentials = new GuestCredentials();
sharedState.put(AbstractLoginModule.SHARED_KEY_CREDENTIALS, guestCredentials);
return true;
}
} catch (IOException e) {
log.debug("Login: Failed to retrieve Credentials from CallbackHandler", e);
} catch (UnsupportedCallbackException e) {
log.debug("Login: Failed to retrieve Credentials from CallbackHandler", e);
}
}
// ignore this login module
return false;
}
@Override
public boolean commit() throws LoginException {
if (guestCredentials != null) {
subject.getPublicCredentials().add(guestCredentials);
subject.getPrincipals().add(EveryonePrincipal.getInstance());
}
return true;
}
@Override
public boolean abort() throws LoginException {
// nothing to do
return true;
}
@Override
public boolean logout() throws LoginException {
// nothing to do.
return true;
}
}