/**
* 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.hadoop.gateway.preauth.filter;
import java.io.IOException;
import java.security.Principal;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Set;
import javax.security.auth.Subject;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.hadoop.gateway.security.PrimaryPrincipal;
/**
*
*/
public abstract class AbstractPreAuthFederationFilter implements Filter {
private static final String VALIDATION_METHOD_PARAM = "preauth.validation.method";
private static final String IP_VALIDATION_METHOD_VALUE = "preauth.ip.validation";
private static final String IP_ADDRESSES_PARAM = "preauth.ip.addresses";
private PreAuthValidator validator = null;
/**
*
*/
public AbstractPreAuthFederationFilter() {
super();
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
String validationMethod = filterConfig.getInitParameter(VALIDATION_METHOD_PARAM);
if (validationMethod != null) {
if (IP_VALIDATION_METHOD_VALUE.equals(validationMethod)) {
validator = new IPValidator(filterConfig.getInitParameter(IP_ADDRESSES_PARAM));
}
}
else {
validator = new DefaultValidator();
// TODO: log the fact that there is no verification going on to validate
// who is asserting the identity with the a header. Without some validation
// we are assuming the network security is the primary protection method.
}
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest)request;
String principal = getPrimaryPrincipal(httpRequest);
if (principal != null) {
if (isValid(httpRequest)) {
Subject subject = new Subject();
subject.getPrincipals().add(new PrimaryPrincipal(principal));
addGroupPrincipals(httpRequest, subject.getPrincipals());
doAs(httpRequest, response, chain, subject);
}
else {
// TODO: log preauthenticated SSO validation failure
((HttpServletResponse)response).sendError(HttpServletResponse.SC_FORBIDDEN, "SSO Validation Failure.");
}
}
else {
((HttpServletResponse)response).sendError(HttpServletResponse.SC_FORBIDDEN, "Missing Required Header for PreAuth SSO Federation");
}
}
/**
* @return
*/
private boolean isValid(HttpServletRequest httpRequest) {
try {
return validator.validate(httpRequest);
} catch (PreAuthValidationException e) {
// TODO log exception
return false;
}
}
@Override
public void destroy() {
}
private void doAs(final ServletRequest request, final ServletResponse response, final FilterChain chain, Subject subject)
throws IOException, ServletException {
try {
Subject.doAs(
subject,
new PrivilegedExceptionAction<Object>() {
public Object run() throws Exception {
chain.doFilter(request, response);
return null;
}
}
);
}
catch (PrivilegedActionException e) {
Throwable t = e.getCause();
if (t instanceof IOException) {
throw (IOException) t;
}
else if (t instanceof ServletException) {
throw (ServletException) t;
}
else {
throw new ServletException(t);
}
}
}
/**
* @param httpRequest
*/
abstract protected String getPrimaryPrincipal(HttpServletRequest httpRequest);
/**
* @param principals
*/
abstract protected void addGroupPrincipals(HttpServletRequest request, Set<Principal> principals);
class DefaultValidator implements PreAuthValidator {
/* (non-Javadoc)
* @see org.apache.hadoop.gateway.preauth.filter.PreAuthValidator#validate(java.lang.String, java.lang.String)
*/
@Override
public boolean validate(HttpServletRequest request)
throws PreAuthValidationException {
return true;
}
}
}