SpoofShibbolethRequestWrapper.java

/**
 * Copyright 2008 The University of North Carolina at Chapel Hill
 *
 * Licensed 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 edu.unc.lib.dl.acl.filter;

import java.io.IOException;
import java.net.URLDecoder;
import java.security.Principal;
import java.util.Arrays;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

/**
 * RequestWrapper which pulls shibboleth authentication spoofing cookies from the
 * request and uses them to override both the remote user and groups.
 * 
 * Only to be used for test instances.
 * 
 * @author bbpennel
 *
 */
public class SpoofShibbolethRequestWrapper extends HttpServletRequestWrapper {

	private final static String SPOOF_COOKIE_PREFIX = "AUTHENTICATION_SPOOFING-";
	
	private HashMap<String, String> values;
	
	private HttpServletRequest request;
	
	public SpoofShibbolethRequestWrapper(HttpServletRequest request) throws IOException {
		super(request);
		this.request = request;
		
		extractSpoofValues();
	}
	
	private void extractSpoofValues() throws IOException {
		Cookie[] cookies = request.getCookies();
		
		if (cookies != null) {
			values = new HashMap<String, String>();
			
			for (Cookie c : cookies) {
				if (c.getName().startsWith(SPOOF_COOKIE_PREFIX)) {
					String key = c.getName().substring(SPOOF_COOKIE_PREFIX.length());
					String value = URLDecoder.decode(c.getValue(), "UTF-8");
					values.put(key, value);
				}
			}
		}
	}
	
	@Override
	public String getRemoteUser() {
		if (values == null) {
			return super.getRemoteUser();
		}
		
		String remoteUser = request.getRemoteUser();
		if (remoteUser == null) {
			remoteUser = values.get("REMOTE_USER");
		}
		
		return remoteUser;
	}

	@Override
	public Principal getUserPrincipal() {
		if (values == null) {
			return super.getUserPrincipal();
		}
		
		String remoteUser = request.getRemoteUser();
		if (remoteUser == null) {
			remoteUser = values.get("REMOTE_USER");
		}
		
		final String user = remoteUser;
		
		return new Principal() {
			@Override
			public String getName() {
				return user;
			}
		};
	}
	
	@Override
	public Enumeration<String> getHeaders(String name) {
		if (values == null || !values.containsKey(name)) {
			return super.getHeaders(name);
		}
		
		return Collections.enumeration(Arrays.asList(values.get(name)));
	}
	
	@Override
	public Enumeration<String> getHeaderNames() {
		if (values == null) {
			return super.getHeaderNames();
		}
		
		// Combine existing header name enum with spoofed headers
		Set<String> headerSet = new HashSet<>();
		Enumeration<String> headerEnum = request.getHeaderNames();
		while (headerEnum.hasMoreElements()) {
			headerSet.add(headerEnum.nextElement());
		}
		headerSet.addAll(values.keySet());
		
		return Collections.enumeration(headerSet);
	}
	
	@Override
	public String getHeader(String name) {
		if (values == null || !values.containsKey(name)) {
			return super.getHeader(name);
		}
		
		return values.get(name);
	}
}