/*
 * Copyright 2005-2014 the original author or authors.
 *
 * 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 org.springframework.ws.soap.security.x509.populator;

import java.security.cert.X509Certificate;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.MessageSource;
import org.springframework.context.MessageSourceAware;
import org.springframework.context.support.MessageSourceAccessor;
import org.springframework.security.authentication.AuthenticationServiceException;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.SpringSecurityMessageSource;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.util.Assert;
import org.springframework.ws.soap.security.x509.X509AuthoritiesPopulator;

/**
 * Populates the X509 authorities via an {@link org.springframework.security.core.userdetails.UserDetailsService}.
 * <p>Migrated from Spring Security 2 since it has been removed in Spring Security 3.</p>
 *
 * @author Luke Taylor
 * @version $Id: DaoX509AuthoritiesPopulator.java 2544 2008-01-29 11:50:33Z luke_t $
 */
public class DaoX509AuthoritiesPopulator implements X509AuthoritiesPopulator, InitializingBean, MessageSourceAware {

	//~ Instance fields ================================================================================================

	protected MessageSourceAccessor messages = SpringSecurityMessageSource.getAccessor();
	private Pattern subjectDNPattern;
	private String subjectDNRegex = "CN=(.*?),";
	private UserDetailsService userDetailsService;

	//~ Methods ========================================================================================================

	@Override
	public void afterPropertiesSet() throws Exception {
		Assert.notNull(userDetailsService, "An authenticationDao must be set");
		Assert.notNull(this.messages, "A message source must be set");

		subjectDNPattern = Pattern.compile(subjectDNRegex, Pattern.CASE_INSENSITIVE);
	}

	@Override
	public UserDetails getUserDetails(X509Certificate clientCert) throws AuthenticationException {
		String subjectDN = clientCert.getSubjectDN().getName();

		Matcher matcher = subjectDNPattern.matcher(subjectDN);

		if (!matcher.find()) {
			throw new BadCredentialsException(messages.getMessage("DaoX509AuthoritiesPopulator.noMatching",
					new Object[] {subjectDN}, "No matching pattern was found in subjectDN: {0}"));
		}

		if (matcher.groupCount() != 1) {
			throw new IllegalArgumentException("Regular expression must contain a single group ");
		}

		String userName = matcher.group(1);

		UserDetails user = this.userDetailsService.loadUserByUsername(userName);

		if (user == null) {
			throw new AuthenticationServiceException(
				"UserDetailsService returned null, which is an interface contract violation");
		}

		return user;
	}

	@Override
	public void setMessageSource(MessageSource messageSource) {
		this.messages = new MessageSourceAccessor(messageSource);
	}

	/**
	 * Sets the regular expression which will by used to extract the user name from the certificate's Subject
	 * DN.
	 * <p>It should contain a single group; for example the default expression "CN=(.?)," matches the common
	 * name field. So "CN=Jimi Hendrix, OU=..." will give a user name of "Jimi Hendrix".</p>
	 * <p>The matches are case insensitive. So "emailAddress=(.?)," will match "EMAILADDRESS=jimi@hendrix.org,
	 * CN=..." giving a user name "jimi@hendrix.org"</p>
	 *
	 * @param subjectDNRegex the regular expression to find in the subject
	 */
	public void setSubjectDNRegex(String subjectDNRegex) {
		this.subjectDNRegex = subjectDNRegex;
	}

	public void setUserDetailsService(UserDetailsService userDetailsService) {
		this.userDetailsService = userDetailsService;
	}
}