package samples.gae.security;
import java.io.IOException;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.google.appengine.api.users.User;
import com.google.appengine.api.users.UserServiceFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.security.authentication.AuthenticationDetailsSource;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.AuthenticationFailureHandler;
import org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler;
import org.springframework.security.web.authentication.WebAuthenticationDetails;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.security.web.authentication.preauth.PreAuthenticatedAuthenticationToken;
import org.springframework.util.Assert;
import org.springframework.web.filter.GenericFilterBean;
import samples.gae.users.GaeUser;
/**
* @author Luke Taylor
*/
public class GaeAuthenticationFilter extends GenericFilterBean {
private static final String REGISTRATION_URL = "/register.htm";
private final Logger logger = LoggerFactory.getLogger(getClass());
private final AuthenticationDetailsSource<HttpServletRequest, WebAuthenticationDetails> ads = new WebAuthenticationDetailsSource();
private AuthenticationManager authenticationManager;
private AuthenticationFailureHandler failureHandler = new SimpleUrlAuthenticationFailureHandler();
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
User googleUser = UserServiceFactory.getUserService().getCurrentUser();
if (authentication != null && !loggedInUserMatchesGaeUser(authentication, googleUser)) {
SecurityContextHolder.clearContext();
authentication = null;
((HttpServletRequest)request).getSession().invalidate();
}
if (authentication == null) {
if (googleUser != null) {
logger.debug("Currently logged on to GAE as user " + googleUser);
logger.debug("Authenticating to Spring Security");
// User has returned after authenticating via GAE. Need to authenticate through Spring Security.
PreAuthenticatedAuthenticationToken token = new PreAuthenticatedAuthenticationToken(googleUser, null);
token.setDetails(ads.buildDetails((HttpServletRequest) request));
try {
authentication = authenticationManager.authenticate(token);
SecurityContextHolder.getContext().setAuthentication(authentication);
if (authentication.getAuthorities().contains(AppRole.NEW_USER)) {
logger.debug("New user authenticated. Redirecting to registration page");
((HttpServletResponse) response).sendRedirect(REGISTRATION_URL);
return;
}
} catch (AuthenticationException e) {
failureHandler.onAuthenticationFailure((HttpServletRequest)request, (HttpServletResponse)response, e);
return;
}
}
}
chain.doFilter(request, response);
}
private boolean loggedInUserMatchesGaeUser(Authentication authentication, User googleUser) {
assert authentication != null;
if (googleUser == null) {
// User has logged out of GAE but is still logged into application
return false;
}
GaeUser gaeUser = (GaeUser)authentication.getPrincipal();
if (!gaeUser.getEmail().equals(googleUser.getEmail())) {
return false;
}
return true;
}
@Override
public void afterPropertiesSet() throws ServletException {
Assert.notNull(authenticationManager, "AuthenticationManager must be set");
}
public void setAuthenticationManager(AuthenticationManager authenticationManager) {
this.authenticationManager = authenticationManager;
}
public void setFailureHandler(AuthenticationFailureHandler failureHandler) {
this.failureHandler = failureHandler;
}
}