Handle spring security authentication exceptions w

Question

I'm using Spring MVC's @ControllerAdvice and @ExceptionHandler to handle all the exception of a REST Api. It works fine for exceptions thrown by web mvc controllers but it does not work for exceptions thrown by spring security custom filters because they run before the controller methods are invoked.

I have a custom spring security filter that does a token based auth:

public class AegisAuthenticationFilter extends GenericFilterBean {

...

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {

        try {

            ...         
        } catch(AuthenticationException authenticationException) {

            SecurityContextHolder.clearContext();
            authenticationEntryPoint.commence(request, response, authenticationException);

        }

    }

}

With this custom entry point:

@Component("restAuthenticationEntryPoint")
public class RestAuthenticationEntryPoint implements AuthenticationEntryPoint{

    public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException authenticationException) throws IOException, ServletException {
        response.sendError(HttpServletResponse.SC_UNAUTHORIZED, authenticationException.getMessage());
    }

}

And with this class to handle exceptions globally:

@ControllerAdvice
public class RestEntityResponseExceptionHandler extends ResponseEntityExceptionHandler {

    @ExceptionHandler({ InvalidTokenException.class, AuthenticationException.class })
    @ResponseStatus(value = HttpStatus.UNAUTHORIZED)
    @ResponseBody
    public RestError handleAuthenticationException(Exception ex) {

        int errorCode = AegisErrorCode.GenericAuthenticationError;
        if(ex instanceof AegisException) {
            errorCode = ((AegisException)ex).getCode();
        }

        RestError re = new RestError(
            HttpStatus.UNAUTHORIZED,
            errorCode, 
            "...",
            ex.getMessage());

        return re;
    }
}

What I need to do is to return a detailed JSON body even for spring security AuthenticationException. Is there a way make spring security AuthenticationEntryPoint and spring mvc @ExceptionHandler work together?

I'm using spring security 3.1.4 and spring mvc 3.2.4.

Answer 1

The best way I've found is to delegate the exception to the HandlerExceptionResolver

@Component("restAuthenticationEntryPoint")
public class RestAuthenticationEntryPoint implements AuthenticationEntryPoint {

    @Autowired
    private HandlerExceptionResolver resolver;

    @Override
    public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException exception) throws IOException, ServletException {
        resolver.resolveException(request, response, null, exception);
    }
}

then you can use @ExceptionHandler to format the response the way you want.

Answer 2

I'm using the objectMapper. Every Rest Service is mostly working with json, and in one of your configs you have already configured an object mapper.

Code is written in Kotlin, hopefully it will be ok.

@Bean
fun objectMapper(): ObjectMapper {
    val objectMapper = ObjectMapper()
    objectMapper.registerModule(JodaModule())
    objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false)

    return objectMapper
}

class UnauthorizedAuthenticationEntryPoint : BasicAuthenticationEntryPoint() {

    @Autowired
    lateinit var objectMapper: ObjectMapper

    @Throws(IOException::class, ServletException::class)
    override fun commence(request: HttpServletRequest, response: HttpServletResponse, authException: AuthenticationException) {
        response.addHeader("Content-Type", "application/json")
        response.status = HttpServletResponse.SC_UNAUTHORIZED

        val responseError = ResponseError(
            message = "${authException.message}",
        )

        objectMapper.writeValue(response.writer, responseError)
     }}

Answer 3

We need to use HandlerExceptionResolver in that case.

@Component
public class RESTAuthenticationEntryPoint implements AuthenticationEntryPoint {

    @Autowired
    //@Qualifier("handlerExceptionResolver")
    private HandlerExceptionResolver resolver;

    @Override
    public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException authException) throws IOException {
        resolver.resolveException(request, response, null, authException);
    }
}

Also, you need to add in the exception handler class to return your object.

@RestControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {

    @ExceptionHandler(AuthenticationException.class)
    public GenericResponseBean handleAuthenticationException(AuthenticationException ex, HttpServletResponse response){
        GenericResponseBean genericResponseBean = GenericResponseBean.build(MessageKeys.UNAUTHORIZED);
        genericResponseBean.setError(true);
        response.setStatus(HttpStatus.UNAUTHORIZED.value());
        return genericResponseBean;
    }
}

may you get an error at the time of running a project because of multiple implementations of HandlerExceptionResolver, In that case you have to add @Qualifier("handlerExceptionResolver") on HandlerExceptionResolver

Answer 4

This is a very interesting problem that Spring Security and Spring Web framework is not quite consistent in the way they handle the response. I believe it has to natively support error message handling with MessageConverter in a handy way.

I tried to find an elegant way to inject MessageConverter into Spring Security so that they could catch the exception and return them in a right format according to content negotiation. Still, my solution below is not elegant but at least make use of Spring code.

I assume you know how to include Jackson and JAXB library, otherwise there is no point to proceed. There are 3 Steps in total.

Step 1 - Create a standalone class, storing MessageConverters

This class plays no magic. It simply stores the message converters and a processor RequestResponseBodyMethodProcessor. The magic is inside that processor which will do all the job including content negotiation and converting the response body accordingly.

public class MessageProcessor { // Any name you like
    // List of HttpMessageConverter
    private List<HttpMessageConverter<?>> messageConverters;
    // under org.springframework.web.servlet.mvc.method.annotation
    private RequestResponseBodyMethodProcessor processor;

    /**
     * Below class name are copied from the framework.
     * (And yes, they are hard-coded, too)
     */
    private static final boolean jaxb2Present =
        ClassUtils.isPresent("javax.xml.bind.Binder", MessageProcessor.class.getClassLoader());

    private static final boolean jackson2Present =
        ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", MessageProcessor.class.getClassLoader()) &&
        ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", MessageProcessor.class.getClassLoader());

    private static final boolean gsonPresent =
        ClassUtils.isPresent("com.google.gson.Gson", MessageProcessor.class.getClassLoader());

    public MessageProcessor() {
        this.messageConverters = new ArrayList<HttpMessageConverter<?>>();

        this.messageConverters.add(new ByteArrayHttpMessageConverter());
        this.messageConverters.add(new StringHttpMessageConverter());
        this.messageConverters.add(new ResourceHttpMessageConverter());
        this.messageConverters.add(new SourceHttpMessageConverter<Source>());
        this.messageConverters.add(new AllEncompassingFormHttpMessageConverter());

        if (jaxb2Present) {
            this.messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
        }
        if (jackson2Present) {
            this.messageConverters.add(new MappingJackson2HttpMessageConverter());
        }
        else if (gsonPresent) {
            this.messageConverters.add(new GsonHttpMessageConverter());
        }

        processor = new RequestResponseBodyMethodProcessor(this.messageConverters);
    }

    /**
     * This method will convert the response body to the desire format.
     */
    public void handle(Object returnValue, HttpServletRequest request,
        HttpServletResponse response) throws Exception {
        ServletWebRequest nativeRequest = new ServletWebRequest(request, response);
        processor.handleReturnValue(returnValue, null, new ModelAndViewContainer(), nativeRequest);
    }

    /**
     * @return list of message converters
     */
    public List<HttpMessageConverter<?>> getMessageConverters() {
        return messageConverters;
    }
}

Step 2 - Create AuthenticationEntryPoint

As in many tutorials, this class is essential to implement custom error handling.

public class CustomEntryPoint implements AuthenticationEntryPoint {
    // The class from Step 1
    private MessageProcessor processor;

    public CustomEntryPoint() {
        // It is up to you to decide when to instantiate
        processor = new MessageProcessor();
    }

    @Override
    public void commence(HttpServletRequest request,
        HttpServletResponse response, AuthenticationException authException)
        throws IOException, ServletException {

        // This object is just like the model class, 
        // the processor will convert it to appropriate format in response body
        CustomExceptionObject returnValue = new CustomExceptionObject();
        try {
            processor.handle(returnValue, request, response);
        } catch (Exception e) {
            throw new ServletException();
        }
    }
}

Step 3 - Register the entry point

As mentioned, I do it with Java Config. I just show the relevant configuration here, there should be other configuration such as session stateless, etc.

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.exceptionHandling().authenticationEntryPoint(new CustomEntryPoint());
    }
}

Try with some authentication fail cases, remember the request header should include Accept : XXX and you should get the exception in JSON, XML or some other formats.

Answer 5

Ok, I tried as suggested writing the json myself from the AuthenticationEntryPoint and it works.

Just for testing I changed the AutenticationEntryPoint by removing response.sendError

@Component("restAuthenticationEntryPoint")
public class RestAuthenticationEntryPoint implements AuthenticationEntryPoint{

    public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException authenticationException) throws IOException, ServletException {

        response.setContentType("application/json");
        response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
        response.getOutputStream().println("{ \"error\": \"" + authenticationException.getMessage() + "\" }");

    }
}

In this way you can send custom json data along with the 401 unauthorized even if you are using Spring Security AuthenticationEntryPoint.

Obviously you would not build the json as I did for testing purposes but you would serialize some class instance.

Answer 6

In case of Spring Boot and @EnableResourceServer, it is relatively easy and convenient to extend ResourceServerConfigurerAdapter instead of WebSecurityConfigurerAdapter in the Java configuration and register a custom AuthenticationEntryPoint by overriding configure(ResourceServerSecurityConfigurer resources) and using resources.authenticationEntryPoint(customAuthEntryPoint()) inside the method.

Something like this:

@Configuration
@EnableResourceServer
public class CommonSecurityConfig extends ResourceServerConfigurerAdapter {

    @Override
    public void configure(ResourceServerSecurityConfigurer resources) throws Exception {
        resources.authenticationEntryPoint(customAuthEntryPoint());
    }

    @Bean
    public AuthenticationEntryPoint customAuthEntryPoint(){
        return new AuthFailureHandler();
    }
}

There's also a nice OAuth2AuthenticationEntryPoint that can be extended (since it's not final) and partially re-used while implementing a custom AuthenticationEntryPoint. In particular, it adds "WWW-Authenticate" headers with error-related details.

Hope this will help someone.