Spring with two security configurations - failed API login redirects to form login page. How to change? - spring-boot

Question

I have a Spring Boot application with two security configurations (two WebSecurityConfigurerAdapters), one for a REST API with "/api/**" endpoints, and one for a web front-end at all other endpoints. The security configuration is here on Github and here's some relevant parts of it:
#Configuration
#Order(1)
public static class APISecurityConfiguration extends WebSecurityConfigurerAdapter {
#Override
protected void configure(HttpSecurity http) throws Exception {
JWTAuthenticationFilter jwtAuthenticationFilter = new JWTAuthenticationFilter(authenticationManager());
jwtAuthenticationFilter.setFilterProcessesUrl("/api/login");
jwtAuthenticationFilter.setPostOnly(true);
http.antMatcher("/api/**")
.sessionManagement()
.sessionCreationPolicy(SessionCreationPolicy.STATELESS)
.and()
.csrf().disable()
.authorizeRequests()
.anyRequest().authenticated()
.and()
.addFilter(jwtAuthenticationFilter)
.addFilter(new JWTAuthorizationFilter(authenticationManager()));
}
}
#Configuration
public static class FrontEndSecurityConfiguration extends WebSecurityConfigurerAdapter {
#Override
protected void configure(HttpSecurity http) throws Exception {
http
.formLogin()
.loginPage("/login").permitAll()
.defaultSuccessUrl("/")
.and()
.logout()
.logoutUrl("/logout")
.logoutSuccessUrl("/?logout")
.and()
.authorizeRequests()
.mvcMatchers("/").permitAll()
.mvcMatchers("/home").authenticated()
.anyRequest().denyAll()
.and();
}
}
The JWTAuthenticationFilter is a custom subclass of UsernamePasswordAuthenticationFilter that processes sign-in attempts to the REST API (by HTTP POST with a JSON body to /api/login) and returns a JWT token in the "Authorization" header if successful.
So here's the issue: failed login attempts to /api/login (either with bad credentials or missing JSON body) are redirecting to the HTML login form /api/login. Non-authenticated requests to other "/api/**" endpoints result in a simple JSON response such as:
{
"timestamp": "2019-11-22T21:03:07.892+0000",
"status": 403,
"error": "Forbidden",
"message": "Access Denied",
"path": "/api/v1/agency"
}
{
"timestamp": "2019-11-22T21:04:46.663+0000",
"status": 404,
"error": "Not Found",
"message": "No message available",
"path": "/api/v1/badlink"
}
Attempts to access other protected URLs (not starting with "/api/") by a non-authenticated user redirect to the login form /login, which is the desired behavior. But I don't want API calls to /api/login to redirect to that form!
How can I code the correct behavior for failed API logins? Is it a question of adding a new handler for that filter? Or maybe adding an exclusion to some behavior I've already defined?
More detail on the exception and handling:
I looked at the logs, and the exception being thrown for either bad credentials or malformed JSON is a subclass of org.springframework.security.authentication.AuthenticationException. The logs show, for example:
webapp_1 | 2019-11-25 15:30:16.048 DEBUG 1 --- [nio-8080-exec-5] n.j.w.g.config.JWTAuthenticationFilter : Authentication request failed: org.springframework.security.authentication.BadCredentialsException: Bad credentials
(...stack trace...)
webapp_1 | 2019-11-25 15:30:16.049 DEBUG 1 --- [nio-8080-exec-5] n.j.w.g.config.JWTAuthenticationFilter : Updated SecurityContextHolder to contain null Authentication
webapp_1 | 2019-11-25 15:30:16.049 DEBUG 1 --- [nio-8080-exec-5] n.j.w.g.config.JWTAuthenticationFilter : Delegating to authentication failure handler org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler#7f9648b6
webapp_1 | 2019-11-25 15:30:16.133 DEBUG 1 --- [nio-8080-exec-6] n.j.webapps.granite.home.HomeController : Accessing /login page.
When I access another URL, for example one that doesn't exist such as /api/x, it looks very different. It's pretty verbose but it looks like the server is trying to redirect to /error and is not finding that to be an authorized URL. Interestingly if I try this in a web browser I get the error formatted with my custom error page (error.html), but if I access it with Postman I just get a JSON message. A sample of the logs:
webapp_1 | 2019-11-25 16:07:22.157 DEBUG 1 --- [nio-8080-exec-6] o.s.s.w.a.ExceptionTranslationFilter : Access is denied (user is anonymous); redirecting to authentication entry point
webapp_1 |
webapp_1 | org.springframework.security.access.AccessDeniedException: Access is denied
...
webapp_1 | 2019-11-25 16:07:22.174 DEBUG 1 --- [nio-8080-exec-6] o.s.s.w.a.ExceptionTranslationFilter : Calling Authentication entry point.
webapp_1 | 2019-11-25 16:07:22.175 DEBUG 1 --- [nio-8080-exec-6] o.s.s.w.a.Http403ForbiddenEntryPoint : Pre-authenticated entry point called. Rejecting access
...
webapp_1 | 2019-11-25 16:07:22.211 DEBUG 1 --- [nio-8080-exec-6] o.s.s.w.u.matcher.AntPathRequestMatcher : Checking match of request : '/error'; against '/api/**'
...
webapp_1 | 2019-11-25 16:07:22.214 DEBUG 1 --- [nio-8080-exec-6] o.s.security.web.FilterChainProxy : /error reached end of additional filter chain; proceeding with original chain
webapp_1 | 2019-11-25 16:07:22.226 DEBUG 1 --- [nio-8080-exec-6] o.s.web.servlet.DispatcherServlet : "ERROR" dispatch for GET "/error", parameters={}
webapp_1 | 2019-11-25 16:07:22.230 DEBUG 1 --- [nio-8080-exec-6] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped to public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
webapp_1 | 2019-11-25 16:07:22.564 DEBUG 1 --- [nio-8080-exec-6] o.s.w.s.m.m.a.HttpEntityMethodProcessor : Using 'application/json', given [*/*] and supported [application/json, application/*+json, application/json, application/*+json]
webapp_1 | 2019-11-25 16:07:22.577 DEBUG 1 --- [nio-8080-exec-6] o.s.w.s.m.m.a.HttpEntityMethodProcessor : Writing [{timestamp=Mon Nov 25 16:07:22 GMT 2019, status=403, error=Forbidden, message=Access Denied, path=/a (truncated)...]
webapp_1 | 2019-11-25 16:07:22.903 DEBUG 1 --- [nio-8080-exec-6] w.c.HttpSessionSecurityContextRepository : SecurityContext is empty or contents are anonymous - context will not be stored in HttpSession.
webapp_1 | 2019-11-25 16:07:22.905 DEBUG 1 --- [nio-8080-exec-6] o.s.web.servlet.DispatcherServlet : Exiting from "ERROR" dispatch, status 403
So it looks like what I maybe need to do is to configure the "authentication failure handler" for the REST API to go to "/error" instead of going to "/login", but only for endpoints under /api/**.

Answer 1

I added an #Override of unsuccessfulAuthentication() to my Authentication filter
The grandparent class (AbstractAuthenticationProcessingFilter) has a method for unsuccessful authentications (i.e. AuthenticationException) which delegates to an authentication failure handler class. I could have created my own custom authentication failure handler, but instead decided to simply override the unsuccessfulAuthentication method with some code that sends back a response with a 401 status and a JSON error message:
#Override
protected void unsuccessfulAuthentication(HttpServletRequest request, HttpServletResponse response, AuthenticationException e) throws IOException, ServletException {
// TODO: enrich/improve error messages
response.setStatus(response.SC_UNAUTHORIZED);
response.setContentType(MediaType.APPLICATION_JSON_VALUE);
response.setCharacterEncoding(StandardCharsets.UTF_8.toString());
response.getWriter().write("{\"error\": \"authentication error?\"}");
}
...and added a custom AuthenticationEntryPoint to make the other errors match
This doesn't have the exact form of the error messages I had seen at other endpoints, so I also created a custom AuthenticationEntryPoint (the class that handles unauthorized requests to protected endpoints) and it does basically the same thing. My implementation:
public class RESTAuthenticationEntryPoint implements AuthenticationEntryPoint {
#Override
public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException e) throws IOException, ServletException {
// TODO: enrich/improve error messages
response.setStatus(response.SC_UNAUTHORIZED);
response.setContentType(MediaType.APPLICATION_JSON_VALUE);
response.setCharacterEncoding(StandardCharsets.UTF_8.toString());
response.getWriter().write("{\"error\": \"unauthorized?\"}");
}
}
Now the security configuration for the REST endpoints looks like this (note the addition of ".exceptionHandling().authenticationEntryPoint()":
#Configuration
#Order(1)
public static class APISecurityConfiguration extends WebSecurityConfigurerAdapter {
#Override
protected void configure(HttpSecurity http) throws Exception {
JWTAuthenticationFilter jwtAuthenticationFilter = new JWTAuthenticationFilter(authenticationManager());
jwtAuthenticationFilter.setFilterProcessesUrl("/api/login");
http.antMatcher("/api/**")
.sessionManagement()
.sessionCreationPolicy(SessionCreationPolicy.STATELESS)
.and()
.csrf().disable()
.authorizeRequests()
.anyRequest().authenticated()
.and()
.exceptionHandling()
.authenticationEntryPoint(new RESTAuthenticationEntryPoint())
.and()
.addFilter(jwtAuthenticationFilter)
.addFilter(new JWTAuthorizationFilter(authenticationManager()));
}
}
I'll need to work on my error messages so they're more informative and secure.
And this doesn't exactly answer my original question, which was how to get those default-style JSON responses I liked, but it does allow me to customize the errors from all types of access failures independently of the web configuration. (Endpoints outside of /api/** still work with the web form login.)
Full code as of the current commit: github