[FIXED] Spring Security Redirecting After Successful Authentication

Issue

I am trying to add access control to a set of api endpoints and the problem I am running into is that the service is redirecting to / regardless of whether the original request was /api/apple or /api/orange. I currently have a filter set up to read a custom http header to do the authentication and the filter I am using is extended from AbstractAuthenticationProcessingFilter. The documentation is saying that it is intended for the AbstractAuthenticationProcessingFilter to redirect to a specific url upon successful authentication, but this is not the behavior I want for an api. I think I may be using the wrong Filter, but I don't know which one I should be using. Can I get some help on what I may be doing wrong and what I should be doing?

Filter Chain Configuration:

@Configuration
@EnableWebSecurity
public class SecurityConfig {

  @Bean
  AuthenticationManager customAuthenticationManager(PreAuthProvider preAuthProvider) {
    return new ProviderManager(List.of(preAuthProvider));
  }

  @Bean
  SessionAuthFilter customAuthFilter(AuthenticationManager authManager, CustomUserDetails userDetails) {
    return new SessionAuthFilter(
        new OrRequestMatcher(
            new AntPathRequestMatcher("/apple/**"),
            new AntPathRequestMatcher("/orange/**")
        ),
        authManager,
        userDetails);
  }

  @Bean
  public SecurityFilterChain filterChain(HttpSecurity http, SessionAuthFilter authFilter) throws Exception {
    http.exceptionHandling()
        .authenticationEntryPoint(new Http403ForbiddenEntryPoint())
        .accessDeniedHandler(new AccessDeniedHandlerImpl())
        .and()
        .formLogin().disable()
        .httpBasic().disable()
        .authorizeRequests()
        .antMatchers(
            "/",
            "/error",
            "/v3/api-docs/**",
            "/swagger-ui/**",
            "/swagger-ui.html",
            "/actuator/**"
        ).permitAll()
        .antMatchers(GET, "/apple").hasAuthority("getApples")
        .antMatchers(GET, "/orange").hasAuthority("getOranges")
        .anyRequest().authenticated()
        .and()
        .addFilterBefore(authFilter, AbstractPreAuthenticatedProcessingFilter.class)
        .sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS);

    return http.build();
  }

Filter Implementation:

public class SessionAuthFilter extends AbstractAuthenticationProcessingFilter {
  private final CustomUserDetails userDetails;

  protected SessionAuthFilter(RequestMatcher requestMatcher, AuthenticationManager authenticationManager,
                              CustomUserDetails userDetails) {
    super(requestMatcher, authenticationManager);
    this.userDetails = userDetails;
  }

  @Override
  public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response)
      throws AuthenticationException {
    var sessionToken = request.getHeader("SessionToken") != null ? request.getHeader("SessionToken").trim() : null;
    var user = userDetails.loadUserByUsername(sessionToken);
    var authentication = new PreAuthenticatedAuthenticationToken(user.getUsername(), user.getPassword(),
        user.getAuthorities());
    authentication.setAuthenticated(user.isCredentialsNonExpired());
    authentication.setDetails(userDetails);

    SecurityContextHolder.getContext().setAuthentication(authentication);
    return this.getAuthenticationManager().authenticate(authentication);
  }
}

Authentication Provider:

@Component
@Slf4j
public class PreAuthProvider implements AuthenticationProvider {

  private boolean throwExceptionWhenTokenRejected;

  @Override
  public Authentication authenticate(Authentication authentication) throws AuthenticationException {
    if (!this.supports(authentication.getClass())) {
      return null;
    }  else {
      log.debug(String.valueOf(LogMessage.format("PreAuthenticated authentication request: %s", authentication)));
      if (authentication.getPrincipal() == null) {
        log.debug("No pre-authenticated principal found in request.");
        if (this.throwExceptionWhenTokenRejected) {
          throw new BadCredentialsException("No pre-authenticated principal found in request.");
        } else {
          return null;
        }
      } else if (authentication.getCredentials() == null) {
        log.debug("No pre-authenticated credentials found in request.");
        if (this.throwExceptionWhenTokenRejected) {
          throw new BadCredentialsException("No pre-authenticated credentials found in request.");
        } else {
          return null;
        }
      } else if (!authentication.isAuthenticated()) {
        throw new InsufficientAuthenticationException("Session token likely no longer valid.");
      }

      return authentication;
    }
  }

  @Override
  public boolean supports(Class<?> authentication) {
    return authentication.equals(PreAuthenticatedAuthenticationToken.class);
  }

  public void setThrowExceptionWhenTokenRejected(boolean throwExceptionWhenTokenRejected) {
    this.throwExceptionWhenTokenRejected = throwExceptionWhenTokenRejected;
  }
}

Solution

It looks like if you set continueChainBeforeSuccessfulAuthentication in your AbstractAuthenticationProcessingFilter implementation to true, you can stop the redirection. I only needed to modify the filter constructor which came out to be:

protected SessionAuthFilter(RequestMatcher requestMatcher, AuthenticationManager authenticationManager,
                              CustomUserDetails userDetails) {
    super(requestMatcher, authenticationManager);
    this.userDetails = userDetails;
    this.setContinueChainBeforeSuccessfulAuthentication(true);
}

The other approach would be to implement a different Filter such as OncePerRequestFilter or a GenericFilterBean to handle the authentication yourself.

Answered By - superflux
Answer Checked By - Mary Flores (JavaFixing Volunteer)