Spring Boot Security OAuth2 custom exception message

Question

I have somewhat special case in my spring boot RESTfull project, not the standard customization of error message on auth exception. I need a different message depending if the username or password is wrong, or if username doesn't exists, or if the user was deactivated in the database. Currently I can only get message "Bad credentials" and I haven't found any solutions how to customize message depending on some user properties or special cases.

I currently have custom authentication provider like this:

@Component
public class CustomAuthenticationProvider implements AuthenticationProvider {

    @Autowired
    private CustomUserDetailsService userDetailsService;

    @Autowired
    PasswordEncoder passwordEncoder;

    @Override
    public Authentication authenticate(Authentication authentication)
            throws org.springframework.security.core.AuthenticationException {


        String name = authentication.getName();
        String password = authentication.getCredentials().toString();

        UserDetails userDetails = userDetailsService.loadUserByUsername(name);


        if(passwordEncoder.matches(password, userDetails.getPassword())) {
            return new UsernamePasswordAuthenticationToken(userDetails.getUsername(), userDetails.getPassword(),
                    userDetails.getAuthorities());
        }

        return null;
    }

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


}

And I have custom user details service like this:

@Service
public class CustomUserDetailsService implements org.springframework.security.core.userdetails.UserDetailsService{

    @Autowired
    UserService userService; //my custom user service

    @Override
    public UserDetails loadUserByUsername(String username) {
        try {
            User user = userService.getUserByUsername(username);

            if(user == null) {
                throw new UsernameNotFoundException("Username doesn't exist");
            } else if(user.isDeactivated()) {
                throw new UsernameNotFoundException("User deactivated");
            }

            List<Authority> listOfAuthorities = userService.getAllAuthoritiesFromUser(user.getUserId());
            List<GrantedAuthority> grantedAuthorities = new ArrayList<>();

            for(Authority authority : listOfAuthorities) {
                grantedAuthorities.add(new SimpleGrantedAuthority(authority.getName()));
            }

            org.springframework.security.core.userdetails.User userNew =
            new org.springframework.security.core.userdetails.User(user.getUsername(), user.getPassword(), grantedAuthorities);
            return userNew;

        }
        catch(Exception ex) {
            throw new UsernameNotFoundException("Username or password not correct");
        }

    }
}

Where can I process the message from throw new UsernameNotFoundException and return it as "error_description" ?

EDIT Here is also my SecurityConfig and ResourceServerConfig :

@Configuration
@EnableWebSecurity
@Order(Ordered.LOWEST_PRECEDENCE)
public class SecurityConfig extends WebSecurityConfigurerAdapter{

    @Autowired
    CustomUserDetailsService userDetailsService;

    @Autowired
    private CustomAuthenticationProvider authProvider;

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.authenticationProvider(authProvider)  
        .userDetailsService(userDetailsService)
        .passwordEncoder(passwordEncoder());
    }


    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.csrf().disable();
        http.addFilterBefore(new AuthenticationTokenFilter(authenticationManager()), BasicAuthenticationFilter.class);
    }

    // must be overriden and exposed as @Bean, otherwise boot's AuthenticationManagerConfiguration will take precedence
    @Bean @Override
    public AuthenticationManager authenticationManagerBean() throws Exception {
        return super.authenticationManagerBean();
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }
}

@Configuration
@EnableResourceServer
public class ResourceServerConfig extends ResourceServerConfigurerAdapter{

    @Autowired
    private AuthExceptionEntryPoint myEntryPoint;

    @Override
    public void configure(HttpSecurity http) throws Exception {
        http.anonymous().and().authorizeRequests().antMatchers("/**")
                .authenticated()
                .and()
                .exceptionHandling().authenticationEntryPoint(myEntryPoint).accessDeniedHandler(new OAuth2AccessDeniedHandler());
    }

}

Answer 1

This generic message on Spring Security has a purpose, and it's to obfuscate what's the actual reason for the failure in the login.

Once you give specific messages as you want, eg Username doesn't exist , User deactivated , Password incorrect , and so on, you're starting to give too much information for a malicious user.

Update

If you still want to go that way, you can implement your own AuthenticationFailureHandler , something like this should work:

public class DefaultAuthenticationFailureHandler extends SimpleUrlAuthenticationFailureHandler {

        @Override
        public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, 
                                            AuthenticationException exception) throws IOException, ServletException {
            super.onAuthenticationFailure(request, response, exception);
            if (exception.getClass().isAssignableFrom(UsernameNotFoundException.class)) {
                response.sendRedirect("User not found")
            } else if (exception.getClass().isAssignableFrom(LockedException.class)) {
                response.sendRedirect("User Locked")
            }
        }
    }