Quiero tener una aplicación REST básica protegida con autenticación. Seguí las instrucciones generales dehttp://www.baeldung.com/spring-security-authentication-provider para que la seguridad funcione.

Terminé creando mi implementación deAuthenticationProvider, pero nunca lo llama Spring. Todas las solicitudes terminan con un error:

{"timestamp":1460199213227,"status":401,"error":"Unauthorized","message":"Full authentication is required to access this resource","path":"/test"}

sin que AuthenticationProvider haya hecho nada.

La aplicación está basada en anotaciones y aquí están los bits relevantes:

Configuración de seguridad

@Configuration
@Order(SecurityProperties.ACCESS_OVERRIDE_ORDER)
public class ApplicationSecurity extends WebSecurityConfigurerAdapter {
    @Autowired
    CustomAuthenticationProvider authenticationProvider;

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

    @Override
    public void configure(HttpSecurity http) throws Exception {
        http
                .csrf().disable()
                .authenticationProvider(authenticationProvider)
                .authorizeRequests()
                .anyRequest().authenticated().and().httpBasic();
    }
}

Proveedor de autenticación

@Component
public class CustomAuthenticationProvider implements AuthenticationProvider {
    @Autowired
    private UserDAO userDAO;
    @Autowired
    private Authenticator authenticator;

    @Override
    public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        // This never gets called, I checked with debugger
        String username = authentication.getName();
        String password = authentication.getCredentials().toString();

        User user = userDAO.findByUsername(username);
        User authenticatedUser = authenticator.authenticate(user, password);
        if (authenticatedUser == null){
            throw new RESTAuthenticationException("Auth failed");
        }

        List<GrantedAuthority> authorityList = new ArrayList<>();
        return new UsernamePasswordAuthenticationToken(user, authorityList);
    }

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

Controlador

@RestController
public class UserController {
    @RequestMapping(value = "/test")
    public ResponseEntity test(@AuthenticationPrincipal User user) {
        return ResponseEntity.ok().body(user);
    }
}