Handle error on Spring Boot at custom authentication filter

Question

I'm working in a spring-boot application on my backend and I want to use firebase to make the authentication process. I setup properly the firebase in my spring-boot project and added the security layer following this open source repository: https://github.com/savicprvoslav/Spring-Boot-starter

Because the Firebase token has a lifetime of 1 hour I need to handle an error when the Firebase SDK throws a FirebaseAuthException. The issue is I'm not being able to handle exception inside of my FirebaseFilter. The backend always returns the default error page with timestamp, error, message and status 500. I want to change it to return only the HTTP status code 401.

I also would like to change the default error page when the URL path doesn't exist to return only 404 as a good REST API should returns.

I tried to use @ExceptionHandler and @ControllerAdvice (following this article https://www.baeldung.com/exception-handling-for-rest-with-spring) but it didn't work. I'm very new Spring Framework developer so I guess I'm missing something...

My .gradle file:

implementation('org.springframework.boot:spring-boot-starter-data-jpa')
implementation('org.springframework.boot:spring-boot-starter-web')
implementation('org.springframework.boot:spring-boot-starter-security')
implementation('org.flywaydb:flyway-core:5.2.1')
implementation('com.fasterxml.jackson.module:jackson-module-kotlin')
implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
implementation("org.jetbrains.kotlin:kotlin-reflect")
implementation('com.google.firebase:firebase-admin:6.5.0')
implementation('io.springfox:springfox-swagger2:2.9.2')
implementation('io.springfox:springfox-swagger-ui:2.9.2')
runtimeOnly('org.postgresql:postgresql')
testImplementation('org.springframework.boot:spring-boot-starter-test')

My WebSecurityConfigurerAdapter:

@Configuration
inner class ApplicationSecurity : WebSecurityConfigurerAdapter(false) {
    @Autowired(required = false)
    lateinit var firebaseService: FirebaseServiceContract

    override fun configure(web: WebSecurity) {
        web.ignoring().antMatchers(
            "/api/users",
            "/v2/api-docs",
            "/configuration/ui",
            "/swagger-resources",
            "/configuration/security", "/swagger-ui.html",
            "/webjars/**", "/swagger-resources/configuration/ui",
            "/swagge‌r-ui.html", "/docs/**",
            "/swagger-resources/configuration/security"
        )
    }

    override fun configure(http: HttpSecurity) {
        http.addFilterBefore(tokenAuthorizationFilter(), BasicAuthenticationFilter::class.java)
            .authorizeRequests()
            .antMatchers("/api/**").hasAnyRole(Roles.USER)
            .and().csrf().disable().anonymous().authorities(Roles.ROLE_ANONYMOUS)
    }

    private fun tokenAuthorizationFilter(): FirebaseFilter? {
        return FirebaseFilter(firebaseService)
    }
}

My FirebaseFilter:

class FirebaseFilter(private val firebaseService: FirebaseServiceContract) : OncePerRequestFilter() {
override fun doFilterInternal(request: HttpServletRequest, response: HttpServletResponse, chain: FilterChain) {
    val xAuth = request.getHeader(HEADER_NAME)?.removePrefix("Bearer ")
    if (xAuth.isNullOrBlank()) {
        chain.doFilter(request, response)
        return
    } else {
        try {
            // Fire FirebaseAuth.getInstance().verifyIdToken
            val holder = firebaseService.parseToken(xAuth)

            val userName = holder.getUid()

            val auth = FirebaseAuthenticationToken(userName, holder)
            SecurityContextHolder.getContext().authentication = auth

            chain.doFilter(request, response)
        } catch (e: FirebaseTokenInvalidException) {
            throw SecurityException(e)
        }
    }
}

My Firebase parser:

class FirebaseParser {

fun parseToken(idToken: String): FirebaseTokenHolder {
    if (idToken.isBlank()) {
        throw IllegalArgumentException("Blank Token")
    }

    try {
        val authTask = FirebaseAuth.getInstance().verifyIdToken(idToken)
        FirebaseAuth.getInstance().getUser(authTask.uid)

        return FirebaseTokenHolder(authTask)
    } catch (e: FirebaseAuthException) {
        throw FirebaseTokenInvalidException(e.message)
    }
  }
}

Answer 1

Basically, the answer is here: https://stackoverflow.com/a/34633687/496038

Implement the ExceptionHandlerFilter class as in the above answer (similar to), and in your extension of WebSecurityConfigurerAdapter add something like this :

      @Override
      protected void configure(HttpSecurity http) throws Exception {
    http.csrf().disable().cors().and().authorizeRequests().anyRequest().authenticated().and()
            .addFilterBefore(
                new ExceptionHandlerFilter(), CorsFilter.class);
      }

This should do the work.