Custom authentication with spring-security and reactive spring - spring-boot

Question

I'm having a custom authentication scheme. I'm having a REST endpoint that has userId in http uri path and token in http header. I would like to check that such request is perform by valid user with valid token. Users and tokens are stored in mongo collection.
I don't know in which class I should authorize user.
My SecurityConfig:
#EnableWebFluxSecurity
class SecurityConfig {
#Bean
fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
val build = http
.httpBasic().disable()
.formLogin().disable()
.csrf().disable()
.logout().disable()
.authenticationManager(CustomReactiveAuthenticationManager())
.securityContextRepository(CustomServerSecurityContextRepository())
.authorizeExchange().pathMatchers("/api/measurement/**").hasAuthority("ROLE_USER")
.anyExchange().permitAll().and()
return build.build()
}
#Bean
fun userDetailsService(): MapReactiveUserDetailsService {
val user = User.withDefaultPasswordEncoder()
.username("sampleDeviceIdV1")
.password("foo")
.roles("USER")
.build()
return MapReactiveUserDetailsService(user)
}
}
My ServerSecurityContextRepository:
class CustomServerSecurityContextRepository : ServerSecurityContextRepository {
override fun load(exchange: ServerWebExchange): Mono<SecurityContext> {
val authHeader = exchange.request.headers.getFirst(HttpHeaders.AUTHORIZATION)
val path = exchange.request.uri.path
return if (path.startsWith("/api/measurement/") && authHeader != null && authHeader.startsWith(prefix = "Bearer ")) {
val deviceId = path.drop(17)
val authToken = authHeader.drop(7)
val auth = UsernamePasswordAuthenticationToken(deviceId, authToken)
Mono.just(SecurityContextImpl(auth))
} else {
Mono.empty()
}
}
override fun save(exchange: ServerWebExchange?, context: SecurityContext?): Mono<Void> {
return Mono.empty()
}
}
Two questions arise:
Is ServerSecurityContextRepository good place to obtain username and token from exchange - or there is a better place to do it?
Where should I perform authentication (check token and username against mongo collection)?
My custom AuthenticationManager does not get called anywhere. Should I do everything inside ServerSecurityContextRepository or perform user and token validation inside ReactiveAuthenticationManager? Or maybe other class would be even more suitable?

Answer 1

It turns out that some tutorials on the web are plain wrong.
I've managed to configure everything using following code:
class DeviceAuthenticationConverter : Function<ServerWebExchange, Mono<Authentication>> {
override fun apply(exchange: ServerWebExchange): Mono<Authentication> {
val authHeader: String? = exchange.request.headers.getFirst(HttpHeaders.AUTHORIZATION)
val path: String? = exchange.request.uri.path
return when {
isValidPath(path) && isValidHeader(authHeader) -> Mono.just(UsernamePasswordAuthenticationToken(path?.drop(17), authHeader?.drop(7)))
else -> Mono.empty()
}
}
private fun isValidPath(path: String?) = path != null && path.startsWith(API_MEASUREMENT)
private fun isValidHeader(authHeader: String?) = authHeader != null && authHeader.startsWith(prefix = "Bearer ")
}
And config:
#EnableWebFluxSecurity
class SecurityConfig {
companion object {
const val API_MEASUREMENT = "/api/measurement/"
const val API_MEASUREMENT_PATH = "$API_MEASUREMENT**"
const val DEVICE = "DEVICE"
const val DEVICE_ID = "deviceId"
}
#Bean
fun securityWebFilterChain(http: ServerHttpSecurity, authenticationManager: ReactiveAuthenticationManager) =
http
.httpBasic().disable()
.formLogin().disable()
.csrf().disable()
.logout().disable()
.authorizeExchange().pathMatchers(API_MEASUREMENT_PATH).hasRole(DEVICE)
.anyExchange().permitAll().and().addFilterAt(authenticationWebFilter(authenticationManager), AUTHENTICATION).build()
#Bean
fun userDetailsService(tokenRepository: TokenRepository) = MongoDeviceTokenReactiveUserDetailsService(tokenRepository)
#Bean
fun tokenRepository(template: ReactiveMongoTemplate, passwordEncoder: PasswordEncoder) = MongoTokenRepository(template, passwordEncoder)
#Bean
fun tokenFacade(tokenRepository: TokenRepository) = TokenFacade(tokenRepository)
#Bean
fun authManager(userDetailsService: ReactiveUserDetailsService) = UserDetailsRepositoryReactiveAuthenticationManager(userDetailsService)
private fun authenticationWebFilter(reactiveAuthenticationManager: ReactiveAuthenticationManager) =
AuthenticationWebFilter(reactiveAuthenticationManager).apply {
setAuthenticationConverter(DeviceAuthenticationConverter())
setRequiresAuthenticationMatcher(
ServerWebExchangeMatchers.pathMatchers(HttpMethod.POST, API_MEASUREMENT_PATH)
)
}
#Bean
fun passwordEncoder() = PasswordEncoderFactories.createDelegatingPasswordEncoder()
}