Autowire a particular password encoder for Spring Authorization Server

Question

My app has two PasswordEncoder beans and wants to use spring-security-oauth2-authorization-server.

implementation("org.springframework.security:spring-security-oauth2-authorization-server:1.0.0")

• Two passwordEncoder Beans

    @Bean("v1-encoder")
    fun v1Encoder(): PasswordEncoder {
        return V1PasswordEncoder()
    }

    @Bean("v0-encoder")
    fun v0Encoder(): PasswordEncoder {
        return V0PasswordEncoder()
    } 

• So Spring Authorization Server complains about multiple beans:

Parameter 0 of method setFilterChains in org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration required a single bean, but 2 were found:

• The code fails at https://github.com/spring-projects/spring-authorization-server/blob/1.0.0/oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/config/annotation/web/configurers/OAuth2ClientAuthenticationConfigurer.java#L231

PasswordEncoder passwordEncoder = OAuth2ConfigurerUtils.getOptionalBean(httpSecurity, PasswordEncoder.class);

How can I autowire v1-encoder for OAuth2ServerSecurityConfig so it can find the v1-encoder bean?

• My simple spring auth server config

@Configuration
class OAuth2ServerSecurityConfig {

   @Bean
   @Order(1)
   fun authorizationServerSecurityFilterChain(http: HttpSecurity): SecurityFilterChain {
      OAuth2AuthorizationServerConfiguration.applyDefaultSecurity(http)
      http.getConfigurer(OAuth2AuthorizationServerConfigurer::class.java)
         .oidc(Customizer.withDefaults())
      return http.build()
   }

   @Bean
   fun authorizationServerSettings(): AuthorizationServerSettings {
      return AuthorizationServerSettings.builder().build()
   }

   @Bean
   fun registeredClientRepository(): RegisteredClientRepository {
      val registeredClient = RegisteredClient.withId(UUID.randomUUID().toString())
         .clientId("client")
         .clientSecret("{bcrypt}secret")
         .authorizationGrantType(AuthorizationGrantType.CLIENT_CREDENTIALS)
         .build()

      return InMemoryRegisteredClientRepository(registeredClient)
   }

Answer 1

Unfortunately, the framework does strictly expect 0 or 1 beans to exist. If you can explain your use case, there might be other solutions. One option (workaround) is to wrap your second PasswordEncoder in another component, for example:

@Bean
public PasswordEncoderHolder passwordEncoderHolder() {
    return new PasswordEncoderHolder();
}

public static final class PasswordEncoderHolder {
    private final PasswordEncoder passwordEncoder = new V0PasswordEncoder();

    public PasswordEncoder getInstance() {
        return this.passwordEncoder;
    }
}

Then you only need an @Bean for v1-encoder.