Spring Security 5 populating authorities based on JWT claims

Question

As I see Spring Security OAuth2.x project was moved to Spring Security 5.2.x. I try to implement authorization and resource server in new way. Everythin is working correctly except one thing - @PreAuthorize annotation. When I try to use this with standard @PreAuthorize("hasRole('ROLE_USER')") I always get forbidden. What I see is that the Principal object which is type of org.springframework.security.oauth2.jwt.Jwt is not able to resolve authorities and I have no idea why.

org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationToken@44915f5f: Principal: org.springframework.security.oauth2.jwt.Jwt@2cfdbd3; Credentials: [PROTECTED]; Authenticated: true; Details: org.springframework.security.web.authentication.WebAuthenticationDetails@ffffa64e: RemoteIpAddress: 172.19.0.1; SessionId: null; Granted Authorities: SCOPE_read, SCOPE_write

And claims after casting it to Jwt

{user_name=user, scope=["read","write"], exp=2019-12-18T13:19:29Z, iat=2019-12-18T13:19:28Z, authorities=["ROLE_USER","READ_ONLY"], client_id=sampleClientId}

Security Server Configuration

@Configuration
@EnableAuthorizationServer
public class AuthorizationServerConfiguration extends AuthorizationServerConfigurerAdapter {

  @Autowired
  private DataSource dataSource;

  @Autowired
  private AuthenticationManager authenticationManager;

  @Bean
  public KeyPair keyPair() {
    ClassPathResource ksFile = new ClassPathResource("mytest.jks");
    KeyStoreKeyFactory keyStoreKeyFactory = new KeyStoreKeyFactory(ksFile, "mypass".toCharArray());
    return keyStoreKeyFactory.getKeyPair("mytest");
  }

  @Bean
  public JwtAccessTokenConverter accessTokenConverter() {
    JwtAccessTokenConverter converter = new JwtAccessTokenConverter();
    converter.setKeyPair(keyPair());
    return converter;
  }

  @Bean
  public JWKSet jwkSet() {
    RSAKey key = new Builder((RSAPublicKey) keyPair().getPublic()).build();
    return new JWKSet(key);
  }

  @Bean
  public TokenStore tokenStore() {
    return new JwtTokenStore(accessTokenConverter());
  }

  @Override
  public void configure(ClientDetailsServiceConfigurer clients) throws Exception {
    clients.jdbc(dataSource);
  }

  @Override
  public void configure(AuthorizationServerEndpointsConfigurer endpoints) {
    endpoints.tokenStore(tokenStore())
        .accessTokenConverter(accessTokenConverter())
        .authenticationManager(authenticationManager);
  }

  @Override
  public void configure(AuthorizationServerSecurityConfigurer security) {
    security.tokenKeyAccess("permitAll()")
        .checkTokenAccess("isAuthenticated()");
  }
}

@EnableWebSecurity
public class SecurityConfiguration extends WebSecurityConfigurerAdapter {

  private UserDetailsService userDetailsService;

  public SecurityConfiguration(UserDetailsService userDetailsService) {
    this.userDetailsService = userDetailsService;
  }

  @Override
  protected void configure(HttpSecurity http) throws Exception {
    http.authorizeRequests()
            .mvcMatchers("/.well-known/jwks.json")
            .permitAll()
            .anyRequest()
            .authenticated();
  }

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

  @Bean
  @Override
  public AuthenticationManager authenticationManagerBean() throws Exception {
    return super.authenticationManagerBean();
  }

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

Resource server configuration

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class ResuorceServerConfiguration extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
                .anyRequest()
                .authenticated()
                .and()
                .oauth2ResourceServer()
                .jwt();
    }
}

Maybe someone had similar issue?

Answer 1

By default, the resource server populates the authorities based on the "scope" claim.
If the Jwt contains a claim with the name "scope" or "scp", then Spring Security will use the value in that claim to construct the authorities by prefixing each value with "SCOPE_".

In your example, one of the claims is scope=["read","write"].
This means that the authority list will consist of "SCOPE_read" and "SCOPE_write".

You can modify the default authority mapping behaviour by providing a custom authentication converter in your security configuration.

http
    .authorizeRequests()
        .anyRequest().authenticated()
        .and()
    .oauth2ResourceServer()
        .jwt()
            .jwtAuthenticationConverter(getJwtAuthenticationConverter());

Then in your implementation of getJwtAuthenticationConverter, you can configure how the Jwt maps to the list of authorities.

Converter<Jwt, AbstractAuthenticationToken> getJwtAuthenticationConverter() {
    JwtAuthenticationConverter converter = new JwtAuthenticationConverter();
    converter.setJwtGrantedAuthoritiesConverter(jwt -> {
        // custom logic
    });
    return converter;
}