Allow OPTIONS HTTP Method for oauth/token request

Same problem with Spring-Boot 1.4.7.RELEASE

My WebSecurityConfigurerAdapter was using SecurityProperties.ACCESS_OVERRIDE_ORDER so, selected answer did not work.

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
@Order(SecurityProperties.ACCESS_OVERRIDE_ORDER)
public class AuthServerSecurityConfig extends WebSecurityConfigurerAdapter 

Thus, I added the following filter configuration with preceding order:

  @Bean
  public FilterRegistrationBean corsFilter() {
    FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(corsConfigurationSource()));
    bean.setOrder(SecurityProperties.DEFAULT_FILTER_ORDER);
    return bean;
  }

  @Bean
  public CorsConfigurationSource corsConfigurationSource() {
    UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
    CorsConfiguration config = new CorsConfiguration();
    config.setAllowCredentials(true);
    config.addAllowedOrigin("*");
    config.addAllowedHeader("*");
    config.addAllowedMethod("*");
    source.registerCorsConfiguration("/**", config);
    return source;
  }

and it got the job done.

Note: equivalent result can be achieved with a javax.servlet.Filter bean with @Order(SecurityProperties.DEFAULT_FILTER_ORDER) annotation as below:

@Component
@Order(SecurityProperties.DEFAULT_FILTER_ORDER)
public class CorsFilter implements Filter {

  @Override
  public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
    final HttpServletResponse response = (HttpServletResponse) res;

    response.setHeader("Access-Control-Allow-Origin"  , "*"                               );
    response.setHeader("Access-Control-Allow-Methods" , "POST, PUT, GET, OPTIONS, DELETE" );
    response.setHeader("Access-Control-Allow-Headers" , "Authorization, Content-Type"     );
    response.setHeader("Access-Control-Max-Age"       , "3600"                            );

    if("OPTIONS".equalsIgnoreCase(((HttpServletRequest) req).getMethod())) {
      response.setStatus(HttpServletResponse.SC_OK);
    }
    else {
      chain.doFilter(req, res);
    }
  }
  // ...
}

@EnableAuthorizationServer is adding http security configuration for endpoints like /oauth/token, /oauth/token_key etc at order 0. So what you should do is to define a http security rule for /oauth/token endpoint only for the OPTIONS http method which is at a higher order.

Something like this:

@Order(-1)
@Configuration
public class MyWebSecurity extends WebSecurityConfigurerAdapter {
   @Override
   protected void configure(HttpSecurity http) throws Exception {
       http
          .authorizeRequests()
          .antMatchers(HttpMethod.OPTIONS, "/oauth/token").permitAll()
   }
}

I just add

@Order(Ordered.HIGHEST_PRECEDENCE)

in

public class OAuth2SecurityConfig extends WebSecurityConfigurerAdapter {....}

and config the support of spring

@Bean
public CorsConfigurationSource corsConfigurationSource() {
  CorsConfiguration configuration = new CorsConfiguration();
  configuration.setAllowedOrigins(Arrays.asList("*"));
  configuration.setAllowedMethods(Arrays.asList("*"));
  configuration.setAllowedHeaders(Arrays.asList("*"));

  UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
  source.registerCorsConfiguration("/**", configuration);
  return source;
}

Worked for me.

I was using the solution proposed by idursun. The OPTION call started to work, but still had problems with Access-Control-Allow-Origin.

This filter implementation definitively worked for me:

Standalone Spring OAuth2 JWT Authorization Server + CORS