Monday, May 1, 2017

Spring Security Support for CORS (Cross Origin Resource Sharing)

Since Spring Security 4.2, this is the proper way to make Spring Security support CORS (also needed in Spring Boot 1.4/1.5):
@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedMethods("HEAD", "GET", "PUT", "POST", "DELETE", "PATCH");
    }
}
and:
@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
//        http.csrf().disable();
        http.cors();
    }

    @Bean
    public CorsConfigurationSource corsConfigurationSource() {
        final CorsConfiguration configuration = new CorsConfiguration();
        configuration.setAllowedOrigins(ImmutableList.of("*"));
        configuration.setAllowedMethods(ImmutableList.of("HEAD",
                "GET", "POST", "PUT", "DELETE", "PATCH"));
        // setAllowCredentials(true) is important, otherwise:
        // The value of the 'Access-Control-Allow-Origin' header in the response must not be the wildcard '*' when the request's credentials mode is 'include'.
        configuration.setAllowCredentials(true);
        // setAllowedHeaders is important! Without it, OPTIONS preflight request
        // will fail with 403 Invalid CORS request
        configuration.setAllowedHeaders(ImmutableList.of("Authorization", "Cache-Control", "Content-Type"));
        final UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);
        return source;
    }
}
Do not do any of below, which are the wrong way to attempt solving the problem:
  • http.authorizeRequests().antMatchers(HttpMethod.OPTIONS, "/**").permitAll();
  • web.ignoring().antMatchers(HttpMethod.OPTIONS);

To learn more about Spring Boot, I highly recommend Spring Boot in Action: