Spring Boot : CORS Issue - spring

Question

I am using Spring Boot version 2.0.2Release.
Below is my security configuration
#Configuration
#EnableWebSecurity
#EnableGlobalMethodSecurity(
prePostEnabled = true,
securedEnabled = true,
jsr250Enabled = true)
#ComponentScan("com.mk")
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
#Autowired
private AuthenticationProvider myAuthenticationProvider;
#Override
protected void configure(HttpSecurity http) throws Exception {
http.csrf().disable();
http.cors().configurationSource(corsConfigurationSource())
.and()
.csrf().disable()
.anonymous().and()
.authorizeRequests()
.antMatchers(HttpMethod.GET,"/index.html").permitAll()
.antMatchers(HttpMethod.POST,"/login").permitAll()
.antMatchers(HttpMethod.GET,"*").authenticated()
.and().httpBasic();
}
#Bean
CorsConfigurationSource corsConfigurationSource() {
CorsConfiguration configuration = new CorsConfiguration();
configuration.setAllowedOrigins(Arrays.asList("*"));
configuration.setAllowedMethods(Arrays.asList("GET","POST"));
configuration.setAllowCredentials(true);
UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
source.registerCorsConfiguration("/**", configuration);
return source;
}
I am unable to invoke any API (including login which is permitAll) because of CORS issue.
On Browser I am getting (It works with Postman, since CORS check is not made there)
Failed to load http://localhost:8080/myurl: Response to preflight
request doesn't pass access control check: No
'Access-Control-Allow-Origin' header is present on the requested
resource. Origin 'http://localhost:4200' is therefore not allowed
access. The response had HTTP status code 403.

Answer 1

Although Spring security provides a way to configure CORS in http configurer, there's a much cleaner approach to add CORS filter to the application-
#Component
#Order(Ordered.HIGHEST_PRECEDENCE)
public class MyCORSFilter implements Filter {
#Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
response.setHeader("Access-Control-Allow-Origin", request.getHeader("Origin"));
response.setHeader("Access-Control-Allow-Credentials", "true");
response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
response.setHeader("Access-Control-Max-Age", "3600");
response.setHeader("Access-Control-Allow-Headers", "Content-Type, Accept, X-Requested-With, remember-me");
chain.doFilter(req, res);
}
#Override
public void init(FilterConfig filterConfig) {
}
#Override
public void destroy() {
}
}
Ordering the filter with highest precedence makes sure that MyCORSFilter implementation of javax.servlet.Filter is the first one in the chain. Hope this helps

Answer 2

Checkout this guide from Spring:
https://spring.io/guides/gs/rest-service-cors/
There are few ways to add CORS support in Spring Boot.
Using global configuration:
#Bean
public WebMvcConfigurer corsConfigurer() {
return new WebMvcConfigurerAdapter() {
#Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/greeting-javaconfig").allowedOrigins("http://localhost:9000");
}
};
}
And using #CrossOrigin annotation:
#CrossOrigin(origins = "http://localhost:9000")
#GetMapping("/greeting")
public Greeting greeting(#RequestParam(required=false, defaultValue="World") String name) {
System.out.println("==== in greeting ====");
return new Greeting(counter.incrementAndGet(), String.format(template, name));
}

Answer 3

There is no need of adding any additional Filters or WebMvcConfigurer. The main problem is 'Access-Control-Allow-Origin' does not present in the header because corsConfigurationSource does not add the necessary configuration to get the relevant CORS response headers. Hence, the below missing configurations have to be added when we configure CorsConfigurationSource
configuration.addAllowedOrigin("*");
configuration.addAllowedHeader("*");
configuration.addAllowedMethod("*");
We have to configure cors CorsConfigurationSource as below
#Override
protected void configure(HttpSecurity http) throws Exception {
http.csrf().disable()
.cors().configurationSource(corsConfigurationSource())
.and()
.....
}
#Bean
CorsConfigurationSource corsConfigurationSource() {
CorsConfiguration configuration = new CorsConfiguration();
configuration.setAllowedOrigins(Arrays.asList("*"));
configuration.setAllowedMethods(Arrays.asList("GET","POST"));
configuration.setAllowCredentials(true);
//the below three lines will add the relevant CORS response headers
configuration.addAllowedOrigin("*");
configuration.addAllowedHeader("*");
configuration.addAllowedMethod("*");
UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
source.registerCorsConfiguration("/**", configuration);
return source;
}
If anyone facing CORS issue with Spring Boot 2.4.0 plus versions when having the following combination then refer to answer
CorsConfigurationSource#setAllowedOrigins value as *
and
CorsConfigurationSource#setAllowCredentials value as true

Answer 4

Ok, so I realized that it was deprecated. If you look on baeldung it has how to do it the new way since they updated webmvcconfigurer:
#Configuration
#EnableWebMvc
public class WebConfig implements WebMvcConfigurer {
#Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/**").allowedMethods("*").allowedOrigins(frontDomain);
}
}