Keycloak and Spring Oauth2 - CORS issue [duplicate] - reactjs

Question

I am using keycloak to secure my rest service. I am refering to the tutorial given here. I created the rest and front end. Now when I add keycloak on the backend I get CORS error when my front end makes api call.
Application.java file in spring boot looks like
#SpringBootApplication
public class Application
{
public static void main( String[] args )
{
SpringApplication.run(Application.class, args);
}
#Bean
public WebMvcConfigurer corsConfiguration() {
return new WebMvcConfigurerAdapter() {
#Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/api/*")
.allowedMethods(HttpMethod.GET.toString(), HttpMethod.POST.toString(),
HttpMethod.PUT.toString(), HttpMethod.DELETE.toString(), HttpMethod.OPTIONS.toString())
.allowedOrigins("*");
}
};
}
}
The keycloak properties in the application.properties file look like
keycloak.realm = demo
keycloak.auth-server-url = http://localhost:8080/auth
keycloak.ssl-required = external
keycloak.resource = tutorial-backend
keycloak.bearer-only = true
keycloak.credentials.secret = 123123-1231231-123123-1231
keycloak.cors = true
keycloak.securityConstraints[0].securityCollections[0].name = spring secured api
keycloak.securityConstraints[0].securityCollections[0].authRoles[0] = admin
keycloak.securityConstraints[0].securityCollections[0].authRoles[1] = user
keycloak.securityConstraints[0].securityCollections[0].patterns[0] = /api/*
The sample REST API that I am calling
#RestController
public class SampleController {
#RequestMapping(value ="/api/getSample",method=RequestMethod.GET)
public string home() {
return new string("demo");
}
}
the front end keycloak.json properties include
{
"realm": "demo",
"auth-server-url": "http://localhost:8080/auth",
"ssl-required": "external",
"resource": "tutorial-frontend",
"public-client": true
}
The CORS error that I get
XMLHttpRequest cannot load http://localhost:8090/api/getSample. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:9000' is therefore not allowed access. The response had HTTP status code 401.

Answer 1

I know.. the Problem is quite Old.
But if you've Problems with the local development with Spring Boot + Keycloak you can use the Config
keycloak.cors=true
in your application.properties.
Cheers :)

Answer 2

Try creating your CORS bean like my example. I recently went through the same thing (getting CORS to work) and it was a nightmare because the SpringBoot CORS support is currently not as robust or straightforward as the MVC CORS.
#Bean
public FilterRegistrationBean corsFilter() {
UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
CorsConfiguration config = new CorsConfiguration();
config.setAllowCredentials(true);
config.addAllowedOrigin("*");
config.addAllowedHeader("*");
config.addAllowedMethod("*");
source.registerCorsConfiguration("/**", config);
FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));
bean.setOrder(0);
return bean;
}
This is how I set it up to accept any origin application-wide, but if you change a few of the parameters you should be able to replicate what you want. ie. if you wanted to add only the methods you mentioned, chain some addAllowedMethod(). Allowed origins would be the same, and then your addMapping("/api/*") would become source.registerCorsConfiguration("/api/*", config);.
Edit:
Spring Data Rest and Cors
Take a look at this. Sebastian is on the Spring engineering team so this is about as good as you're going to get for an official answer.

Answer 3

I came here with the same problem and fix it ommiting authentication for OPTIONS method only, like this:
keycloak.securityConstraints[0].security-collections[0].omitted-methods[0]=OPTIONS
It worked for me because the OPTIONS request Keycloack does, does not include Authentication header.
UPDATE
There was something with my browser's cache so I could not see the real impact of a change in my backend code. It looks like what really worked for me was enabling all CORS origins at #RestController level, like this:
#CrossOrigin(origins = "*")
#RestController
public class UsersApi {...}

Answer 4

I don't have access to code examples, but based on the code configurations you have included, it looks like a missing configuration is causing spring to exclude CORS headers.
J. West's response is similar to recent issues I encountered with Spring and CORS, I would however caution you to look into which implementation a spring example references, because there are two. Spring Security and Spring MVC Annotations. Both of these implementations work independent of each other, and can not be combined.
When using the filter based approach as you are (even boiled down), the key was to set allow credentials to true, in order for the authentication headers to be sent by the browser across domains. I would also advise using the full code method proposed above, as this will allow you to create a far more configurable web application for deployment across multiple domains or environments by property injection or a service registry.

Answer 5

Access-Control-Allow-Origin header is supposed to be set by the server application basis the Origin request header provided in the request to the server application. Usually browsers set the Origin header in request whenever they sense a cross origin request being made. And they expect a Access-Control-Allow-Origin header in response to allow it.
Now, for keycloak, I struggled with the same issue. Looking at this, it seems like keycloak does not add Access-Control-Allow-Origin header in case of error response. However, for me it was not adding this header in the response even in case of success response.
Looking into the code and adding breakpoints, I noticed that the webOrigin for client object was not getting populated from the Origin header even if passed and hence CORS was not adding the access control response header.
I was able to get it working by adding the following line of code just before the CORS build call:
client.addWebOrigin(headers.getRequestHeader("Origin").get(0));
before:
Cors.add(request, Response.ok(res, MediaType.APPLICATION_JSON_TYPE)).auth().allowedOrigins(client).allowedMethods("POST").exposedHeaders(Cors.ACCESS_CONTROL_ALLOW_METHODS).build();
Once I built the code with this change and started the server, I started getting the three access control response headers:
Access-Control-Expose-Headers: Access-Control-Allow-Methods
Access-Control-Allow-Origin: http://localhost:9000
Access-Control-Allow-Credentials: true
I am using client credentials grant type; hence i added it only in the buildClientCredentialsGrant at TokenEndpoint.java#L473.
I still need to do some more code diving in order to say for sure that it is a bug for success responses at well and to find a better place to set this on the client object in keycloak code (like where client object is being constructed)
You are welcome to give it a try.
UPDATE:
I take this back. I re-registered my client in keycloak with Root URL as http://localhost:9000 (which is my front-end's application port) and i started getting the proper access control response headers. Hope this helps you.

Answer 6

I know the problem is too old but, I found better solution.
Read more at official documentation
Inside your application.yml file
keycloak:
auth-server-url: http://localhost:8180/auth
realm: CollageERP
resource: collage-erp-web
public-client: true
use-resource-role-mappings: true
cors: true
cors-max-age: 0
principal-attribute: preferred_username
cors-allowed-methods: POST, PUT, DELETE, GET
cors-allowed-headers: X-Requested-With, Content-Type, Authorization, Origin, Accept, Access-Control-Request-Method, Access-Control-Request-Headers
or you can config using application.properties file
keycloak.auth-server-url= http://localhost:8180/auth
keycloak.realm= CollageERP
keycloak.resource= collage-erp-web
keycloak.public-client= true
keycloak.use-resource-role-mappings= true
keycloak.cors= true
keycloak.cors-max-age= 0
keycloak.principal-attribute= preferred_username
keycloak.cors-allowed-methods= POST, PUT, DELETE, GET
keycloak.cors-allowed-headers= X-Requested-With, Content-Type, Authorization, Origin, Accept, Access-Control-Request-Method, Access-Control-Request-Headers
and my java adaper class
import org.keycloak.adapters.KeycloakConfigResolver;
import org.keycloak.adapters.springboot.KeycloakSpringBootConfigResolver;
import org.keycloak.adapters.springsecurity.KeycloakConfiguration;
import org.keycloak.adapters.springsecurity.config.KeycloakWebSecurityConfigurerAdapter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.core.session.SessionRegistryImpl;
import org.springframework.security.web.authentication.session.RegisterSessionAuthenticationStrategy;
import org.springframework.security.web.authentication.session.SessionAuthenticationStrategy;
import javax.ws.rs.HttpMethod;
#KeycloakConfiguration
#EnableGlobalMethodSecurity(jsr250Enabled = true)
public class KeycloakSecurityConfig extends KeycloakWebSecurityConfigurerAdapter {
#Override
protected void configure(HttpSecurity http) throws Exception {
super.configure(http);
http.cors().and().authorizeRequests()
.antMatchers(HttpMethod.OPTIONS).permitAll()
.antMatchers("/api/**")
.authenticated()
.anyRequest().permitAll();
http.csrf().disable();
}
#Autowired
public void configureGlobal(AuthenticationManagerBuilder auth) {
auth.authenticationProvider(keycloakAuthenticationProvider());
}
#Bean
#Override
protected SessionAuthenticationStrategy sessionAuthenticationStrategy() {
return new RegisterSessionAuthenticationStrategy(new SessionRegistryImpl());
}
#Bean
public KeycloakConfigResolver KeycloakConfigResolver() {
return new KeycloakSpringBootConfigResolver();
}
}

Answer 7

I want to share with you the solution that worked for me hoping to help whoever is facing the same issue. I am going to give you two solutions actually.
Spring reactive:
#Configuration
#EnableWebFluxSecurity
public class SecurityConfig {
#Autowired
private ReactiveClientRegistrationRepository clientRegistrationRepository;
#Bean
SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
CorsConfiguration cors_config = new CorsConfiguration();
cors_config.setAllowCredentials(true);
cors_config.applyPermitDefaultValues();
cors_config.setAllowedOrigins(Arrays.asList("http://localhost:3000", "null"));
cors_config.setAllowedMethods(List.of("GET","POST","OPTIONS","DELETE"));
cors_config.setAllowedHeaders(List.of("*"));
http.cors().configurationSource(source -> cors_config)
.and()
.csrf().disable()
.authorizeExchange(exchanges -> exchanges.anyExchange().authenticated())
.oauth2Login()//Setting Oauth2Login
.authenticationSuccessHandler(new RedirectServerAuthenticationSuccessHandler("")).and()
.logout(logout -> logout //Setting Oauth2Logout
.logoutHandler(logoutHandler())
.logoutSuccessHandler(oidcLogoutSuccessHandler()));
return http.build();
}
private ServerLogoutSuccessHandler oidcLogoutSuccessHandler() {
OidcClientInitiatedServerLogoutSuccessHandler oidcLogoutSuccessHandler =
new OidcClientInitiatedServerLogoutSuccessHandler(this.clientRegistrationRepository);
// Sets the location that the End-User's User Agent will be redirected to
// after the logout has been performed at the Provider
oidcLogoutSuccessHandler.setPostLogoutRedirectUri("");
return oidcLogoutSuccessHandler;
}
private DelegatingServerLogoutHandler logoutHandler() {
//Invalidate session on logout
return new DelegatingServerLogoutHandler(
new SecurityContextServerLogoutHandler(), new WebSessionServerLogoutHandler());
}
}
Spring MVC:
#Configuration
public class SecurityConfig {
#Bean
public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
CorsConfiguration cors_config = new CorsConfiguration();
cors_config.setAllowCredentials(true);
cors_config.applyPermitDefaultValues();
cors_config.setAllowedOrigins(Arrays.asList("http://localhost:3000", "null"));
cors_config.setAllowedMethods(List.of("GET","POST","OPTIONS","DELETE"));
cors_config.setAllowedHeaders(List.of("*"));
http.cors().configurationSource(source -> cors_config).and()...
return http.build();
}
}
Be sure to have cors enabled on Keycloak too, navigate to
realm->clients->settings->weborigins
and submit your permitted origins.
If you are sending credentials or cookies in your requests, be sure to configure it, for example, if you are using ReactJS:
const httpConfig = { withCredentials: true };
axios.get('YourUrl', httpConfig)
.then(response => {})
.catch(error => {})
.finally(() => {});

Answer 8

When your client is sending an Authentication header, you cannot use
allowedOrigins("*"). You must configure a specific origin URL.

Answer 9

Since you have set the property keycloak.cors = true in your application.properties file, you have to mention the CORS enabled origins in the Keycloak server. To do that follow the below steps.
Go to Clients -> Select the client (Token owner) -> Settings -> Web Origins
Add origins one by one or add * to allow all.
After doing this you have to get a new token. (If you decode the token you will see your origins as allowed-origins": ["*"])
Setting the property keycloak.cors = false is another option. But this completely disables CORS.