Spring Security 5 OAuth2 select a client programmatically - spring

Question

I have an application with Spring Security 5 OAuth2 support. I have a number of OAuth2 clients to select from. I would like to execute programatic logic and, based on the incoming request, to select the target client. Now I got it to work using a custom login page and executing the logic in this custom page's controller.
In my configuration:
#Bean
public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
logger.info("SecurityConfig.filterChain(): Entry ...");
http.authorizeRequests(authorizeRequests -> {
try {
authorizeRequests.antMatchers("/oauth2/custom-login-page").permitAll().anyRequest().authenticated().and().
oauth2Login().loginPage("/oauth2/custom-login-page");
}
catch (Exception exception) {
exception.printStackTrace();
}
});
return http.build();
}
In the controller:
#GetMapping("/oauth2/custom-login-page")
public String getCustomLoginPage(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, HttpSession httpSession, Model model) throws Exception {
String targetClientRegistrationID = null;
// Custom logic to pick registrationId
...
return "redirect:/oauth2/authorization/" + targetClientRegistrationID;
}
I would like to confirm that this is the right way to do it. If not, what would be the right/alternative way(s) to wire in such selection logic.
Thank you!

Answer 1

You can specify multiple oauth2 providers in the config (fe: application.yml) file and it should be handled by the framework:
spring:
security:
oauth2:
client:
registration:
<custom-oauth-name>:
client-id: <client-id>
client-secret: <secret>
provider:
<custom-oauth-name>:
issuer-uri: https://accounts.google.com
More you can read here https://www.baeldung.com/spring-security-openid-connect#discovery