Spring Boot error: "No converter found capable of converting from type [java.lang.String] to type [....client.OAuth2ClientProperties$Registration]"

Question

application.yaml

security:
    oauth2:
      resourceserver:
        jwt:
          issuer-uri: <okta issuer uri>
      client:
        registration:
          internal-client: okta
          client-id: <My- client id>
          client-secret: <My client secret>
          authorization-grant-type: client_credentails
          scope: internal
        provider:
          okta:
            issuer-uri: <okta issuer uri>
            
          
        
okta:
  oauth2:
    issuer: <okta issuer uri>
    audience: api://default

Above code is my application.yaml file of spring boot application.

package DemoService.ConfigClasses;

import java.util.ArrayList;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
import org.springframework.security.oauth2.client.OAuth2AuthorizedClientProvider;
import org.springframework.security.oauth2.client.OAuth2AuthorizedClientProviderBuilder;
import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
import org.springframework.security.oauth2.client.web.DefaultOAuth2AuthorizedClientManager;
import org.springframework.security.oauth2.client.web.OAuth2AuthorizedClientRepository;
import org.springframework.web.client.RestTemplate;

import DemoService.ConfigClasses.Interceptors.RestTemplateInterceptor;

@Configuration
public class DemoConf {

    @Autowired
    private ClientRegistrationRepository clientRegistrationRepository;
    @Autowired
    private OAuth2AuthorizedClientRepository oAuth2AuthorizedClientRepository;
    
    @Bean
    public RestTemplate restTemplate() {
        RestTemplate restTemplate= new RestTemplate();
        List<ClientHttpRequestInterceptor> interceptor=new ArrayList<>();
        interceptor.add(new RestTemplateInterceptor(manager(clientRegistrationRepository,oAuth2AuthorizedClientRepository)));
        return restTemplate;
    }
    @Bean
    public OAuth2AuthorizedClientManager manager(ClientRegistrationRepository clientRegistrationRepository,
            OAuth2AuthorizedClientRepository auth2AuthorizedClientRepository) {
        OAuth2AuthorizedClientProvider provider=OAuth2AuthorizedClientProviderBuilder.builder().clientCredentials().build();
        DefaultOAuth2AuthorizedClientManager defaultOAuth2AuthorizedClientManager=new DefaultOAuth2AuthorizedClientManager(clientRegistrationRepository, auth2AuthorizedClientRepository);
        defaultOAuth2AuthorizedClientManager.setAuthorizedClientProvider(provider);
        return defaultOAuth2AuthorizedClientManager;
    }

}

It is my configuration class

package DemoService.ConfigClasses;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
import org.springframework.security.config.annotation.web.reactive.EnableWebFluxSecurity;
import org.springframework.security.config.web.server.ServerHttpSecurity;
import org.springframework.security.web.SecurityFilterChain;
import org.springframework.security.web.server.SecurityWebFilterChain;

@Configuration
@EnableWebFluxSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class WebSecurityConfig {

    @Bean
    public SecurityWebFilterChain securityFilterChain(ServerHttpSecurity httpSecurity) {
        httpSecurity.authorizeExchange()
                    .anyExchange()
                    .authenticated()
                    .and()
                    .oauth2ResourceServer()
                    .jwt();
        
        return httpSecurity.build();
    }
}

web security config class

package DemoService.ConfigClasses.Interceptors;

import java.io.IOException;

import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.security.oauth2.client.OAuth2AuthorizeRequest;
import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;

public class RestTemplateInterceptor implements ClientHttpRequestInterceptor{

    private OAuth2AuthorizedClientManager manager;
    
    
    
    public RestTemplateInterceptor(OAuth2AuthorizedClientManager manager) {
        super();
        this.manager = manager;
    }



    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution)
            throws IOException {
        String token=manager.authorize(OAuth2AuthorizeRequest.withClientRegistrationId("internal-client").principal("internal").build()).getAccessToken().getTokenValue();
        
        request.getHeaders().add("Authorization", "Bearer "+token);
        return execution.execute(request, body);
    }
    
}

Rest Template interceptor class

I am trying to create a internal service and add spring security with okta oauth2 for securing the service. I am implementing token based authorization for this service. While starting the service the following error is showing:

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v3.1.9)

2024-03-24T12:26:08.837+05:30  INFO 11772 --- [           main] DemoService.DemoServApplication          : Starting DemoServApplication using Java 17.0.3 with PID 11772 (C:\Users\lenovo\Downloads\DemoServ\DemoServ\target\classes started by lenovo in C:\Users\lenovo\Downloads\DemoServ\DemoServ)
2024-03-24T12:26:08.843+05:30  INFO 11772 --- [           main] DemoService.DemoServApplication          : No active profile set, falling back to 1 default profile: "default"
2024-03-24T12:26:10.280+05:30  WARN 11772 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanDefinitionStoreException: Failed to process import candidates for configuration class [org.springframework.boot.autoconfigure.security.oauth2.client.servlet.OAuth2ClientAutoConfiguration]: Error processing condition on org.springframework.boot.autoconfigure.security.oauth2.client.servlet.OAuth2ClientRegistrationRepositoryConfiguration
2024-03-24T12:26:10.314+05:30  INFO 11772 --- [           main] .s.b.a.l.ConditionEvaluationReportLogger : 

Error starting ApplicationContext. To display the condition evaluation report re-run your application with 'debug' enabled.
2024-03-24T12:26:10.413+05:30 ERROR 11772 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to bind properties under 'spring.security.oauth2.client.registration.internal-client' to org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientProperties$Registration:

    Reason: org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [java.lang.String] to type [org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientProperties$Registration]

Action:

Update your application's configuration

Answer 1

You have at least two mistakes in your properties:

• one level is missing under registration property: the registration-id you later reference as internal-client
• in your registration, you reference the provider with internal-client (instead of provider)

The cause for your current exception is that in org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientProperties, registration is defined as a Map<String, Registration> (where the key is the registration-id), not as just one Registration.

Try:

okta-issuer: change-me
internal-client-id: change-me
internal-client-secret: change-me

security:
    oauth2:
      resourceserver:
        jwt:
          issuer-uri: ${okta-issuer}
      client:
        registration:
          internal-client:
            provider: okta
            client-id: ${internal-client-id}
            client-secret: ${internal-client-secret}
            authorization-grant-type: client_credentails
            scope: internal
        provider:
          okta:
            issuer-uri: ${okta-issuer}