[[oauth2client]]
= OAuth 2.0 Client
:page-section-summary-toc: 1

The OAuth 2.0 Client features provide support for the Client role as defined in the https://tools.ietf.org/html/rfc6749#section-1.1[OAuth 2.0 Authorization Framework].

At a high-level, the core features available are:

.Authorization Grant support
* https://tools.ietf.org/html/rfc6749#section-1.3.1[Authorization Code]
* https://tools.ietf.org/html/rfc6749#section-6[Refresh Token]
* https://tools.ietf.org/html/rfc6749#section-1.3.4[Client Credentials]
* https://tools.ietf.org/html/rfc6749#section-1.3.3[Resource Owner Password Credentials]
* https://datatracker.ietf.org/doc/html/rfc7523#section-2.1[JWT Bearer]

.Client Authentication support
* https://datatracker.ietf.org/doc/html/rfc7523#section-2.2[JWT Bearer]

.HTTP Client support
* xref:servlet/oauth2/client/authorized-clients.adoc#oauth2Client-webclient-servlet[`WebClient` integration for Servlet Environments] (for requesting protected resources)

The `HttpSecurity.oauth2Client()` DSL provides a number of configuration options for customizing the core components used by OAuth 2.0 Client.
In addition, `HttpSecurity.oauth2Client().authorizationCodeGrant()` enables the customization of the Authorization Code grant.

The following code shows the complete configuration options provided by the `HttpSecurity.oauth2Client()` DSL:

.OAuth2 Client Configuration Options
[tabs]
======
Java::
+
[source,java,role="primary"]
----
@Configuration
@EnableWebSecurity
public class OAuth2ClientSecurityConfig {

	@Bean
	public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
		http
			.oauth2Client(oauth2 -> oauth2
				.clientRegistrationRepository(this.clientRegistrationRepository())
				.authorizedClientRepository(this.authorizedClientRepository())
				.authorizedClientService(this.authorizedClientService())
				.authorizationCodeGrant(codeGrant -> codeGrant
					.authorizationRequestRepository(this.authorizationRequestRepository())
					.authorizationRequestResolver(this.authorizationRequestResolver())
					.accessTokenResponseClient(this.accessTokenResponseClient())
				)
			);
		return http.build();
	}
}
----

Kotlin::
+
[source,kotlin,role="secondary"]
----
@Configuration
@EnableWebSecurity
class OAuth2ClientSecurityConfig {

    @Bean
    open fun filterChain(http: HttpSecurity): SecurityFilterChain {
        http {
            oauth2Client {
                clientRegistrationRepository = clientRegistrationRepository()
                authorizedClientRepository = authorizedClientRepository()
                authorizedClientService = authorizedClientService()
                authorizationCodeGrant {
                    authorizationRequestRepository = authorizationRequestRepository()
                    authorizationRequestResolver = authorizationRequestResolver()
                    accessTokenResponseClient = accessTokenResponseClient()
                }
            }
        }
        return http.build()
    }
}
----
======

In addition to the `HttpSecurity.oauth2Client()` DSL, XML configuration is also supported.

The following code shows the complete configuration options available in the xref:servlet/appendix/namespace/http.adoc#nsa-oauth2-client[ security namespace]:

.OAuth2 Client XML Configuration Options
[source,xml]
----
<http>
	<oauth2-client client-registration-repository-ref="clientRegistrationRepository"
				   authorized-client-repository-ref="authorizedClientRepository"
				   authorized-client-service-ref="authorizedClientService">
		<authorization-code-grant
				authorization-request-repository-ref="authorizationRequestRepository"
				authorization-request-resolver-ref="authorizationRequestResolver"
				access-token-response-client-ref="accessTokenResponseClient"/>
	</oauth2-client>
</http>
----

The `OAuth2AuthorizedClientManager` is responsible for managing the authorization (or re-authorization) of an OAuth 2.0 Client, in collaboration with one or more `OAuth2AuthorizedClientProvider`(s).

The following code shows an example of how to register an `OAuth2AuthorizedClientManager` `@Bean` and associate it with an `OAuth2AuthorizedClientProvider` composite that provides support for the `authorization_code`, `refresh_token`, `client_credentials`, and `password` authorization grant types:

[tabs]
======
Java::
+
[source,java,role="primary"]
----
@Bean
public OAuth2AuthorizedClientManager authorizedClientManager(
		ClientRegistrationRepository clientRegistrationRepository,
		OAuth2AuthorizedClientRepository authorizedClientRepository) {

	OAuth2AuthorizedClientProvider authorizedClientProvider =
			OAuth2AuthorizedClientProviderBuilder.builder()
					.authorizationCode()
					.refreshToken()
					.clientCredentials()
					.password()
					.build();

	DefaultOAuth2AuthorizedClientManager authorizedClientManager =
			new DefaultOAuth2AuthorizedClientManager(
					clientRegistrationRepository, authorizedClientRepository);
	authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider);

	return authorizedClientManager;
}
----

Kotlin::
+
[source,kotlin,role="secondary"]
----
@Bean
fun authorizedClientManager(
        clientRegistrationRepository: ClientRegistrationRepository,
        authorizedClientRepository: OAuth2AuthorizedClientRepository): OAuth2AuthorizedClientManager {
    val authorizedClientProvider: OAuth2AuthorizedClientProvider = OAuth2AuthorizedClientProviderBuilder.builder()
            .authorizationCode()
            .refreshToken()
            .clientCredentials()
            .password()
            .build()
    val authorizedClientManager = DefaultOAuth2AuthorizedClientManager(
            clientRegistrationRepository, authorizedClientRepository)
    authorizedClientManager.setAuthorizedClientProvider(authorizedClientProvider)
    return authorizedClientManager
}
----
======