The OAuth 2.0 Login feature provides an application with the capability to have users log in to the application by using their existing account at an OAuth 2.0 Provider (e.g. GitHub) or OpenID Connect 1.0 Provider (such as Google).
NOTE: OAuth 2.0 Login is implemented by using the *Authorization Code Grant*, as specified in the https://tools.ietf.org/html/rfc6749#section-4.1[OAuth 2.0 Authorization Framework] and https://openid.net/specs/openid-connect-core-1_0.html#CodeFlowAuth[OpenID Connect Core 1.0].
This section shows how to configure the {gh-samples-url}/reactive/webflux/java/oauth2/login[*OAuth 2.0 Login WebFlux sample*] using _Google_ as the _Authentication Provider_ and covers the following topics:
NOTE: https://developers.google.com/identity/protocols/OpenIDConnect[Google's OAuth 2.0 implementation] for authentication conforms to the https://openid.net/connect/[OpenID Connect 1.0] specification and is https://openid.net/certification/[OpenID Certified].
Follow the instructions on the https://developers.google.com/identity/protocols/OpenIDConnect[OpenID Connect] page, starting in the section, "Setting up OAuth 2.0".
After completing the "Obtain OAuth 2.0 credentials" instructions, you should have a new OAuth Client with credentials consisting of a Client ID and a Client Secret.
The redirect URI is the path in the application that the end-user's user-agent is redirected back to after they have authenticated with Google and have granted access to the OAuth Client _(<<webflux-oauth2-login-sample-setup,created in the previous step>>)_ on the Consent page.
IMPORTANT: If the OAuth Client is running behind a proxy server, it is recommended to check xref:features/exploits/http.adoc#http-proxy-server[Proxy Server Configuration] to ensure the application is correctly configured.
Also, see the supported xref:reactive/oauth2/client/authorization-grants.adoc#oauth2Client-auth-code-redirect-uri[ `URI` template variables] for `redirect-uri`.
<2> Following the base property prefix is the ID for the xref:reactive/oauth2/client/core.adoc#oauth2Client-client-registration[`ClientRegistration`], such as google.
At this point, the OAuth Client retrieves your email address and basic profile information from the https://openid.net/specs/openid-connect-core-1_0.html#UserInfo[UserInfo Endpoint] and establishes an authenticated session.
The following table outlines the mapping of the Spring Boot 2.x OAuth Client properties to the xref:reactive/oauth2/client/core.adoc#oauth2Client-client-registration[ClientRegistration] properties.
A `ClientRegistration` can be initially configured using discovery of an OpenID Connect Provider's https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfig[Configuration endpoint] or an Authorization Server's https://tools.ietf.org/html/rfc8414#section-3[Metadata endpoint], by specifying the `spring.security.oauth2.client.provider._[providerId]_.issuer-uri` property.
[[webflux-oauth2-login-common-oauth2-provider]]
== CommonOAuth2Provider
`CommonOAuth2Provider` pre-defines a set of default client properties for a number of well known providers: Google, GitHub, Facebook, and Okta.
For example, the `authorization-uri`, `token-uri`, and `user-info-uri` do not change often for a Provider.
Therefore, it makes sense to provide default values in order to reduce the required configuration.
As demonstrated previously, when we <<webflux-oauth2-login-sample-config,configured a Google client>>, only the `client-id` and `client-secret` properties are required.
The auto-defaulting of client properties works seamlessly here because the `registrationId` (`google`) matches the `GOOGLE` `enum` (case-insensitive) in `CommonOAuth2Provider`.
For cases where you may want to specify a different `registrationId`, such as `google-login`, you can still leverage auto-defaulting of client properties by configuring the `provider` property.
The following listing shows an example:
[source,yaml]
----
spring:
security:
oauth2:
client:
registration:
google-login: <1>
provider: google <2>
client-id: google-client-id
client-secret: google-client-secret
----
<1> The `registrationId` is set to `google-login`.
<2> The `provider` property is set to `google`, which will leverage the auto-defaulting of client properties set in `CommonOAuth2Provider.GOOGLE.getBuilder()`.
There are some OAuth 2.0 Providers that support multi-tenancy, which results in different protocol endpoints for each tenant (or sub-domain).
For example, an OAuth Client registered with Okta is assigned to a specific sub-domain and have their own protocol endpoints.
For these cases, Spring Boot 2.x provides the following base property for configuring custom provider properties: `spring.security.oauth2.client.provider._[providerId]_`.
The following example shows how to register a `SecurityWebFilterChain` `@Bean` with `@EnableWebFluxSecurity` and enable OAuth 2.0 login through `serverHttpSecurity.oauth2Login()`:
.OAuth2 Login Configuration
====
.Java
[source,java,role="primary"]
----
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {
@Bean
public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
http
.authorizeExchange(authorize -> authorize
.anyExchange().authenticated()
)
.oauth2Login(withDefaults());
return http.build();
}
}
----
.Kotlin
[source,kotlin,role="secondary"]
----
@EnableWebFluxSecurity
class OAuth2LoginSecurityConfig {
@Bean
fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
The following example shows how to completely override the auto-configuration by registering a `ReactiveClientRegistrationRepository` `@Bean` and a `SecurityWebFilterChain` `@Bean`.
If you are not able to use Spring Boot 2.x and would like to configure one of the pre-defined providers in `CommonOAuth2Provider` (for example, Google), apply the following configuration:
.OAuth2 Login Configuration
====
.Java
[source,java,role="primary"]
----
@EnableWebFluxSecurity
public class OAuth2LoginConfig {
@Bean
public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
http
.authorizeExchange(authorize -> authorize
.anyExchange().authenticated()
)
.oauth2Login(withDefaults());
return http.build();
}
@Bean
public ReactiveClientRegistrationRepository clientRegistrationRepository() {
return new InMemoryReactiveClientRegistrationRepository(this.googleClientRegistration());
}
@Bean
public ReactiveOAuth2AuthorizedClientService authorizedClientService(
The OAuth 2.0 Authorization Framework defines the https://tools.ietf.org/html/rfc6749#section-3[Protocol Endpoints] as follows:
The authorization process utilizes two authorization server endpoints (HTTP resources):
* Authorization Endpoint: Used by the client to obtain authorization from the resource owner via user-agent redirection.
* Token Endpoint: Used by the client to exchange an authorization grant for an access token, typically with client authentication.
As well as one client endpoint:
* Redirection Endpoint: Used by the authorization server to return responses containing authorization credentials to the client via the resource owner user-agent.
The OpenID Connect Core 1.0 specification defines the https://openid.net/specs/openid-connect-core-1_0.html#UserInfo[UserInfo Endpoint] as follows:
The UserInfo Endpoint is an OAuth 2.0 Protected Resource that returns claims about the authenticated end-user.
To obtain the requested claims about the end-user, the client makes a request to the UserInfo Endpoint by using an access token obtained through OpenID Connect Authentication.
These claims are normally represented by a JSON object that contains a collection of name-value pairs for the claims.
`ServerHttpSecurity.oauth2Login()` provides a number of configuration options for customizing OAuth 2.0 Login.
The following code shows the complete configuration options available for the `oauth2Login()` DSL:
By default, the OAuth 2.0 Login Page is auto-generated by the `LoginPageGeneratingWebFilter`.
The default login page shows each configured OAuth Client with its `ClientRegistration.clientName` as a link, which is capable of initiating the Authorization Request (or OAuth 2.0 Login).
In order for `LoginPageGeneratingWebFilter` to show links for configured OAuth Clients, the registered `ReactiveClientRegistrationRepository` needs to also implement `Iterable<ClientRegistration>`.
See `InMemoryReactiveClientRegistrationRepository` for reference.
The link's destination for each OAuth Client defaults to the following:
To override the default login page, configure the `exceptionHandling().authenticationEntryPoint()` and (optionally) `oauth2Login().authorizationRequestResolver()`.
The Redirection Endpoint is used by the Authorization Server for returning the Authorization Response (which contains the authorization credentials) to the client via the Resource Owner user-agent.
[TIP]
OAuth 2.0 Login leverages the Authorization Code Grant.
Therefore, the authorization credential is the authorization code.
The default Authorization Response redirection endpoint is `/login/oauth2/code/{registrationId}`.
If you would like to customize the Authorization Response redirection endpoint, configure it as shown in the following example:
.Redirection Endpoint Configuration
====
.Java
[source,java,role="primary"]
----
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {
@Bean
public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
After the user successfully authenticates with the OAuth 2.0 Provider, the `OAuth2User.getAuthorities()` (or `OidcUser.getAuthorities()`) may be mapped to a new set of `GrantedAuthority` instances, which will be supplied to `OAuth2AuthenticationToken` when completing the authentication.
[TIP]
`OAuth2AuthenticationToken.getAuthorities()` is used for authorizing requests, such as in `hasRole('USER')` or `hasRole('ADMIN')`.
There are a couple of options to choose from when mapping user authorities:
* <<webflux-oauth2-login-advanced-map-authorities-grantedauthoritiesmapper, Using a GrantedAuthoritiesMapper>>
* <<webflux-oauth2-login-advanced-map-authorities-reactiveoauth2userservice, Delegation-based strategy with ReactiveOAuth2UserService>>
===== Delegation-based strategy with ReactiveOAuth2UserService
This strategy is advanced compared to using a `GrantedAuthoritiesMapper`, however, it's also more flexible as it gives you access to the `OAuth2UserRequest` and `OAuth2User` (when using an OAuth 2.0 UserService) or `OidcUserRequest` and `OidcUser` (when using an OpenID Connect 1.0 UserService).
The `OAuth2UserRequest` (and `OidcUserRequest`) provides you access to the associated `OAuth2AccessToken`, which is very useful in the cases where the _delegator_ needs to fetch authority information from a protected resource before it can map the custom authorities for the user.
`DefaultReactiveOAuth2UserService` is an implementation of a `ReactiveOAuth2UserService` that supports standard OAuth 2.0 Provider's.
[NOTE]
`ReactiveOAuth2UserService` obtains the user attributes of the end-user (the resource owner) from the UserInfo Endpoint (by using the access token granted to the client during the authorization flow) and returns an `AuthenticatedPrincipal` in the form of an `OAuth2User`.
`DefaultReactiveOAuth2UserService` uses a `WebClient` when requesting the user attributes at the UserInfo Endpoint.
If you need to customize the pre-processing of the UserInfo Request and/or the post-handling of the UserInfo Response, you will need to provide `DefaultReactiveOAuth2UserService.setWebClient()` with a custom configured `WebClient`.
Whether you customize `DefaultReactiveOAuth2UserService` or provide your own implementation of `ReactiveOAuth2UserService`, you'll need to configure it as shown in the following example:
`OidcReactiveOAuth2UserService` is an implementation of a `ReactiveOAuth2UserService` that supports OpenID Connect 1.0 Provider's.
The `OidcReactiveOAuth2UserService` leverages the `DefaultReactiveOAuth2UserService` when requesting the user attributes at the UserInfo Endpoint.
If you need to customize the pre-processing of the UserInfo Request and/or the post-handling of the UserInfo Response, you will need to provide `OidcReactiveOAuth2UserService.setOauth2UserService()` with a custom configured `ReactiveOAuth2UserService`.
Whether you customize `OidcReactiveOAuth2UserService` or provide your own implementation of `ReactiveOAuth2UserService` for OpenID Connect 1.0 Provider's, you'll need to configure it as shown in the following example:
====
.Java
[source,java,role="primary"]
----
@EnableWebFluxSecurity
public class OAuth2LoginSecurityConfig {
@Bean
public SecurityWebFilterChain securityWebFilterChain(ServerHttpSecurity http) {
http
...
.oauth2Login(withDefaults());
return http.build();
}
@Bean
public ReactiveOAuth2UserService<OidcUserRequest, OidcUser> oidcUserService() {
fun securityWebFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
http {
oauth2Login { }
}
return http.build()
}
@Bean
fun oidcUserService(): ReactiveOAuth2UserService<OidcUserRequest, OidcUser> {
// ...
}
}
----
====
[[webflux-oauth2-login-advanced-idtoken-verify]]
=== ID Token Signature Verification
OpenID Connect 1.0 Authentication introduces the https://openid.net/specs/openid-connect-core-1_0.html#IDToken[ID Token], which is a security token that contains Claims about the Authentication of an End-User by an Authorization Server when used by a Client.
The ID Token is represented as a https://tools.ietf.org/html/rfc7519[JSON Web Token] (JWT) and MUST be signed using https://tools.ietf.org/html/rfc7515[JSON Web Signature] (JWS).
The `ReactiveOidcIdTokenDecoderFactory` provides a `ReactiveJwtDecoder` used for `OidcIdToken` signature verification. The default algorithm is `RS256` but may be different when assigned during client registration.
For these cases, a resolver may be configured to return the expected JWS algorithm assigned for a specific client.
The JWS algorithm resolver is a `Function` that accepts a `ClientRegistration` and returns the expected `JwsAlgorithm` for the client, eg. `SignatureAlgorithm.RS256` or `MacAlgorithm.HS256`
The following code shows how to configure the `OidcIdTokenDecoderFactory` `@Bean` to default to `MacAlgorithm.HS256` for all `ClientRegistration`:
For MAC based algorithms such as `HS256`, `HS384` or `HS512`, the `client-secret` corresponding to the `client-id` is used as the symmetric key for signature verification.
[TIP]
If more than one `ClientRegistration` is configured for OpenID Connect 1.0 Authentication, the JWS algorithm resolver may evaluate the provided `ClientRegistration` to determine which algorithm to return.
[[webflux-oauth2-login-advanced-oidc-logout]]
=== OpenID Connect 1.0 Logout
OpenID Connect Session Management 1.0 allows the ability to log out the End-User at the Provider using the Client.
One of the strategies available is https://openid.net/specs/openid-connect-session-1_0.html#RPLogout[RP-Initiated Logout].
If the OpenID Provider supports both Session Management and https://openid.net/specs/openid-connect-discovery-1_0.html[Discovery], the client may obtain the `end_session_endpoint` `URL` from the OpenID Provider's https://openid.net/specs/openid-connect-session-1_0.html#OPMetadata[Discovery Metadata].
This can be achieved by configuring the `ClientRegistration` with the `issuer-uri`, as in the following example:
[source,yaml]
----
spring:
security:
oauth2:
client:
registration:
okta:
client-id: okta-client-id
client-secret: okta-client-secret
...
provider:
okta:
issuer-uri: https://dev-1234.oktapreview.com
----
...and the `OidcClientInitiatedServerLogoutSuccessHandler`, which implements RP-Initiated Logout, may be configured as follows:
