Hi, I’ve been using keycloak to secure the company’s webpage for a while. There’s a new requirement that I use Oracle IDCS IDP. Because the IDP doesn’t support user access level/authorization, I’m forced to use the IDP as Keycloak’s parent IDP. The IDCS supports OpenID Connect 1.0 and so I tried to add it as an external IDP using two of the possible methods i.e. OpenID Connect 1.0 and Keycloak OpenId Connect. Both methods failed at the point where an eccess token was requested with the following stack trace: 09:56:33,923 ERROR [org.keycloak.broker.oidc.AbstractOAuth2IdentityProvider] (default task-15) Failed to make identity provider oauth callback: org.keycloak.broker.provider.IdentityBrokerException: No access_token from server.         at org.keycloak.broker.oidc.OIDCIdentityProvider.verifyAccessToken(OIDCIdentityProvider.java:443)         at org.keycloak.broker.oidc.OIDCIdentityProvider.getFederatedIdentity(OIDCIdentityProvider.java:345)         at org.keycloak.broker.oidc.AbstractOAuth2IdentityProvider$Endpoint.authResponse(AbstractOAuth2IdentityProvider.java:407)         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)         at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)         at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)         at java.lang.reflect.Method.invoke(Method.java:498)         at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:140)         at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:295)         at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:249)         at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:138)         at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:107)         at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:133)         at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:101)         at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:406)         at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:213)         at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:228)         at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56)         at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51)         at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)         at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)         at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)         at org.keycloak.services.filters.KeycloakSessionServletFilter.doFilter(KeycloakSessionServletFilter.java:90)         at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)         at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)         at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)         at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)         at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)         at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)         at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)         at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)         at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)         at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)         at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)         at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)         at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)         at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)         at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)         at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)         at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)         at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)         at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)         at org.wildfly.extension.undertow.deployment.GlobalRequestControllerHandler.handleRequest(GlobalRequestControllerHandler.java:68)         at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)         at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:292)         at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:81)         at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:138)         at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:135)         at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)         at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)         at org.wildfly.extension.undertow.security.SecurityContextThreadSetupAction.lambda$create$0(SecurityContextThreadSetupAction.java:105)         at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1508)         at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1508)         at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1508)         at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1508)         at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272)         at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)         at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104)         at io.undertow.server.Connectors.executeRootHandler(Connectors.java:326)         at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:812)         at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)         at java.lang.Thread.run(Thread.java:748) 09:56:33,948 WARN [org.keycloak.events] (default task-15) type=LOGIN_ERROR, realmId=onesys, clientId=null, userId=null, ipAddress=10.255.0.2, error=identity_provider_login_failure ------------------------------------- I’m not really a Keycloak expert but it seems to me that the protocol breaks because Keycloak and IDCS ‘talks’ different dialects. Could it be that there’s some way to configure it in Keycloak to make it work? Oracle came back with the following, I quote: ·         IDCS OIDC discovery endpoint says this: "token_endpoint_auth_methods_supported": [         "client_secret_basic",         "client_secret_jwt"     ], ·         It seems that when Keycloak is an OIDC RP, it might be ignoring this directive and sending the client_secret in POST body anyways. Please check with Keycloak team if there is a way to configure Keycloak to use one of the IDCS supported ways. This is something that is not our skillset and people with Keycloak knowledge will be more effective in helping you with this. ·         If Keycloak doesn’t support one of these two ways, you will need to raise a ticket with them to provide support for at least one of these ways of client_authentication. ·         On the other hand, IDCS doesn’t yet support “client_secret_post”. There is already an internal bug filed against IDCS for this - BUG 27981356 - TOKEN EXCHANGE SHOULD ACCEPT CLIENT_ID AND CLIENT_SECRET IN POST PAYLOAD. However, it doesn’t seem that the scheduled delivery of this feature will meet your timelines.