Show info page after successful logout, including a link to the passed service url

 src/main/java/org/keycloak/protocol/cas/CASLoginProtocol.java

@@ -5,6 +5,7 @@
import org.keycloak.common.util.KeycloakUriBuilder;
import org.keycloak.events.EventBuilder;
import org.keycloak.events.EventType;
import org.keycloak.forms.login.LoginFormsProvider;
import org.keycloak.models.*;
import org.keycloak.protocol.LoginProtocol;
import org.keycloak.protocol.cas.utils.LogoutHelper;
@@ -32,6 +33,8 @@

    public static final String SERVICE_TICKET_PREFIX = "ST-";
    public static final String SESSION_SERVICE_TICKET = "service_ticket";

    public static final String LOGOUT_REDIRECT_URI = "CAS_LOGOUT_REDIRECT_URI";

    protected KeycloakSession session;
    protected RealmModel realm;
@@ -131,9 +134,17 @@

    @Override
    public Response finishLogout(UserSessionModel userSession) {
        String redirectUri = userSession.getNote(CASLoginProtocol.LOGOUT_REDIRECT_URI);

        event.event(EventType.LOGOUT);
        event.user(userSession.getUser()).session(userSession).success();
        return Response.ok().build();
        LoginFormsProvider infoPage = session.getProvider(LoginFormsProvider.class).setSuccess("Logout successful");
        if (redirectUri != null) {
            infoPage.setAttribute("pageRedirectUri", redirectUri);
        } else {
            infoPage.setAttribute("skipLink", true);
        }
        return infoPage.createInfoPage();
    }

    @Override

 src/main/java/org/keycloak/protocol/cas/endpoints/LogoutEndpoint.java

@@ -5,13 +5,18 @@
import org.jboss.resteasy.spi.HttpRequest;
import org.keycloak.common.ClientConnection;
import org.keycloak.events.EventBuilder;
import org.keycloak.models.ClientModel;
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.RealmModel;
import org.keycloak.models.UserSessionModel;
import org.keycloak.protocol.cas.CASLoginProtocol;
import org.keycloak.protocol.oidc.utils.RedirectUtils;
import org.keycloak.services.ErrorPage;
import org.keycloak.services.managers.AuthenticationManager;
import org.keycloak.services.messages.Messages;

import javax.ws.rs.GET;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.Response;
@@ -37,6 +42,8 @@

    private RealmModel realm;
    private EventBuilder event;
    private ClientModel client;
    private String redirectUri;

    public LogoutEndpoint(RealmModel realm, EventBuilder event) {
        this.realm = realm;
@@ -45,18 +52,36 @@

    @GET
    @NoCache
    public Response logout() {
    public Response logout(@QueryParam(CASLoginProtocol.SERVICE_PARAM) String service) {
        checkClient(service);

        AuthenticationManager.AuthResult authResult = AuthenticationManager.authenticateIdentityCookie(session, realm, false);
        if (authResult != null) {
            UserSessionModel userSession = authResult.getSession();
            userSession.setNote(AuthenticationManager.KEYCLOAK_LOGOUT_PROTOCOL, CASLoginProtocol.LOGIN_PROTOCOL);
            if (redirectUri != null) userSession.setNote(CASLoginProtocol.LOGOUT_REDIRECT_URI, redirectUri);

            logger.debug("Initiating CAS browser logout");
            Response response =  AuthenticationManager.browserLogout(session, realm, authResult.getSession(), uriInfo, clientConnection, headers);
            logger.debug("finishing CAS browser logout");
            return response;
        }
        return Response.ok().build();
        return ErrorPage.error(session, Messages.FAILED_LOGOUT);
    }

    private void checkClient(String service) {
        if (service == null) {
            return;
        }

        client = realm.getClients().stream()
                .filter(c -> CASLoginProtocol.LOGIN_PROTOCOL.equals(c.getProtocol()))
                .filter(c -> RedirectUtils.verifyRedirectUri(uriInfo, service, realm, c) != null)
                .findFirst().orElse(null);
        if (client != null) {
            redirectUri = RedirectUtils.verifyRedirectUri(uriInfo, service, realm, client);

            session.getContext().setClient(client);
        }
    }
}