keycloak-scim/adapters/oidc/js/src/main/resources/login-status-iframe.html

<script>
    function getCookie(cname)
    {
        var name = cname + "=";
        var ca = document.cookie.split(';');
        for(var i=0; i<ca.length; i++)
        {
            var c = ca[i].trim();
            if (c.indexOf(name)==0) return c.substring(name.length,c.length);
        }
        return null;
    }
    function receiveMessage(event)
    {
        if (event.origin !== "ORIGIN") {
            console.log(event.origin + " does not match built origin");
            return;

        }
        var data = JSON.parse(event.data);
        data.loggedIn = false;
        var cookie = getCookie('KEYCLOAK_SESSION');
        if (cookie) {
            data.loggedIn = true;
            data.session = cookie;
        }

        event.source.postMessage(JSON.stringify(data),
                event.origin);
    }
    window.addEventListener("message", receiveMessage, false);
</script>