I'm working on SAML 2.0 integration on totally clean 18.104.22.168 instance.
Login works properly. However, logout fails with NPE. In logs I see:
19.06.2020 11:32:21.061 *ERROR* [0:0:0:0:0:0:0:1  GET /system/sling/logout.html HTTP/1.1] com.adobe.granite.auth.saml.SamlAuthenticationHandler Unable to perform SAML logout. java.lang.NullPointerException: null at com.adobe.granite.auth.saml.SamlAuthenticationHandler.createLogoutRequest(SamlAuthenticationHandler.java:916) [com.adobe.granite.auth.saml:1.0.10.CQ640-B0012] at com.adobe.granite.auth.saml.SamlAuthenticationHandler.dropCredentials(SamlAuthenticationHandler.java:663) [com.adobe.granite.auth.saml:1.0.10.CQ640-B0012] at org.apache.sling.auth.core.impl.AuthenticationHandlerHolder.doDropCredentials(AuthenticationHandlerHolder.java:95) [org.apache.sling.auth.core:1.4.2] at org.apache.sling.auth.core.impl.AbstractAuthenticationHandlerHolder.dropCredentials(AbstractAuthenticationHandlerHolder.java:103) [org.apache.sling.auth.core:1.4.2]
In settings dropCredentials set to true and logoutUrl is filled with KeyCloak logout URL.
According to my investigation, the handler's code might try to get NameQualifier and SpNameQualifier. SAML 2.0 specification defines these attributes as optional. Also, these attributes are not present in the IdP response.
I'm confused since I have just two logout-related configuration options and there is nothing I can do more.
that looks really strange; when I look at the code that mentioned line it makes me think that the request doesn't have an assertion at all (unfortunately there a number of chances where a NPE can occur).
Please raise a request with support and report your problem (at best including the relevant details about the SAML assertion attached to the request).
The saml response XML gets stored in encrypted form under the user node. That xml isn't complying with the xmil structure that the createLogoutRequest method expects. So we might need to do some debugging there.