We are facing an issue and I will try to explain it the best that I can.
We have a working configuration using Jira with CAS for one client (in the diagram the green square), and now what we want is to integrate Confluence with Jira but using local authentication. When we test this it works from Jira to Confluence but not from Confluence to Jira. Is there a way to isolate the authentication methods? So that we can use Jira with CAS and apart Jira with Confluence using local authentication.

2018-08-14 10:30:25,839 https-jsse-nio-8443-exec-3 ERROR [o.a.c.c.C.[.[localhost].[/].[default]] Servlet.service() para servlet default lanzó excepción
java.lang.NullPointerException
at com.atlassian.jira.security.login.JiraSeraphAuthenticator.getUserFromBasicAuthentication(JiraSeraphAuthenticator.java:149)
at com.atlassian.seraph.auth.DefaultAuthenticator.getUser(DefaultAuthenticator.java:339)
at org.jasig.cas.client.integration.atlassian.Jira44CasAuthenticator.getUser(Jira44CasAuthenticator.java:76)
at com.atlassian.seraph.auth.AbstractAuthenticator.getUser(AbstractAuthenticator.java:45)
at com.atlassian.seraph.filter.BaseLoginFilter$SecurityHttpRequestWrapper.getUserPrincipal(BaseLoginFilter.java:238)
... 1 filtered
at javax.servlet.http.HttpServletRequestWrapper.getRemoteUser(HttpServletRequestWrapper.java:168)
... 27 filtered
at com.atlassian.jira.security.JiraSecurityFilter.lambda$doFilter$0(JiraSecurityFilter.java:76)
... 1 filtered
at com.atlassian.jira.security.JiraSecurityFilter.doFilter(JiraSecurityFilter.java:74)
... 10 filtered
at org.jasig.cas.client.session.SingleSignOutFilter.doFilter(SingleSignOutFilter.java:100)
... 8 filtered
at com.atlassian.plugins.rest.module.servlet.RestSeraphFilter.doFilter(RestSeraphFilter.java:37)
... 3 filtered
Does anyone been through something like this? any help you could give us? Thanks!