Ok... so in case anyone else faces this issue, note that you need to use a different port. According to (https://lists.internet2.edu/sympa/arc/shibboleth-users/2008-06/msg00039.html), you need to use port 3268 for regular GC LDAP. Changing this was all I needed to do to go from errors, no logon, etc. to working. This is not in the Spring documentation, in fact in the Spring documentation it directs you to use the standard LDAP port of 389...