Apache HTTPD can authenticate to NCSA LDAP by using the mod_authnz_ldap module. Below are some example configurations using this module.
Apache 2.2 Examples
Allow access to any valid user:
Allow access to a specific LDAP group:
Multiple groups can be specified by repeating the
Require ldap-group line for each group that should have access.
Note that Apache caches LDAP queries for 10 minutes, so if you're testing things it could take ten minutes for your LDAP change to show up.
Apache 2.4 Example
Allow access to any NCSA user who is not disabled:
To create the SSL certificate file (used at top of previous example) you can run the following: