Greetings,
For anyone who needs to authenticate API users via LDAP and apply role permissions, the LAC documentation covers this but as of a few days ago the LDAP Auth provider javascript was taken down from EspressoLogic Github. I've found that code very useful so I'm attaching it here.
I've also adapted the code and tested it with MS Active Directory, the original (SimpleLDAPAuthProvider.js) has trouble reading group membership in AD but works well with other LDAP directories (tested with CA Directory). I've provided both attached here.