user-fn

Specifies the name of the user-provided function that to be used to perform authentication in place of the built-in authentication. If authentication succeeds, the function returns REQ-PROCEED and if authentication fails, it returns REQ-NOACTION.

userdb

Specifies the full path and base file name of the user database in the server’s native format. The native format is a system DBM file, which is a hashed file format allowing instantaneous access to large numbers of users.