updaterpms obtains the the copies of the RPMs for installation from an NFS-mounted repository. This repository is replicated on several servers by an LCFG subsystem script which synchronises the copies before the nightly update.
A program called rpmsubmit allows authorised users to submit new RPMs into the master repository. This is capable of insisting on valid PGP signatures, and ensuring that corresponding source RPMs are available for all submitted RPMs. Currently, rpmsubmit uses NFS to copy the files into the repository, but this is not ideal because signature verification occurs on the submitting client; we would like to rewrite this an a client-server application.