The Clarens web services architecture

Clarens is a uniquely flexible web services infrastructure providing a unified access protocol to a diverse set of functions useful to the HEP community. It uses the standard HTTP protocol combined with application layer, certificate based authentication to provide single sign-on to individuals, organizations and hosts, with fine-grained access control to services, files and virtual organization (VO) management. This contribution describes the server functionality, while client applications are described in a subsequent talk.