A CVS-Server Security Architecture — Concepts and Formal Analysis

We present a secure architecture of a CVS-server, its implementation (i.e. mainly its configuration) and its formal analysis. Our CVS-server is uses cvsauth, that provides protection of passwords and protection of some internal data of the CVS repository. In contrast to other (security oriented) CVS-architectures, our approach allows the CVS-server run on an open filesystem, i.e. a filesystem where users can have direct access both by CVS-commands and by standard UNIX/POSIX commands such as mv. For our secure architecture of the CVS-server, we provide a formal specification and security analysys. The latter is based on a refinement mapping high-level security requirements on the architecture on low-level security mechanisms on the UNIX/POSIX filesystem level. The purpose of the formal analysis of the secure CVS-server architecture is twofold: First, it is the bases for the specification of mutual security properties such as non-repudiation, authentication and access control for this architecture. Second, the mapping of the architecture on standard security implementation technology is described. Thus, our approach can be seen as a method to give a formal underpinning for the usually tricky business of system administrators.