What is RSBAC

• Free Open Source (GPL) Linux kernel security extension
• Independent of governments and big companies
• Several well-known and new security models, e.g. MAC, ACL and RC
• On-access virus scanning with Dazuko interface
• Detailed control over individual user and program network accesses
• Fully access controlled kernel level user management
• Any combination of security models possible
• Easily extensible: write your own model for runtime registration
• Support for latest kernels
• Stable for production use

RSBAC is a flexible, powerful and fast (low overhead) open source access control framework for current Linux kernels, which has been in stable production use since January 2000 (version 1.0.9a). All development is independent of governments and big companies, and no existing access control code has been reused.

Practically, it allows full fine grained control over objects (files, processes, users, devices, etc.), memory execution prevention (PaX, NX), real time integrated virus detection, and much more.

First of all, RSBAC is not a security model by itself. It is a framework. This framework allows several different decision modules (interfaced easily with our Runtime Registration Facility: REG). Theses modules are the security models you want to use, to name a few:

• MAC: Mandatory Access Control
• ACL: Access Control Lists
• DAZ: Antivirus Scanner Interface
• RC: Role Compatibility

To get a list and explanation of every model included in RSBAC, see the different models documentation.

RSBAC framework logic is based on the work done for the Generalized Framework for Access Control (GFAC) by Abrams and LaPadula. All security relevant system calls are extended by security enforcement code. This code calls the central decision component, which in turn calls all active decision modules (the different modules implementing different security models) and generates a combined final decision. This decision is then enforced by the system call extensions.

Decisions are based on the type of access (request type), the access target and on the values of attributes attached to the subject calling and to the target to be accessed. Additional independent attributes can be used by individual modules, e.g. the privacy module (PM). All attributes are stored in fully protected directories, one on each mounted device. Thus changes to attributes require special system calls provided.

As all types of access decisions are based on general decision requests, many different security policies can be implemented as a decision module. Apart from the builtin models, the optional Module Registration (REG) allows for registration of additional, individual decision modules at runtime.

A general goal of RSBAC design has been to some day reach (obsolete) Orange Book (TCSEC) B1 level. Now it is mostly targeting to be useful as secure and multi-purposed networked system, with special interest in firewalls.