earticle

영어

Configuration of security policies is one of the most important prerequisites for secure and credible running of secure operating systems. Although it is a hard, tedious and complicated task within which errors and bugs are incidental at all time. Accordingly, methods for automatic analysis of SELinux security policies are discussed in this paper. Firstly, security mechanism, security models and policy description language for SELinux are briefly introduced. Then a security analysis model is constructed in order to verify validity and integrity of security policies and all rules for Type Enhancement (TE), Role-Based Access Control (RBAC) are rewritten as formal expressions while all subjects, objects and elements are described as sets and mappings formally. Algorithms for analysis are designed based on such model. Comparing with that in SELinux Access Control (SELAC) model, scope of possible values for role can be reduced and thus a great many invalid security contexts are eliminated in our model. Finally, a prototype is implemented in C language and a security policy configuration case as to an application system called Student-Teacher system is designed to be used to test the prototype. Test results show that the prototype and corresponding methods can verify validity and integrity of policy configuration and are potential to be used to assist people to complete correct and reliable configuration.