Comparative Study of Containment Strategies in Solaris and Security Enhanced Linux

• Main Authors: Eriksson, Magnus, Palmroos, Staffan
• Format: Others
• Language: English
• Published: Linköpings universitet, Institutionen för datavetenskap 2007
• Subjects: Solaris Zones; Solaris Containers; SELinux; containment strategies; virtualization; Computer Sciences; Datavetenskap (datalogi)
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-9078

To minimize the damage in the event of a security breach it is desirable to limit the privileges of remotely available services to the bare minimum and to isolate the individual services from the rest of the operating system. To achieve this there is a number of different containment strategies and process privilege security models that may be used. Two of these mechanisms are Solaris Containers (a.k.a. Solaris Zones) and Type Enforcement, as implemented in the Fedora distribution of Security Enhanced Linux (SELinux). This thesis compares how these technologies can be used to isolate a single service in the operating system. As these two technologies differ significantly we have examined how the isolation effect can be achieved in two separate experiments. In the Solaris experiments we show how the footprint of the installed zone can be reduced and how to minimize the runtime overhead associated with the zone. To demonstrate SELinux we create a deliberately flawed network daemon and show how this can be isolated by writing a SELinux policy. We demonstrate how both technologies can be used to achieve isolation for a single service. Differences between the two technologies become apparent when trying to run multiple instances of the same service where the SELinux implementation suffers from lack of namespace isolation. When using zones the administration work is the same regardless of the services running in the zone whereas SELinux requires a separate policy for each service. If a policy is not available from the operating system vendor the administrator needs to be familiar with the SELinux policy framework and create the policy from scratch. The overhead of the technologies is small and is not a critical factor for the scalability of a system using them.