Authorization is an intrinsic part of a software’s security. Determining whether a user is allowed to access a resource or not is crucial, not only in safety-critical applications but also in everyday applications to prevent misuse of data or software. There is plenty of research dealing with validating and verifying authorization policies in the security community. Still, an implemented authorization policy does not necessarily match the planned authorization policy, i.e., even a validated and verified authorization policy can pose security issues when implemented incorrectly. This gap between planned and implemented authorization policy poses the risk of unauthorized access to sensitive resources due to insufficient authorization checks. Therefore, it is essential to ensure a system’s security to validate the implemented authorization policy against the planned one. We, therefore, describe the authorization pattern and present an algorithm to extract authorization graphs from implemented authorization policies, which can then be used to compare against the planned authorization policy. To that end, we developed a configurable context-sensitive analysis tailored to Java-based software systems, where the context is the authorization facts that hold on each point. Using a configuration for Apache Shiro, a security library that supports authorization, we evaluated our implementation using an open-source repository system for the management and dissemination of digital content and a closed-source manufacturing execution system. We discuss additional usage scenarios of the analysis results and describe how to transfer the approach to other authorization policies and programming languages.
展开▼
