Automating ROS2 Security Policies Extraction through Static Analysis

Cybersecurity in mission-critical robotic applications is a necessity to scale deployments securely. ROS2 builds upon DDS-Security specs in ROS Client Library (RCL) to implement its security features. Utilizing SROS2, developers have access to a set of utilities to help set up security in a way RCL can use. Through SROS2, security deployment is eased for developers. However, while access control is handled by DDS and consequently based on the SROS2-generated permission artifacts, the necessary authorization policies are manually generated by developers. This requires an entire system exercise to be sampled via live extraction and, per each node, list all the necessary Topics, Services, and Actions, which is a daunting and laborious process. Developers first have to generate tests. Then, they obtain a ’snapshot’ of the system for each test. Later, these snapshots must be collected and grouped into a policy by a minimum set of rules. All this procedure is quite error-prone. This paper introduces LiSA4ROS2, a tool for automatically extract the ROS2 computational graph via static analysis to derive a minimal correct configuration for ROS2 security policies. Our approach relies on the abstract interpretation theory to statically overapproximate all possible executions to extract a minimal and complete configuration per node. We evaluate our approach with minimal examples covering all the main communication patterns in ROS2 tutorials and all publicly available real-world ROS2 Python systems extracted from GitHub. The results of the minimal examples show that LiSA4ROS2 precisely supports all the main communication patterns. The extensive evaluation underlines that our prototype implementation of the analysis in LiSA4ROS2 is already able to precisely analyze 66% of existing repositories, automatically producing detailed computational graphs and access policies. All the results of the analysis, as well as a Docker artifact to reproduce them, are publicly available.