Input splitting for cloud-based static application security testing platforms

As software development teams adopt DevSecOps practices, application security is increasingly the responsibility of development teams, who are required to set up their own Static Application Security Testing (SAST) infrastructure.

Since development teams often do not have the necessary infrastructure and expertise to set up a custom SAST solution, there is an increased need for cloud-based SAST platforms that operate as a service and run a variety of static analyzers. Adding a new static analyzer to a cloud-based SAST platform can be challenging because static analyzers greatly vary in complexity, from linters that scale efficiently to interprocedural dataflow engines that use cubic or even more complex algorithms. Careful manual evaluation is needed to decide whether a new analyzer would slow down the overall response time of the platform or may timeout too often.

We explore the question of whether this can be simplified by splitting the input to the analyzer into partitions and analyzing the partitions independently. Depending on the complexity of the static analyzer, the partition size can be adjusted to curtail the overall response time. We report on an experiment where we run different analysis tools with and without splitting the inputs. The experimental results show that simple splitting strategies can effectively reduce the running time and memory usage per partition without significantly affecting the findings produced by the tool.