Instrumentation Blueprints: Towards Combining Several Android Instrumentation Tools

The explosive growth of the amount of Android apps has given rise to a pressing need to analyse these apps, most importantly for security purposes. Many Android app analysis and hardening tools rely on bytecode instrumentation: the modification of the compiled app code. App instrumentation tools have all kinds of purposes, ranging from the measurement of code coverage to placing probes for malware detection. Given this variety, it may be useful to work with multiple tools that rely on instrumentation at the same time. The composition of such tools can however lead to issues, since their changes to the applications under analysis may conflict with each other. To facilitate the composition of multiple instrumentation tools, we propose a two-step approach involving instrumentation blueprints, reports of the instrumentation changes a tool needs to apply. We have designed a prototype syntax for these blueprints, adapted a modern instrumentation tool to emit them and implemented a prototype blueprint application program. Our evaluation shows that the proposed approach is viable.