SmartFuzzDriverGen: Smart Contract Fuzzing Automation for Golang

Abstract

Greybox fuzzers require intermediate programs called fuzz drivers to test smart contract APIs. These fuzz drivers use the semi-random inputs (bytes) generated by fuzzers to prepare suitable inputs required to test APIs. Further, fuzz driver also uses this input to decide sequence in which APIs to be invoked and enables the fuzzer to execute the APIs in that sequence to find the vulnerabilities, if any. Manually writing such complex and intelligent fuzz drivers is laborious, requires deep technical skills, hence can be cumbersome and error prone. In this paper, we propose SmartFuzzDriverGen framework to automatically generate fuzz drivers which invoke smart contract APIs using different strategies: unit-level, sequence-based (random, user-defined), and heuristics based. We evaluate the proposed framework by testing a prototype implementation of it with Golang smart contracts (targeted for Hyperledger Fabric platform) and study the effectiveness of the generated fuzz drivers in terms of code coverage as well as bug finding abilities. We observed that fuzzing of APIs in random sequences performed better than the other methods.