Fuzz Go with LibAFL

This is a project to get you started with fuzzing Go server controllers. The fuzzing test setup is very similar to how fuzz tests work in Go. Create a request with httptest, run the controller and record its response. You will also find the harness.c, which is ran by the fuzzer, and main.go which works as a "sub harness", to help us prepare the environment for Go related stuff (like taking the incoming bytes and placing them all in a single struct field etc). At the moment, we prefer to run black-box fuzzing and build the target without instrumentation. It would be difficult though, since I do not know any proper way to build instrumentation inside a Go binary. We run it with Qemu which gives us some modules to observe the runtime like CmpLog.

Build and run :

make run

Notes:

• In order to run the fuzzer, you have to download jvob a small tool to find the json values byte offsets in a json byte vector.
• Sometimes it fails with "No entries in corpus". Simply re-run it
• In Makefile, the fuzzer is called with --offset 600. 600 is the length of the FuzzMeController controller in the the Go library. TODO: find it automatically before start fuzzing.

TODO:

• Improve CmpLog utilization
• Create a wordlist mutator (token mutator)
• Add json values offsets in metadata
• Fix fails on first runs with error "No entries in corpus"
• Improve performance