gofuzz is a CLI tool to add bug detection capabilities into your Go code.
It transforms the source code and replaces calls to functions/methods of interest by calls to corresponding hooks in the github.com/CodeIntelligenceTesting/gofuzz/sanitizers module.
gofuzz does not change the code in-place, but generates the instrumented source code in a temporary directory.
It produces an overlay file that can be used by Go's standard build tools.
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(Once) Install the gofuzz CLI
go install github.com/CodeIntelligenceTesting/gofuzz/cmd/gofuzz@latest
The minimum required Golang version is Go 1.18.
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(Once) Add the sanitizers package as a dependency for the code base you want to test. This package contains the implementation of the hooks inserted by gofuzz into your code, and therefore must be available when the instrumented code is being compiled.
cd <my project> go get -u github.com/CodeIntelligenceTesting/gofuzz/sanitizers@latest
This command also adds the sanitizers package as a dependency in the
go.modfile. -
Instrument your code using the sanitize subcommand
gofuzz sanitize <package> -o <overlay.json>
This instruments the specified package and writes the instrumented file into a temporary directory. The corresponding file replacements are stored in the <overlay.json> file. By default, gofuzz writes a file named overlay.json in the current directory.
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Instrument your code for fuzzing using go114-fuzz-build. Note that we use a fork of the original repo because we need a change that has not yet been merged upstream.
go114-fuzz-build -o target.a -func <fuzz_test> -overlay <overlay.json> <package>
This tool uses the host Go to instrument the code using the libFuzzer mode. We recommend using a Go version later than 1.19 as it contains several improvements to make fuzzing considerably more effective.
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Link the created archive with libFuzzer
clang -fsanitize=fuzzer target.a -o fuzzer
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Run the fuzzer
./fuzzer [fuzzer args]