Fuzzcheck (a structure-aware Rust fuzzer)

Fuzzcheck is a structure-aware fuzzer for rust. "Fuzzing" means feeding large amounts of data into a program and checking for crashes (Fuzzcheck also checks to make sure that all the properties your program should uphold – e.g. a sorting algorithm applied to a list of n items should always return a list of n items – are upheld). Fuzzcheck is an "evolutionary" fuzzer – this means that it generates a set of random inputs, sees what percentage of the program is executed for each input, and keeps inputs which have high levels of percentage of program executed. It then "mutates" these inputs – whereas fuzzers such as AFL/Hongfuzz/etc mutate raw bytes in place (e.g. they swap bytes at different positions, or insert a random byte at a given position to generate inputs similar to the chosen "high coverage" inputs), Fuzzcheck works directly on the Rust types (so it might swap the order of two items in a vec, or randomly insert a new item). It's a really powerful tool for finding lots of bugs.

There's a tutorial as well!