This is a small project for fuzzing DynaHist with the jazzer fuzzing tool.
See Fuzzing for a general description of the theory behind fuzzy testing.
Because Java uses a runtime environment which does not crash on invalid actions of an
application (unless native code is invoked), Fuzzing of Java-based applications
focuses on the following:
- verify if only expected exceptions are thrown
- verify any JNI or native code calls
- find cases of unbounded memory allocations
DynaHist does not use JNI or native code, therefore the fuzzing target mainly tries to trigger unexpected exceptions and unbounded memory allocations.
Build the fuzzing target:
./gradlew shadowJar
Prepare a corpus of test-files (i.e. valid and invalid lines) and put them
into directory corpus
mkdir corpus
Download Jazzer from the releases page,
choose the latest version and select the file jazzer-<os>-<version>.tar.gz
Unpack the archive:
tar xzf jazzer-*.tar.gz
Invoke the fuzzing:
./jazzer --cp=build/libs/dynahist-fuzz-all.jar --instrumentation_includes=com.dynatrace.** --target_class=com.dynatrace.dynahist.fuzz.Fuzz -rss_limit_mb=4096 --jvm_args=-Xss4m corpus
In this mode Jazzer will stop whenever it detects an unexpected exception or crashes.
You can use --keep_going=10 to report a given number of exceptions before stopping.
See ./jazzer for options which can control details of how Jazzer operates.