In order to use jCupid you must download and compile the modified OpenJDK. This is taken care of by the setup script. It will clone our modified OpenJDK
from https://github.com/cuplv/OpenJDK and configure and compile for you.
Thus after cloning this repository, you simply need to run ./setup
In order to install OpenJDK you will need a version of Oracles JDK 7. You can acquire that here, this version should be in your PATH variable, or if it is not you should add the line --with-boot-jdk=path to the configures line in the setup script.
Additional system requirements are alsa, freetype, cups, and xrender, these are required to build the OpenJDK and can be installed with:
If any of the above are missing the configure step will and it will suggest how to install missing dependencies.
The script assumes you are on a 64-bit machine, if you are on a 32-bit machine you must delete part of one line of this script. The line containing ./configure --enable-debug --with-target-bits=64, simply remove the whole --with-target-bits flag
Main use is through the jCupid.py script. It has a number of necessary flags:
./jCupid -f fileName -c mainClass [-n stripClass] -m methodName -l length [-i its] [-k input]
-f - path to java file to run, can be relative.
-c - name of the class which contains the main method.
-n - class name to find a difference around, if ommitted the main class is used.
-m - method name to find a difference around.
-l - the length of inputs to be randomly generated, this must be an integer
-i - the number of iterations for jCupid to try different inputs, must be and integer. If ommitted jCupid uses 100 iterations.
-k - allows the user to supply the input, generally used for debugging.
With this we can run our tool:
./jCupid.py -l 5 -i 20 -c repeatedSquaring -f Examples/repeatedSquaring.java -m repeatedSquare
This will run the jCupid tool, fuzzing at most 20 inputs of length 5. jCupid will compile the file Examples/repeatedSquaring.java, the main method is in the class repeatedSquaring and jCupid will trace around the method repeatedSquare.
The Examples directory contains a few examples. You can test the tool is finding differences on any of these
examples.