jaffy v1

"Look ma, I made a fuzzer" edition.

That's nice, dear.

Jaffy fuzzes binaries that you run on the command line. You guessed it, it fuzzes the command line options. Since it utilizes subprocess.run() it requires Python 3.5 or greater. It is assumed that /usr/local/bin/python is pointed to python3.5 in some way. You can change the first line of the jaffy python file to suite your needs if you want. Jaffy uses the untangle library to parse XML files. You're going to need to find that, it's on pip and git. Jaffy runs everything with shell=True so like don't run the fuzzer over the internet or something. All file output is stored in a folder with the date and time of the scan as the name, like 20160930162013. Inside you will find the outputs of the fuzzed binary as defined in your XML file. Each file name is a UUID that looks something like f718c144-f008-4fc7-96a5-164f42863868.

Below is an example of the chariter.xml XML file with comments so you can see what is going on. You should customize it to your own specifications.

<?xml version="1.0"?>
<fuzzer>
  <!-- Path to the binary -->
	<bin path="/bin/ls" />
  <!-- prestatic options are run before the fuzzed option -->
	<opt type="prestatic" value="-v" />
  <!-- poststatic options are run after the fuzzed options -->
	<opt type="poststatic" value="/home" />
  <!-- Fuzz option. Explained in readme -->
	<fuzz type="chariter" prefix="-" char="a" length="9999" />
  <!-- The shell command to run before each fuzz -->
  <prefuzz cmd="" />
  <!-- The shell command to run after each fuzz -->
	<postfuzz cmd="" />
  <!-- Decide to exit jaffy if the return code is not 0 -->
  <!-- ! = Don't exit at all. -->
  <!-- !0 = Exit only when not 0 -->
  <!-- You can also specify a shell command to run when jaffy exits -->
	<exit level="!0" cmd="" />
  <!-- Display output to the screen based on return code -->
  <!-- * = Display everything no matter what. -->
  <!-- ! = Don't display anything at all. -->
  <!-- !0 = Display only when not 0 -->
	<display level="!0" />
  <!-- Write output to file based on return code -->
  <!-- * = Write everything no matter what. -->
  <!-- ! = Don't write anything at all. -->
  <!-- !0 = Write only when not 0 -->
	<write level="!0" />
</fuzzer>

Chariter Fuzz

The chariter fuzzer is the only fuzzer available in jaffy right now. It simply creates a command line option that grows in length by one character each iteration of the fuzz. If the length is 6 and the char is a then the first fuzz will be a, then the second will be aa, and so one until you reach aaaaaa. You can add a prefix to a each iteration as well. If your prefix is - then your first fuzz will look like -a, then -aa, and so on.