Open Sourcing Fuzz Testing Library for Java
source link: https://github.com/fuzzitdev/javafuzz
Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.
Javafuzz: coverage-guided fuzz testing for Java
Javafuzz is coverage-guided fuzzer for testing Java packages.
Fuzzing for safe languages like nodejs is a powerful strategy for finding bugs like unhandled exceptions, logic bugs, security bugs that arise from both logic bugs and Denial-of-Service caused by hangs and excessive memory usage.
Fuzzing can be seen as a powerful and efficient strategy in real-world software in addition to classic unit-tests.
Usage
Fuzz Target
The first step is to implement the following function (also called a fuzz target):
public class FuzzExample extends AbstractFuzzTarget { public void fuzz(byte[] data) { try { BufferedImage image = ImageIO.read(new ByteArrayInputStream(data)); } catch (IOException e) { // ignore as we expect this exception } } }
Features of the fuzz target:
buf
Installing
Add this to your pom.xml
<dependencies> <dependency> <groupId>dev.fuzzit.javafuzz</groupId> <artifactId>core</artifactId> <version>1.23-SNAPSHOT</version> <scope>test</scope> </dependency> </dependencies> <plugin> <plugin> <groupId>dev.fuzzit.javafuzz</groupId> <artifactId>javafuzz-maven-plugin</artifactId> <version>1.22</version> </plugin> </plugins>
Running
The next step is to javafuzz with your fuzz target function
wget -O jacocoagent https://github.com/fuzzitdev/javafuzz/raw/master/javafuzz-maven-plugin/src/main/resources/jacocoagent-exp.jar MAVEN_OPTIONS="-javaagent:jacoco.jar" mvn javafuzz:fuzz -DclassName=your.full.class.name
# Output: #0 READ units: 0 #1 NEW cov: 61 corp: 0 exec/s: 1 rss: 23.37 MB #23320 PULSE cov: 61 corp: 1 exec/s: 10614 rss: 35.3 MB #96022 NEW cov: 70 corp: 1 exec/s: 11320 rss: 129.95 MB #96971 NEW cov: 78 corp: 2 exec/s: 10784 rss: 129.95 MB #97046 NEW cov: 79 corp: 3 exec/s: 9375 rss: 129.95 MB #97081 NEW cov: 81 corp: 4 exec/s: 11666 rss: 129.95 MB #97195 NEW cov: 93 corp: 5 exec/s: 9500 rss: 129.95 MB #97216 NEW cov: 97 corp: 6 exec/s: 10500 rss: 129.95 MB #97238 NEW cov: 102 corp: 7 exec/s: 11000 rss: 129.95 MB #97303 NEW cov: 108 corp: 8 exec/s: 10833 rss: 129.96 MB #97857 PULSE cov: 108 corp: 9 exec/s: 225 rss: 129.96 MB #97857 PULSE cov: 108 corp: 9 exec/s: 0 rss: 940.97 MB #97857 PULSE cov: 108 corp: 9 exec/s: 0 rss: 1566.01 MB #97857 PULSE cov: 108 corp: 9 exec/s: 0 rss: 2053.49 MB MEMORY OOM: exceeded 2048 MB. Killing worker Worker killed crash was written to crash-819587841e3c275338593b0d195b6163d5208866870e2abf3be8cfc781d2688d crash(hex)=ffd8ffc09dfdb0ffff0e5296bd7fbbc4f9579096bd7fbbfc0e80d50000ffff36fa400100236701bf73ffaf8003a57f097f5e000000008023c4f9579096bd7fbb008000001500b34e8c018fda5212
This example quickly finds an infinite hang which takes all the memory in jpeg-js
.
Corpus
Javafuzz will generate and test various inputs in an infinite loop. corpus
is optional directory and will be used to
save the generated testcases so later runs can be started from the same point and provided as seed corpus.
Javafuzz can also start with an empty directory (i.e no seed corpus) though some valid test-cases in the seed corpus may speed up the fuzzing substantially.
Javafuzz tries to mimic some of the arguments and output style from libFuzzer .
More fuzz targets examples (for real and popular libraries) are located under the examples directory and bugs that were found using those targets are listed in the trophies section.
Coverage
For coverage instrumentation we use JaCoCo library
Other languages
Currently this library also exists for the following languages:
- javascript jsfuzz
- python via pythonfuzz
Credits & Acknowledgments
Javafuzz is a port of fuzzitdev/jsfuzz .
Which in turn based based on go-fuzz originally developed by Dmitry Vyukov's . Which is in turn heavily based on Michal Zalewski AFL .
Another solid fuzzing with coverage library for java is JQF but is more focused on semantic fuzzing (i.e structure aware) and thus depends on quickcheck. JavaFuzz does not depends on any framework an focuses on mutations producing buffer array and using coverage to find more bugs.
Contributions
Contributions are welcome!:) There are still a lot of things to improve, and tests and features to add. We will slowly post those in the issues section. Before doing any major contribution please open an issue so we can discuss and help guide the process before any unnecessary work is done.
Recommend
About Joyk
Aggregate valuable and interesting links.
Joyk means Joy of geeK