Metadata-Version: 2.1
Name: pythonfuzz
Version: 1.0.2
Summary: coverage-guided fuzz testing for python
Home-page: https://github.com/fuzzitdev/pythonfuzz
Author: fuzzit.dev
Author-email: support@fuzzit.dev
License: UNKNOWN
Description: # pythonfuzz: coverage-guided fuzz testing for python
        [![Join the chat at https://slack.fuzzit.dev](https://app.fuzzit.dev/static/slack-join.svg)](https://slack.fuzzit.dev)
        
        
        PythonFuzz is coverage-guided [fuzzer](https://developer.mozilla.org/en-US/docs/Glossary/Fuzzing) for testing python packages.
        
        Fuzzing for safe languages like python 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). Here is an example of a simple fuzz function for the built-in `html` module
        
        ```python
        from html.parser import HTMLParser
        from pythonfuzz.main import PythonFuzz
        
        
        @PythonFuzz
        def fuzz(buf):
            try:
                string = buf.decode("ascii")
                parser = HTMLParser()
                parser.feed(string)
            except UnicodeDecodeError:
                pass
        
        
        if __name__ == '__main__':
            fuzz()
        ```
        
        Features of the fuzz target:
        
        * fuzz will call the fuzz target in an infinite loop with random data (according to the coverage guided algorithm) passed to `buf`( in a separate process).
        * The function must catch and ignore any expected exceptions that arise when passing invalid input to the tested package.
        * The fuzz target must call the test function/library with with the passed buffer or a transformation on the test buffer 
        if the structure is different or from different type.
        * Fuzz functions can also implement application level checks to catch application/logical bugs - For example: 
        decode the buffer with the testable library, encode it again, and check that both results are equal. To communicate the results
        the result/bug the function should throw an exception.
        * pythonfuzz will report any unhandled exceptions as crashes as well as inputs that hit the memory limit specified to pythonfuzz
        or hangs/they run more the the specified timeout limit per testcase.
        
        
        ### Running
        
        The next step is to download pythonfuzz and then run your fuzzer
        
        ```bash
        pip install pythonfuzz
        python examples/htmlparser/fuzz.py
        
        #394378 NEW     cov: 608 corp: 24 exec/s: 1119 rss: 10.73828125 MB
        subclasses of ParserBase must override error()
        Traceback (most recent call last):
          File "/Users/yevgenyp/fuzzitdev/pythonfuzz/pythonfuzz/fuzzer.py", line 21, in worker
            target(buf)
          File "examples/htmlparser/fuzz.py", line 12, in fuzz
            pass
          File "/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/html/parser.py", line 111, in feed
            self.goahead(0)
          File "/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/html/parser.py", line 179, in goahead
            k = self.parse_html_declaration(i)
          File "/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/html/parser.py", line 264, in parse_html_declaration
            return self.parse_marked_section(i)
          File "/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/_markupbase.py", line 159, in parse_marked_section
            self.error('unknown status keyword %r in marked section' % rawdata[i+3:j])
          File "/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/_markupbase.py", line 34, in error
            "subclasses of ParserBase must override error()")
        NotImplementedError: subclasses of ParserBase must override error()
        crash was written to crash-dbfa437e5956643645681fe6a3ac76997be0b29a7c7af82d88c8c390f379502d
        crash = 3c215b63612121
        ```
        
        This example quickly finds an an unhandled exception/flow in a few minutes.
        
        ### Corpus
        
        PythonFuzz 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.
        
        PythonFuzz 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.  
        
        PythonFuzz tries to mimic some of the arguments and output style from [libFuzzer](https://llvm.org/docs/LibFuzzer.html).
        
        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.
        
        ## Credits & Acknowledgments
        
        PythonFuzz is a port of [fuzzitdev/jsfuzz](https://github.com/fuzzitdev/jsfuzz)
        
        which is in turn heavily based on [go-fuzz](https://github.com/dvyukov/go-fuzz) originally developed by [Dmitry Vyukov's](https://twitter.com/dvyukov).
        Which is in turn heavily based on [Michal Zalewski](https://twitter.com/lcamtuf) [AFL](http://lcamtuf.coredump.cx/afl/).
        
        For coverage PythonFuzz is using [coverage](https://coverage.readthedocs.io/en/v4.5.x/) instrumentation and coverage library. 
        
        ## 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.
        
        
        ## Trophies
        
        * [python built-in HTMLParser - unhandled exception](https://bugs.python.org/msg355287)
        
        **Feel free to add bugs that you found with pythonfuzz to this list via pull-request**
        
Platform: UNKNOWN
Classifier: Programming Language :: Python :: 3
Classifier: License :: OSI Approved :: Apache Software License
Classifier: Operating System :: OS Independent
Classifier: Topic :: Software Development :: Testing
Requires-Python: >=3.5.3
Description-Content-Type: text/markdown
