Chepy¶

Solving a CTF with Chepy

Chepy is a python library with a handy cli that is aimed to mirror some of the capabilities of CyberChef. A reasonable amount of effort was put behind Chepy to make it compatible to the various functionalities that CyberChef offers, all in a pure Pythonic manner. There are some key advantages and disadvantages that Chepy has over Cyberchef. The Cyberchef concept of stacking different modules is kept alive in Chepy.

There is still a long way to go for Chepy as it does not offer every single ability of Cyberchef.

Docs¶

Refer to the docs for full usage information

Example¶

For all usage and examples, see the docs.

Chepy has a stacking mechanism similar to Cyberchef. For example, this in Cyberchef:

This is equivalent to

from chepy import Chepy

file_path = "/tmp/demo/encoding"

print(
    Chepy(file_path)
    .load_file()
    .reverse()
    .rot_13()
    .base64_decode()
    .base32_decode()
    .hexdump_to_str()
    .o
)

Installation¶

Chepy can be installed in a few ways.

Pypi¶

pip3 install chepy

Git¶

git clone https://github.com/securisec/chepy.git
cd chepy
pip3 install -e .
# I use -e here so that if I update later with git pull, I dont have it install it again (unless dependencies have changed)

Pipenv¶

git clone https://github.com/securisec/chepy.git
cd chepy
pipenv install

Docker¶

docker run --rm -ti -v $PWD:/data securisec/chepy "some string" [somefile, "another string"]

Chepy vs Cyberchef¶

Advantages¶

Chepy is pure python with a supporting and accessible python api
Chepy has a CLI
Chepy CLI has full autocompletion.
Extendable via plugins
Infinitely scalable as it can leverage the full Python library.
Chepy can interface with the full Cyberchef web app to a certain degree. It is easy to move from Chepy to Cyberchef if need be.
The Chepy python library is significantly faster than the Cyberchef Node library.
Works with HTTP/S requests without CORS issues.

Disadvantages¶

Chepy is not a web app (at least for now).
Chepy does not offer every single thing that Cyberchef does
Chepy does not have the magic method (at the moment)

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