ChopChop

ChopChop is a command-line tool for dynamic application security testing on web applications, initially written by the Michelin CERT.

Its goal is to scan several endpoints and identify exposition of services/files/folders through the webroot. Checks/Signatures are declared in a config file (by default: chopchop.yml), fully configurable, and especially by developers.

"Chop chop" is a phrase rooted in Cantonese. "Chop chop" means "hurry" and suggests that something should be done now and without delay.

Table of Contents

• Building
• Usage
  • Available flags
  • Advanced usage
• Creating a new check/signature
• External Libraries
• Talks
• Licence
• Authors

Building

We tried to make the build process painless and hopefully, it should be as easy as:

$ go mod download
$ go build .

There should be a resulting gochopchop binary in the folder.

Using Docker

Thanks to Github Container Registry, we are able to provide you some freshly-build Docker images!

docker run ghcr.io/michelin/gochopchop scan https://foobar.com -v debug

But if you prefer, you can also build it locally, see below:

Build locally

docker build -t gochopchop .

Usage

We are continuously trying to make goChopChop as easy as possible. Scanning a host with this utility is as simple as :

$ ./gochopchop scan https://foobar.com

Using Docker

docker run gochopchop scan https://foobar.com

Custom configuration file

docker run -v ./:/app chopchop scan -c /app/chopchop.yml https://foobar.com

What's next

The Golang rewrite took place a couple of months ago but there's so much to do, still. Here are some features we are planning to integrate : [x] Threading for better performance [x] Ability to specify the number of concurrent threads [x] Colors and better formatting [x] Ability to filter checks/signatures to search for [x] Mock and unit tests [x] Github CI And much more!

Testing

To quickly end-to-end test chopchop, we provided a web-server in tests/server.go. To try it, please run go run tests/server.go then run chopchop with the following command ./gochopchop scan http://localhost:8000 --verbosity Debug. ChopChop should print "no vulnerabilities found".

There are also unit test that you can launch with go test -v ./.... These tests are integrated in the github CI workflow.

Available flags

You can find the available flags available for the scan command :

Advanced usage

Here is a list of advanced usage that you might be interested in. Note: Redirectors like > for post processing can be used.

• Ability to scan and disable SSL verification

$ ./gochopchop scan https://foobar.com --insecure

• Ability to scan with a custom configuration file (including custom plugins)

$ ./gochopchop scan https://foobar.com --insecure --signature test_config.yml

• Ability to list all the plugins or by severity : plugins or plugins --severity High

$ ./gochopchop plugins --severity High

• Ability to specify number of concurrent threads : --threads 4 for 4 workers

$ ./gochopchop plugins --threads 4

• Ability to block the CI pipeline by severity level (equal or over specified severity) : --max-severity Medium

$ ./gochopchop scan https://foobar.com --max-severity Medium

• Ability to specify specific signatures to be checked

./gochopchop scan https://foobar.com --timeout 1 --verbosity --export=csv,json --export-filename boo --plugin-filters=Git,Zimbra,Jenkins

• Ability to list all the plugins

$ ./gochopchop plugins

• List High severity plugins

$ ./gochopchop plugins --severity High

• Set a list or URLs located in a file

$ ./gochopchop scan --url-file url_file.txt

• Export GoChopChop results in CSV and JSON format

$ ./gochopchop scan https://foobar.com  --export=csv,json --export-filename results

Creating a new check

Writing a new check is as simple as :

  - endpoint: "/.git/config"
    checks:
      - name: Git exposed
        match:
          - "[branch"
        remediation: Do not deploy .git folder on production servers
        description: Verifies that the GIT repository is accessible from the site
        severity: "High"

An endpoint (eg. /.git/config) is mapped to multiple checks which avoids sending X requests for X checks. Multiple checks can be done through a single HTTP request. Each check needs those fields:

External Libraries

Please, refer to the third-party.txt file for further information.

Talks

• PyCon FR 2019 (The tool was initially developed in Python) - https://docs.google.com/presentation/d/1uVXGUpt7tC7zQ1HWegoBbEg2LHamABIqfDfiD9MWsD8/edit
• DEFCON AppSec Village 2020 "Turning offsec mindset to developer's toolset" - https://drive.google.com/file/d/15P8eSarIohwCVW-tR3FN78KJPGbpAtR1/view

License

ChopChop has been released under Apache License 2.0. Please, refer to the LICENSE file for further information.

Authors

• Paul A.
• David R. (For the Python version)
• Stanislas M. (For the Golang version)