RegFinder

Fast, simple regex matcher that should be used as a simple manual checker for secrets in your project. It is helpful for secret detection in your codebase and makes it very easy to extend existing regex patterns. RegFinder comes in handy in situations where more manual work is required (e.g., security code review, Pentest, etc.).

Accuracy

This tool might have a high false positive rate depending on your regexes. It is a trade-off between a low false negative rate and a high positive rate, which you control with the regexes you are using.

Comparison with grep

The functionality of this tool is more or less the same as GNU grep, in the grep you can achieve the functionality with the following command: grep -n -r your_app/ -Ef regex_dir/general.txt

The advantages of RegFinder are that it is multithreaded and faster on larger projects, then it automatically ignores some files that typically have no secrets such as PDFs, images, etc. At the same time, it is very easily expandable for your purposes, it is statically linked (like everything in Golang) and portable. There are executables for both Linux and Windows.

Setup

Copy the executable from the /build folder to /usr/local/bin.

wget https://github.com/matejsmycka/regfinder/raw/main/build/regfinder.elf
chmod +x ./regfinder.elf
sudo mv ./regfinder.elf /usr/local/bin/regfinder

Usage

Usage of regfinder:
  -d string
    	Directory to search for files (recursively)
  -f string
    	File containing regular expressions to search for
  -no-color
    	Disable color output

To build the binary, run make in the root directory of the project, output dir is built.

Example

$ ./regfinder.elf -d your_app/ -f regex_dir/general.txt

Regex directory

Regex for each use-case are included in regex_dir directory. You can use them as a base for your own regexes.

Dev

make run ARGS="-d your_app/ -f regex_dir/general.txt"