Coraza Web Application Firewall

Welcome to Coraza Web Application Firewall, this project is a Golang port of ModSecurity with the goal to become the first enterprise-grade Open Source Web Application Firewall, flexible and powerful enough to serve as the baseline for many projects.


  • Linux distribution (Debian and Centos are recommended, Windows is not supported)
  • Golang compiler v1.16
  • libpcre-dev (apt install libpcre++-dev for Ubuntu)
  • CGO_ENABLED environmental variable must be set to 1
  • libinjection must be installed and linked

You may install libinjection with the following command:

# Must be run as root
sudo make deps

Note this command will compile and install libinjection to your LIBRARY_PATH and LD_LIBRARY_PATH.

Running the test suite

Run the go tests:

go test ./...
go test -race ./...

Run the test suite against OWASP CRS

You can run the testsuite using our OWASP CRS test docker image, it will run a Coraza instance using Caddy and go-ftw

git clone
cd coraza-ruleset
docker build . -t crs
docker run crs -name crs

Your first Coraza WAF project

Make sure CGO_ENABLED=1 env is set before compiling and all dependencies are met.

package main

func main() {
	// First we initialize our waf and our seclang parser
	waf := engine.NewWaf()
	parser := seclang.NewParser(waf)

	// Now we parse our rules
	parser.FromString(`SecRule REMOTE_ADDR "@rx .*" "id:1,phase:1,drop"`)

	// Then we create a transaction and assign some variables
	tx := waf.NewTransaction()
	tx.ProcessConnection("", 8080, "", 12345)


	// Finally we check the transaction status
	if tx.Interrupted() {
		fmt.Println("Transaction was interrupted")

Integrate with any framework

Using the standard net/http library:

package main

func SomeErrorPage(w http.ResponseWriter) {
	w.Write([]byte("WAF ERROR")

func someHandler(waf *engine.Waf) http.Handler {
  return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    tx := waf.NewTransaction()
	if tx.Interruption != nil {

Responses are harder to handle, because we must intercept the response writers and integrate them with the Coraza BodyReader.

Handling HTTP responses with Coraza

Responses are usually long buffers, so duplicating the response or buffering it in memory is hard. In order to avoid issues while handling long buffers Coraza provides the engine.BodyReader struct, it will handle long buffers storing them to temporary files if needed.

func someHandler(waf *engine.Waf) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		tx := waf.NewTransaction()
		if tx.Interruption != nil {
		// We will use the Coraza response reader:
		tx.ResponseBuffer.Write([]byte("Some of the response body"))
		// We will dump the buffered response into the response writer:
		io.Copy(w, tx.ResponseBuffer)

Compatibility status

We have currently achieved a 91% compatibility with OWASP CRS, some features are under development, like:

  • Persistent Collections
  • Some operators: fuzzyHash
  • Lua is still being tested, it may be replaced with WASM

Why Coraza WAF?


  • Simplicity: Anyone should be able to understand and modify Coraza WAF's source code
  • Extensibility: It should be easy to extend Coraza WAF with new functionalities
  • Innovation: Coraza WAF isn't just a ModSecurity port, it must include awesome new functions (in the meantime it's just a port ![sweat_smile]( =20x20))
  • Community: Coraza WAF is a community project and everyone's idea will be heard

Roadmap (long term)

  • WASM scripts support, Lua was removed
  • Performance improvements
  • More tests and documentation
  • Integrated DDOS protection and directives with iptables(And others) integration
  • Integrated protocol validations (rfc2616)
  • Integrated CSRF protection
  • Integrated bot detection with captcha
  • More loggers and persistence engines
  • More integrations (traefik, gin and buffalo)
  • Open Policy Agent package (OPA)
  • Online sandbox
  • HTTP/2 and HTTP/3 support
  • Enhanced rule profiling
  • Native antivirus integration (maybe)
  • Automatic coreruleset integration (download and setup) (maybe)
  • Enhanced data masking features
  • Enhanced data signing features (cookies, forms, etc)
  • OpenAPI enforcement
  • JWT enforcement
  • JSON and YAML query