Coraza - Web Application Firewall

Coraza is an open source, enterprise-grade, high performance Web Application Firewall (WAF) ready to protect your beloved applications. It is written in Go, supports ModSecurity SecLang rulesets and is 100% compatible with the OWASP Core Rule Set v4.

Website: https://coraza.io
Forum: Github Discussions
OWASP Slack Community (#coraza): https://owasp.org/slack/invite
Rule testing: Coraza Playground

Key Features:

⇲ Drop-in - Coraza is an alternative engine that has partial compatibility with ~~Trustwave~~OWASP ModSecurity Engine and supports industry-standard SecLang rule sets.
🔥 Security - Coraza runs the OWASP CRS v4 (Formerly known as Core Rule Set) to protect your web applications from a wide range of attacks, including the OWASP Top Ten, with a minimum of false alerts. CRS protects from many common attack categories including: SQL Injection (SQLi), Cross Site Scripting (XSS), PHP & Java Code Injection, HTTPoxy, Shellshock, Scripting/Scanner/Bot Detection & Metadata & Error Leakages. Note that older versions of the CRS are not compatible.
🔌 Extensible - Coraza is a library at its core, with many integrations to deploy on-premise Web Application Firewall instances. Audit Loggers, persistence engines, operators, actions, create your own functionalities to extend Coraza as much as you want.
🚀 Performance - From huge websites to small blogs, Coraza can handle the load with minimal performance impact. Check our Benchmarks
﹡ Simplicity - Anyone is able to understand and modify the Coraza source code. It is easy to extend Coraza with new functionality.
💬 Community - Coraza is a community project, contributions are accepted and all ideas will be considered. Find contributor guidance in the CONTRIBUTION document.

Integrations

The Coraza Project maintains implementations and plugins for the following servers:

Caddy Reverse Proxy and Webserver Plugin - stable, needs a maintainer
Proxy WASM extension for proxies with proxy-wasm support (e.g. Envoy) - stable, still under development
HAProxy SPOE Plugin - experimental
Coraza C Library (For nginx, etc) - experimental

Prerequisites

Go v1.21+ or tinygo compiler
Linux distribution (Debian or Centos recommended), Windows or Mac.

Coraza Core Usage

Coraza can be used as a library for your Go program to implement a security middleware or integrate it with existing application & webservers.

package main

import (
	"fmt"

	"github.com/corazawaf/coraza/v3"
)

func main() {
	// First we initialize our waf and our seclang parser
	waf, err := coraza.NewWAF(coraza.NewWAFConfig().
		WithDirectives(`SecRule REMOTE_ADDR "@rx .*" "id:1,phase:1,deny,status:403"`))
	// Now we parse our rules
	if err != nil {
		fmt.Println(err)
	}

	// Then we create a transaction and assign some variables
	tx := waf.NewTransaction()
	defer func() {
		tx.ProcessLogging()
		tx.Close()
	}()
	tx.ProcessConnection("127.0.0.1", 8080, "127.0.0.1", 12345)

	// Finally we process the request headers phase, which may return an interruption
	if it := tx.ProcessRequestHeaders(); it != nil {
		fmt.Printf("Transaction was interrupted with status %d\n", it.Status)
	}
}

Examples/http-server provides an example to practice with Coraza.

Build tags

Go build tags can tweak certain functionality at compile-time. These are for advanced use cases only and do not have compatibility guarantees across minor versions - use with care.

coraza.disabled_operators.* - excludes the specified operator from compilation. Particularly useful if overriding the operator with plugins.RegisterOperator to reduce binary size / startup overhead.
coraza.rule.multiphase_valuation - enables evaluation of rule variables in the phases that they are ready, not only the phase the rule is defined for.
memoize_builders - enables memoization of builders for regex and aho-corasick dictionaries to reduce memory consumption in deployments that launch several coraza instances. For more context check this issue
no_fs_access - indicates that the target environment has no access to FS in order to not leverage OS' filesystem related functionality e.g. file body buffers.
coraza.rule.case_sensitive_args_keys - enables case-sensitive matching for ARGS keys, aligning Coraza behavior with RFC 3986 specification. It will be enabled by default in the next major version.

E2E Testing

http/e2e/ provides an utility to run e2e tests. It can be used standalone against your own waf deployment:

go run github.com/corazawaf/coraza/v3/http/e2e/cmd/httpe2e@main --proxy-hostport localhost:8080 --httpbin-hostport localhost:8081

or as a library by importing:

"github.com/corazawaf/coraza/v3/http/e2e"

As a reference for library usage, see testing/e2e/e2e_test.go. Expected directives that have to be loaded and available flags can be found in http/e2e/cmd/httpe2e/main.go.

Tools

Go FTW: Rule testing engine
Coraza Playground: Sandbox rule testing web interface
OWASP Core Ruleset: Awesome rule set, compatible with Coraza

Development

Coraza only requires Go for development. You can run mage.go to issue development commands.

See the list of commands

$ go run mage.go -l
Targets:
  check        runs lint and tests.
  coverage     runs tests with coverage and race detector enabled.
  doc          runs godoc, access at http://localhost:6060
  format       formats code in this repository.
  fuzz         runs fuzz tests
  lint         verifies code quality.
  precommit    installs a git hook to run check when committing
  test         runs all tests.

For example, to format your code before submission, run

go run mage.go format

Contribute

Contributions are welcome! Please refer to CONTRIBUTING.md for guidance.

Security

To report a security issue, please follow this link and add a description of the issue, the steps you took to create the issue, affected versions, and, if known, mitigations for the issue.

Our vulnerability management team will respond within 3 working days of your report. If the issue is confirmed as a vulnerability, we will open a Security Advisory. This project follows a 90 day disclosure timeline.