How to: Security Tools
[SELinux](https://github.com/SELinuxProject/selinux) is a security enhancement to Linux which allows users and administrators more control over access control. Access can be constrained on such variables as which users and applications can access which resources. These resources may take the form of files. Standard Linux access controls, such as file modes (-rwxr-xr-x) are modifiable by the user and the applications which the user runs. Conversely, SELinux access controls are determined by a policy loaded on the system which may not be changed by careless users or misbehaving applications.

[AppArmor](https://www.apparmor.net/) is an effective and easy-to-use Linux application security system. AppArmor proactively protects the operating system and applications from external or internal threats, even zero-day attacks, by enforcing good behavior and preventing both known and unknown application flaws from being exploited. AppArmor supplements the traditional Unix discretionary access control (DAC) model by providing mandatory access control (MAC). It has been included in the mainline Linux kernel since version 2.6.36 and its development has been supported by Canonical since 2009.

[Control Groups(Cgroups)](https://www.redhat.com/sysadmin/cgroups-part-one) is a Linux kernel feature that allows you to allocate resources such as CPU time, system memory, network bandwidth, or any combination of these resources for user-defined groups of tasks (processes) running on a system.

[EarlyOOM](https://github.com/rfjakob/earlyoom) is a daemon for Linux that enables users to more quickly recover and regain control over their system in low-memory situations with heavy swap usage. 

[Libgcrypt](https://www.gnupg.org/related_software/libgcrypt/) is a general purpose cryptographic library originally based on code from GnuPG.

[Kali Linux](https://www.kali.org/)  is an open source project that is maintained and funded by Offensive Security, a provider of world-class information security training and penetration testing services.

[Pi-hole](https://pi-hole.net/) is a [DNS sinkhole](https://en.wikipedia.org/wiki/DNS_Sinkhole) that protects your devices from unwanted content, without installing any client-side software, intended for use on a private network. It is designed for use on embedded devices with network capability, such as the Raspberry Pi, but it can be used on other machines running Linux and cloud implementations.

[Aircrack-ng](https://www.aircrack-ng.org/) is a network software suite consisting of a detector, packet sniffer, WEP and WPA/WPA2-PSK cracker and analysis tool for 802.11 wireless LANs. It works with any wireless network interface controller whose driver supports raw monitoring mode and can sniff 802.11a, 802.11b and 802.11g traffic.

[Burp Suite](https://portswigger.net/burp) is a leading range of cybersecurity tools.

[KernelCI](https://foundation.kernelci.org/) is a community-based open source distributed test automation system focused on upstream kernel development. The primary goal of KernelCI is to use an open testing philosophy to ensure the quality, stability and long-term maintenance of the Linux kernel.

[Continuous Kernel Integration project](https://github.com/cki-project) helps find bugs in kernel patches before they are commited to an upstram kernel tree. We are team of kernel developers, kernel testers, and automation engineers.

[eBPF](https://ebpf.io) is a revolutionary technology that can run sandboxed programs in the Linux kernel without changing kernel source code or loading kernel modules. By making the Linux kernel programmable, infrastructure software can leverage existing layers, making them more intelligent and feature-rich without continuing to add additional layers of complexity to the system.

[Cilium](https://cilium.io/) uses eBPF to accelerate getting data in and out of L7 proxies such as Envoy, enabling efficient visibility into API protocols like HTTP, gRPC, and Kafka. 

[Hubble](https://github.com/cilium/hubble) is a Network, Service & Security Observability for Kubernetes using eBPF.

[Istio](https://istio.io/) is an open platform to connect, manage, and secure microservices. Istio's control plane provides an abstraction layer over the underlying cluster management platform, such as Kubernetes and Mesos.

[Certgen](https://github.com/cilium/certgen) is a convenience tool to generate and store certificates for Hubble Relay mTLS.

[Scapy](https://scapy.net/) is a python-based interactive packet manipulation program & library.

[syzkaller](https://github.com/google/syzkaller) is an unsupervised, coverage-guided kernel fuzzer.

[SchedViz](https://github.com/google/schedviz) is a tool for gathering and visualizing kernel scheduling traces on Linux machines.

[oss-fuzz](https://google.github.io/oss-fuzz/) aims to make common open source software more secure and stable by combining modern fuzzing techniques with scalable, distributed execution.

[OSSEC](https://www.ossec.net/) i