John the Ripper is a fast password cracker, currently available for many flavors of Unix, Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. It supports several crypt(3) password hash types commonly found on Unix systems, as well as Windows LM hashes. On top of this, lots of other hashes and ciphers are added in the community-enhanced version (-jumbo), and some are added in John the Ripper Pro.
Endian Firewall is an all-in-on Linux security distribution that turns any system into a full-featured security appliance. It features a stateful packet inspection firewall, application-level proxies for various protocols (HTTP, POP3, SMTP), anti-virus support, virus and spam filtering for email traffic (POP and SMTP), content filtering of Web traffic, and a "hassle free" VPN system based on OpenVPN.
afick is another file integrity checker, designed to be fast and fully portable between Unix and Windows platforms. It works by first creating a database that represents a snapshot of the most essential parts of your computer system. You can then run the script to discover all modifications made since the snapshot was taken (i.e. files added, changed, or removed). The configuration syntax is very close to that of aide or tripwire, and a graphical interface is provided.
ZoneMinder is a suite of applications intended for use in video camera security applications, including theft prevention and child or family member monitoring. It supports capture, analysis, recording, and monitoring of video data coming from one or more video or network cameras attached to a Linux system. It also features a user-friendly Web interface which allows viewing, archival, review, and deletion of images and movies captured by the cameras. The image analysis system is highly configurable, permitting retention of specific events, while eliminating false positives. ZoneMinder supports both directly connected and network cameras and is built around the definition of a set of individual 'zones' of varying sensitivity and functionality for each camera. This allows the elimination of regions which should be ignored or the definition of areas which will alarm if various thresholds are exceeded in conjunction with other zones. All management, control, and other functions are supported through the Web interface.
TinyCA is a simple GUI written in Perl-Gtk to manage a small certification authority. It works as a frontend to OpenSSL. TinyCA lets you manage x509 certificates. It is possible to export data in PEM or DER format for use with servers, as PKCS#12 for use with clients, or as S/MIME certificates for use with email programs. It is also possible to import your own PKCS#10 requests and generate certificates from them. It also lets you create and manage SubCAs for more complex setups. The most important certificate extensions can be configured with the graphical frontend. English, German, Spanish, and Czech translations are included.
PacketFence is a fully supported, trusted network access control (NAC) system. It includes a captive portal for registration and remediation, centralized wired and wireless management, 802.1X support, layer-2 isolation of problematic devices, and integration with the Snort IDS and the Nessus vulnerability scanner. It can be used to effectively secure networks, from small to very large heterogeneous networks.
AMaViS (A Mail Virus Scanner) scans e-mail attachments for viruses using third-party virus scanners available for UNIX environments. It resides on a UNIX (Linux) machine and looks through the attached files arriving via e-mail, generates reports when a virus is found and sets the delivery on hold.
Owl (Openwall GNU/*/Linux) is a small security-enhanced Linux distribution for servers. Owl also makes a good base system for customized virtual machine images and embedded systems, and Owl live CDs with remote SSH access are good for recovering or installing systems (whether with Owl or not). A single Owl CD includes the full live system, installable packages, the installer program, as well as full source code and the build environment capable of rebuilding the entire system from source. Owl supports multiple architectures (x86, x86-64, SPARC, and Alpha) and offers some compatibility for packages developed for other Linux distributions. The primary approaches to security are proactive source code review, privilege reduction, privilege separation, careful selection of third-party software, safe defaults, and "hardening" to reduce the likelihood of successful exploitation of security flaws.
fwknop implements an authorization scheme called Single Packet Authorization that requires only a single encrypted packet to communicate various pieces of information, including desired access through an iptables, ipfw, or pf firewall policy and/or specific commands to execute on the target system. The main application of this program is to protect services such as SSH with an additional layer of security in order to make the exploitation of vulnerabilities much more difficult. The authorization server works by passively monitoring authorization packets via libpcap. Also supported is a robust port knocking implementation based around iptables log messages.