Autossh is a program to monitor and automatically reestablish SSH connections. It is similar to rstunnel (Reliable SSH Tunnel), however, it is implemented in C, and is easier to set up and use, especially for connections to multiple hosts. Autossh has been compiled and tested on OpenBSD, Linux, and Solaris, and should run without needing changes on FreeBSD and NetBSD.
BFBTester is good for doing quick, proactive security checks of binary programs. BFBTester will perform checks of single and multiple argument command line overflows and environment variable overflows. It can also watch for tempfile creation activity to alert the user of any programs using unsafe tempfile names.
C-Kermit is a combined serial and network communication software package offering a consistent, medium-independent, cross-platform approach to connection establishment, terminal sessions, file transfer, character-set translation, numeric and alphanumeric paging, and automation of communication tasks. Recent versions include FTP and HTTP clients as well as an SSH interface, all of which can be scripted and aware of character-sets. It supports built-in security methods, including Kerberos IV, Kerberos V, SSL/TLS, and SRP, FTP protocol features such as MLSD, and source-code parity with Kermit 95 2.1 for Windows and OS/2.
Campagnol is a distributed IP-based VPN program able to open new connections through NATs or firewalls without any configuration. It uses UDP for the transport layer, and utilizes tunneling and encryption (with DTLS) and the UDP hole punching NAT traversal technique. The established connections are P2P.
CyaSSL is a C-language-based SSL library targeted for embedded and RTOS environments, primarily because of its small size and speed. CyaSSL supports the industry standards up to the current TLS 1.2 level, is up to 20 times smaller than OpenSSL, includes SSL client libraries and an SSL server implementation, includes an OpenSSL compatibility layer, and offers several progressive ciphers such as RABBIT and HC-128. Dual licensed under both the GPLv2 and standard commercial licensing, it caters to a wide range of projects.
DansGuardian is a Web content filtering proxy that uses Squid to do all the fetching. It filters using multiple methods including, but not limited to, phrase matching, file extension matching, MIME type matching, PICS filtering, and URL/domain blocking. It has the ability to switch off filtering by certain criteria including username, domain name, source IP, etc. The configurable logging produces a log in an easy to read format. It has the option to only log text-based pages, thus significantly reducing redundant information (such as every image on a page).
Email Security through Procmail (the Procmail Sanitizer) provides methods to sanitize email, removing obvious exploit attempts and disabling the channels through which exploits are delivered. Facilities for detecting and blocking Trojan Horse exploits and worms are also provided.
Ettercap is a network sniffer/interceptor/logger for ethernet LANs. It supports active and passive dissection of many protocols (even ciphered ones, like SSH and HTTPS). Data injection in an established connection and filtering on the fly is also possible, keeping the connection synchronized. Many sniffing modes were implemented to give you a powerful and complete sniffing suite. Plugins are supported. It has the ability to check whether you are in a switched LAN or not, and to use OS fingerprints (active or passive) to let you know the geometry of the LAN.