Dar is a shell command that makes backup of a directory tree and files. Its features include splitting archives over several files, DVD, CD, ZIP, or floppies, compression, full or differential backups, strong encryption, proper saving and restoration of hard links, extended attributes, file forks, Door inodes, and sparse files, remote backup using pipes and external commands (such as ssh), and rearrangement of the "slices" of an existing archive. It can run commands between slices, before and after saving some defined files or directories (for a proper database backup, for example), and quickly retrieve individual files from differential and full backups. Several external GUIs exist as alternatives to its CLI interface, like kdar, DarGUI, SaraB, etc.
Botan is a crypto library written in C++. It provides a variety of cryptographic algorithms, including common ones such as AES, MD5, SHA, HMAC, RSA, Diffie-Hellman, DSA, and ECDSA, as well as many others that are more obscure or specialized. It also offers SSL/TLS (client and server), X.509v3 certificates and CRLs, and PKCS #10 certificate requests. A message processing system that uses a filter/pipeline metaphor allows for many common cryptographic tasks to be completed with just a few lines of code. Assembly and SIMD optimizations for common CPUs offers speedups for critical algorithms like AES and SHA-1.
OpenVPN is a robust and highly configurable VPN (Virtual Private Network) daemon which can be used to securely link two or more private networks using an encrypted tunnel over the Internet. OpenVPN's principal strengths include wide cross-platform portability, excellent stability, support for dynamic IP addresses and NAT, adaptive link compression, single TCP/UDP port usage, a modular design that offloads most crypto tasks to the OpenSSL library, and relatively easy installation that in most cases doesn't require a special kernel module.
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.
Stegdetect is an automated tool for detecting steganographic content in images. It is capable of detecting several different steganographic methods to embed hidden information in JPEG images. Currently, the detectable schemes are jsteg, jphide, invisible secrets, outguess 01.3b, F5, appendX, and camouflage. Using linear discriminant analysis, it also supports detection of new stego systems. Stegbreak is used to launch dictionary attacks against JSteg-Shell, JPHide, and OutGuess 0.13b.
vpnd is a daemon which connects two networks on network level either via TCP/IP or a (virtual) leased line attached to a serial interface. All data transfered between the two networks are encrypted using the unpatented free Blowfish encryption algorithm with a key length of up to 576 bits (may be downgraded to a minimum of 0 bits to suit any legal restrictions).
The Shrew Soft VPN Client for Unix is a free IPsec Client for FreeBSD, NetBSD, and Linux based operating systems. It can be used to communicate with systems running ipsec-tools. The Unix client utilizes the IPsec kernel support included with the operating system, and comes with the complete Internet Key Exchange daemon and client front end application source code. A Windows version is also available.
Suhosin is an advanced protection system for PHP installations. It was designed to protect servers and users from known and unknown flaws in PHP applications and the PHP core. Suhosin comes in two independent parts that can be used separately or in combination. The first part is a small patch against the PHP core that implements a few low-level protections against buffer overflows or format string vulnerabilities. The second part is a powerful PHP extension that implements all the other protections. Suhosin is binary compatible with plain PHP installations.