CDSA stands for Common Data Security Architecture. It provides a security framework that includes cryptographically signed modules to present an abstracted unified API to the application developer to perform cryptographic and security related operations. It also includes hardware support for cryptographic tokens and biometric devices, such as thumbprint scanners. Intel has implemented the CDSA 2 specification and released it as open source.
Libmcrypt is a library which provides a uniform interface to several symmetric encryption algorithms. It is intended to have a simple interface to access encryption algorithms in ofb, cbc, cfb, and ecb modes. The algorithms it supports are DES, 3DES, RIJNDAEL, Twofish, IDEA, GOST, CAST-256, ARCFOUR, SERPENT, SAFER+, and more. The algorithms and modes are also modular so you can add and remove them on the fly without recompiling the library.
The MD5 message digest library implements the MD5 message digest algorithm specified in RFC 1321 directly from the specification, without copying from the reference implementation and therefore without requiring mention of RSA when used. It uses the same unrestricted-distribution license as zlib.
Mod_auth_kerb is an Apache module designed to provide Kerberos user authentication to the Apache web server. Using the Basic Auth mechanism, it retrieves a username/password pair from the browser and checks them against a Kerberos server as set up by your particular organization. It also supports mutual ticket authentication, although most browsers do not support that natively.