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.
OpenSC provides a set of libraries and utilities to work with smart cards. Its main focus is on cards that support cryptographic operations, and facilitates their use in security applications such as authentication, mail encryption, and digital signatures. OpenSC implements the PKCS#11 API so that applications supporting this API (such as Mozilla Firefox and Thunderbird) can use it. On the card, OpenSC implements the PKCS#15 standard, and aims to be compatible with every software/card that does so.
GNU SASL is an implementation of the Simple Authentication and Security Layer framework and a few common SASL mechanisms. SASL is used by network servers such as IMAP and SMTP to request authentication from clients, and in clients to authenticate against servers. The library includes support for the SASL framework (with authentication functions and application data privacy and integrity functions) and at least partial support for the CRAM-MD5, EXTERNAL, GSSAPI, ANONYMOUS, PLAIN, SECURID, DIGEST-MD5, LOGIN, NTLM, and KERBEROS_V5 mechanisms.
The Enhanced File Crypt/eXtended File Stealth System (EFC/XFSS) makes your uploaded files safe on the server so that no one can read them without knowing a few details to decipher the files. It generates different obfuscated names and encrypted files so no one will know what the original format or name was.
MatrixSSL is an embedded SSL and TLS implementation designed for small footprint devices and applications requiring low overhead per connection. The library is less than 50K on disk with cipher suites. It includes SSL and TLS client and server support, session resumption, and implementations of RSA, AES, 3DES, ARC4, SHA1, and MD5. The source is well documented and contains portability layers for additional operating systems, cipher suites, and cryptography providers.
Engine_pkcs11 is an implementation of an engine for OpenSSL. It can be loaded using code, config file, or command line and will pass any function call by openssl to a PKCS#11 module. Engine_pkcs11 is meant to be used with smart cards and software for using smart cards in PKCS#11 format, such as OpenSC. Originaly this engine was a part of OpenSC, until OpenSC was split into several small projects for improved flexibility.