Crypto++ Library is a free C++ class library of cryptographic schemes.
See <a href="http://www.cryptopp.com/">http://www.cryptopp.com/</a> for a list of supported algorithms.
One purpose of Crypto++ is to act as a repository of public domain
(not copyrighted) source code. Although the library is copyrighted as a
compilation, the individual files in it are in the public domain.