I'm looking for a free C or C++ cryptography library that can be embedded in a closed-source applicationand supports RSA public-key cyphering. I've found OpenSSL and Crypto++ but neither have a good documentation for a beginner.
Anyone knows a good, free, C or C++ cryptography library with a decent documentation for a starter?
Or maybe a link to a good Starter Guide for Crypto++ or OpenSSL.
I'd say try again with Crypto++, I have used it, it's mature, popular, provides a lot of algorithms, abstraction(C++-style) to make encrypting a file or a string only a couple of lines away, and it has a non-viral license.
Are you on windows?
If so then use the Cryptographic Next Generation (CNG) crypto algorithms. They are all FIPS certified and have been tested. Of course you can also link to these in a closed source application, but only if you are on windows.