Create API to sign data / verify signature using RSA/OpenSSL

The suggestions is to develop API which will allow to achieve this without the necessity to use OpenSSL directly.

Qt already using OpenSSL and probably it already has all the required algorithms in its code (maybe in QSslSocket implementation).

Two things will be required:

1. Generate/load private/public RSA keys.
2. Create/verify signature using these keys from step 1.

Addition #1. OK, it seems there is no need to generate key pair programmatically. Please see my attached file as an example and probably API design proposal.