About the OpenSSL/GPL issue.

The LibRHash is compiled with runtime loading of the OpenSSL library.
It loads OpenSSL assembly optimized algorithms only if package libssl is installed.
The SHA1, for example, is computed 2 times faster with OpenSSL loaded.

If a GPL program uses LibRHash, then the library acts as a wrapper to libssl.
The LibRHash exports only its own ABI, thus solving the OpenSSL/GPL
incompatibility issue.

In any way, calling rhash_set_openssl_mask(0) before rhash_library_init()
explicitly prevents LibRHash from loading OpenSSL.