Provides OpenSSL::SignatureAlgorithm::ECDSA, OpenSSL::SignatureAlgorithm::RSAPSS and OpenSSL::SignatureAlgorithm::RSAPKCS1 ruby object wrapers on top of OpenSSL::PKey::EC and OpenSSL::PKey::RSA, so that one can reason in terms of signature algorithms when signing and/or verifying signatures, instead of keys.