RSA_meth_get_priv_dec
LCRYPTO_USED(RSA_meth_get_priv_dec);
int (*RSA_meth_get_priv_dec(const RSA_METHOD *meth))(int flen,
LCRYPTO_ALIAS(RSA_meth_get_priv_dec);
return (RSA_meth_get_priv_dec(rsa_default)(flen, from, to, rsa, padding));