Function decrypt_rsa 

pub fn decrypt_rsa(
    text: &str,
    private: &RsaPrivateKey,
) -> Result<Zeroizing<Vec<u8>>, Problem>

An EncString opened with an RSA key: type 3 (OAEP-SHA256), 4 (OAEP-SHA1), 5 and 6 (the same, their MAC unused).