Function nettle::ed25519::sign

pub fn sign(
    public: &[u8], 
    private: &[u8], 
    msg: &[u8], 
    signature: &mut [u8]
) -> Result<()>

Signs the message msg using the given public/private, producing signature. Fails if public or private is not ED25519_KEY_SIZE bytes large or if signature is not ED25519_SIGNATURE_SIZE bytes.