pub unsafe extern "C" fn sgx_calculate_ecdsa_priv_key(
    hash_drg: *const u8,
    hash_drg_len: i32,
    sgx_nistp256_r_m1: *const u8,
    sgx_nistp256_r_m1_len: i32,
    out_key: *mut u8,
    out_key_len: i32
) -> SgxStatus