//bodyData.getBytes("UTF-8").length % 16 == 0
//如果除得尽，用NoPadding，否则ZeroPadding
string Sm4Alg = "SM4/ECB/ZeroBytePadding";
if (bodyDataLen % 16 == 0)
    Sm4Alg = "SM4/ECB/NoPadding";
var encBody = GmUtil.Sm4EncryptECB(Encoding.UTF8.GetBytes(sm4Key), bodyBytes, Sm4Alg);
var bodyData = Hex.ToHexString(encBody).ToUpper();