public static String signatureString message String sm4key String prvKey byte messageByte; try JObject jsonObject = JObjectParsemessage;

public static string Signature(string message, string sm4key, string prvKey) { byte[] messageByte; try { JObject jsonObject = JObject.Parse(message); removeEmpty(jsonObject); messageByte = SignUtil.getSignText(jsonObject, sm4key).getBytes("UTF-8"); } catch (Exception e) { messageByte = Encoding.UTF8.GetBytes(message); } byte[] chnlSecretByte = Encoding.UTF8.GetBytes(sm4key); byte[] prvkey = Convert.FromBase64String(prvKey); return Convert.ToBase64String(EasyGmUtils.signSm3WithSm2(messageByte, chnlSecretByte, prvkey));