从C＃中的sha512加密消息计算校验和

Question

我需要使用hmac-sha512算法调用身份验证。要使用密钥加密的邮件（例如： vU372pd8pS4AN2XEzt2aQn6CRq6dT5 ）是：

“ entityReference = 3000001222＆caseReference = SilviaTemplate1＆type = 16＆name = example_WS2.jpg＆content = [binary]” 。

我的代码：

public string ChecksumCalc(string entityReference, string caseReference, string type,string name, byte[] content, string key)
    {
        string message = "entityReference=" + entityReference + "&caseReference=" + caseReference + "&type=" + type + "&name=" + name + "&content=" + BitConverter.ToString(content).Replace("-",string.Empty).ToLower();

        string checksum = "";
        try
        {
            var encoding = new System.Text.ASCIIEncoding();
            byte[] keyByte = encoding.GetBytes(key);
            byte[] messageBytes = encoding.GetBytes(message);

            using (var hmacsha512 = new HMACSHA512(keyByte))
            {
                byte[] hashmessage = hmacsha512.ComputeHash(messageBytes);
                //First method
                checksum = BitConverter.ToString(hashmessage).Replace("+", "").Replace("/", "").Replace("=", "").Replace("-", "").ToLower();

                //Second method
                StringBuilder hex = new StringBuilder(hashmessage.Length * 2);
                foreach (byte b in hashmessage)
                    hex.AppendFormat("{0:x2}", b);
                checksum = hex.ToString();

                //Same result
            }

            Console.WriteLine(checksum);
        }
        catch (Exception ex)
        {
            log.Error("Error on checksumCalc. Exception: " + ex.Message);
            throw ex;
        }

        return checksum;
    }

我评论了我的其他尝试可以解决我的问题，但是没有用。