Hello,

I recently began working on integrating with the new Webhook API to subscribe to events.  This is being integrated into an existing ASP.NET solution written in C#.  I would like to validate webhook messages using the X-ANET-Signature header, but so far have not been able to produce a matching signature in my test setup.  My code is as follows:

        protected void Page_Load(object sender, EventArgs e)
        {

                string keytext = "MY AUTHORIZE.NET SIGNATURE KEY";

                byte[] key = HexDecode(keytext);

                HMACSHA512 hmacsha = new HMACSHA512(key);

                byte[] hash = hmacsha.ComputeHash(Request.InputStream);

                string computedHash = HashEncode(hash);

                 //compare with the X-ANET-Signature, they don't match
        }

        private static byte[] HexDecode(string hex)
        {
            var bytes = new byte[hex.Length / 2];
            for (int i = 0; i < bytes.Length; i++)
            {
                bytes[i] = byte.Parse(hex.Substring(i * 2, 2), NumberStyles.HexNumber);
            }
            return bytes;
        }

        private static string HashEncode(byte[] hash)
        {
            return BitConverter.ToString(hash).Replace("-", "").ToLower();
        }

Any guidance would be much appreciated!