//轉2進制
public static string HmacSHA256(string message, string secret)
{
secret = secret ?? "";
var encoding = new System.Text.UTF8Encoding();
byte[] keyByte = encoding.GetBytes(secret);
byte[] messageBytes = encoding.GetBytes(message);
using (var hmacsha256 = new HMACSHA256(keyByte))
{
byte[] hashmessage = hmacsha256.ComputeHash(messageBytes);
StringBuilder builder = new StringBuilder();
for (int i = 0; i < hashmessage.Length; i++)
{
builder.Append(hashmessage[i].ToString("x2"));
}
return builder.ToString();
}
}