public static string GenerateAuthenticatedMessage(string message, long timestamp, string password)
{
if (message.Contains(":[:BR:]:"))
{
throw new MessageUnallowedCharsException("Message can't contain :[:BR:]:");
}
var prepare = message + ":[:BR:]:" + Convert.ToString(timestamp);
return(prepare + ":[:BR:]:" + Sha.HashToString(Sha.Sha512Hmac(Sha.Sha512(password), new UTF8Encoding().GetBytes(prepare))));
}
public static AuthenticatedMessage AuthenticateMessage(string message, long timestamp, string password)
{
if (!message.Contains(":[:BR:]:"))
{
throw new MessageAuthenticationFailureException("Malformed message.");
}
var msg = message.Split(new string[] { ":[:BR:]:" }, StringSplitOptions.None);
if (msg.Length < 2 || msg.Length > 3)
{
throw new MessageAuthenticationFailureException("Malformed message.");
}
if (msg[1] == "Guest")
{
return(new AuthenticatedMessage(msg[0], false));
}
try
{
if (!Time.ValidateTimestamp(timestamp, Convert.ToInt64(msg[1]), 5000))
{
throw new MessageExpiredException();
}
}
catch (MessageExpiredException)
{
throw new MessageAuthenticationFailureException();
}
catch
{
throw new MessageAuthenticationFailureException("Malformed message - timestamp can't be converted to long.");
}
if (Sha.HashToString(Sha.Sha512Hmac(Sha.Sha512(password), new UTF8Encoding().GetBytes(msg[0] + ":[:BR:]:" + msg[1]))) != msg[2])
{
throw new MessageAuthenticationFailureException("Invalid authentication code.");
}
return(string.IsNullOrEmpty(password) || password == "none" ? new AuthenticatedMessage(msg[0], false) : new AuthenticatedMessage(msg[0], true));
}
