// Visible for testing.
internal static IList <IPEndPoint> ParseUserList(IEnumerable <string> userNames)
{
var addresses = new List <IPEndPoint>();
foreach (var user in userNames)
{
// All BitCoin peers start their nicknames with a 'u' character.
if (!user.StartsWith("u"))
{
continue;
}
// After "u" is stripped from the beginning array contains unsigned chars of:
// 4 byte IP address, 2 byte port, 4 byte hash check (ipv4)
byte[] addressBytes;
try
{
// Strip off the "u" before decoding. Note that it's possible for anyone to join these IRC channels and
// so simply beginning with "u" does not imply this is a valid BitCoin encoded address.
//
// decodeChecked removes the checksum from the returned bytes.
addressBytes = Base58.DecodeChecked(user.Substring(1));
}
catch (AddressFormatException)
{
_log.WarnFormat("IRC nick does not parse as base58: {0}", user);
continue;
}
// TODO: Handle IPv6 if one day the official client uses it. It may be that IRC discovery never does.
if (addressBytes.Length != 6)
{
continue;
}
var ipBytes = new[] { addressBytes[0], addressBytes[1], addressBytes[2], addressBytes[3] };
var port = Utils.ReadUint16Be(addressBytes, 4);
var ip = new IPAddress(ipBytes);
var address = new IPEndPoint(ip, port);
addresses.Add(address);
}
return(addresses);
}