tech | xr.gs

Webradio via Spotify and SHOUTcast

SHOUTcast is one of the most popular software suites for web radios nowdays. But by default (read: without much hassle) the only way to broadcast sounds is via Winamp and its SHOUTcast plugin. However, when ludde from Spotify created his tribute Spotiamp, he included an embedded SHOUTcast server so you could stream Spotify via SHOUTcast to Sonos devices etc.

But this also makes it possible to setup a web radio that streams via Spotify, by using the stream relay function in SHOUTcast DNAS server.
(The reason Spotiamp alone can’t act as a SHOUTcast server is because it doesn’t support more than one connected client)

Step 1

Obviously, install Spotiamp. Then enable its SHOUTcast server on the default address.

Step 2

Install SHOUTcast DNAS from their website. Configure DNAS to your liking, but in your stream config, specify the streamrelayurl/relayurl as your Spotiamp SHOUTcast url.

(Look at your specific DNAS version for the correct way to do this)

After this Spotiamp should be feeding the SHOUTcast DNAS server live music and a title.

Security patches for CoD4 servers

August 5, 2014 assembly cod4 security tech

Call of Duty 4 has been a popular game for many years, and its population has remained even though newer Call of Duty titles have been released.

Long time ago the CoD 4 servers I was maintaining were being targeted by hackers that had found a new method to become unbannable on Call of Duty 4 servers.
The exploit was based on the fact that cracked Call of Duty 4 servers never verified user GUID’s and therefore allowed all players, even cracked, to connect. As the server skipped verifying GUIDs towards a master server, anything could be sent to the server, while the server itself was only prepared to get a 32 char hash in the range of 0123456789abcdef.

This caused issues with external admin tools and banning players (which is done by GUID), because they in turn also only expected 0123456789abcdef, and hackers were sending all kinds of russian/hebrew/random characters.

Solution

To solve this the servers had to be patched with a custom routine that validated player GUID’s to their normal format [0-9a-z]{32}, and killed any connecting players not matching that.

Luckily, CoD4 is based on Quake 3 Arena which has an open source nowdays, so I found a pretty worthless function that normally validates if an IP is local or external, and overwrote it with my custom Assembly. =)

In short, it does: