getting forge players modlist on a non forge server using a fake forge handshake

[Th0rgal]

Hey everybody!
 

I am the developer of a spigot plugin which allows to detect forge mods of a player. This is very useful because it allows to see when a player uses banned mods (like wurst forge for example). In order to do that I have to send a special packet (known as plugin message or PacketPkayOutCustomPayload) consisting of a String (the name of the channel) and a byte[] (the data contained in the message). Unfortunately since 1.13 this packet has changed and the channel is no longer a simple String but a MinecraftKey. This is not necessarily a problem because a MinecraftKey can be initialized from a String matching a certain regex ([^ a-z0-9 /_.-]+), the old channel being "FML|HS", the new theoretically would have been "fml:hs" or "fml:handshake", however neither of them works and I can not find any additional information on wiki.vg.
 

If anyone can help me I would be very grateful to him, Thomas!

[DiamondMiner88]

5 hours ago, Th0rgal said:

spigot plugin

This should be moved to Modder support

[Th0rgal]

On 5/19/2019 at 9:00 PM, diesieben07 said:

The mod list cannot be relied upon and you should not try to trick the client into thinking it's connected to a Forge server.

I know that this isn't perfect but it allowed me to find a lot of cheaters so it's a really nice feature. What's the problem with faking forge handshake?

[Th0rgal]

On 5/19/2019 at 6:39 PM, DiamondMiner88 said:

This should be moved to Modder support

how to do that?

[Th0rgal]

So what's the problem? The client just think that this is a forge server without any mods: there is no issue for the client. 

[Draco18s]

Well, there's still the problem that a banned mod need not report itself to the "Forge" server.

 

Remember:

The client is a lying, cheating bastard. Never, ever trust the client.