I don't know too much about this, but I think I have some knowledge of what's going on.
Forge sends an extra bit of data: "/00FML/00" in it's handshake between the client and a server (I believe). I want someone to make a simple mod where I can change that extra handshake data, let's say from "/00FML/00" to "/00Forge Mod Loader/00". That's it. No GUI or anything fancy, if I want to change the data, I will just edit the source code of the mod.
Surely it can't be TOO hard. I would do it myself but I don't have much free time on my hands. I'm willing to pay $4 USD if someone can make this. MUST NOT BE OBFUSCATED!
Thanks for reading.
EDIT: Apparently the $4 incentive is not a good idea ¯\_(ツ)_/¯
I doubt a mod like this can circumvent a server ban. Non-forge servers will simply discard the extra details of the handshake packet, and normal Forge servers would just think that the client is not using any mods. If you are talking about a server that verifies the client by looking for extra bits in the handshake, I doubt anyone would be stupid enough to implement such a system.
Perhaps not everything in this world is evil, and sometimes we should give people the benefit of the doubt?
Blind trust or not, I am pretty sure this mod is unable to do any harmful things, and therefore I don't believe this request is suspicious. Can you even give me a scenario that such a mod can do any harm? Your suspicion of OP's intent seems to be more of a trust issue rather than actual rational suspicion.
You really have no idea of what you're talking about, do you?
The difference between a vanilla C00Handshake and a forge C00Handshake is that Forge adds '\00FML\00' in the IP field. The purpose is to let the client knows if the server has forge installed, not letting the server know what mod the client has installed. What OP is saying is that he wished to change this tag to something else. No matter what the intention is, this mod is unlikely to do any shady stuff.
Edit: This website probably explains way better than I can. As you can see, the part where client and server sends each others' mod list is way after C00Handshake is sent.
Another edit: In case you need even more proof, take a look at the source code of Forge. The Modlist packet is completely different than C00Handshake. They are two completely different and seperate packets.