(This is purely to make sure roblox’s search engine makes this thread pop up on search)
Anti Cheat RemoteEvent RemoteFunction Dynamic Communication Anti Exploit [hookmetamethod]
Here’s a script I wrote together for my future portfolios and to help people who doesn’t know what a handshake is or how to write one.
Before you start throwing shade on me for using Base64 encoding / decoding, IT SHOULD NOT BE USED IN PRODUCTION. Base64 is a well known Encoding function which itself makes it really unsafe to use it as a main Encoding function. I Recommend changing the Encoding function + Decoding function to something more complex.
Usage :
Handshakes main usage is to make sure the client behaves a certain way through server confirmation.
Can be used to detect whenever a certain localscript has been disabled, removed or destroyed.
Can be used to detect whenever a exploiter is trying to yield a RemoteEvent.
You need :
3 Module Scripts,1 ServerScript,1 LocalScript and 1 RemoteEvent (ReplicatedStorage)
(See picture at the end of the thread if struggling to understand)
Server Script Code (Parent of ConfigurationModule and DecodingModule)
ServerScript
-- // Service variables
local HttpService = game.HttpService
local ReplicatedStorage = game.ReplicatedStorage
-- // Module variables
local Configuration = require(script.Configuration)
local Decoding = require(script.Decoding)
-- // Remote
local RemoteEvent = ReplicatedStorage.RemoteEvent
-- // Player storage variables
local PlayerLastCommunications = {}
local PlayerThreads = {}
game.Players.PlayerAdded:Connect(function(Player)
-- // Create a Player specific thread for each player in the upon join
PlayerThreads[Player] = task.spawn(function()
-- // Set values of Player specific communications(sent / recieved)
PlayerLastCommunications[Player] = {
Numbers = {
Sent = 0,
Misses = 0,
},
Strings = {
GeneratedKey = "",
CurrentKey = "",
},
}
while task.wait(Configuration.Numbers.CommunicationSpeed) do
-- // Timeout detection trigger
if PlayerLastCommunications[Player].Numbers.Sent and PlayerLastCommunications[Player].Numbers.Misses >= 1 then
if tick() - PlayerLastCommunications[Player].Numbers.Sent > Configuration.Numbers.TimeoutLimit then
PlayerLastCommunications[Player].Numbers.Misses += Configuration.Numbers.TimeoutLimit * 2
end
end
-- // Timeout punishment
if PlayerLastCommunications[Player].Numbers.Misses >= Configuration.Numbers.TimeoutLimit then
Player:Kick("Handshake timeout")
else
PlayerLastCommunications[Player].Numbers.Misses = 0
end
-- // Generate a new key for every player every 1 second
PlayerLastCommunications[Player].Strings.GeneratedKey = HttpService:GenerateGUID(false)
-- // Pass a Client the new key
RemoteEvent:FireClient(Player, PlayerLastCommunications[Player].Strings.GeneratedKey)
-- // Reset
PlayerLastCommunications[Player].Numbers.Misses += 1
end
end)
end)
RemoteEvent.OnServerEvent:Connect(function(Player, PassedKey)
-- // Type check
if type(PassedKey) ~= "string" then
Player:Kick("Key must be string")
end
-- // Decode key and store it as Player specific
PlayerLastCommunications[Player].Strings.CurrentKey = Decoding.Decode(PassedKey)
-- // Check if key has changed or not
if PlayerLastCommunications[Player].Strings.GeneratedKey ~= PlayerLastCommunications[Player].Strings.CurrentKey then
Player:Kick("Key missmatch")
end
-- // Timeout reset
PlayerLastCommunications[Player].Numbers.Sent = tick()
end)
game.Players.PlayerRemoving:Connect(function(Player)
-- // Clears all Player specific values upon leaving
PlayerLastCommunications[Player] = nil
task.defer(PlayerThreads[Player])
PlayerThreads[Player] = nil
end)
ConfigurationModule (Child of ServerScript)
ConfigurationModule
local ConfigurationModule = {
Numbers = {
TimeoutLimit = 3,
CommunicationSpeed = 1,
},
}
return ConfigurationModule
DecodingModule (Child of ServerScript)
DecodingModule
local DecodingModule = {
Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
}
-- // Base64 decoding [I didn't write this]
DecodingModule.Decode = function(Data)
Data = string.gsub(Data, '[^'..DecodingModule.Alphabet..'=]', '')
return (Data:gsub('.', function(x)
if (x == '=') then return '' end
local r,f='',(DecodingModule.Alphabet:find(x)-1)
for i=6,1,-1 do r=r..(f%2^i-f%2^(i-1)>0 and '1' or '0') end
return r;
end):gsub('%d%d%d?%d?%d?%d?%d?%d?', function(x)
if (#x ~= 8) then return '' end
local c=0
for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(8-i) or 0) end
return string.char(c)
end))
end
return DecodingModule
LocalScript (Parent of EncodingModule)
LocalScript
if not game:IsLoaded() then
game.Loaded:Wait()
end
-- // Variables
local Encoding = require(script.Encoding)
local RemoteEvent = game:GetService("ReplicatedStorage").RemoteEvent
RemoteEvent.OnClientEvent:Connect(function(RecievedKey)
-- // Upon client receiving key we Encode the Key and pass the newly encoded key to the server
RecievedKey = Encoding.Encode(RecievedKey)
RemoteEvent:FireServer(RecievedKey)
end)
EncodingModule (Child of LocalScript)
EncodingModule
local EncodingModule = {
Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
}
-- // Base64 encoding [I didn't write this]
EncodingModule.Encode = function(Data)
return ((Data:gsub('.', function(x)
local r,b='',x:byte()
for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end
return r;
end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x)
if (#x < 6) then return '' end
local c=0
for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end
return EncodingModule.Alphabet:sub(c+1,c+1)
end)..({ '', '==', '=' })[#Data%3+1])
end
return EncodingModule
If you struggled to understand how it was set up then here’s a picture.
