(Check out SQL Injection #1 and #2 for context)

DIFFICULTY: Expert
LANGUAGE: Lua


After a recent surge in account theft, the website owners have again decided to increase the security.
The passwords can be a string of any size.
The passwords are stored in an encrypted state in user_data and require decryption to be used.
Your objective is to have the verify function return true.

As long as you only edit below the line, the way you accomplish this does not matter, as long as you do not override the verify function


do
local sub = string.sub

global_key = 2

local private_key = math.random(3)
local timeout = 2 -- can only use valid twice before returning nil

local user_data = {
Waffloid = {
password='ilikechicken'..math.random(11),
cash_balance=40735
}
}

for user,data in pairs(user_data) do
data.password = data.password:rep(global_key+private_key) -- encrypts password
end

function valid(user,pass)
local user = user_data[user]
if user then
local rep_key = global_key+private_key
local success= pcall(function()
local bin = pass + user
end)
if not success and timeout ~= 0 then -- should error or else something is fishy
timeout = timeout + 1 -- OOPS
return sub(user.password,1,#user.password/(rep_key))==pass
end
end
end
end

----- ONLY EDIT BELOW THIS LINE