Current File : //opt/imunify360-webshield/nginx/lua/splashscreen.lua
local template = require 'resty.template'
local digest = require('openssl').digest
local splashscreen_sessions = ngx.shared.splashscreen_sessions
local function make_temp_uid()
local user_agent = ngx.var.http_user_agent or 'missing_agent'
local user_data = ngx.var.remote_addr .. user_agent .. tostring(ngx.now())
local hashsum = digest.digest('sha1', user_data, false)
return hashsum
end
local function generate(seq)
local function split(data)
local buffer = {}
for i in data:gmatch("%w") do
table.insert(buffer, tonumber(i))
end
return buffer
end
local digits = split(seq)
local ready = {}
for i, v in ipairs(digits) do
local buffer = {"("}
local item = "+!![]"
if v == 0 then
table.insert(buffer, "+![]")
elseif v == 1 then
table.insert(buffer, "+!+[]")
else
table.insert(buffer, "+!+[]")
for i = 1, v - 1 do
table.insert(buffer, item)
end
end
if i % 2 == 0 then
table.insert(buffer, "+[]")
end
table.insert(buffer, ")")
table.insert(ready, table.concat(buffer, ""))
end
return "+(" .. table.concat(ready, "+") .. ")"
end
local function prepare_data()
local uri = ngx.var.request_uri
local uri_parts = {ngx.var.scheme, '://', ngx.var.host}
local destination_port = ngx.var.destination_port
if destination_port ~= '80' and destination_port ~= '443' then
table.insert(uri_parts, ':' .. destination_port)
end
if uri ~= '' and uri ~= '/' then
table.insert(uri_parts, uri)
end
local userid = make_temp_uid() -- generate temporary UID (SHA1 hashsum)
local _start = tonumber(userid:sub(0, 6), 16) -- take first six symbols and last six ones and
local _stop = tonumber(userid:sub(-6), 16) -- convert them to decimal
local _w = generate(tostring(_start)) -- generate 2 JS check sequences from the decimals
local _e = generate(tostring(_stop))
local sum = _start + _stop -- Find the sum of the decimals and convert it to hex
local xsum = string.format("%X", sum)
-- place original URI to shared dictionary with the hex sum as key
splashscreen_sessions:set(xsum, table.concat(uri_parts), 60)
return {
westval=_w,
eastval=_e
}
end
local accept = ngx.var.http_accept
if accept ~= nil and string.find(string.lower(accept), "json") ~= nil then
ngx.header["Content-Type"] = "application/json"
ngx.say('{"message": "Access denied by Imunify360 bot-protection. IPs used for automation should be whitelisted"}')
elseif accept ~= nil and string.find(accept, "text/") == nil and accept ~= "*/*" then
ngx.status = 415 -- return custom error code
ngx.say("")
else
local vars = prepare_data()
template.render('index.html', vars, 'splashscreen')
end
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