--[[
Introduction and details :
Copyright Conor McKnight
https://github.com/C0nw0nk/Nginx-Lua-Anti-DDoS
Information :
My name is Conor McKnight I am a developer of Lua, PHP, HTML, Javascript, MySQL, Visual Basics and various other languages over the years.
This script was my soloution to check web traffic comming into webservers to authenticate that the inbound traffic is a legitimate browser and request,
It was to help the main internet structure aswell as every form of webserver that sends traffic by HTTP(S) protect themselves from the DoS / DDoS (Distributed Denial of Service) antics of the internet.
If you have any bugs issues or problems just post a Issue request. https://github.com/C0nw0nk/Nginx-Lua-Anti-DDoS/issues
If you fork or make any changes to improve this or fix problems please do make a pull request for the community who also use this. https://github.com/C0nw0nk/Nginx-Lua-Anti-DDoS/pulls
Disclaimer :
I am not responsible for what you do with this script nor liable,
This script was released under default Copyright Law as a proof of concept.
For those who want to know what that means for your use of this script read the following : http://choosealicense.com/no-license/
Legal Usage :
For those who wish to use this in production you should contact me to purchase a private license to use this legally.
For those who wish to use this in a commerical enviorment contact me to come to an agreement and purchase a commerical usage license.
For those who wish to purchase the rights to this from me contact me also to discuss pricing and terms and come to a sensible agreement.
Contact : (You can also contact me via github)
https://www.facebook.com/C0nw0nk
]]
--[[
Configuration :
]]
local AntiDDoSAuth = AntiDDoSAuth or {} --Define our local Table to easly change the name at anytime to prevent collisions with other scripts or global Lua variables on the server.
--[[
Shared memory cache
]]
--AntiDDoSAuth.shared_memory = ngx.shared.antiddos_auth_memory_space --What ever memory space your server has set / defined for this to use
--[[
This is a password that encrypts our puzzle and cookies unique to your sites and servers you should change this from the default.
]]
local secret = " enigma" --Signature secret key --CHANGE ME FROM DEFAULT!
--[[
Unique id to identify each individual user and machine trying to access your website IP address works well.
ngx.var.http_cf_connecting_ip --If you proxy your traffic through cloudflare use this
ngx.var.http_x_forwarded_for --If your traffic is proxied through another server / service.
ngx.var.remote_addr --Users IP address
ngx.var.binary_remote_addr --Users IP address in binary
ngx.var.http_user_agent --use this to protect Tor servers from DDoS
You can combine multiple if you like. You can do so like this.
local remote_addr = ngx.var.remote_addr .. ngx.var.http_user_agent
]]
local remote_addr = ngx.var.remote_addr --Users IP address
--[[
How long when a users request is authenticated will they be allowed to browse and access the site until they will see the auth page again.
The time is expressed in seconds.
None : 0 (This would result in every page and request showing the auth before granting access) --DO NOT SET AS 0 I recommend nothing less than 30 seconds.
One minute: 60
One hour: 3600
One day: 86400
One week: 604800
One month: 2628000
One year: 31536000
Ten years: 315360000
]]
local expire_time = 86400 --One day
--[[
The type of javascript based pingback authentication method to use if it should be GET or POST or can switch between both making it as dynamic as possible.
1 = GET
2 = POST
3 = DYNAMIC
]]
local javascript_REQUEST_TYPE = 3 --Default 3
--[[
Timer to refresh auth page
Time is in seconds only.
]]
local refresh_auth = 5
--[[
Javascript variable checks
These custom javascript checks are to prevent our authentication javascript puzzle / question being solved by the browser if the browser is a fake ghost browser / bot etc.
Only if the web browser does not trigger any of these or does not match conditions defined will the browser solve the authentication request.
]]
local JavascriptVars_opening = [[
if(!window._phantom || !window.callPhantom){/*phantomjs*/
if(!window.__phantomas){/*phantomas PhantomJS-based web perf metrics + monitoring tool*/
if(!window.Buffer){/*nodejs*/
if(!window.emit){/*couchjs*/
if(!window.spawn){/*rhino*/
if(!window.webdriver){/*selenium*/
if(!window.domAutomation || !window.domAutomationController){/*chromium based automation driver*/
if(!window.document.documentElement.getAttribute("webdriver")){
/*if(navigator.userAgent){*/
if(!/bot|curl|kodi|xbmc|wget|urllib|python|winhttp|httrack|alexa|ia_archiver|facebook|twitter|linkedin|pingdom/i.test(navigator.userAgent)){
/*if(navigator.cookieEnabled){*/
/*if(document.cookie.match(/^(?:.*;)?\s*[0-9a-f]{32}\s*=\s*([^;]+)(?:.*)?$/)){*//*HttpOnly Cookie flags prevent this*/
]]
--[[
Javascript variable blacklist
]]
local JavascriptVars_closing = [[
/*}*/
/*}*/
}
/*}*/
}
}
}
}
}
}
}
}
]]
--[[
Javascript Puzzle for web browser to solve do not touch this unless you understand Javascript, HTML and Lua
]]
--Simple static Javascript puzzle where every request all year round the question and answer would be the same pretty predictable for bots.
--local JavascriptPuzzleVars = [[22 + 22]] --44
--local JavascriptPuzzleVars_answer = "44" --if this does not equal the equation above you will find access to your site will be blocked make sure you can do maths!?
--Make our Javascript puzzle a little bit more dynamic than the static equation above it will change every 24 hours :) I made this because the static one is pretty poor security compared to this but this can be improved allot though.
--TODO: IMPROVE THIS!
local JavascriptPuzzleVars = [[]] .. os.date("%Y%m%d",os.time()-24*60*60) .. [[ + ]] .. os.date("%d%m%Y",os.time()-24*60*60) ..[[]] --Javascript output of our two random numbers
local JavascriptPuzzleVars_answer = os.date("%Y%m%d",os.time()-24*60*60) + os.date("%d%m%Y",os.time()-24*60*60) --lua output of our two random numbers
local JavascriptPuzzleVars_answer = math.floor(JavascriptPuzzleVars_answer+0.5) --fix bug removing the 0. decimal on the end of the figure
local JavascriptPuzzleVars_answer = tostring(JavascriptPuzzleVars_answer) --convert the numeric output to a string
--ngx.log(ngx.ERR, "expected answer"..JavascriptPuzzleVars_answer) --output the answer to the log
--[[
X-Auth-Header to be static or Dynamic setting this as dynamic is the best form of security
1 = Static
2 = Dynamic
]]
local x_auth_header = 2 --Default 2
local x_auth_header_name = "x-auth-answer" --the header our server will expect the client to send us with the javascript answer this will change if you set the config as dynamic
--[[
Cookie Anti-DDos names
]]
local challenge = "__uip" --this is the first main unique identification of our cookie name
local cookie_name_start_date = challenge.."_start_date" --our cookie start date name of our firewall
local cookie_name_end_date = challenge.."_end_date" --our cookie end date name of our firewall
local cookie_name_encrypted_start_and_end_date = challenge.."_combination" --our cookie challenge unique id name
--[[
Anti-DDoS Cookies to be Encrypted for better security
1 = Cookie names will be plain text above
2 = Encrypted cookie names unique to each individual client/user
]]
local encrypt_anti_ddos_cookies = 2 --Default 2
--[[
Encrypt/Obfuscate Javascript output to prevent content scrappers and bots decrypting it to try and bypass the browser auth checks. Wouldn't want to make life to easy for them now would I.
0 = Random Encryption Best form of security and default
1 = No encryption / Obfuscation
2 = Base64 Data URI only
3 = Hex encryption
4 = Base64 Javascript Encryption
]]
local encrypt_javascript_output = 0
--[[
IP Address Whitelist
Any IP Addresses specified here will be whitelisted to grant direct access to your site bypassing our firewall checks
you can specify IP's like search engine crawler ip addresses here most search engines are smart enough they do not need to be specified,
Major search engines can execute javascript such as Google, Yandex, Bing, Baidu and such so they can solve the auth page puzzle and index your site same as how companies like Cloudflare, Succuri, BitMitigate etc work and your site is still indexed.
]]
local ip_whitelist_remote_addr = ngx.var.remote_addr --Users IP address
local ip_whitelist = {
--"127.0.0.1", --localhost
--"192.168.0.1", --localhost
}
--[[
IP Address Blacklist
To block access to any abusive IP's that you do not want to ever access your website
]]
local ip_blacklist_remote_addr = ngx.var.remote_addr --Users IP address
local ip_blacklist = {
--"127.0.0.1", --localhost
--"192.168.0.1", --localhost
}
--[[
TODO:
Google ReCaptcha
]]
--[[
Charset output of HTML page and scripts
]]
local default_charset = "utf-8"
--[[
End Configuration
Users with little understanding don't edit beyond this point you will break the script most likely. (You should not need to be warned but now you have been told.) Proceed at own Risk!
Please do not touch anything below here unless you understand the code you read and know the consiquences.
This is where things get very complex. ;)
]]
--[[
Begin Required Functions
]]
--function to check if ip address is whitelisted to bypass our auth
local function check_ip_whitelist(ip_table)
for key,value in pairs(ip_table) do
if value == ip_whitelist_remote_addr then --if our ip address matches with one in the whitelist
local output = ngx.exit(ngx.OK) --Go to content
return output
end
end
return --no ip was in the whitelist
end
check_ip_whitelist(ip_whitelist) --run whitelist check function
local function check_ip_blacklist(ip_table)
for key,value in pairs(ip_table) do
if value == ip_blacklist_remote_addr then
local output = ngx.exit(ngx.HTTP_FORBIDDEN) --deny user access
return output
end
end
return --no ip was in blacklist
end
check_ip_blacklist(ip_blacklist) --run blacklist check function
--function to encrypt strings with our secret key / password provided
local function calculate_signature(str)
return ngx.encode_base64(ngx.hmac_sha1(secret, ngx.md5(str)))
:gsub("[+/=]", {["+"] = "-", ["/"] = "_", ["="] = ""}) --Replace + with - and replace / with _ and remove =
end
--calculate_signature(str)
--generate random strings on the fly
--qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM1234567890
local charset = {}
for i = 48, 57 do table.insert(charset, string.char(i)) end --0-9 numeric
--for i = 65, 90 do table.insert(charset, string.char(i)) end --A-Z uppercase
--for i = 97, 122 do table.insert(charset, string.char(i)) end --a-z lowercase
table.insert(charset, string.char(95)) --insert number 95 underscore
local function stringrandom(length)
--math.randomseed(os.time())
if length > 0 then
--return "a"
return stringrandom(length - 1) .. charset[math.random(1, #charset)]
else
return ""
end
end
--stringrandom(10)
--for my javascript Hex output
local function sep(str, patt, re)
local rstr = str:gsub(patt, "%1%" .. re)
return rstr:sub(1, #rstr - #re)
end
local function stringtohex(str)
return str:gsub('.', function (c)
return string.format('%02X', string.byte(c))
end)
end
--encrypt_javascript function
local function encrypt_javascript(string1, type, defer_async, num_encrypt, encrypt_type, methods) --Function to generate encrypted/obfuscated output
local output = "" --Empty var
if type == 0 then
type = math.random(3, 4) --Random encryption
end
if type == 1 or type == nil then --No encryption
if defer_async == "0" or defer_async == nil then --Browser default loading / execution order
output = ""
end
if defer_async == "1" then --Defer
output = ""
end
if defer_async == "2" then --Async
output = ""
end
end
--https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs
--pass other encrypted outputs through this too ?
if type == 2 then --Base64 Data URI
local base64_data_uri = string1
if tonumber(num_encrypt) ~= nil then --If number of times extra to rencrypt is set
for i=1, #num_encrypt do --for each number
string1 = ngx.encode_base64(base64_data_uri)
end
end
if defer_async == "0" or defer_async == nil then --Browser default loading / execution order
output = ""
end
if defer_async == "1" then --Defer
output = ""
end
if defer_async == "2" then --Async
output = ""
end
end
if type == 3 then --Hex
local hex_output = stringtohex(string1) --ndk.set_var.set_encode_hex(string1) --Encode string in hex
local hexadecimal_x = "" --Create var
local encrypt_type_origin = encrypt_type --Store var passed to function in local var
if tonumber(encrypt_type) == nil or tonumber(encrypt_type) <= 0 then
encrypt_type = math.random(1, 2) --Random encryption
end
--I was inspired by http://www.hightools.net/javascript-encrypter.php so i built it myself
if tonumber(encrypt_type) == 1 then
hexadecimal_x = "%" .. sep(hex_output, "%x%x", "%") --hex output insert a char every 2 chars %x%x
end
if tonumber(encrypt_type) == 2 then
hexadecimal_x = "\\x" .. sep(hex_output, "%x%x", "\\x") --hex output insert a char every 2 chars %x%x
end
--TODO: Fix this.
--num_encrypt = "3" --test var
if tonumber(num_encrypt) ~= nil then --If number of times extra to rencrypt is set
for i=1, num_encrypt do --for each number
if tonumber(encrypt_type) ~= nil then
encrypt_type = math.random(1, 2) --Random encryption
if tonumber(encrypt_type) == 1 then
--hexadecimal_x = "%" .. sep(ndk.set_var.set_encode_hex("eval(decodeURIComponent('" .. hexadecimal_x .. "'))"), "%x%x", "%") --hex output insert a char every 2 chars %x%x
end
if tonumber(encrypt_type) == 2 then
--hexadecimal_x = "\\x" .. sep(ndk.set_var.set_encode_hex("eval(decodeURIComponent('" .. hexadecimal_x .. "'))"), "%x%x", "\\x") --hex output insert a char every 2 chars %x%x
end
end
end
end
--https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/decodeURIComponent
output = ""
end
if type == 4 then --Base64 javascript decode
local base64_javascript = "eval(decodeURIComponent(escape(window.atob('" .. ngx.encode_base64(string1) .. "'))))"
if tonumber(num_encrypt) ~= nil then --If number of times extra to rencrypt is set
for i=1, num_encrypt do --for each number
base64_javascript = "eval(decodeURIComponent(escape(window.atob('" .. ngx.encode_base64(base64_javascript) .. "'))))"
end
end
if defer_async == "0" or defer_async == nil then --Browser default loading / execution order
output = ""
end
if defer_async == "1" then --Defer
output = ""
end
if defer_async == "2" then --Defer
output = ""
end
end
return output
end
--end encrypt_javascript function
local currenttime = ngx.time() --Current time on server
local currentdate = "" --make current date a empty var
--Make sure our current date is in align with expires_time variable so that the auth page only shows when the cookie expires
if expire_time <= 60 then --less than equal to one minute
currentdate = os.date("%M",os.time()-24*60*60) --Current minute
end
if expire_time > 60 then --greater than one minute
currentdate = os.date("%H",os.time()-24*60*60) --Current hour
end
if expire_time > 3600 then --greater than one hour
currentdate = os.date("%d",os.time()-24*60*60) --Current day of the year
end
if expire_time > 86400 then --greater than one day
currentdate = os.date("%W",os.time()-24*60*60) --Current week
end
if expire_time > 6048000 then --greater than one week
currentdate = os.date("%m",os.time()-24*60*60) --Current month
end
if expire_time > 2628000 then --greater than one month
currentdate = os.date("%Y",os.time()-24*60*60) --Current year
end
if expire_time > 31536000 then --greater than one year
currentdate = os.date("%z",os.time()-24*60*60) --Current time zone
end
--ngx.log(ngx.ERR, "Current date output: "..currentdate)
local scheme = ngx.var.scheme --scheme is HTTP or HTTPS
local host = ngx.var.host --host is website domain name
local request_uri = ngx.var.request_uri --request uri is full URL link including query strings and arguements
local URL = scheme .. "://" .. host .. request_uri
local user_agent = ngx.var.http_user_agent --user agent of browser
local expected_header_status = 200 --503
local authentication_page_status_output = 200
local domain = ""
if host == nil then
domain = host:match("[%w%.]*%.(%w+%.%w+)") --Remove subdomains from the server_name (host) to output .domain.com
else
domain = "localhost"
end
local answer = calculate_signature(remote_addr) --create our encrypted unique identification for the user visiting the website.
if x_auth_header == 2 then --if x-auth-header is dynamic
x_auth_header_name = calculate_signature(remote_addr .. currentdate):gsub("_","") --make the header unique to the client and for todays date encrypted so every 24 hours this will change and can't be guessed by bots gsub because header bug with underscores so underscore needs to be removed
end
if encrypt_anti_ddos_cookies == 2 then --if Anti-DDoS Cookies are to be encrypted
--make the cookies unique to the client and for todays date encrypted so every 24 hours this will change and can't be guessed by bots
challenge = calculate_signature(remote_addr .. challenge .. currentdate)
cookie_name_start_date = calculate_signature(remote_addr .. cookie_name_start_date .. currentdate)
cookie_name_end_date = calculate_signature(remote_addr .. cookie_name_end_date .. currentdate)
cookie_name_encrypted_start_and_end_date = calculate_signature(remote_addr .. cookie_name_encrypted_start_and_end_date .. currentdate)
end
--[[
Grant access function to either grant or deny user access to our website
]]
local function grant_access()
--our uid cookie
local cookie_name = "cookie_" .. challenge
local cookie_value = ngx.var[cookie_name] or ""
--our start date cookie
local cookie_name_start_date_name = "cookie_" .. cookie_name_start_date
local cookie_name_start_date_value = ngx.var[cookie_name_start_date_name] or ""
--our end date cookie
local cookie_name_end_date_name = "cookie_" .. cookie_name_end_date
local cookie_name_end_date_value = ngx.var[cookie_name_end_date_name] or ""
--our start date and end date combined to a unique id
local cookie_name_encrypted_start_and_end_date_name = "cookie_" .. cookie_name_encrypted_start_and_end_date
local cookie_name_encrypted_start_and_end_date_value = ngx.var[cookie_name_encrypted_start_and_end_date_name] or ""
--ngx.log(ngx.ERR, "cookie name " .. cookie_name .. " | cookie value is "..cookie_value)
if cookie_value ~= answer then --if cookie value not equal to or matching our expected cookie they should be giving us
return --return to refresh the page so it tries again
end
--if x-auth-answer is correct to the user unique id time stamps etc meaning browser figured it out then set a new cookie that grants access without needed these checks
local req_headers = ngx.req.get_headers() --get all request headers
if req_headers["x-requested-with"] == "XMLHttpRequest" then --if request header matches request type of XMLHttpRequest
--ngx.log(ngx.ERR, "x-auth-answer result | "..req_headers[x_auth_header_name]) --output x-auth-answer to log
if req_headers[x_auth_header_name] == JavascriptPuzzleVars_answer then --if the answer header provided by the browser Javascript matches what our Javascript puzzle answer should be
set_cookie1 = challenge.."="..cookie_value.."; path=/; expires=" .. ngx.cookie_time(currenttime+expire_time) .. "; Max-Age=" .. expire_time .. ";" --apply our uid cookie incase javascript setting this cookies time stamp correctly has issues
set_cookie2 = cookie_name_start_date.."="..ngx.cookie_time(currenttime).."; path=/; expires=" .. ngx.cookie_time(currenttime+expire_time) .. "; Max-Age=" .. expire_time .. ";" --start date cookie
set_cookie3 = cookie_name_end_date.."="..ngx.cookie_time(currenttime+expire_time).."; path=/; expires=" .. ngx.cookie_time(currenttime+expire_time) .. "; Max-Age=" .. expire_time .. ";" --end date cookie
set_cookie4 = cookie_name_encrypted_start_and_end_date.."="..calculate_signature(remote_addr .. ngx.cookie_time(currenttime) .. ngx.cookie_time(currenttime+expire_time) ).."; path=/; expires=" .. ngx.cookie_time(currenttime+expire_time) .. "; Max-Age=" .. expire_time .. ";" --start and end date combined to unique id
set_cookies = {set_cookie1 , set_cookie2 , set_cookie3 , set_cookie4}
ngx.header["Access-Control-Allow-Origin"] = "*"
ngx.header["Access-Control-Allow-Credentials"] = "true"
ngx.header["Access-Control-Allow-Methods"] = "GET, POST, PUT, HEAD"
ngx.header["Access-Control-Allow-Headers"] = "Content-Type"
end
end
--ngx.log(ngx.ERR, "cookie start date | "..cookie_name_start_date_value) --log user provided cookie start date
--ngx.log(ngx.ERR, "cookie end date | "..cookie_name_end_date_value) --log user provided cookie end date
--ngx.log(ngx.ERR, "cookie encrypted combination value | "..cookie_name_encrypted_start_and_end_date_value) --log user provided cookie combined encrypted value
if cookie_name_start_date_value ~= nil and cookie_name_end_date_value ~= nil and cookie_name_encrypted_start_and_end_date_value ~= nil then --if all our cookies exist
local cookie_name_end_date_value_unix = ngx.parse_http_time(cookie_name_end_date_value) or nil --convert our cookie end date provided by the user into a unix time stamp
if cookie_name_end_date_value_unix == nil or cookie_name_end_date_value_unix == "" then --if our cookie end date date in unix does not exist
return --return to refresh the page so it tries again
end
if cookie_name_end_date_value_unix <= currenttime then --if our cookie end date is less than or equal to the current date meaning the users authentication time expired
--ngx.log(ngx.ERR, "cookie less than current time : " .. cookie_name_end_date_value_unix .. " | " .. currenttime ) --log output the users provided cookie time
return --return to refresh the page so it tries again
end
if cookie_name_encrypted_start_and_end_date_value ~= calculate_signature(remote_addr .. cookie_name_start_date_value .. cookie_name_end_date_value) then --if users authentication encrypted cookie not equal to or matching our expected cookie they should be giving us
return --return to refresh the page so it tries again
end
end
--else all checks passed bypass our firewall and show page content
local output = ngx.exit(ngx.OK) --Go to content
return output
end
--grant_access()
--[[
End Required Functions
]]
grant_access() --perform checks to see if user can access the site or if they will see our denial of service status below
--[[
Build HTML Template
]]
local title = host .. [[ | Anti-DDoS Flood Protection and Firewall by Conor McKnight]]
--[[
Javascript after setting cookie run xmlhttp GET request
if cookie did exist in GET request then respond with valid cookie to grant access
also
if GET request contains specific required headers provide a SETCOOKIE
then if GET request response had specific passed security check response header
run window.location.reload(); Javascript
]]
if javascript_REQUEST_TYPE == 3 then --Dynamic Random request
javascript_REQUEST_TYPE = math.random (1, 2) --Randomize between 1 and 2
end
if javascript_REQUEST_TYPE == 1 then --GET request
javascript_REQUEST_TYPE = "GET"
end
if javascript_REQUEST_TYPE == 2 then --POST request
javascript_REQUEST_TYPE = "POST"
end
local javascript_POST_headers = "" --Create empty var
local javascript_POST_data = "" --Create empty var
if javascript_REQUEST_TYPE == "POST" then
-- https://www.w3schools.com/xml/tryit.asp?filename=tryajax_post2
javascript_POST_headers = [[xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
]]
javascript_POST_data = [["name1=Henry&name2=Ford"]]
end
local JavascriptPuzzleVariable_name = "_" .. stringrandom(10)
local javascript_REQUEST_headers = [[
xhttp.setRequestHeader(']] .. x_auth_header_name .. [[', ]] .. JavascriptPuzzleVariable_name .. [[); //make the answer what ever the browser figures it out to be
xhttp.setRequestHeader('X-Requested-with', 'XMLHttpRequest');
xhttp.setRequestHeader('X-Requested-TimeStamp', '');
xhttp.setRequestHeader('X-Requested-TimeStamp-Expire', '');
xhttp.setRequestHeader('X-Requested-TimeStamp-Combination', '');
xhttp.setRequestHeader('X-Requested-Type', 'GET');
xhttp.setRequestHeader('X-Requested-Type-Combination', 'GET'); //Encrypted for todays date
xhttp.withCredentials = true;
]]
local JavascriptPuzzleVariable = [[
var ]] .. JavascriptPuzzleVariable_name .. [[=]] .. JavascriptPuzzleVars ..[[;
]]
-- https://www.w3schools.com/xml/tryit.asp?filename=try_dom_xmlhttprequest
local javascript_anti_ddos = [[
(function(){
var a = function() {try{return !!window.addEventListener} catch(e) {return !1} },
b = function(b, c) {a() ? document.addEventListener("DOMContentLoaded", b, c) : document.attachEvent("onreadystatechange", b)};
b(function(){
var timeleft = ]] .. refresh_auth .. [[;
var downloadTimer = setInterval(function(){
timeleft--;
document.getElementById("countdowntimer").textContent = timeleft;
if(timeleft <= 0)
clearInterval(downloadTimer);
},1000);
setTimeout(function(){
var now = new Date();
var time = now.getTime();
time += 300 * 1000;
now.setTime(time);
document.cookie = ']] .. challenge .. [[=]] .. answer .. [[' + '; expires=' + ']] .. ngx.cookie_time(currenttime+expire_time) .. [[' + '; path=/';
//javascript puzzle for browser to figure out to get answer
]] .. JavascriptVars_opening .. [[
]] .. JavascriptPuzzleVariable .. [[
]] .. JavascriptVars_closing .. [[
//end javascript puzzle
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == ]] .. expected_header_status .. [[) { //status may be 503 so local var to control both response and switch between POST and GET
location.reload(true);
document.getElementById("status").innerHTML = "Refresh your page.";
}
};
xhttp.open("]] .. javascript_REQUEST_TYPE .. [[", "]] .. request_uri .. [[", true);
]] .. javascript_REQUEST_headers .. [[
]] .. javascript_POST_headers .. [[
xhttp.send(]] .. javascript_POST_data .. [[);
}, ]] .. refresh_auth+1 .. [[000); /*if correct data has been sent then the auth response will allow access*/
}, false);
})();
]]
--TODO: include Captcha like Google ReCaptcha
--[[
encrypt/obfuscate the javascript output
]]
if encrypt_javascript_output == 1 then --No encryption/Obfuscation of Javascript so show Javascript in plain text
javascript_anti_ddos = [[]]
else --some form of obfuscation has been specified so obfuscate the javascript output
javascript_anti_ddos = encrypt_javascript(javascript_anti_ddos, encrypt_javascript_output) --run my function to encrypt/obfuscate javascript output
end
--Adverts positions
local head_ad_slot = [[
]]
local top_body_ad_slot = [[
]]
local left_body_ad_slot = [[
]]
local right_body_ad_slot = [[
]]
local footer_body_ad_slot = [[
]]
--End advert positions
local ddos_credits = [[