local b='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
function base64_encode(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 b:sub(c+1,c+1)
end)..({ '', '==', '=' })[#data%3+1])
end
function base64_decode(data)
data = string.gsub(data, '[^'..b..'=]', '')
return (data:gsub('.', function(x)
if (x == '=') then return '' end
local r,f='',(b: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
function in_array(tab, val)
for index, value in ipairs(tab) do
if value == val then
return true
end
end
end
local gd = require("gd")
function displaycap()
math.randomseed(ngx.now())
local img_width = 150;
local img_height = 150;
local capgrid = {}
local checkmin = 1
local checkmax = 6
local checktotal = 0
local sessiondice = "";
while checktotal < checkmin do
for i=1,9,1 do
check = math.random(0,1)
if checktotal < checkmax and check == 1 then capgrid[i] = check else capgrid[i] = 0 end
if check == 1 then
checktotal = checktotal + 1
sessiondice = sessiondice .. tostring(i)
end
end
end
local cookie, err = cook:new()
if not cookie then
ngx.log(ngx.ERR, err)
ngx.say("cookie error")
ngx.exit(200)
end
local tstamp = ngx.now()
local newcookdata = "cap_not_solved|" .. tstamp .. "|"
newcookdata = newcookdata .. sessiondice
local ciphertext = tohex(aes_128_cbc_sha512x1:encrypt(newcookdata))
local ok, err = cookie:set({
key = "dcap", value = ciphertext, path = "/",
domain = ngx.var.host, httponly = true,
max_age = 21600,
samesite = "Strict"
})
if not ok then
ngx.say("cookie error")
ngx.exit(200)
end
local symbols_zero = {'○','□','♘','♢','▽','△','♖','✧','♔','♘','♕','♗','♙','♧'};
local symbols_one = {'●','■','♞','♦','▼','▲','♜','✦','♚','♞','♛','♝','♟','♣'};
local img = gd.createFromJpeg("/tmp/background-" .. math.random(0,25) .. ".jpg")
if img == nil then
img = gd.createTrueColor(150, 150)
local white = img:colorAllocate(255, 255, 255)
img:filledRectangle(0, 0, img_width, img_height, white)
end
img:setThickness(1)
-- if 0 each row will be horizontal
local draw_angle = 0
local current_row = 1
local capstring = ""
for i=1,9,1 do
local symbol_id = math.random(1,14)
local fillcolor = img:colorAllocate(math.random(5,255), math.random(5,255), math.random(5,255))
if capgrid[i] == 1 then
capstring = capstring .. symbols_one[symbol_id]
else
capstring = capstring .. symbols_zero[symbol_id]
end
capstring = capstring .. " "
if i % 3 == 0 then
if draw_angle == 1 then
angle = math.rad(math.random(0,10))
else
angle = 0
end
if current_row == 1 then
img:stringFT(fillcolor, "/etc/nginx/font.ttf", math.random(18,22), angle, math.random(10,50), math.random(30,60), capstring)
elseif current_row == 2 then
img:stringFT(fillcolor, "/etc/nginx/font.ttf", math.random(18,22), angle, math.random(10,50), math.random(60,90), capstring)
else
img:stringFT(fillcolor, "/etc/nginx/font.ttf", math.random(18,22), angle, math.random(10,50), math.random(100,130), capstring)
end
current_row = current_row + 1
capstring = ""
end
end
imgbase64 = base64_encode(img:pngStrEx(6))
ngx.header.content_type = 'text/html';
ngx.say(" \
\
DDOS Protection \
\
\
\
\
\
\
\
\
dread
\
")
if caperror ~= nil
then
ngx.say("
Error: " .. caperror .. "
")
else
ngx.say("
Due to on-going DDOS attacks against our servers, you must complete a captcha challenge to prove you are human.