feat: added action to validate ddos protection cookie

haproxy/haproxy.cfg

@@ -13,9 +13,13 @@ defaults
 frontend http-in
     bind *:80
     default_backend servers
-    # http-request lua.test-payload
-    http-request use-service lua.hello-world   if { path /hello_world }
-    http-request use-service lua.hcaptcha-view   if { path /captcha }
+    http-request lua.hcaptcha-redirect          if !{ path -m beg /captcha }
+    http-request use-service lua.hello-world    if { path /hello_world }
+    http-request use-service lua.hcaptcha-view  if { path /captcha/ }
+
+    acl captcha_passed var(txn.captcha_passed) -m bool
+    acl on_captcha_url path -m beg /captcha
+    redirect prefix /captcha code 301 if !captcha_passed !on_captcha_url
 
 backend servers
     server server1 nginx:80 maxconn 32

scripts/cookie.lua

@@ -0,0 +1,82 @@
+-- Copyright (C) 2013-2016 Jiale Zhi (calio), CloudFlare Inc.
+-- See RFC6265 http://tools.ietf.org/search/rfc6265
+-- require "luacov"
+
+local type          = type
+local byte          = string.byte
+local sub           = string.sub
+
+local EQUAL         = byte("=")
+local SEMICOLON     = byte(";")
+local SPACE         = byte(" ")
+local HTAB          = byte("\t")
+
+
+local _M = {}
+_M._VERSION = '0.01'
+
+
+function _M.get_cookie_table(text_cookie)
+    if type(text_cookie) ~= "string" then
+        return {}
+    end
+
+    local EXPECT_KEY    = 1
+    local EXPECT_VALUE  = 2
+    local EXPECT_SP     = 3
+
+    local n = 0
+    local len = #text_cookie
+
+    for i=1, len do
+        if byte(text_cookie, i) == SEMICOLON then
+            n = n + 1
+        end
+    end
+
+    local cookie_table  = {}
+
+    local state = EXPECT_SP
+    local i = 1
+    local j = 1
+    local key, value
+
+    while j <= len do
+        if state == EXPECT_KEY then
+            if byte(text_cookie, j) == EQUAL then
+                key = sub(text_cookie, i, j - 1)
+                state = EXPECT_VALUE
+                i = j + 1
+            end
+        elseif state == EXPECT_VALUE then
+            if byte(text_cookie, j) == SEMICOLON
+                    or byte(text_cookie, j) == SPACE
+                    or byte(text_cookie, j) == HTAB
+            then
+                value = sub(text_cookie, i, j - 1)
+                cookie_table[key] = value
+
+                key, value = nil, nil
+                state = EXPECT_SP
+                i = j + 1
+            end
+        elseif state == EXPECT_SP then
+            if byte(text_cookie, j) ~= SPACE
+                and byte(text_cookie, j) ~= HTAB
+            then
+                state = EXPECT_KEY
+                i = j
+                j = j - 1
+            end
+        end
+        j = j + 1
+    end
+
+    if key ~= nil and value == nil then
+        cookie_table[key] = sub(text_cookie, i)
+    end
+
+    return cookie_table
+end
+
+return _M

scripts/hcaptcha.lua

@@ -4,13 +4,12 @@ local url = require("net.url")
 local https = require("ssl.https")
 local json = require("json")
 local utils = require("utils")
-
+local cookie = require("cookie")
 local floating_hash = utils.get_floating_hash()
 
 function hcaptcha.view(applet)
     local hcaptcha_secret = os.getenv("HCAPTCHA_SECRET")
     local hcaptcha_sitekey = os.getenv("HCAPTCHA_SITEKEY")
-
     local response
     if applet.method == "GET" then
         response =
@@ -37,7 +36,7 @@ function hcaptcha.view(applet)
 
             if api_response.success == true then
                 print("HCAPTCHA SUCCESSFULLY PASSED")
-                applet:add_header("set-cookie", string.format("z_ddos_protection=%s; Max-Age=14400", floating_hash))
+                applet:add_header("set-cookie", string.format("z_ddos_protection=%s; Max-Age=14400; Path=/", floating_hash))
             else
                 print("HCAPTCHA FAILED", body)
             end
@@ -52,3 +51,19 @@ function hcaptcha.view(applet)
     applet:start_response()
     applet:send(response)
 end
+
+function hcaptcha.check_captcha_status(txn)
+    print("CAPTCHA STATUS CHECK START")
+    local raw_request_cookies = txn.sf:hdr("Cookie")
+    local parsed_request_cookies = cookie.get_cookie_table(raw_request_cookies)
+
+    print("RECEIVED SECRET COOKIE: ", parsed_request_cookies["z_ddos_protection"])
+    print("OUR SECRET COOKIE: ", floating_hash)
+
+    if parsed_request_cookies["z_ddos_protection"] == floating_hash then
+        print("CAPTCHA STATUS CHECK SUCCESS")
+        return txn:set_var("txn.captcha_passed", true);
+    end
+
+    print("CAPTCHA STATUS CHECK FINISH")
+end

scripts/register.lua

@@ -5,3 +5,4 @@ require("hcaptcha")
 
 core.register_service("hello-world", "http", guard.hello_world)
 core.register_service("hcaptcha-view", "http", hcaptcha.view)
+core.register_action("hcaptcha-redirect", { 'http-req', }, hcaptcha.check_captcha_status)