├── .gitignore ├── LICENSE ├── README.md ├── captcha.lua ├── cookie.lua ├── nla.conf ├── nla.lua └── nla_captcha.conf /.gitignore: -------------------------------------------------------------------------------- 1 | # Build and Release Folders 2 | bin/ 3 | bin-debug/ 4 | bin-release/ 5 | 6 | # Other files and folders 7 | .settings/ 8 | 9 | # Project files, i.e. `.project`, `.actionScriptProperties` and `.flexProperties` 10 | # should NOT be excluded as they contain compiler settings and other important 11 | # information for Eclipse / Flash Builder. 12 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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We also recommend that a 185 | file or class name and description of purpose be included on the 186 | same "printed page" as the copyright notice for easier 187 | identification within third-party archives. 188 | 189 | Copyright {yyyy} {name of copyright owner} 190 | 191 | Licensed under the Apache License, Version 2.0 (the "License"); 192 | you may not use this file except in compliance with the License. 193 | You may obtain a copy of the License at 194 | 195 | http://www.apache.org/licenses/LICENSE-2.0 196 | 197 | Unless required by applicable law or agreed to in writing, software 198 | distributed under the License is distributed on an "AS IS" BASIS, 199 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 200 | See the License for the specific language governing permissions and 201 | limitations under the License. 202 | 203 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # ngx_lua_anticc 2 | **ngx_lua_anticc** is a CC(ChallengeCollapsar) attack mitigation tool for Nginx. CC attack (i.e. HTTP request flood) is kind of layer 7 DDoS attack. ngx_lua_anticc is an extension of Nginx based on [ngx_lua](https://github.com/openresty/lua-nginx-module). With it, you can easily add CC attack protection for your web server. 3 | 4 | # Download 5 | Current release: [ngx_lua_anticc-0.1.0.tar.gz](https://github.com/leeyiw/ngx_lua_anticc/archive/v0.1.0.tar.gz). 6 | 7 | # Configure && Install 8 | ## 1. Prepare your nginx 9 | To use ngx_lua_anticc, you must recompile your nginx with ngx_lua support, see the installation document over [HERE](http://wiki.nginx.org/HttpLuaModule#Installation). ngx_lua depends on LuaJIT (recommended) or Lua, please make sure you have installed LuaJIT/Lua before any further configuration. 10 | 11 | ## 2. Deploy ngx_lua_anticc with your nginx 12 | 1. Uncompress the tarball to the same directory with the `nginx.conf` file. 13 | 14 | 2. Edit your `nginx.conf`, add `include ngx_lua_anticc/nla.conf;` into the *http* section. 15 | 16 | 3. Add `include ngx_lua_anticc/nla_captcha.conf;` into the *server* section. 17 | 18 | ## 3. Configure ngx_lua_anticc (IMPORTANT) 19 | 1. Edit the config file `ngx_lua_anticc/nla.conf`. You **MUST** change the value of `cookie_key` to your own secret value. Otherwise, the attackers will generate verification cookie (by default `cookie_key` in source code) to bypass the protection mechanism designed by ngx_lua_anticc. Example: 20 | ``` 21 | config:add("cookie_key", "f136f204e0586f02") 22 | ``` 23 | 24 | 2. Add trusted IP into whitelist: 25 | ``` 26 | whitelist:add("127.0.0.1", true) 27 | ``` 28 | The boolean value means if the whitelist entry is enabled (true) or not. 29 | 30 | ## 4. Restart nginx 31 | After you restart nginx, the Anti-CC protection is automatically enabled. Enjoy your web service without CC attacks! 32 | -------------------------------------------------------------------------------- /captcha.lua: -------------------------------------------------------------------------------- 1 | -- global shared dict 2 | local config = ngx.shared.nla_config 3 | 4 | local _M = {} 5 | 6 | _M.CAPTCHA_VALIDATE_PAGE = config:get("captcha_validate_page") 7 | _M.CAPTCHA_VALIDATE_API = config:get("captcha_validate_api") 8 | _M.CAPTCHA_COOKIE_NAME = config:get("captcha_cookie_name") 9 | 10 | _M.challenge_code_tmpl = [[ 11 | 12 | 13 | 20 | 21 | 22 | 23 |
24 | Please input the verification code to continue:
25 | 26 | 27 |
28 | 29 | ]] 30 | 31 | function _M.challenge(captcha_user_id) 32 | -- set origin URL to cookie 33 | ngx.header["Set-Cookie"] = _M.CAPTCHA_COOKIE_NAME .. "=" .. ngx.var.request_uri 34 | local challenge_code = string.format(_M.challenge_code_tmpl, 35 | captcha_user_id, 36 | _M.CAPTCHA_VALIDATE_PAGE) 37 | ngx.say(challenge_code) 38 | end 39 | 40 | function _M.validate(captcha_user_id) 41 | local uri_args = ngx.req.get_uri_args() 42 | if not uri_args["code"] then 43 | return false 44 | end 45 | local args = {img = captcha_user_id, ans = uri_args["code"]} 46 | local res = ngx.location.capture(_M.CAPTCHA_VALIDATE_API, {args = args}) 47 | return (res.body == "pass") 48 | end 49 | 50 | return _M 51 | -------------------------------------------------------------------------------- /cookie.lua: -------------------------------------------------------------------------------- 1 | local _M = {} 2 | 3 | _M.challenge_code_tmpl = [[ 4 | 5 | 6 | 13 | 14 | 15 | 16 | ]] 17 | 18 | function _M.get() 19 | local headers = ngx.req.get_headers(); 20 | local ret = {} 21 | if not headers["Cookie"] then 22 | return ret 23 | end 24 | for k, v in string.gmatch(headers["Cookie"], "([^=]+)=([^;]+);?%s*") do 25 | ret[k] = v 26 | end 27 | return ret 28 | end 29 | 30 | function _M.challenge(cookie_name, cookie_value) 31 | -- if static resource is requested, use Set-Cookie and 302 to challenge 32 | if ngx.ctx.nla_rtype == "resource" then 33 | ngx.header["Set-Cookie"] = cookie_name .. "=" .. cookie_value 34 | ngx.redirect(ngx.var.request_uri) 35 | return 36 | end 37 | 38 | -- use JS set cookie to challenge 39 | local challenge_code = string.format(_M.challenge_code_tmpl, cookie_name, 40 | cookie_value) 41 | ngx.say(challenge_code) 42 | end 43 | 44 | return _M 45 | -------------------------------------------------------------------------------- /nla.conf: -------------------------------------------------------------------------------- 1 | lua_shared_dict nla_config 1m; 2 | lua_shared_dict nla_req_count 10m; 3 | lua_shared_dict nla_captcha_pass_list 10m; 4 | lua_shared_dict nla_whitelist 1m; 5 | 6 | lua_package_path 'conf/ngx_lua_anticc/?.lua;;'; 7 | 8 | init_by_lua ' 9 | local config = ngx.shared.nla_config 10 | config:add("cookie_name", "__nla_uid") 11 | config:add("cookie_key", "f3d843b5da") 12 | config:add("captcha_validate_page", "/__nla_captcha_validate") 13 | config:add("captcha_validate_api", "/__nla_captcha_validate_api") 14 | config:add("captcha_cookie_name", "__nla_orig_uri") 15 | 16 | local whitelist = ngx.shared.nla_whitelist 17 | whitelist:add("127.0.0.1", true) 18 | '; 19 | 20 | access_by_lua_file conf/ngx_lua_anticc/nla.lua; 21 | -------------------------------------------------------------------------------- /nla.lua: -------------------------------------------------------------------------------- 1 | -- global shared dict 2 | local config = ngx.shared.nla_config 3 | local req_count = ngx.shared.nla_req_count; 4 | local captcha_pass_list = ngx.shared.nla_captcha_pass_list 5 | local whitelist = ngx.shared.nla_whitelist 6 | 7 | -- config options 8 | local COOKIE_NAME = config:get("cookie_name") 9 | local COOKIE_KEY = config:get("cookie_key") 10 | local CAPTCHA_VALIDATE_PAGE = config:get("captcha_validate_page") 11 | local CAPTCHA_COOKIE_NAME = config:get("captcha_cookie_name") 12 | 13 | -- library 14 | local cookie = require("cookie") 15 | local captcha = require("captcha") 16 | 17 | local headers = ngx.req.get_headers(); 18 | local cookies = cookie.get() 19 | local user_id = ngx.md5(ngx.var.remote_addr .. ngx.var.uri .. COOKIE_KEY) 20 | local captcha_user_id = ngx.md5(ngx.var.remote_addr .. (headers["User-Agent"] or "") .. COOKIE_KEY) 21 | 22 | -- if request captcha validate page, then validate captcha code 23 | if ngx.var.uri == CAPTCHA_VALIDATE_PAGE then 24 | if captcha.validate(captcha_user_id) then 25 | captcha_pass_list:set(captcha_user_id, true, 3600) 26 | end 27 | return ngx.redirect(cookies[CAPTCHA_COOKIE_NAME] or "/") 28 | end 29 | 30 | -- if client IP is in whitelist, pass 31 | in_whitelist = whitelist:get(ngx.var.remote_addr) 32 | if in_whitelist then 33 | return 34 | end 35 | 36 | local count, err = req_count:incr(user_id, 1) 37 | if not count then 38 | req_count:add(user_id, 1, 1) 39 | return 40 | end 41 | 42 | -- identify if request is page or resource 43 | if ngx.re.find(ngx.var.uri, "\\.(bmp|css|gif|ico|jpe?g|js|png|swf)$", "ioj") then 44 | ngx.ctx.nla_rtype = "resource" 45 | else 46 | ngx.ctx.nla_rtype = "page" 47 | end 48 | 49 | -- if QPS is exceed 5, start cookie challenge 50 | if count > 5 then 51 | if cookies[COOKIE_NAME] ~= user_id then 52 | cookie.challenge(COOKIE_NAME, user_id) 53 | return 54 | end 55 | end 56 | 57 | -- if cookie challenge is passed and QPS is exceed 10, start captcha challenge 58 | if count > 10 then 59 | if ngx.ctx.nla_rtype ~= "resource" and (not captcha_pass_list:get(captcha_user_id)) then 60 | captcha.challenge(captcha_user_id) 61 | return 62 | end 63 | end 64 | -------------------------------------------------------------------------------- /nla_captcha.conf: -------------------------------------------------------------------------------- 1 | location /__nla_captcha_validate_api { 2 | proxy_pass http://www.opencaptcha.com/validate.php; 3 | proxy_pass_request_headers off; 4 | } 5 | --------------------------------------------------------------------------------