openresty实现WAF功能

1、系统基础信息

 
[root@tiejiang-src1 ~]# ifconfig eth0|grep 'inet addr'|awk -F ":" '{print $2}'|awk '{print $1}'
192.168.83.129
[root@tiejiang-src1 ~]# cat /etc/redhat-release
CentOS release 6.5 (Final)
[root@tiejiang-src1 ~]# uname -r
2.6.32-431.el6.x86_64

2、安装基础依赖包

 
[root@tiejiang-src1 ~]# yum install -y readline-devel pcre-devel openssl-devel

3、下载并编译安装openresty

 
[root@tiejiang-src1 ~]# cd /usr/local/src/
[root@tiejiang-src1 src]# wget https://openresty.org/download/ngx_openresty-1.9.3.2.tar.gz
[root@tiejiang-src1 src]# tar zxvf ngx_openresty-1.9.3.2.tar.gz
[root@tiejiang-src1 src]# cd ngx_openresty-1.9.3.2
[root@tiejiang-src1 ngx_openresty-1.9.3.2]# ./configure --prefix=/usr/local/openresty-1.9.3.2 --with-luajit --with-http_stub_status_module --with-pcre --with-pcre-jit
[root@tiejiang-src1 ngx_openresty-1.9.3.2]# gmake && gmake install
[root@tiejiang-src1 ngx_openresty-1.9.3.2]# ln -s /usr/local/openresty-1.9.3.2/ /usr/local/openresty

4、测试openresty安装

 
[root@tiejiang-src1 ~]# vim /usr/local/openresty/nginx/conf/nginx.conf
    server {
        location /hello {
                default_type text/html;
                content_by_lua_block {
                    ngx.say("HelloWorld")
                }
            }
    }
[root@tiejiang-src1 ~]# /usr/local/openresty/nginx/sbin/nginx -t
    nginx: the configuration file /usr/local/openresty-1.9.3.2/nginx/conf/nginx.conf syntax is ok
    nginx: configuration file /usr/local/openresty-1.9.3.2/nginx/conf/nginx.conf test is successful
[root@tiejiang-src1 ~]# /usr/local/openresty/nginx/sbin/nginx

5、WAF部署：在github上克隆下代码

 
[root@tiejiang-src1 ~]# yum -y install git
[root@tiejiang-src1 ~]# cd /usr/local/openresty/nginx/conf/
[root@tiejiang-src1 conf]# git clone https://github.com/unixhot/waf.git

6、修改Nginx的配置文件，加入（http字段）以下配置。注意路径，同时WAF日志默认存放在/tmp/日期_waf.log

 
[root@tiejiang-src1 ~]# vim /usr/local/openresty/nginx/conf/nginx.conf
    http {
        include       mime.types;
        default_type  application/octet-stream;
    #WAF
        lua_shared_dict limit 50m;
        lua_package_path "/usr/local/openresty/nginx/conf/waf/?.lua";
        init_by_lua_file "/usr/local/openresty/nginx/conf/waf/init.lua";
        access_by_lua_file "/usr/local/openresty/nginx/conf/waf/access.lua";
[root@tiejiang-src1 conf]# /usr/local/openresty/nginx/sbin/nginx -t
    nginx: the configuration file /usr/local/openresty-1.9.3.2/nginx/conf/nginx.conf syntax is ok
    nginx: configuration file /usr/local/openresty-1.9.3.2/nginx/conf/nginx.conf test is successful
[root@tiejiang-src1 conf]# /usr/local/openresty/nginx/sbin/nginx -s reload

7、根据日志记录位置，创建日志目录

 
[root@tiejiang-src1 conf]# mkdir /tmp/waf_logs
[root@tiejiang-src1 conf]# chown www.www /tmp/waf_logs

二、启用waf并做测试

1、模拟sql注入即url攻击

检测顺序：先检查白名单，通过即不检测；再检查黑名单，不通过即拒绝，检查UA，UA不通过即拒绝；检查cookie；URL检查;URL参数检查，post检查；

日志显示如下,记录了UA，匹配规则，URL，客户端类型，攻击的类型，请求的数据

[root@tiejiang-src1 ~]# tail -f /tmp/2018-07-30_waf.log
    {"user_agent":"Mozilla//5.0 (Windows NT 10.0; Win64; x64) AppleWebKit//537.36 (KHTML, like Gecko) Chrome//67.0.3396.99 Safari//537.36","rule_tag":"//.(bak|inc|old|mdb|sql|backup|java|class|tgz|gz|tar|zip)$","req_url":"//eastmonet.sql","client_ip":"192.168.83.1","local_time":"2018-07-30 10:46:52","attack_method":"Deny_URL","req_data":"-","server_name":"localhost"}

2、使用ab压力测试工具模拟防CC攻击

[root@tiejiang-src2 ~]# ifconfig eth0|grep 'inet addr'|awk -F ":" '{print $2}'|awk '{print $1}'
192.168.83.131

将对方IP放入黑名单

[root@tiejiang-src1 ~]# echo 192.168.83.131 >> /usr/local/openresty/nginx/conf/waf/rule-config/blackip.rule
[root@tiejiang-src1 ~]# /usr/local/openresty/nginx/sbin/nginx -s reload

再拿192.168.83.131访问的时候就提示403了

将对方IP放入白名单

[root@tiejiang-src1 ~]# echo 192.168.83.131 >> /usr/local/openresty/nginx/conf/waf/rule-config/whiteip.rule
[root@tiejiang-src1 ~]# /usr/local/openresty/nginx/sbin/nginx -s reload

此时将不对此ip进行任何防护措施，所以sql注入时应该返回404

目录：

waf目录：/usr/local/openresty/nginx/conf/waf
lua配置文件：/usr/local/openresty/nginx/conf/waf/config.lua
Waf的ip黑名单：/usr/local/openresty/nginx/conf/waf/rule-config/blackip.rule
Waf的ip白名单：/usr/local/openresty/nginx/conf/waf/rule-config/whiteip.rule
Waf的规则存放目录：/usr/local/openresty/nginx/conf/waf/rule-config