Nginx修复CORS漏洞的实现方法

GET /external/ HTTP/1.1
Host: xxx.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Language: en
Origin: https://xxx.com.qa5bnet.cn
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: none
Sec-Fetch-User: ?1
Upgrade-Insecure-Requests: 1
Accept-Encoding: gzip

HTTP/1.1 401 
Access-Control-Allow-Methods: GET,POST,OPTIONS,PUT,DELETE
Access-Control-Allow-Origin: https://xxx.com.qa5bnet.cn
Connection: keep-alive
Content-Length: 0
Date: Mon, 13 Nov 2023 02:07:00 GMT
Www-Authenticate: BASIC realm="application"

        set $flag 0;

        if ($http_origin = ''){
            set $flag "${flag}1";
        }

        if ($http_origin !~* ^(http|https)://test\.test\.com$){
            set $flag "${flag}1";
        }

        if ($flag = "01"){
            return 403;
        }

        if ($http_origin ~* ^(http|https)://test\.test\.com$) {
            add_header Access-Control-Allow-Origin $http_origin;
            add_header Access-Control-Allow-Methods GET,POST;
            add_header Access-Control-Allow-Credentials true;
            add_header Access-Control-Allow-Headers DNT,Keep-Alive,User-Agent,If-Modified-Since,Cache-Control,Content-Type;
}

  server {
        listen 80;
        server_name test.test.com;

        location / {
            set $flag 0;
    
            if ($http_origin = ''){
                set $flag "${flag}1";
            }
    
            if ($http_origin !~* ^(http|https)://test\.test\.com$){
                set $flag "${flag}1";
            }
    
            if ($flag = "01"){
                return 403;
            }
    
            if ($http_origin ~* ^(http|https)://test\.test\.com$) {
                add_header Access-Control-Allow-Origin $http_origin;
                add_header Access-Control-Allow-Methods GET,POST;
                add_header Access-Control-Allow-Credentials true;
                add_header Access-Control-Allow-Headers DNT,Keep-Alive,User-Agent,If-Modified-Since,Cache-Control,Content-Type;
    				}
        
            #将IP和端口改为DataEase服务器的访问地址和端口
            proxy_pass   http://192.168.110.251:81/;
            server_name_in_redirect off;

            # websocket 代理
            proxy_http_version      1.1;
            proxy_set_header        Upgrade         $http_upgrade;
            proxy_set_header        Connection "upgrade";

            proxy_set_header           Host $host:$server_port;
            proxy_set_header           X-Real-IP $remote_addr;
            proxy_set_header           X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header           X-Forwarded-Proto $scheme;

           
        }
  }