nginx.conf

# Do not send nginx version number in error pages or server header
server_tokens off;

add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; img-src 'self'; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; font-src 'self'; frame-src 'self'; object-src 'none'";

server {
  listen 80;
  rewrite ^ https://$host$request_uri? permanent;
}

server {
  listen 443;

  ssl on;
  ssl_certificate CER_FILE;
  ssl_certificate_key KEY_FILE;

  ssl_prefer_server_ciphers on;
  ssl_ciphers 'ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA';

  ssl_dhparam DHPARAM_FILE;

  ssl_session_cache shared:SSL:10m;
  ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
  ssl_stapling on;
  ssl_stapling_verify on;
  resolver 8.8.8.8 8.8.4.4 valid=300s;
  resolver_timeout 5s;

  add_header X-Frame-Options DENY;
  add_header X-Content-Type-Options nosniff;
  add_header Strict-Transport-Security "max-age=31536000; includeSubdomains;";
  
  add_header Cache-Control "no-cache, no-store";
  add_header Pragma "no-cache";
  expires -1;

  root CTFPATH;
  index index.php;
  location ~ \.php$ {
    try_files $uri =404;
    fastcgi_pass  unix:/var/run/hhvm/sock;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include fastcgi_params;
  }
  error_page 400 401 402 403 404 500 /error.php;
  client_max_body_size 25M;
}