Nginx

Warning:

These instructions were only tested on Debian. It will probably work for other Linux distributions, but you might need to adapt the provided instructions.

Nginx is a fast and powerful web server.

Install

The version of nginx in Debian Jessie support the deprecated SPDY protocol. Using the version from jessie-backports allows to get support for HTTP/2.

# apt install nginx-extras/jessie-backports

Configure

conf.d

The conf.d folder stores shared configuration shared between all the sites hosted on your server.

Create the following files:

• /etc/nginx/conf.d/dns.conf

  # DNS resolver
  # It is required for OCSP Stapling. It might also be used if you use a hostname for upstream servers
  resolver 127.0.0.1;
  # If you don't have a DNS resolver on your machine you can use google public ones instead
  #resolver 8.8.8.8 8.8.4.4;
  

• /etc/nginx/conf.d/gzip.conf

  # Insert header "Vary: Accept-Encoding" in responses
  # https://www.maxcdn.com/blog/accept-encoding-its-vary-important/
  gzip_vary on;
  
  gzip_comp_level 6;
  
  gzip_proxied any;
  
  gzip_types text/plain text/css application/json application/javascript application/x-javascript text/xml application/xml application/xml+rss text/javascript image/svg+xml;
  

• /etc/nginx/conf.d/php*.conf
  See documentation to install PHP.
• /etc/nginx/conf.d/server_tokens.conf

  # Hide nginx version
  # This doesn't provides any real security but makes hackers life a bit more difficult
  server_tokens off;
  

• /etc/nginx/conf.d/ssl.conf

  # These two settings are now included by default in nginx.conf
  #ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
  #ssl_prefer_server_ciphers on;
  
  ssl_ciphers "ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA:AES256-SHA:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS:!RC4:!CAMELLIA:!SEED";
  
  # Parameters for Diffie-Hellman handshake
  # Generate the file with the command:
  #    openssl dhparam 2048 -out /etc/nginx/dh2048.pem
  ssl_dhparam /etc/nginx/dh2048.pem;
  
  # Support OSCP Stapling. Check that resolver from in dns.conf is working
  ssl_stapling on;
  ssl_stapling_verify on;
  ssl_trusted_certificate /etc/ssl/certs/ca-certificates.crt;
  
  # Support SSL session cache
  ssl_session_cache shared:NginxCache:50m;
  ssl_session_tickets off; # https://timtaubert.de/blog/2014/11/the-sad-state-of-server-side-tls-session-resumption-implementations/
  

  Generate file /etc/nginx/dh2048.pem with

  # openssl dhparam 2048 -out /etc/nginx/dh2048.pem
  

snippets

The snippets folder allows you to store bits of configuration that you can later include in virtual hosts configuration.This saves a lot of typing and errors when creating a new site.

• /etc/nging/conf.d/acme-challenge.conf
  See Let’s Encrypt
• /etc/nging/conf.d/hsts.conf

  # Activate HTTP Strict Transport Security
  # max-age value is in seconds. 31536000 is 6 months
  
  # add_header only works for 2xx and 3xx response code
  # Use module ngx_headers_more to add header for any response. 
  # If you don't have this module, remove the first line and uncomment the second one
  more_set_headers "Strict-Transport-Security: max-age=31536000";
  #add_header Strict-Transport-Security max-age=31536000;
  

• /etc/nginx/snippets/https-permanent-redirect.conf

  # Reply to the browser with a permanent redirect to the secure version of the page
  # Wrapped in a location block so that other snippets (acme-challenge.conf) can override that.
  location / {
      return 301 https://$host$request_uri;
  }
  

• /etc/nginx/snippets/listen-http.conf
/etc/nginx/snippets/listen-https.conf
  Obviously, you need to replace the example IP addresses by the one of your server. You can get the IP of your server with the commands curl https://ipv6.meurisse.org and curl https://ipv4.meurisse.org.

  listen [2001:db8:3:47d0::2e:7]:80;
  listen 203.0.113.23:80;
  

  listen [2001:db8:3:47d0::2e:7]:443 ssl http2;
  listen 203.0.113.23:443 ssl http2;
  

• /etc/nginx/snippets/ssl.conf

  ssl on;
  ssl_stapling on;
  

Fail2Ban

Webservers are usually a good target for hackers. A lot of them contain outdated, insecure and misconfigured software and if your server run languages like PHP, the attacker would be able to execute pretty much any action once he cracked your server.

Warning: The rules described here protect against generic attacks on your webserver. If you install some specific software that has it's own authentication (owncoud, roundcube...) you need to create rules for it.

nginx-http-auth

First rule is pretty simple simple. It protect against http authentication (the ugly popups asking your password before you enter the site).

Create file /etc/fail2ban/jail.d/nginx-http-auth.conf

[nginx-http-auth]
enabled = true
port    = http,https
logpath = /var/log/nginx/*error.log

nginx-botsearch

This rule match 404 errors when bots try to find unsecure software on your server. While it should generally work fine, you should check ban report to make sure you don't lock out legitimate users.

Create file /etc/fail2ban/jail.d/nginx-botsearch.conf

[nginx-botsearch]
enabled  = true
port     = http,https
logpath  = /var/log/nginx/*error.log
maxretry = 2