Best nginx configuration for improved security(and performance). Complete blog post here http://tautt.com/best-nginx-configuration-for-security/

nginx.conf

# config to don't allow the browser to render the page inside an frame or iframe
# and avoid clickjacking http://en.wikipedia.org/wiki/Clickjacking
# if you need to allow [i]frames, you can use SAMEORIGIN or even set an uri with ALLOW-FROM uri
# https://developer.mozilla.org/en-US/docs/HTTP/X-Frame-Options
add_header X-Frame-Options SAMEORIGIN;

# when serving user-supplied content, include a X-Content-Type-Options: nosniff header along with the Content-Type: header,
# to disable content-type sniffing on some browsers.
# https://www.owasp.org/index.php/List_of_useful_HTTP_headers
# currently suppoorted in IE > 8 http://blogs.msdn.com/b/ie/archive/2008/09/02/ie8-security-part-vi-beta-2-update.aspx
# http://msdn.microsoft.com/en-us/library/ie/gg622941(v=vs.85).aspx
# 'soon' on Firefox https://bugzilla.mozilla.org/show_bug.cgi?id=471020
add_header X-Content-Type-Options nosniff;

# This header enables the Cross-site scripting (XSS) filter built into most recent web browsers.
# It's usually enabled by default anyway, so the role of this header is to re-enable the filter for 
# this particular website if it was disabled by the user.
# https://www.owasp.org/index.php/List_of_useful_HTTP_headers
add_header X-XSS-Protection "1; mode=block";

# with Content Security Policy (CSP) enabled(and a browser that supports it(http://caniuse.com/#feat=contentsecuritypolicy),
# you can tell the browser that it can only download content from the domains you explicitly allow
# http://www.html5rocks.com/en/tutorials/security/content-security-policy/
# https://www.owasp.org/index.php/Content_Security_Policy
# I need to change our application code so we can increase security by disabling 'unsafe-inline' 'unsafe-eval'
# directives for css and js(if you have inline css or js, you will need to keep it too).
# more: http://www.html5rocks.com/en/tutorials/security/content-security-policy/#inline-code-considered-harmful
add_header Content-Security-Policy "default-src * 'unsafe-inline' data:";


# enabling Public Key Pinning Extension for HTTP (HPKP)
# https://developer.mozilla.org/en-US/docs/Web/Security/Public_Key_Pinning
# to generate use on of these:
# $ openssl rsa -in my-website.key -outform der -pubout | openssl dgst -sha256 -binary | base64
# $ openssl req -in my-website.csr -pubkey -noout | openssl rsa -pubin -outform der | openssl dgst -sha256 -binary | base64
# $ openssl x509 -in my-website.crt -pubkey -noout | openssl rsa -pubin -outform der | openssl dgst -sha256 -binary | base64
add_header Public-Key-Pins 'pin-sha256="base64+info1="; max-age=31536000; includeSubDomains'; 

server {
  listen 443 ssl deferred;
  server_name _;

  root /var/www/html/public/;
  index index.php index.html index.htm;

  location ~ \.(htaccess|htpasswd|ini|sh|bak)$ {
          deny all;
  }


  location ~ /(theme|cache)/ {
    expires 1M;
    access_log off;
    add_header Cache-Control "public";
  }

  location / {
    try_files $uri /index.php?$query_string;
  }

  location ~ \.php$ {
    try_files $uri =404;
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_read_timeout 30;
    fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;
    fastcgi_index index.php;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
  }

  ssl_certificate /etc/ssl/SSL.crt;
  ssl_certificate_key /etc/ssl/server.key;

  # enable session resumption to improve https performance
  # http://vincent.bernat.im/en/blog/2011-ssl-session-reuse-rfc5077.html
  ssl_session_cache shared:SSL:50m;
  ssl_session_timeout 5m;

  # to generate your dhparam.pem file, run in the terminal
  # openssl dhparam -out /etc/ssl/dhparam.pem 2048
  # Diffie-Hellman parameter for DHE ciphersuites, recommended 2048 bits
  ssl_dhparam /etc/ssl/dhparam.pem;

  # ciphers chosen for forward secrecy and compatibility
  # http://blog.ivanristic.com/2013/08/configuring-apache-nginx-and-openssl-for-forward-secrecy.html
  ssl_ciphers "ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA:ECDHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES256-GCM-SHA384:AES128-GCM-SHA256:AES256-SHA256:AES128-SHA256:AES256-SHA:AES128-SHA:DES-CBC3-SHA:HIGH:!aNULL:!eNULL:!EXPORT:!DES:!MD5:!PSK:!RC4";

  # enable ocsp stapling (mechanism by which a site can convey certificate revocation information to visitors in a privacy-preserving, scalable manner)
  # http://blog.mozilla.org/security/2013/07/29/ocsp-stapling-in-firefox/
  resolver 8.8.8.8;
  ssl_stapling on;

  # config to enable HSTS(HTTP Strict Transport Security) https://developer.mozilla.org/en-US/docs/Security/HTTP_Strict_Transport_Security
  # to avoid ssl stripping https://en.wikipedia.org/wiki/SSL_stripping#SSL_stripping
  add_header Strict-Transport-Security "max-age=31536000; includeSubdomains;";

}