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

create_key.sh

# to generate your dhparam.pem file, run in the terminal
openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048

nginx.conf

user www-data;
worker_processes 4;
pid /run/nginx.pid;

events {
	worker_connections 768;
	# multi_accept on;
}

http {

	##
	# Basic Settings
	##

	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;
	keepalive_timeout 65;
	types_hash_max_size 2048;
	# server_tokens off;

	# server_names_hash_bucket_size 64;
	# server_name_in_redirect off;

	include /etc/nginx/mime.types;
	default_type application/octet-stream;

	##
	# SSL Settings
	##

	ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
	ssl_trusted_certificate /etc/nginx/ssl/server.crt;

	# make the server choose the best cipher instead of the browser
	# Perfect Forward Secrecy(PFS) is frequently compromised without this
	ssl_prefer_server_ciphers on;

	# support only believed secure ciphersuites using the following priority:
	# 1.) prefer PFS enabled ciphers
	# 2.) prefer AES128 over AES256 for speed (AES128 has completely adequate security for now)
	# 3.) Support DES3 for IE8 support
	#
	# disable the following ciphersuites completely
	# 1.) null ciphers
	# 2.) ciphers with low security
	# 3.) fixed ECDH cipher (does not allow for PFS)
	# 4.) known vulnerable cypers (MD5, RC4, etc)
	# 5.) little-used ciphers (Camellia, Seed)
	ssl_ciphers 'kEECDH+ECDSA+AES128 kEECDH+ECDSA+AES256 kEECDH+AES128 kEECDH+AES256 kEDH+AES128 kEDH+AES256 DES-CBC3-SHA +SHA !aNULL !eNULL !LOW !kECDH !DSS !MD5 !EXP !PSK !SRP !CAMELLIA !SEED';

	# Use 2048 bit Diffie-Hellman RSA key parameters
	# (otherwise Nginx defaults to 1024 bit, lowering the strength of encryption # when using PFS)
	# Generated by OpenSSL with the following command:
	# openssl dhparam -outform pem -out /etc/nginx/ssl/dhparam2048.pem 2048
	ssl_dhparam /etc/nginx/ssl/dhparam2048.pem;

	# enable HSTS including subdomains
	add_header Strict-Transport-Security "max-age=31536000; includeSubdomains;";

	# allow Nginx to send OCSP results during the connection process
	ssl_stapling on;

	# Cache SSL Sessions for up to 10 minutes
	# This improves performance by avoiding the costly session negotiation process where possible
	ssl_session_cache builtin:1000 shared:SSL:10m;

	##
	# Logging Settings
	##

	access_log /var/log/nginx/access.log;
	error_log /var/log/nginx/error.log;

	##
	# Gzip Settings
	##

	gzip on;
	gzip_disable "msie6";

	# gzip_vary on;
	# gzip_proxied any;
	# gzip_comp_level 6;
	# gzip_buffers 16 8k;
	# gzip_http_version 1.1;
	# gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

	##
	# Virtual Host Configs
	##

	include /etc/nginx/conf.d/*.conf;
	include /etc/nginx/sites-enabled/*;
}


#mail {
#	# See sample authentication script at:
#	# http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
# 
#	# auth_http localhost/auth.php;
#	# pop3_capabilities "TOP" "USER";
#	# imap_capabilities "IMAP4rev1" "UIDPLUS";
# 
#	server {
#		listen     localhost:110;
#		protocol   pop3;
#		proxy      on;
#	}
# 
#	server {
#		listen     localhost:143;
#		protocol   imap;
#		proxy      on;
#	}
#}

nginx_.conf

# read more here http://tautt.com/best-nginx-configuration-for-security/

# don't send the nginx version number in error pages and Server header
server_tokens off;

# 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 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://ssl.google-analytics.com https://assets.zendesk.com https://connect.facebook.net; img-src 'self' https://ssl.google-analytics.com https://s-static.ak.facebook.com https://assets.zendesk.com; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com https://assets.zendesk.com; font-src 'self' https://themes.googleusercontent.com; frame-src https://assets.zendesk.com https://www.facebook.com https://s-static.ak.facebook.com https://tautt.zendesk.com; object-src 'none'";

server {
  listen 443 ssl default deferred;
  server_name .forgott.com;

  ssl_certificate /etc/nginx/ssl/star_forgott_com.crt;
  ssl_certificate_key /etc/nginx/ssl/star_forgott_com.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;

  # Diffie-Hellman parameter for DHE ciphersuites, recommended 2048 bits
  ssl_dhparam /etc/nginx/ssl/dhparam.pem;

  # enables server-side protection from BEAST attacks
  # http://blog.ivanristic.com/2013/09/is-beast-still-a-threat.html
  ssl_prefer_server_ciphers on;
  # disable SSLv3(enabled by default since nginx 0.8.19) since it's less secure then TLS http://en.wikipedia.org/wiki/Secure_Sockets_Layer#SSL_3.0
  ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
  # 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;
  ssl_trusted_certificate /etc/nginx/ssl/star_forgott_com.crt;

  # 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;";

  # ... the rest of your configuration
}

# redirect all http traffic to https
server {
  listen 80;
  server_name .forgott.com;
  return 301 https://$host$request_uri;
}

proxy_params

proxy_connect_timeout   59s;
proxy_send_timeout      600;
proxy_read_timeout      36000s;  ## Timeout after 10 hours
proxy_buffer_size       64k;
proxy_buffers           16 32k;
proxy_pass_header       Set-Cookie;
proxy_hide_header       Vary;
 
proxy_busy_buffers_size         64k;
proxy_temp_file_write_size      64k;
 
proxy_set_header        Accept-Encoding         '';
proxy_ignore_headers    Cache-Control           Expires;
proxy_set_header        Referer                 $http_referer;
proxy_set_header        Host                    $host;
proxy_set_header        Cookie                  $http_cookie;
proxy_set_header        X-Real-IP               $remote_addr;
proxy_set_header        X-Forwarded-Host        $host;
proxy_set_header        X-Forwarded-Server      $host;
proxy_set_header        X-Forwarded-For         $proxy_add_x_forwarded_for;
proxy_set_header        X-Forwarded-Port        '443';
proxy_set_header        X-Forwarded-Ssl         on;
proxy_set_header        X-Forwarded-Proto       https;
proxy_set_header        Authorization           '';
 
proxy_buffering         off;
proxy_redirect          off;

https://juliansimioni.com/blog/https-on-nginx-from-zero-to-a-plus-part-2-configuration-ciphersuites-and-performance/