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

gistfile1.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 auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

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_prefer_server_ciphers on;

	# SSL Security
	# https://ssl-config.mozilla.org/#server=nginx&version=1.17.7&config=intermediate&openssl=1.1.1k&guideline=5.6

	# curl https://ssl-config.mozilla.org/ffdhe2048.txt > /path/to/dhparam
	ssl_dhparam /etc/nginx/dhparam;

	# intermediate configuration
	ssl_protocols TLSv1.2 TLSv1.3;
	ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;
	ssl_prefer_server_ciphers off;

	# HSTS (ngx_http_headers_module is required) (63072000 seconds)
	add_header Strict-Transport-Security "max-age=63072000" always;

	# Include HTTP Security Headers
	# https://gist.github.com/jcchikikomori/10d2bb97485864c060d1d488b9eb4efd
	include /etc/nginx/conf.d/security.conf;

	# END of SSL Security

	##
	# Logging Settings
	##

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

	##
	# Gzip Settings
	##

	gzip on;

	# 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;
#	}
#}

security.conf

# Web Security configs
# @author John Cyrill Corsanes
# @source https://gist.github.com/jcchikikomori/10d2bb97485864c060d1d488b9eb4efd

# 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 * 'unsafe-inline' 'unsafe-eval'; script-src * 'unsafe-inline' 'unsafe-eval'; connect-src * 'unsafe-inline'; img-src * data: blob: 'unsafe-inline'; frame-src *; style-src * 'unsafe-inline';";

# Permissions-Policy:
# Permissions Policy is a new header that allows a site to control which features and APIs can be used in the browser.
# Currently unstable and very recent: https://csplite.com/pp/test397/
# add_header Permissions-Policy "geolocation=(),midi=(),sync-xhr=(),microphone=(),camera=(),magnetometer=(),gyroscope=(),fullscreen=(self),payment=()";
add_header Permissions-Policy "geolocation=(),sync-xhr=(),microphone=(),camera=(),fullscreen=(self),payment=()";

# https://scotthelme.co.uk/hsts-the-missing-link-in-tls/
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains";

# https://scotthelme.co.uk/a-new-security-header-referrer-policy/
add_header Referrer-Policy same-origin