# Test OCSP with:
# openssl s_client -connect $site:443 -tls1 -tlsextdebug -status
#
# also test with:
# openssl s_client -connect $site:443 -CAfile /etc/ssl/certs/ca-certificates.crt -showcerts -status -tlsextdebug -cipher RSA </dev/null
#
# openssl s_client -connect $site:443 -CAfile /etc/ssl/certs/ca-certificates.crt -showcerts -status -tlsextdebug -cipher ECDSA </dev/null


# Duration client SSL session tickets are valid for:
ssl_session_timeout 1d;
# NOTE NOTE NOTE NOTE NOTE
# nginx only regenerates its ssl_session_ticket_key on reload or restart.
# the ticket key is basically a symmetric key that effectively breaks
# forward secrecy if leaked.
# With ssl_session_tickets enabled, you should reload nginx daily to reset
# the internal cached ticket key.
# If you are using external ticket keys, those should also be rotated daily.
# END NOTE END NOTE END NOTE

# Internal cache of SSL sessions
ssl_session_cache shared:SSL:500m; # 500MB = 2M cached sessions (4k sessions/MB)

# session tickets are reused for the life of the server.
# For multiple servers serving the same host,
# have them all share the same key and rotate as necessary:
# ssl_session_ticket_key [keyfile];
# Without a ticket key file defined, a reload of nginx resets the key.
ssl_session_tickets on;

# Individual cipher files are included externally
# (one of ssl_ciphers_{intermediate,modern})
ssl_prefer_server_ciphers on;

# HSTS (ngx_http_headers_module is required) (15768000 seconds = 6 months)
add_header Strict-Transport-Security "max-age=15768000; includeSubdomains";

# OCSP Stapling ---
# fetch OCSP records from URL in ssl_certificate and cache them
ssl_stapling on;
ssl_stapling_verify on;

# See: https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_trusted_certificate
ssl_trusted_certificate /etc/ssl/lets-encrypt-x3-cross-signed.pem;

# Instead of using resolver, take response from file:
# ssl_stapling_file <-- must be set PER domain, but nginx so far has refused
# to add the ability to have one stapling file per certificate now that nginx
# supports both RSA and EC per domain. So, this is useless if you have multiple
# certificates per domain.

# 'valid' ignores DNS TTL and caches lookups for specified duration
# This should be replaced with a local dnsmasq resolver at 127.0.0.1
resolver 127.0.0.53 4.2.2.2 8.8.8.8 1.1.1.1 valid=600s ipv6=off;
resolver_timeout 4s;