web: update TLS config to Mozilla security guidelines

web/rootfs/defaults/ffdhe2048.txt

@@ -0,0 +1,8 @@
+-----BEGIN DH PARAMETERS-----
+MIIBCAKCAQEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz
++8yTnc4kmz75fS/jY2MMddj2gbICrsRhetPfHtXV/WVhJDP1H18GbtCFY2VVPe0a
+87VXE15/V8k1mE8McODmi3fipona8+/och3xWKE2rec1MKzKT0g6eXq8CrGCsyT7
+YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi
+7MA0BM0oNC9hkXL+nOmFg/+OTxIy7vKBg8P+OxtMb61zO7X8vC7CIAXFjvGDfRaD
+ssbzSibBsu/6iGtCOGEoXJf//////////wIBAg==
+-----END DH PARAMETERS-----

web/rootfs/defaults/ssl.conf

@@ -1,6 +1,6 @@
 # session settings
 ssl_session_timeout 1d;
-ssl_session_cache shared:SSL:50m;
+ssl_session_cache shared:MozSSL:10m;  # about 40000 sessions
 ssl_session_tickets off;
 
 # ssl certs
@@ -13,10 +13,14 @@ ssl_certificate_key /config/keys/cert.key;
 {{ end }}
 
 # protocols
-ssl_protocols TLSv1.2;
-ssl_prefer_server_ciphers on;
-ssl_ecdh_curve secp384r1;
-ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:ECDH+CHACHA20:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!3DES:!MD5:!PSK;
+# Mozilla Guideline v5.6, nginx 1.14.2, OpenSSL 1.1.1d, intermediate configuration, no OCSP
+# https://ssl-config.mozilla.org/#server=nginx&version=1.14.2&config=intermediate&openssl=1.1.1d&ocsp=false&guideline=5.6
+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;
 
-# headers
-add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload";
+# Diffie-Hellman parameter for DHE cipher suites
+ssl_dhparam /defaults/ffdhe2048.txt;
+
+# HSTS (ngx_http_headers_module is required) (63072000 seconds)
+add_header Strict-Transport-Security "max-age=63072000" always;