diff --git a/provision/provision-base.sh b/provision/provision-base.sh
index 4a86ed3..dc14c48 100644
--- a/provision/provision-base.sh
+++ b/provision/provision-base.sh
@@ -99,13 +99,30 @@ popd
 # install and configure nginx to proxy to nexus.
 # see https://help.sonatype.com/repomanager3/planning-your-implementation/run-behind-a-reverse-proxy
 apt-get install -y --no-install-recommends nginx
-rm -f /etc/nginx/sites-enabled/default
-cat >/etc/nginx/sites-available/$config_fqdn.conf <<EOF
-ssl_session_cache shared:SSL:4m;
-ssl_session_timeout 6h;
+wget -qO /etc/ssl/certs/dhparam.pem https://ssl-config.mozilla.org/ffdhe2048.txt
+sed -i -E 's/^(\s*)((ssl_protocols|ssl_ciphers|ssl_prefer_server_ciphers)\s)/\1# \2/' /etc/nginx/nginx.conf
+cat >/etc/nginx/conf.d/local.conf <<EOF
+# NB this is based on the mozilla intermediate configuration.
+# see https://ssl-config.mozilla.org/#server=nginx&version=1.18.0&config=intermediate&openssl=3.0.2&guideline=5.7
+# see https://packages.ubuntu.com/jammy/nginx
+# see https://packages.ubuntu.com/jammy/openssl
+ssl_protocols TLSv1.2 TLSv1.3;
+ssl_ecdh_curve X25519:prime256v1:secp384r1;
+ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-CHACHA20-POLY1305;
+ssl_prefer_server_ciphers off;
+ssl_session_cache shared:SSL:10m; # about 40000 sessions.
+ssl_session_timeout 1d;
+ssl_session_tickets on;
+ssl_dhparam /etc/ssl/certs/dhparam.pem;
+# NB our example ca does not support stapling, so this is commented.
 #ssl_stapling on;
 #ssl_stapling_verify on;
-
+#ssl_trusted_certificate /etc/ssl/certs/jenkins-ca.pem;
+#resolver 127.0.0.53 valid=30s;
+#resolver_timeout 5s;
+EOF
+rm -f /etc/nginx/sites-enabled/default
+cat >/etc/nginx/sites-available/$config_fqdn.conf <<EOF
 server {
   listen 80;
   server_name _;
@@ -119,11 +136,6 @@ server {
 
   ssl_certificate /etc/ssl/private/$config_fqdn-crt.pem;
   ssl_certificate_key /etc/ssl/private/$config_fqdn-keypair.pem;
-  ssl_protocols TLSv1.2 TLSv1.3;
-  # see https://github.com/cloudflare/sslconfig/blob/master/conf
-  # see https://blog.cloudflare.com/it-takes-two-to-chacha-poly/
-  # see https://blog.cloudflare.com/do-the-chacha-better-mobile-performance-with-cryptography/
-  ssl_ciphers EECDH+CHACHA20:EECDH+AES128:RSA+AES128:EECDH+AES256:RSA+AES256:EECDH+3DES:RSA+3DES:!aNULL:!MD5;
 
   tcp_nodelay on;
   client_max_body_size 1G;
@@ -159,11 +171,6 @@ server {
 
   ssl_certificate /etc/ssl/private/$config_fqdn-crt.pem;
   ssl_certificate_key /etc/ssl/private/$config_fqdn-keypair.pem;
-  ssl_protocols TLSv1.2 TLSv1.3;
-  # see https://github.com/cloudflare/sslconfig/blob/master/conf
-  # see https://blog.cloudflare.com/it-takes-two-to-chacha-poly/
-  # see https://blog.cloudflare.com/do-the-chacha-better-mobile-performance-with-cryptography/
-  ssl_ciphers EECDH+CHACHA20:EECDH+AES128:RSA+AES128:EECDH+AES256:RSA+AES256:EECDH+3DES:RSA+3DES:!aNULL:!MD5;
 
   tcp_nodelay on;
   client_max_body_size 10G;
@@ -188,11 +195,6 @@ server {
 
   ssl_certificate /etc/ssl/private/$config_fqdn-crt.pem;
   ssl_certificate_key /etc/ssl/private/$config_fqdn-keypair.pem;
-  ssl_protocols TLSv1.2 TLSv1.3;
-  # see https://github.com/cloudflare/sslconfig/blob/master/conf
-  # see https://blog.cloudflare.com/it-takes-two-to-chacha-poly/
-  # see https://blog.cloudflare.com/do-the-chacha-better-mobile-performance-with-cryptography/
-  ssl_ciphers EECDH+CHACHA20:EECDH+AES128:RSA+AES128:EECDH+AES256:RSA+AES256:EECDH+3DES:RSA+3DES:!aNULL:!MD5;
 
   tcp_nodelay on;
   client_max_body_size 10G;
@@ -217,11 +219,6 @@ server {
 
   ssl_certificate /etc/ssl/private/$config_fqdn-crt.pem;
   ssl_certificate_key /etc/ssl/private/$config_fqdn-keypair.pem;
-  ssl_protocols TLSv1.2 TLSv1.3;
-  # see https://github.com/cloudflare/sslconfig/blob/master/conf
-  # see https://blog.cloudflare.com/it-takes-two-to-chacha-poly/
-  # see https://blog.cloudflare.com/do-the-chacha-better-mobile-performance-with-cryptography/
-  ssl_ciphers EECDH+CHACHA20:EECDH+AES128:RSA+AES128:EECDH+AES256:RSA+AES256:EECDH+3DES:RSA+3DES:!aNULL:!MD5;
 
   tcp_nodelay on;
   client_max_body_size 10G;