Problem Owncloud SSL

Hi, i use Owncloud 8.1.1 with nginx and i have a problem using SSL certificate for private network.
I Have my key file into nginx folder and my /etc/nginx/sites-available/owncloud looks like this

upstream php-handler {
server 127.0.0.1:9000;
#server unix:/var/run/php5-fpm.sock;
}
server {
listen 80;
server_name XX.XX.X.XX;
return 301 https://$server_name$request_uri;  # enforce https
}

server {
listen 443 ssl;
server_name XX.XX.X.XX;
ssl_certificate /etc/nginx/cert.pem;
ssl_certificate_key /etc/nginx/cert.key;
# Path to the root of your installation
root /var/www/owncloud;
client_max_body_size 1000M; # set max upload size
fastcgi_buffers 64 4K;
rewrite ^/caldav(.*)$ /remote.php/caldav$1 redirect;
rewrite ^/carddav(.*)$ /remote.php/carddav$1 redirect;
rewrite ^/webdav(.*)$ /remote.php/webdav$1 redirect;
index index.php;
error_page 403 /core/templates/403.php;
error_page 404 /core/templates/404.php;
location = /robots.txt {
    allow all;
    log_not_found off;
    access_log off;
}
location ~ ^/(?:\.htaccess|data|config|db_structure\.xml|README) {
    deny all;
}
location / {
    # The following 2 rules are only needed with webfinger
    rewrite ^/.well-known/host-meta /public.php?service=host-meta last;
    rewrite ^/.well-known/host-meta.json /public.php?service=host-meta-json last;
    rewrite ^/.well-known/carddav /remote.php/carddav/ redirect;
    rewrite ^/.well-known/caldav /remote.php/caldav/ redirect;
    rewrite ^(/core/doc/[^\/]+/)$ $1/index.html;
    try_files $uri $uri/ index.php;
}
location ~ \.php(?:$|/) {
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param PATH_INFO $fastcgi_path_info;
    fastcgi_param HTTPS on;
    fastcgi_pass php-handler;
   }
   # Optional: set long EXPIRES header on static assets
   location ~* \.(?:jpg|jpeg|gif|bmp|ico|png|css|js|swf)$ {
    expires 30d;
    # Optional: Don't log access to assets
    access_log off;
  }
}

The problem is that i always get the error "Your connection is not private"
How to fix it?

Hi,

ownCloud itself doesn't provide any SSL so that question here is a little bit off-topic (your webserver is handling this).

To make your connection "private" you need to create and use valid certificates. This can be done by following some of the tons of tutorials available on the internet. Great tutorials about this topics are available from Digital Ocean:

https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-14-04

edit

If you have a private network like written which is not reachable from the internet your only chances to have valid certificates are described here: