Access Synology DSM from the internet with a Reverse Proxy

Update:
For DSM 5 the paths are changed:

• DSM 4: /usr/syno/etc/httpd-ssl-vhost.conf-user
• DSM 5: /etc/httpd/sites-enabled-user/httpd-ssl-vhost.conf-user

I want to be able to access my Synology Disk Station Management (DSM) from the internet in a secure way through https.
DSM is standard running on the Synology in https mode on port 5001, so we need to setup a reverse proxy in apache:
Access the Synology with SSH using Putty, en type the following commands in the shell prompt to navigate to the right folder:
For DSM 4:

cd /usr/syno/etc/

For DSM 5:

cd /etc/httpd/sites-enabled-user/

Then we need to edit the ssl host configuration file:

vi httpd-ssl-vhost.conf-user

I want to access my DSM using this domain name: dsm.MYOWNDOMAIN.org, like https://dsm.myowndomain.org, so we need to add a new host section, append this section in the open file:

<VirtualHost *:443>
ServerName dsm.myowndomain.org
SSLEngine On
SSLProxyEngine On
ProxyRequests Off
ProxyVia Off
<Proxy *>
Order deny,allow
Allow from all
</Proxy>
ProxyPass / https://localhost:5001/
ProxyPassReverse / https://localhost:5001/
</VirtualHost>

It’s obvious that you have to change .myonwndomain.org with your real domain name.
Save the file and exit vi.
Don’t forget to set up your DNS to point to your external IP address, and to open port 443 in your router and direct the requests to this port to your Synology internal ip adres.
We need to restart Apache the load the changes we have done:
For DSM 4

/usr/syno/etc.defaults/rc.d/S97apache-user.sh restart

For DSM 5

httpd -k restart

Now you will be able to access your Synology DSM from everywhere using https!