Here are the terminal commands and steps to install a brought SSL Certificate on Ubuntu 16.04 Apache server (not LetsEncrypt).
sudo mkdir /etc/apache2/ssl
sudo mkdir /etc/apache2/ssl/private
sudo chmod 755 /etc/apache2/ssl
sudo chmod 710 /etc/apache2/ssl/private
sudo chown -R root:root /etc/apache2/ssl/
sudo chown -R root:ssl-cert /etc/apache2/ssl/private/
Now, place your SSL public certificate(s) in /etc/apache2/ssl and your SSL private key(s) in /etc/apache2/ssl/private
sudo chmod 644 /etc/apache2/ssl/.crt
sudo chmod 640 /etc/apache2/ssl/private/.key
In /etc/apache2/sites-available update the file paths for SSLCertificateFile, SSLCertificateKeyFile, and SSLCertificateChainFile.
sudo a2enmod ssl
service apache2 restart
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