====== Apache: renew self-signed certificate ======
  - change directory\\ <code bash>cd /etc/apache2/ssl/</code>
  - generate openssl key\\ <code bash>openssl genrsa -out joel.feggm.de.key 2048</code>
  - change file permissions\\ <code bash>chmod 600 joel.feggm.de.key</code>
  - create a certificate request file\\ <code bash>openssl req -new -key joel.feggm.de.key -out joel.feggm.de.csr</code>
  - self-sign the certificate\\ <code bash>openssl x509 -req -days 365 -in joel.feggm.de.csr  -signkey joel.feggm.de.key -out joel.feggm.de.crt</code>
  - move old certificate to *.old\\ <code bash>mv apache.pem apache.pem.old</code>
  - copy new key to old file\\ <code bash>cp joel.feggm.de.key apache.pem</code>
  - attach new certificate to old file\\ <code bash>cat joel.feggm.de.crt >> apache.pem</code>
  - change file permissions\\ <code bash>chmod 600 apache.pem</code>
  - restart apache daemon\\ <code bash>service apache2 restart</code>