How do I create a self-signed SSL certificate?

Question

I've set up SSL on my webserver, now I need two files:

• a certificate
• a certificate Key

How do I create a self-signed certificate for testing purposes?

Answer 1

Ubuntu, even the 'minimal' flavour, comes with the ssl-cert package pre-installed, which means you don't need to do anything.

The files you're looking for are already on your system:

/etc/ssl/certs/ssl-cert-snakeoil.pem
/etc/ssl/private/ssl-cert-snakeoil.key

Advanced:

If for some reason you need to create a fresh certificate, you can run

sudo make-ssl-cert generate-default-snakeoil --force-overwrite 

If you want to change the expiration date of you certificate, you can manipulate the make-ssl-cert script at /usr/sbin/make-ssl-cert. Around like 124 there's a line similar to this:

openssl req -config $TMPFILE -new -x509 -nodes \ 

Where you can change the expiration date by adding the -days argument:

openssl req -config $TMPFILE -new -days 365 -x509 -nodes \ 

More options can be found in the manual page of req.