CAcert.org is a community driven Certificate Authority that issues certificates to the public at large for free.

Prerequisites

To get certificates you have to be a member of CACert.org (membership is free)

To issue certificates for a specific domain you must be owner of that domain. CACert checks this by seinding an email to specific email addresses in this domain e.g. root@mydomain.com. Therefore you must be able to configure email delivery for that domain.

Crating a CSR (Certificate Signing Request) for your server

A CSR or Certificate Signing request is a block of encoded text that is given to a Certificate Authority when applying for an SSL Certificate. Creating a CSR can be done with different tools. https://www.digicert.com provides the free DigiCert® Certificate Utility for Windows which is extremly easy to use and well documented.

Run this tool on the server for which you want to create the certificate.

This tool will create the CSR as text block that can be used on CACert.org to create a domain certificate.

Installing the certificate issued by CACert

Use the CSR on CACert.org to create a certificate.

CACert.org will issue domain certificates in PEM format (an ASCII format). Save that to a file.

On your server. Open the Window's Management Console (mmc.exe). Add the Certificate Snap-In for local machine. Go to Personal > Certificates right click the Certificates node and choose All Tasks > Import select the crt file and import it.

Now you have installed the certificate for your server.

Installing the CACert.org root authority on all clients

CACert.org is usually not by default a trusted root certification authority on computers that access the Redbex Server. You will therefore have to install the CACert.org certificate manually on every client. On CACert.org you can download the root certificate in different formats and then install it on your client(s)