Master CA and Key Setup

[bobjcohen]

I'm reading the "Setting up your own Certificate Authority (CA) and generating certificates and keys for an OpenVPN server and multiple clients" section of the installation how to and am a little confused about CAs and keys.

It says "The first step in building an OpenVPN 2.x configuration is to establish a PKI (public key infrastructure)." I'm pretty sure I did this when setting up my https capabilities and public/private key authentication for my ssh. The files for this are in /etc/pki/tls. E.g.

ca.crt
ca.csr
ca.key
cert.pem -> certs/ca-bundle.crt
certs
misc
openssl.cnf
private

The private directory has keys for several shared hosts.

The How-To says to use easy-rsa to accomplish the task. It seems like these step are already done.

Next it talks about setting up certificates and keys for multiple clients and suggests naming them client1, client2, client3. Do I actually name them thusly or can I give each client different names?

When I try to set up the Diffie Hellman parameters, the system complains,

Please source the vars script first (i.e. "source ./vars")
Make sure you have edited it to reflect your configuration.

So I'm not really sure where to start from.

Thanks in advance for the help. Sorry if these are obnoxious newbie questions.

-Bob