What is a "CSR" and how do I get one?

CSR is a Certificate Signing Request

Basic overview

This file contains pieces of information about your cert and your public key.

It is used by the CA or Certification Authority (here : CAcert Inc.) to sign your cert (and obviously the info included in the cert).

The CA does not need the private key you have generated. You keep your private key secret.

The CA uses this CSR file to grab the info, verifying the info from your account and then generate the real certificate that you ( and your services) will use during secure communications with clients (HTTPS,SSL,POP3/SSL, etc.) and servers.

(based on Bruno ideas on CAcert support mailing list)

Example of CSR

tools to generate CSRs

Analyse your CSR data block

see Analyse CSR

More info

see here and there

Official OpenSSL stuff

You can get some more info reading the official OpenSSL documentation.

http://www.openssl.org/docs/