On UNIX box (I am doing on Linux, actually), run these commands, fill out appropriate information then keep the files generated. You may change file names as needed. From the following example, you have to keep server.csr to request certificate at CAcert.org and privatekey.txt to put it into server configuration. Upon the issuance of certificate, you can name it as you like (eg. certificate.crt)
- openssl genrsa -des3 -out ca.pkey.txt 1024
- openssl rsa -in ca.pkey.txt -out privatekey.txt
- openssl req -new -key ca.pkey.txt -out server.csr