OpenSSL and certificates

Information on certificate generation for CAcert.org signing.

1. Follow instructions on CAcert.org page.
2. That's enough for getting simple signed certificate which is good for exim. For Courier IMAP additionally you will require to perform the following steps.
3. Create a random file: dd if=/dev/urandom of=/tmp/cert.rand count=1
4. Create PEM formated certificate: cat private.key server.crt > server.pem
5. Generate DH pair for certificate: openssl gendh -rand /tmp/cert.rand 512 >>./server.pem
6. Clean-up: rm -f /tmp/cert.rand