So far I'm using self-signed certificates, but decided to at least consider getting the "real" one.
So far I noticed that internal formats of the certificated are a bit different, that is:
- http (nginx) certificate has only CERTIFICATE part (with base64 encoded content) and KEY with also only base64 content
- smtp (exim) crt file contains certificate textual information (issuer, subject, algorithm, dates, and so on), plus CERTIFICATE block with base64 data, while the .key file for exim contains only base64 encoded key
- imap/pop3 (courier) .pem file contains key (base64), certificate info (textual), and certificate itself (base64).
Can I get any "web" certificate from thawte or some company like this, and from this (and key file) generate all formats that I need for nginx, exim4 and courier, or do I need to get separate certificates, or is it something else entirely?