Support for ECC keys

[czocher]

Hello,
First of all thanks for all your hard work on the project, it's at least a time saver if not a lifesaver.
My problem is that the only SSL keys I have for my domain are not RSA keys but ECC keys. From what I know postfix support ECC keys by two config options:

smtpd_tls_eckey_file = smtpd-key-ecdsa.key
smtpd_tls_eccert_file = smtpd-cert-ecdsa.cert

The problem is, from what I see the main.dist.cf file accepts only RSA keys with the smtpd_tls_key_file and smtpd_tls_cert_file directive.

Is there any possibility for ECC key support to be added to the container too?

[huan]

Hello, thanks for like the project.

I believe it's do-able to support the ECC keys to the SMF container.

PR will be welcome. :-)

[czocher]

Testing it right now with a substituted configuration, I only changed smtpd_tls_key_file to smtpd_tls_eckey_file and smtpd_tls_cert_file to smtpd_tls_eccert_file and it seems to work fine. I'll check a few possibilities (mostly whether you can configure both ECC and RSA keys at the same time without causing postfix a lot of headache).
Gonna get back to you with a proper PR as soon as I test it thoroughly.

[czocher]

Okay the PR is ready: #51
Tested it on my setup, it doesn't throw any errors in the logs although the smtp.cert/key is missing, probably cause it sees the smtp.ec.key and smtp.ec.key as a replacement.
Thanks for the mention in the README, it made my day :D