Please consider enabling OCSP stapling, DNSSEC, and/or DANE on *

Mattia Rizzolo mattia at
Mon Apr 17 12:33:05 UTC 2023

Hello John,

On Sat, Apr 15, 2023 at 02:38:04AM +0000, John Scott wrote:
> OCSP stapling is the modern, privacy-friendly way to determine a certificate's revocation status. It incurs very little overhead on the server side. One can use curl to check if OCSP stapling is working, at least for HTTPS:
> $ curl --cert-status
> curl: (91) No OCSP response received

You are quite right on this.

I personally never bothered enabling OCSP stapling despite knowing of
it, but it's something that I can totally look into and do.

> OCSP stapling is useful for other TLS applications, however, including for SMTP on the list server.

I'm not aware of any way to do OCSP in postfix?

> Enabling DNSSEC mitigates DNS spoofing and also ascertains the authenticity of DANE records.

We have no excuses for not having enabled DNSSEC long ago: our DNSs are
hosted by Gandi, which handles DNSSEC with a single button.

Just to be on the safe side, I've now tried to enable DNSSEC on and, and if nothing weird happen I'll
also switch on

> DANE mitigates so-called "SSL stripping" attacks and allows users to validate the authenticity of the TLS certificates without having to rely on the traditional problematic certificate authority system.

DANE of course comes only after DNSSEC (otherwise it's pointless…).

I have in program some work to our email setup (not strictly related to
the lists), so I'll check the DANE-related configurations in the coming

                        Mattia Rizzolo

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