Re: trust anchors and the base system

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Fri, Sep 02, 2022 at 02:23:51PM -0400, Greg Troxel wrote:
> I don't think we have to really address this, but it's important to keep
> it in mind because sometimes people seem to think this is totally
> straightforward and that anyone who doesn't want to just install the
> mozilla set doesn't understand.

I don't think that summarizes my position and what I suspect a lot of
other people think. If you care enough, you are free to configure your
system differently. But that's no excuse for not having a configuration
out of the box that works well enough for 99% of humanity.

>   rule is that NetBSD installs the mozilla set by default and when
>   that's done, it set /etc/openssl/VALIDATE.

This is useless complexity to me and therefore an enemy of a robust
system.

>   there's some fetch/update that happens to get new versions
> 
>   there is some way that there is a config file of certs in mozilla not
>   to use, and some way to put certs that one wants as trust anchors, and
>   this is respected by the update process

There are two common ways to install trust anchors:
(1) A single ca-bundle.pem.
(2) One certificate per trust anchor, with a hashed symlink for
efficient lookup.

If you want to add or drop a certificate in the first schema, you
append/remove it to/from the file. For the second scheme, you add/drop
the symlink. Most installations nowadays prefer the second approach as
it is easier to role out custom CAs. I see little reason to divert from
this scheme.

I don't see a need for inventing a separate update mechanism, we already
have enough mechanisms for updating /etc and the rest of the system. The
only new part we should support IMO is /etc/ssl/certs.bad and having a
replacement for c_rehash in shell or C that looks into that directory,
builds a list of hashes of all certs in it and explicitly removes them
from /etc/ssl/certs as well as skikping the creation in the future. So
if a user thinks that "Crypto AG Trust Root" should not be trusted, they
can copy it to that directory and it will no longer be set up as trust
anchor.

Joerg