[RFC] self-signed certificates for LuCI

[Paul Spooren]

On 30.08.20 12:32, Michael Richardson wrote:
> Paul Spooren <mail at aparcar.org> wrote:
>      > I recently rewrote px5g[1] to use WolfSSL instead of MbedTLS, as the former
>      > will be included in OpenWrt 20.x per default.
>
>      > Both implementations support the generation of RSA and ECC keys, where uhttpd
>      > currently defaults to RSA with 2048 keys.
>
>      > The question came up if we really want RSA certificates for LuCI or if the
>      > faster and "more modern" ECC P-256 wouldn't be a better choice.
>
> Yes, it would be better.
>
>      > If px5g is added to the next release, certificates are generated on first
>      > boot and most users are unlikely to manually recreate RSA ones, not?
>
> But, this will result in a security warning for a self-signed key, and then
> we'd be training users to click through them.
> I am divided on whether this is better or worse than unencrypted.
> browsers are making doing that security exception more and more difficult,
> with the desire to eliminating it entirely.

I think we should write a bit of documentation explaining that a cert 
should be accepted only once or a router reset is required. That seems 
more save than sticking to unencrypted connections. If browsers decide 
to block self-signed certs, most UBNT devices will break, too.

> I have running code that deploys LetsEncrypt certificates to devices in the
> "factory".   This requires a DNS name for dns-01 challenge.
> That's clearly not feasible for random end-users who flash openwrt on their own.
> I would like to explore some additional options here.
Mind sharing this code? Me (and Daniel) had the same idea, so some ACME 
support for px5g would be interesting.
>      > So the question, shouldn't we drop all crypto options from the new px5g
>      > implementation and _only_ offer P-256? Whoever wants something else than the
>      > default may use px5g-mbedtls or some OpenSSL based tool?
>
> uhm, okay.  I can live with that for sure.
> I care more about what's in the certificate than the algorithm.

Fair, however this question is about the algorithm :)

Paul