In the last couple of weeks, I’ve started getting this error ~1/5 times when I try to open one of my own locally hosted services.

I’ve never used ECH, and have always explicitly restricted nginx to TLS1.2 which doesn’t support it. Why am I suddenly getting this, why is it randomly erroring, then working just fine again 2min later, and how can I prevent it altogether? Is anyone else experiencing this?

I’m primarily noticing it with Ombi. I’m also mainly using Chrome Android for this. But, checking just now; DuckDuckGo loads the page just fine everytime, and Firefox is flat out refusing to load it at all.

Firefox refuses to show the cert it claims is invalid, and ‘accept and continue’ just re-loads this error page. Chrome will show the cert; and it’s the correct, valid cert from LE.

There’s 20+ services going through the same nginx proxy, all using the same wildcard cert and identical ssl configurations; but Ombi is the only one suddenly giving me this issue regularly.

The vast majority of my services are accessed via lan/vpn; I don’t need or want ECH, though I’d like to keep a basic https setup at least.

    • Darkassassin07@lemmy.caOPEnglish
      1·
      2 hours ago

      Thanks. That seems to be a similar, but slightly different error. I think the below may apply though.

      I believe I’ve tracked down more of my issue, but fixing it is going to be a hassle:

      When cloudflare proxying is enabled, there are 3 DNS records involved; A record with cloudflares ipv4, AAAA record with cloudflares IPV6, and the key to this puzzle: an HTTPS record with cloudflares ech/https config.

      With pihole I can set DNS records for A/AAAA, but I have no way of blocking/setting the HTTPS record so it gets through from cloudflare.

      The LAN A/AAAA records don’t match the HTTPS record from cloudflare, so browsers freak out.

      Once I disabled cloudflares proxying, I no longer get HTTPS records returned and all works as intended.

      I’ll either have to keep cloudflare proxying disabled, or switch pihole out for a more comprehensive DNS solution so I can set/block HTTPS records :(

      Thank you @bobslaede@feddit.dk for pointing me in the right direction.