Recently I've installed luci-app-banip on my OpenWrt router and blocked most countries from accessing my services on my network. Not seeing why I would want any of that traffic I also blocked the whole of the ARIN registry, responsible for IP addresses from Canada and the United States.
Edit: Note this is only for inbound traffic. Outbound traffic is allowed no matter the target country.
Fast forward a few weeks and my certbot renewals fail with the following error: Failed to renew certificate enter.domain.here with error: HTTPSConnectionPool(host='acme-v02.api.letsencrypt.org', port=443): Read timed out. (read timeout=45)
Confused af I start looking for solutions and as so often only find useless or completely ridiulous solutions (lowering my MTU to 1300, what? WHY?). Finally I find some enlighted figure that says they recently enabled a blocklist for certain countries and that was the issue for them.
Now I make the connection to my use of banIP, re-allow the USA and my cert renewals start working again. Hooray!
However, there are two things bothering me:
- Why would such a block even interrupt my renewals? I'm using DNS challenges and the ACME servers should only check the DNS entries, not where those entries actually redirect to. The DNS server/root isn't in my home network, so isn't affected by any firewall shenanigans I do here.
- How can I make an exception for the Let's Encrypt ACME servers while blocking the rest of the ARIN IP space?
I see there's the option for ASN selection and external allowlists:
Does anybody have an idea on how to configure this so that Let's Encrypt continues to work without compromising on my network security?
(Edit: And just for clarity, I do not live in the US or anywhere on the American continent.)
are you using external DNS hosting? is it in a (now) blocked country? if so, then your local certbot is unable to update the DNS server records (return traffic from your DNS host is being blocked by your iptables/nftables config).
yeah, that would suggest an https renewal method. had you previously configured web server renewal at all before switching over to DNS? any other suspicious notifications in the logs?
edit: in thinking about this a little more... the renewal has to be initiated by your host, and that is likely done via https (you talk https to the acme server and tell it you want a renewal by DNS). so, if you are blocking the acme servers then the same issue applies - no return traffic.