Is this something that we can enable "today" or is it going to take 12 years for browsers and servers to support?

CloudFlare has supported it since 2023: https://blog.cloudflare.com/announcing-encrypted-client-hell... Firefox has had it enabled by default since version 119: https://support.mozilla.org/en-US/kb/faq-encrypted-client-he... so you can use it today.

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bombcar 4 hours ago | parent [-]

https://tls-ech.dev indicates that Safari doesn't support it, but Chrome does.

	▲	altairprime 3 hours ago \| parent [-]
		That’s likely due to iOS/macOS not supporting it in production-default-enabled yet; there’s an experimental opt-in flag at the OS level, but Safari apparently hasn’t (yet) added a dev feature switch for it. https://developer.apple.com/documentation/security/sec_proto... Presumably anyone besides Safari can opt-in to that testing today, but I wouldn’t ship it worldwide and expect nice outcomes until (I suspect) after this fall’s 27 releases. Maybe someone could PR the WebKit team to add that feature flag in the meantime?

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kro 4 hours ago | parent | prev | next [-]

Nginx mainline 1.29.x supports it. So once you get that and also the openssl version on your system, good to go. Likely too late for ubuntu 26.04, maybe in debian 14 next year, or of course rolling release distros / containers.

But, in a personal/single website server, ech does not really add privacy, adversaries can still observe the IP metadata and compare what's hosted there. The real benefits are on huge cloud hosting platforms.

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Bender 3 hours ago | parent [-]

FWIW Nginx 1.30 [1] just released and supports it so most distributions will have support as soon as those responsible for builds and testing builds push it forward.

"Nginx 1.30 incorporates all of the changes from the Nginx 1.29.x mainline branch to provide a lot of new functionality like Multipath TCP (MPTCP)."

"Nginx 1.30 also adds HTTP/2 to backend and Encrypted Client Hello (ECH), sticky sessions support for upstreams, and the default proxy HTTP version being set to HTTP/1.1 with Keep-Alive enabled."

But, in a personal/single website server, ech does not really add privacy, adversaries can still observe the IP metadata and compare what's hosted there

I don't quite follow. I have dozens of throw-away silly hobby domains. I can use any of them as the outer-SNI. How is someone observing the traffic going to know the inner-SNI domain unless someone builds a massive database of all known inner+outer combinations which can be changed on a whim? ECH requires DOH so unless the ISP has tricked the user into using their DOH end-point they can't see the HTTPS resource record.

[1] - https://news.ycombinator.com/item?id=47770007

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ameliaquining an hour ago | parent [-]

It's not that adversaries can directly see the domain name; this doesn't have anything to do with domain fronting. The issue is that ECH doesn't hide the server's IP address, so it's mostly useless for privacy if that IP address uniquely identifies that server. The situation where it helps is if the server shares that IP address with lots of other people, i.e., if it's behind a big cloud CDN that supports ECH (AFAIK that's currently just Cloudflare). But if that's the case, it doesn't matter whether Nginx or whatever other web server you run supports ECH, because your users' TLS negotiations aren't with that server, they're with Cloudflare.

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Bender an hour ago | parent [-]

I can't speak for anyone else but I think I can work around that by moving the site around to different VPS nodes from time to time. I get bored with my silly hobby sites all the time and nuke the VM's then fire them up later which gives them a new IP. I don't know what others might do if anything.

If I had a long running site I could do the same thing by having multiple font-end caching nodes using HAProxy or NGinx that come and go but I acknowledge others may not have the time to do that and most probably would not.

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ameliaquining 11 minutes ago | parent [-]

Anyone who wants to track your users can just follow the IP changes as they occur in real time.

	▲	Bender 4 minutes ago \| parent [-]
		Anyone who wants to track your users can just follow the IP changes as they occur in real time. That's cool. There is always the option to put sites on a .onion domain but I don't host anything nearly exciting or controversial enough. For text that's probably a good option. I don't know if Tor is fast enough for binary or streaming sites yet. No idea how many here even know how to access a .onion site.

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ekr____ 2 hours ago | parent | prev | next [-]

Even if the browsers and servers don't support it, you could still enable it because the system is designed to be backward compatible.

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tialaramex 3 hours ago | parent | prev [-]

TLS (the IETF Working Group not the protocol family named for them) have long experience with the fact that if you specify how B is compatible with A based on how you specified A and ship B what you did won't work because the middleboxes are all cost optimized and don't implement what you specified but instead whatever got the sale for the least investment.

So e.g. they'd work for exactly the way you use say TLS 1.0 in the Netscape 4 web browser which was popular when the middlebox was first marketed, or maybe they cope with exactly the features used in Safari but since Safari never sets this bit flag here they reject all connections with that flag.

What TLS learned is summarized as "have one joint and keep it well oiled" and they invented a technique to provide that oiling for one working joint in TLS, GREASE, Generate Random Extensions And Sustain Extensibility. The idea of GREASE is, if a popular client (say, the Chrome web browser) just insists on uttering random nonsense extensions then to survive in the world where that happens you must not freak out when there are extensions you do not understand. If your middlebox firmware freaks out when seeing this happen, your customers say "This middlebox I bought last week is broken, I want my money back" so you have to spend a few cents more to never do that.

But, since random nonsense is now OK, we can ship a new feature and the middleboxes won't freak out, so long as our feature looks similar enough to GREASE.

ECH achieves the same idea, when a participating client connects to a server which does not support ECH as far as it knows, it acts exactly the same as it would for ECH except, since it has neither a "real" name to hide nor a key to encrypt that name it fills the space where those would fit with random gibberish. As a server, you get this ECH extension you don't understand, and it is filled with random gibberish you also don't understand, this seems fine because you didn't understand any of it (or maybe you've switched it off, either way it's not relevant to you).

But for a middlebox this ensures they can't tell whether you're doing ECH. So, either they reject every client which could do ECH, which again that's how you get a bunch of angry customers, or, they accept such clients and so ECH works.