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Comment by Meekro | Hacker News Reader

Can someone explain why this is important enough to land on the HN front page? Are people being inconvenienced by this or something?

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Statistically, someone, somewhere, has a VAX box that hasn't been rebooted since before the fall of the Soviet Union, running their org's MTA with a comically outdated cryptosuite. Anyone running vaxen that old is bound to be a regular here on HN.

Unfortunately, that box is going to have increasing difficulty connecting to anyone at all. TLS 1.2 was added to OpenSSL around 2010, and de-facto mandated around 2020. Any SSL/TLS software from before that will increasingly find its connections rejected.

The world of email is full of zombie servers that should've died years ago but still linger. Configuring your email server to require the security that was considered "modern" ten years ago in terms of websites will still get you delivery failures when you start dealing with email servers. There's a reason Google is deprecating 3DES now, and not ten years ago when they reasonably should've.

Because email customers on all sides want email to arrive, there's little incentive to modernize configurations or requirements. When you disable ancient cryptography, you'll get blamed for your change making email from someobscurewebsite.gov no longer arriving. For a significant amount of mail servers, you can pick between "accept a random self-signed certificate using a cipher suite from the late 2000s" or "send email over unencrypted SMTP", and you just have to hope that the email server doesn't have your domain configured as "secure transmission required".

I'm in favour of Google just breaking the old, broken mail servers, but I wouldn't assume that TLS 1.2 is available on email servers.

To me it’s surprising in the sense that it was even still supported.

Yeah, apparently OpenSSL dropped it almost 10 years ago.

Because it's interesting?

The 3DES saga is still ongoing...

I had no idea that you can filter/reject certain TLS versions/ciphers (on Gmail servers) before seeing this on the HN front page.

https://support.google.com/a/answer/9795993

If you've never used a TLS library such as Go's crypto/tls, that's understandable-- this is stuff most programmers never need to think about. Fortunately TLS does work pretty well: both sides of an encrypted connection will auto-negotiate and pick the strongest cipher that they both support.

TLS libraries do drop old, weak ciphers from time to time. But thanks to auto-negotiating, this will only be a problem if your TLS lib is so out-of-date that it doesn't support any still-trusted alternatives.

Which brings me back to why this story is so strange: "Gmail upgrades TLS library, drops old insecure algorithm that OpenSSL had dropped almost 10 years ago."

Oh, I meant on Gmail servers.

I always customize TLS versions and cipher suites because I don't trust the defaults.

AFAIK you can customize them on:

- Chrome & Firefox (can only enable/disable ciphers, no reordering, PQ ciphers supported since 2024)

- OpenSSL (by customizing openssl.cnf, PQ ciphers supported since 3.5)

- curl

- nginx/apache

- OpenSSH (I enabled PQ ciphers too)

- Multiple programming libraries

- and others...

Also, clients and servers don't "pick the strongest cipher that they both support". Servers select the cipher ultimately, and they can be misconfigured to pick, for example, 3DES over AES.

I can't explain it, no unfortunately

But what about someone maintaining and developing, say, an obscure e-mail client?

If someone's maintaining an old/obscure email client, I would expect them to be importing a TLS library under the "don't roll your own crypto" principle. Assuming it's been updated at some point in the last ~15 years, it's probably capable of auto-negotiating to something better than 3DES.

And if it hasn't been updated for that long, it probably doesn't support TLS 1.2 and is getting rejected from just about everything for that reason.

Crqpping on google is meta

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