[wolrah]

Well, WebPKI is for the web, if you need TLS for other purposes that don't fit with the goals of those looking to protect web users and web infrastructure you need a different PKI. It's not like it's technically hard to set up your own private PKI, and there are plenty of companies who are happy to provide those services if you don't want to do it yourself, but it is more complicated and costly than just using WebPKI so we of course see WebPKI resources getting used inappropriately and then those users complain when there's a need for revocations and/or changes.

> Now project that onto a TLS implementation that has to run on a Cortex M3 in some infrastructure device, little CPU, little RAM, no DNS, and the code gets updated when the hardware gets replaced after 10-20 years.

Also the OT world needs to accept that they can't have their cake and eat it too. If you need to be able to leave the same code running untouched for 10-20 years, you don't connect it to the internet. If you need it connected to the internet, you accept that it needs to be able to receive updates and potentially have those updates applied in a matter of days. Extremely strict external security controls can mitigate some of these situations but will never eliminate the need for there to be a rapid update process.

[pseudohadamard]

  Also the OT world needs to accept that they can't have their cake and eat it too. If you need to be able to leave the same code running untouched for 10-20 years, you don't connect it to the internet

Why on earth not? Just because most of the code that uses the web PKI is crap and needs constant patching doesn't mean there aren't developers writing code that isn't crap and that you can leave running for 10-20 years without any patching. Years ago someone who created a (at the time) widely-used security tool got asked why there hadn't been any updates in years, and whether it was abandonware. His response was "some people do things properly the first time".

And before you say "even if the code is fine it's old crypto, it's insecure", when was the last time someone got pwned because they ran 25-year-old TLS 1.0?

[wolrah]

> Why on earth not? Just because most of the code that uses the web PKI is crap and needs constant patching doesn't mean there aren't developers writing code that isn't crap and that you can leave running for 10-20 years without any patching.

I never said that's not possible, I said you can't design your systems to assume that it's one of those things. It is certainly possible that after 10-20 years a system might never have needed an update, but you didn't know that when it was built, purchased, or implemented and assuming that will be the case is undeniably irresponsible.

> And before you say "even if the code is fine it's old crypto, it's insecure", when was the last time someone got pwned because they ran 25-year-old TLS 1.0?

The correct answer there would be "none yet", and there's no guarantee it would ever happen, but there are known weaknesses so it's always a possibility. Again, not saying everything will need to be updated regularly, but it's not a good call to assume your thing will never need it.

Let's look at this from another angle. Presumably if you have a desire to expose a device to the internet as a whole it's because you either want it to be able to access external resources or you want external systems to be able to reach it, and the outside world has this tendency to move on over time if protocols are flawed, even if those flaws don't matter to your device. If there's a process for updating regularly, this is no big deal. If there isn't, your thing is going to get progressively more annoying to use wherever it needs to interact with systems outside of its control.