Re: [Ohttp] Meaning of "usage constraints" in charter

[Mark Nottingham <[e-mail]>]

> On 28 Jul 2021, at 6:43 am, Thomas Mangin <[e-mail]> wrote:
> 
> This is why if we want to give users control of who they want to trust as proxies, there should be a way for them to detect and select who they trust to protect their privacy.

There's the rub. If a discovery mechanism allows a network to impose a proxy upon a user (which is by definition how most work), it can be used to take a choice *away* from them. Again, HTTP has *no* standard intermediary discovery mechanism, and the one non-standard one we have is widely used to impose policy upon users, not give them "choice."

A more user-focused approach would be to require implementations to allow a user to explicitly choose an arbitrary proxy. Even then, a great amount of care is required -- if the choice is too easily delegated, that can be an attack vector. If there are too many choices, that leads to cognitive overload -- again, bad for users.

That requirement isn't evident on the wire, nor is it an interop requirement, so whether it's in-scope for the IETF is questionable. Also, arguably a user already makes a trust choice when they choose an implementation -- so bundling together the implementation and the proxy choice can be seen as reducing their cognitive load while still allowing them the freedom to choose another implementation (I don't know that I necessarily agree with this argument, but it's not prima facie invalid).

At any rate, the list of choices that are likely to help the user is _not_ "here's a bunch of different proxies that have advertised themselves to me over the networks you've been on." That's like saying that CAs should be discoverable. Much deeper and more nuanced trust relationships are required.

I'm fine if folks want to continue to talk about the use cases for these proxies, but will strongly oppose any requirement to require support for discovery of them from a network, for the reasons above. 

Cheers,


--
Mark Nottingham   https://www.mnot.net/