On: MITM on HTTPS traffic in Kazakhstan

[y0ghur7_xxx]

There is a Name Constraints extension in X.509[1] that does exactly that, but to my knowledge no browser implements it.

[1] https://tools.ietf.org/html/rfc5280#section-4.2.1.10

[markovbot → y0ghur7_xxx]

and that would have to be baked into the CA certificate, not specified when the CA is trusted. I dont want my browser to ask the CA what it's allowed to do, i want to tell it what it's allowed to do

[y0ghur7_xxx → markovbot]

It has to be baked into the CA, so that a browser vendor can check it before inclusion. If the CA specifies domains it is not allowed to sign certificates for, it will not be included.

[jack12 → y0ghur7_xxx]

> but to my knowledge no browser implements it

Firefox does, though I don't know how much they check beyond just the dNSName constraints. Here's the unit test making sure it stays working: https://github.com/mozilla/gecko-dev/blob/b8157dfaafc42deb3b...