On Tue, Jun 1, 2021 at 7:59 AM Adam Carter <adamcart...@gmail.com> wrote: >> >> And another "wondering" - all the warnings about trusting self signed >> certs seem a bit self serving. Yes, they are trying to certify who you >> are, but at the expense of probably allowing access to your >> communications by "authorised parties" (such as commercial entities >> purchasing access for MITM access - e.g. certain router/firewall >> companies doing deep inspection of SSL via resigning or owning both end >> points). > > AFAIK in an enterprise MITM works by having a local CA added to the cert > stores of the workstation fleet, and having that CA auto generate the certs > for MITM. That didn't work with certificate pinning, but pinning has been > deprecated.
So, I don't know all the ways that pinning is implemented, but if you're talking about using MITM to snoop on enterprise devices on the enterprise network I'd think that pinning wouldn't be an issue, because you control the devices from cradle to grave. Just ensure the pinned certificates are the ones that let you MITM the connections. Now, if your organization has some sort of guest network for non-enterprise devices then pinning would obviously block MITM of connections made by those devices. Really though I'm not sure you'd want to be snooping stuff like this - it seems like more legal headaches than it is worth. You want to sniff your OWN traffic for IDS/etc or other unauthorized use, and since you're sniffing traffic from devices you own you don't have the same legal issues (I won't say no legal issues, but certainly monitoring your own devices is very different from monitoring those you don't own). You shouldn't even be allowing uncontrolled devices on those networks in the first place. If you want to detect unauthorized devices MITM isn't really the best solution - just use positive authentication of known-good devices up-front and anything that doesn't pass that test is treated as a threat and shouldn't even be able to send traffic. -- Rich
