IOXY VS mitmproxy

You may be able to intercept a firmware update and load a binary poisoned with your own CA cert. (Lots of factors at play here, of course.)

I'm working on a similar problem (https://github.com/elahd/esp2ino/issues/16) with a project I maintain to replace IoT device firmware (https://github.com/elahd/esp2ino).

I've been using both mitmproxy and IOXY (https://github.com/NVISOsecurity/IOXY), an intercepting proxy made specifically for MQTT. IOXY is a small, less mature project, but it's definitely worth checking out as a compliment to mitmproxy. Many devices managed via AWS IoT phone home over MQTT and, my limited experience aside, it looks like many don't bother validating certificates when authenticating over this protocol.

This statement gives a false sense of security. You can use a transparent proxy, like mitmproxy, to view HTTPS traffic - https://mitmproxy.org/. https://reedmideke.github.io/networking/2021/01/04/mitmproxy-openwrt.html

You'll need to install mitmproxy and set it up on your computer and iOS. I won't go into too much detail here on how to do this, but there are plenty of guides available. This is a pretty good one: https://nadav.ca/2021/02/26/inspecting-an-iphone-s-https-traffic/

TIL this goes back to 2006, how cool! We nowadays have a much simpler version as a mitmproxy example: https://github.com/mitmproxy/mitmproxy/blob/main/examples/ad.... Although it obviously does not work as well anymore with everything being HTTPS nowadays (unless you trust the cert of course). :)

Perhaps you could have your device use a proxy that can do the HTTPS unwrap for you? https://mitmproxy.org/ maybe?

A great way to test the effectiveness of a pinning implementation is by simulating an MITM attack. Tools like Mitmproxy or Wireshack allow us to create a test environment to monitor, intercept, and proxy network requests for a test host.