Can't see WhatsApp traffic using mitmproxy

Question

I have WhatsApp installed on an iPhone connected to mitmproxy running on a laptop. I can see the intercepted network requests for other apps like safari no problem. But for WhatsApp, I see no traffic, even though it functions correctly. Could it by bypassing the proxy somehow? Is it using a different protocol that's not routed through the proxy or is not intercepted by mitm.

I do appreciate that whatsapp has end to end encryption, so I'm not going to be seeing anything useful, but I'd like to understand the issue as it may help me with other projects.

I also tried kik and snapchat, and in those cases I see some requests being intercepted, but for other activities like sending a message, I see no requests intercepted.

Answer 1

You are running into Certificate Pinning here:

This means that mitmproxy and mitmdump’s certificates will not be accepted by these applications without modifying them. It is recommended to use the passthrough feature in order to prevent mitmproxy and mitmdump from intercepting traffic to these specific domains. If you want to intercept the pinned connections, you need to patch the application manually. For Android and (jailbroken) iOS devices, various tools exist to accomplish this.