Rabbitholes

OpenSSL, Certpinning and Memory patching. Sounds fun right?

01 April 2026 ~9 min By Isak Van Der Walt
Android Certificates Frida Mobile Objection Pinning Tls Certificate Pinning Rabbitholes Research Reverse Engineering
This blogpost will cover the research I presented at BSides JoBurg. You can watch the talk on YouTube, and code can be found on our GitHub page. This journey started after having looked at some certificate-pinned apps. The majority of apps that appear to implement cert pinning, don’t actually have cert pinning but rather just use a custom trust manager or are not proxy aware (this also applies to things like Flutter). Thus the first step is to ensure application traffic is forced through our proxy. I utilised an OpenVPN server when working with a physical device and the Android emulator proxy settings when working with a virtual device.