Or just open up the apk in e.g. apk studio and replace the bundled cert with the one from your mitm proxy. Effectively, that'll repin the app to your proxy specifically. There are more exotic pinning methods that this won't solve (the forever cat-and-mouse game) but it's good for many apps.
It's a problem that, alas, must be tackled somewhat uniquely on every platform, where-as previously users were free to manage their own Certificate Authorities as they wished. Now users are safe & secure from themselves. :/ Admittedly there were a lot of problems with poorly managed CA stores, users being abused, but cert-pinning feels like such a drastic overreach in preventing any form of user control.
Techniques like this "rebuild your apk" are interesting & good to have, but every OS needs it's own bag of tricks. It's probably not a total show-stopper, but news like today's that Windows 10 will only install signed driver software (an admittedly niche-ish case), the closed Apple store,... there's a lot of places side-loading is not an option. Do those apps get a pass, get to be complete black-box software that we the users have zero ability to look at or understand?
You're making this sound so much harder than it is, though. None of the techniques for bypassing the security enhancements is difficult, nor are they undocumented. Who are these hobbyists who want to reverse engineer the whispersync protocol but can't follow a simple tutorial to swap out a CA?
you've listed one platform (of many) where it's possible to (in some cases where there is a .cert or .pem file sitting in an apk), updated that apk pkg, & then use side-loading (not available on os'es) to install that hacked package.
there's a number of caveats to your steps, it will definitely not be this easy in all cases. and i while this wasn't all that difficult, it's still a situation where the OS is actively working to prevent the user from being able to understand their system. and most platforms don't provide even this much of an affordance, of opening, rebuilding, & side-loading packages.
I sincerely do not think so & I genuinely & I think appropriately fear that humankind is quickly approaching an era where they have no power to understand what their softwares are doing.
This is already the case on iphone, I think. You have only outlined the most bare-basic case on Android. if certs were embedded this would not work. Who knows about osx & windows. It's much much much much harder & in many cases already impossible. The security people seem only to want to guard the applications, continually at the expense of the user. Who will fight for the user?
Amazing tool, neat trick. It requires xposed framework though, which is an interception framework for Android that requires root access to install.
Less and less devices seem to have root, and almost no devices these days seem to allow unlocking the bootloader, which is even better.
It feels like users are getting kicked further & further & further out. We are less & less able to have any chance to understand what computing is, & this deeply deeply hurts us, I tend to believe.