Beware of sideloading f.lux for iOS from files obtained on sharing/torrent sites


Apple made the @justgetflux folks remove their [iOS sideloaded app]( due to the use of private APIs (which are a violation of the Apple Developer agreement). The ZIP archive has been pulled from their site (and it really has, too).

This “sideloading”—i.e. installing directly to your device after compiling it from source—_was_ an interesting way to distribute the app. I visually scanned the source code before sideloading (I code for iOS in both Objective C and Swift) and there seemed to be nothing nefarious in it and it works _really_ well. HOWEVER, I’m 100% sure an Xcode project ZIP archive of f.lux is going to hit the torrent and file-sharing sites pretty quickly. But, I’m also 99% sure that folks who want to do Really Bad Things™ to and with your iOS devices will gladly add some code to that Xcode project and most folks won’t take the time (or do not have the knowledge/experience) to validate the veracity of the code before using it.

So, first I implore iOS users to _not_ grab this sideloaded project from torrent or file-sharing sites since you will be putting your devices at risk if you do so.

Since some folks (but not very many, I suspect, since it does involve real work) will no doubt leave my warning unheeded, *please* run:

shasum -a 256

from an Terminal or iTerm2 prompt. If you don’t get:


as a result *DO NOT SIDE LOAD THE APP*. It means the good/safe f.lux source code/project has been modified by someone since November 11th, 2015 and that you are putting your device (i.e. the confidentiality, integrity and availability of your private data) at risk by installing it. You can also post it to [this site]( (I verified that it produces the correct result).

And, please, do not jailbreak your devices. You take a relatively safe operating system and pretty much turn it into an Android (check out the [2015 DBIR]( for more info on iOS vs Android security based on real data vs hype) .

Cover image from Data-Driven Security
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2 Comments Beware of sideloading f.lux for iOS from files obtained on sharing/torrent sites

  1. codythisguy

    (I found a .zip and I’m not installing it until I figure out how to check and make sure it’s safe) I’m not exactly sure how to run that in terminal. Any advice? (Besides don’t do it?)


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