Be careful with app signing keys

Recently, I received an email from Google Play services. “Your app has been removed from the Google Play Store for a policy violation”, or something like that. How odd, I thought. I don’t remember doing anything against their terms of service. The email revealed that I didn’t have a valid privacy policy inside the app or on the store listing.

Oh. Right. The whole GDPR thing. It was time to write some privacy policies. After doing so, I began the process of digging up old files to old apps to make the necessary changes to the code. After about 2 hours of reinstalling Android Studio (my hard drive was wiped as some readers may remember), I began the process of exporting the app from Unity to an .APK.

Eventually, I was able to upload the finished .APK to Google’s servers. However, the Play Console threw an error at me; “The signatures do not match”. Wait, what? It’d been too long since I’d actually done this process. I googled the error to remind myself and broke out into a cold sweat.

Apparently, you generate a .keystore file upon first creating an Android app to sign the application with. It prevents people from uploading versions that aren’t originally from you, in the event that a developer’s account got hacked or something. There was no way to recover said .keystore file if you didn’t have it anymore, meaning there was no way to update my app. Ever. A full, in-depth system scan revealed no .keystore files. Luckily, with the two brain cells that were still functioning, I managed to remember that the other day I had deleted the app-which-I-was-updating’s Android version off my hard drive, because there was no real difference between the iOS and Android version, and I thought it was redundant. Perhaps it was in there?

I checked my Recycle Bin and breathed a sigh of relief. I hadn’t emptied it. It was still there. Opening the folder, the first thing I saw was a “user.keystore” file at the very bottom of the file list. A quick test confirmed that was the one. Phew.

Apparently those things are important. Don’t lose ’em, kids.


HEY, LISTEN! It’d be really cool if you checked out the app here on the play store, since it just got updated. 😉


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Published 2018-09-19 15:02:16