Is it possible to sign App Center APK's with the same key as Play Store AAB?

Question

This is actually being done in Xamarin but thats technically not specific to the question.

I've been running a build CI/CD that currently was signing (with my own custom key) an APK and deploying it to App Center (its actually building an AAB and then making a fat APK from it fyi).

This has all been working fine for months for internal, daily builds of the app.

Now I'm deploying release candidates to Google Play Console and I have my CI/CD deploying AAB bundles.

The first bundle was signed with this same key and as I understand it that key is now the 'upload key' for google play, but because I'm deploying AAB (and I believe, by August we HAVE to), Google insists on signing the AAB for me.

This now means, if someone in our team installs the Internal track AAB, they then can't install an updated test build from AppCenter over the top as they are signed differently.

Is there anyway around this? Can I get the key google signed the build with and use that when uploading to AppCenter (I realise our team will need to at least uninstall an older signed build form AppCenter to then get updates but will be fine from that point out).

Ideally I want to be able to install updates from AppCenter and Google Play over the top of each other as long as their versions are incrementing.

Answer 1

There is unfortunately no way of requesting the signing key from Google. If you didn't provide Google with the signing key when you initially enrolled in Play Signing, then you will likely never have access to the signing key.

What you can do however is download the universal APK signed by Google (from the Bundle Explorer in the Play Console), then upload it to AppCenter. But I'm not sure if there is a download API available today to automate this operation on your CI.

Answer 2

With the thanks of Pierre's answer I didn't realise there was an option to create the Play signing key from an existing key using the pepk.jar

I redid the app this way and its working installing builds from AppCenter and Google Play on top of each other!