AppLicensing fails - signature is empty string

Question

I've implemented App-Licensing for InApp-Billing and now I'm getting Error.NOT_LICENSED and I have no idea what's wrong. The version I'm working on has not been published to the play store yet.

This is the code I use to start the licensing-process:

private void checkLicense(int retries) {
  if (retries != 5) {
    String publicKey = "YOUR KEY";
    final CdcLicenseCheckerCallback callback = new CdcLicenseCheckerCallback();
    String deviceId = mPrefsHandler.getDeviceId();
    deviceId = deviceId != null ? deviceId : UUID.randomUUID().toString();
    mPrefsHandler.setDeviceId(deviceId);
    Crashlytics.setBool("has Device-Id", deviceId != null);
    final LicenseChecker checker = new LicenseChecker(this, new ServerManagedPolicy(this,
        new AESObfuscator(new byte[] { 1, 1, ... , 1 }, getPackageName(),
            deviceId)), publicKey);
    checker.checkAccess(callback);
  }
}

I used a production variant to figure out what's happening and found that in LicenseValidator.java, the parameter signature for the method verify is an empty string, causing the sig.verify(Base64.decode(signature)) to return ERROR.NOT_LICENSED.

if (!sig.verify(Base64.decode(signature))) {
  Log.e(TAG, "Signature verification failed.");
  handleInvalidResponse();
  return;
}

I only have a hint of an idea that UUID.randomUUID().toString() might be the issue, but I have no idea, whether it actually, nor what to do here.

Answer 1

Found the problem. I hadn't actually published the alpha-version to the playstore, so google play explicitly disallowed the newer version, because it didn't know about it

Solution: Check, if your installed app version is lower or equal to the latest version that was published to google play (alpha, beta or production channel)