/** Verifies the developer payload of a purchase. */
boolean verifyDeveloperPayload(Purchase p) {
String payload = p.getDeveloperPayload();
/*
* TODO: verify that the developer payload of the purchase is correct. It will be
* the same one that you sent when initiating the purchase.
*
* WARNING: Locally generating a random string when starting a purchase and
* verifying it here might seem like a good approach, but this will fail in the
* case where the user purchases an item on one device and then uses your app on
* a different device, because on the other device you will not have access to the
* random string you originally generated.
*
* So a good developer payload has these characteristics:
*
* 1. If two different users purchase an item, the payload is different between them,
* so that one user's purchase can't be replayed to another user.
*
* 2. The payload must be such that you can verify it even when the app wasn't the
* one who initiated the purchase flow (so that items purchased by the user on
* one device work on other devices owned by the user).
*
* Using your own server to store and verify developer payloads across app
* installations is recommended.
*/
return true;
}
public void onIabPurchaseFinished(IabResult result, Purchase purchase) {
Log.d(TAG, "Purchase finished: " + result + ", purchase: " + purchase);
if (result.isFailure()) {
complain("Error purchasing: " + result);
setWaitScreen(false);
return;
}
if (!verifyDeveloperPayload(purchase)) {
complain("Error purchasing. Authenticity verification failed.");
setWaitScreen(false);
return;
}
Log.d(TAG, "Purchase successful.");
if (purchase.getSku().equals(SKU_GAS)) {
// bought 1/4 tank of gas. So consume it.
Log.d(TAG, "Purchase is gas. Starting gas consumption.");
mHelper.consumeAsync(purchase, mConsumeFinishedListener);
} else if (purchase.getSku().equals(SKU_PREMIUM)) {
// bought the premium upgrade!
Log.d(TAG, "Purchase is premium upgrade. Congratulating user.");
alert("Thank you for upgrading to premium!");
mIsPremium = true;
updateUi();
setWaitScreen(false);
} else if (purchase.getSku().equals(SKU_INFINITE_GAS)) {
// bought the infinite gas subscription
Log.d(TAG, "Infinite gas subscription purchased.");
alert("Thank you for subscribing to infinite gas!");
mSubscribedToInfiniteGas = true;
mTank = TANK_MAX;
updateUi();
setWaitScreen(false);
}
}
