/** 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;
}
/**
* Serialize purchase data to json
*
* @param purchase purchase data
* @return json string
* @throws JSONException
*/
private String purchaseToJson(Purchase purchase) throws JSONException {
return new JSONStringer()
.object()
.key("itemType")
.value(purchase.getItemType())
.key("orderId")
.value(purchase.getOrderId())
.key("packageName")
.value(purchase.getPackageName())
.key("sku")
.value(purchase.getSku())
.key("purchaseTime")
.value(purchase.getPurchaseTime())
.key("purchaseState")
.value(purchase.getPurchaseState())
.key("developerPayload")
.value(purchase.getDeveloperPayload())
.key("token")
.value(purchase.getToken())
.key("originalJson")
.value(purchase.getOriginalJson())
.key("signature")
.value(purchase.getSignature())
.key("appstoreName")
.value(purchase.getAppstoreName())
.endObject()
.toString();
}