Android-inapp-billing-v3: fake payment (getting invalid order id inside onProductPurchased())

[edcastrahul]

I want to report a bug

What is the current behavior?
When user purchase the application then control come to onProductPurchased() method.Inside this method i got order id from TransactionDetailsObject.purchaseInfo.purchaseData.orderId but some time i got order id that start with integer number like 8456*.** (but as per google - order id generally start with GPA.*..*).Whenever this happened, we never got payment and also it not listed inside "Order Management" section on developer console.This is like a fake payment.

I am not able to repro this issue but it happened with some of users(Application is in live state)

So, please provide solution for that.

• which version of library you use
  compile 'com.anjlab.android.iab.v3:library:1.0.+'

• was it working in previous versions?
  no

• do you use fragments or not
  no

• how do you instanciate BillingProcessor (singleton or not)
  new BillingProcessor(this, null, this);

• have you uploaded it to Google Play or not (if yes, when which channel: Prod/Beta/Alpha)
  on Prod

• do you test with real products, or with a testing onces (e.g. android.test.purchased)
  with real product

[autonomousapps]

Is it a bug?

Sounds like you can check that ID yourself and ignore if you don't find it to be valid.

[edcastrahul]

Hi Tony,

Thank you for your response.

Yes, it's a bug. Whenever control come to onProductPurchased(), i unlock the application (provide full access to the application) but some time i did not get payment, so it's a bug.
Anyone have any solution then please share.

[serggl]

Thats not a bug in the library, it has nothing to do with the order ids. So you need to handle that on your own

[autonomousapps]

Whenever control come to onProductPurchased(), i unlock the application

Don't. Instead, check the order ID for validity.

[edcastrahul]

Hi serggl,
if it's not a bug then why payment not available inside "Order Management" section on developer console for such type of transactions.

[serggl]

This library is only a lightweight wrapper around Google's API.
I bet there are some diffrences/bugs in that API around all the devices/Android versions available, and Im afraid you need to deal with that.
So as per @autonomousapps comment just check the Order Id for validity

[edcastrahul]

Thank you @serggl and @autonomousapps for your feedback.

how to check order id for validity?

can you please guide?

[mchua80]

I am having the same issues. onProductPurchased called several times but no orders in the Google play console. Hope there is a resolution to this.

[autonomousapps]

Hey guys.

This may sound unwelcome, but what you need is a proper backend to validate these purchases. Maybe Firebase?

You should send the info you get in onProductPurchased to your backend to validate with the Google API independently. I haven't personally used Firebase, but perhaps it could help with this.

Either that, or suffer the occasionally "hacker" getting free products.

[edcastrahul]

Hi guys,

Now, Fake payment happened with multiple users,So the owner of this library should check for solution.

Thank You

[mchua80]

It is happening pretty frequent. Almost a few times each day so I am not quite sure if this is a bug or really a fake payment attempt. I hope the author can take a look and advise us. This is a great library.

[erandagan]

I can confirm this issue is also present in a large scale production app. Our backend rejects requests with "fake" (integer) order ids several times a day.
These orders do not pass the google signature validation so the backend considers them invalid, and so does the app.

I'm curious why this happens, but I don't believe it has anything to do with this library.
I'll repeat @autonomousapps's recommendation to have a backend validate all purchases as apps can be easily tampered with.

[edcastrahul]

We solved this issue by back end validation.

[pavelsust]

@edcastrahul how you solve this issue??
If you share it with us it will be very helpful.
Thanks a lot.

[edcastrahul]

Hey,
Just call a google api to verify purchase, go through to below link

https://stackoverflow.com/questions/33850864/how-to-verify-purchase-for-android-app-in-server-side-google-play-in-app-billin
https://developers.google.com/android-publisher/api-ref/purchases/subscriptions/get