candy_check

Check and verify in-app receipts from the AppStore and the PlayStore.

Installation

gem install candy_check

Introduction

This gem tries to simplify the process of server-side in-app purchase and subscription validation for Apple's AppStore and Google's PlayStore.

AppStore

If you have set up an iOS app and its in-app items correctly and the in-app store is working your app should receive a SKPaymentTransaction. Currently this gem assumes that you use the old transactionReceipt which is returned per transaction. The transactionReceipt is a base64 encoded binary blob which you should send to your server for the validation process.

To validate a receipt one normally has to choose between the two different endpoints "production" and "sandbox" which are provided from Apple. During development your app gets receipts from the sandbox while when released from the production system. A special case is the review process because the review team uses the release version of your app but processes payment against the sandbox. Only for receipts that contain auto-renewable subscriptions you need your app's shared secret (a hexadecimal string),

Please keep in mind that you have to use test user account from the iTunes connect portal to test in-app purchases during your app's development.

PlayStore

Google's PlayStore has different kind of server-to-server API to check purchases and requires that you register a so called "service account". You have to register a new account by yourself, export the generated certificate file and grant the correct permissions to the account for your app using the Google Developer Console.

If you have set up the Android app correctly you should get a purchaseToken per purchased item. You should use this string in combination with packageName and productId to verify the purchase.

Usage

AppStore

First you should initialize a verifier instance for your application:

config = CandyCheck::AppStore::Config.new(
  environment: :production # or :sandbox
)
verifier = CandyCheck::AppStore::Verifier.new(config)

For the AppStore the client should deliver a base64 encoded receipt data string which can be verified by using the following call:

verifier.verify(your_receipt_data) # => Receipt or VerificationFailure
# or by using a shared secret for subscriptions
verifier.verify(your_receipt_data, your_secret)

Please see the class documenations CandyCheck::AppStore::Receipt and CandyCheck::AppStore::VerificationFailure for further details about the responses.

For subscription verification, Apple also returns a list of the user's purchases. Essentially, this is a collection of receipts. To verify a subscription, do the following:

# ... create your verifier as above
verifier.verify_subscription(your_receipt_data, your_secret) # => ReceiptCollection or VerificationFailure

If you want to restrict the subscription verification to some specific products, pass their ids as an array:

# ... create your verifier as above
product_ids = ['sk_product_id_1', 'sk_product_id_2'...]
verifier.verify_subscription(your_receipt_data, your_secret, product_ids) # => ReceiptCollection or VerificationFailure

Please see the class documentation for CandyCheck::AppStore::ReceiptCollection for further details.

PlayStore

⚠️ Version 0.2.0 of CandyCheck introduced some breaking changes to the PlayStore functionality to adapt to changes in the Google API. If you're upgrading from a CandyCheck version < 0.2.0 see the migration guide for more.

Authorization

Getting the JSON Key File

First we have to get a .json key file, that gives access to the Google API.

This .json key file can be generated under the following URL (make sure to adapt the project=my-project-name parameter accordingly):

https://console.developers.google.com/apis/credentials/serviceaccountkey?project=my-project-name

Building an Authorization Object

With the .json key file downloaded, we can build an authorization object:

authorization = CandyCheck::PlayStore.authorization("/path/to/key.json")

Note: CandyCheck provides the CandyCheck::PlayStore.authorization method as convenience to build an authorization object. In case you need more control over your authorization object, refer to the google-auth-library-ruby docs, which describes building authorization objects in detail.

Building a verifier

With the authorization object in place, we can build a verifier:

verifier = CandyCheck::PlayStore::Verifier.new(authorization: authorization)

Note: If you need to verify against multiple Google Service Accounts, just instantiate a new verifier with another authorization object that got build with a different .json key file.

Verifying product purchases

This verifier can be used to verify product purchases in the PlayStore, all you need to do is to pass the package_name, product_id and token of the product purchase you want to verify:

result = verifier.verify_product_purchase(
  package_name: "my-package-name",
  product_id: "my product id",
  token: "my token"
)
# => ProductPurchase or VerificationFailure

On success this will return an instance of CandyCheck::Playstore::ProductPurchases::ProductPurchase, which is a wrapper for the raw google-api-ruby-client data, but additionally provides some handy convenience methods. Please see the class documentations CandyCheck::PlayStore::ProductPurchases::ProductPurchase and CandyCheck::PlayStore::VerificationFailure for further details about the responses.

Verifying subscriptions

In order to verify a subscription from the Play Store, do the following:

result = verifier.verify_subscription_purchase(
  package_name: "my-package-name",
  subscription_id: "my-subscription-id",
  token: "my-token"
)
# => SubscriptionPurchase or VerificationFailure

Please see documenation for CandyCheck::PlayStore::SubscriptionPurchases::SubscriptionPurchase for further details.

Building an acknowledger

With the authorization object in place, we can build an acknowledger:

acknowledger = CandyCheck::PlayStore::Acknowledger.new(authorization: authorization)

Note: If you need to acknowledge against multiple Google Service Accounts, just instantiate a new acknowledger with another authorization object that got build with a different .json key file.

Acknowledging the purchase

Google Play purchases if not acknowledged are automatically refunded. The acknowledgement can be done client-side or server-side. If server-side validation is being used we recommend to proceed with the acknowledgement afterwards, since it is the only save way to ensure the users received what they have paid for.

result = acknowledger.acknowledge_product_purchase(
  package_name: "my-package-name",
  product_id: "my-subscription-id",
  token: "my-token"
)
# => ProductAcknowledgements::Response

The acknowledger response has 2 methods:

• #acknowledged? returns a boolean. It returns true only if it has been acknowledged at this moment (that's Google Play behaviour).
• #error returns a hash with status_code and body keys.

CLI

This gem ships with an executable to verify in-app purchases directly from your terminal:

AppStore

You only need to specify the base64 encoded receipt:

$ candy_check app_store RECEIPT_DATA

See all options:

$ candy_check help app_store

PlayStore

For the PlayStore you need to specify at least the issuer, the key file, your package name, the product and the actual purchase token:

$ candy_check play_store PACKAGE_NAME PRODUCT_ID TOKEN --json-key-file=/path/to/key.json

See all options:

$ candy_check help play_store

Todos

• Allow using the combined StoreKit receipt data
• Find a ways to run integration tests

Bugs and Issues

Please submit them here https://github.com/jnbt/candy_check/issues

Test

Simple run

rake

Copyright

Copyright © 2016 Jonas Thiel. See LICENSE.txt for details.