As mentioned, receipt validation is only built into the Parse SDK for downloadable content, but it is fairly simple to to create a Cloud Code function that POSTs the app receipt to the iTunes Store for validation. Here are the Apple docs for server side validation: Validating Receipts with the App Store
Here is a what a basic function would look like:
Parse.Cloud.define('validateReceipt', function (request, response) {
var receiptAsBase64EncodedString = request.params.receiptData;
var postData = {
method: 'POST',
url: 'http://buy.itunes.apple.com/verifyReceipt',
body: { 'receipt-data': receiptAsBase64EncodedString,
'password': SHARED_SECRET }
}
Parse.Cloud.httpRequest(postData).then(function (httpResponse) {
// httpResponse is a Parse.Cloud.HTTPResponse
var json = httpResponse.data; // Response body as a JavaScript object.
var validationStatus = json.status; // App Store validation status code
var receiptJSON = json.receipt; // Receipt data as a JSON object
// TODO: You'll need to check the IAP receipts to retrieve the
// expiration date of the auto-renewing subscription, and
// determine if it is expired yet.
var subscriptionIsActive = true;
if (subscriptionIsActive) {
return response.success('Subscription Active');
}
else {
return response.error('Subscription Expired');
}
});
});
See Receipt Fields for details on interpreting the receipt JSON. It's fairly straight forward for iOS 7+, but auto-renewing subscription receipts for iOS 6 and earlier are tedious.