Implementing Receipt Validation in Swift 3

Question

I am developing an iOS app in Swift 3 and trying to implement receipt validation following this tutorial: http://savvyapps.com/blog/how-setup-test-auto-renewable-subscription-ios-app. However, the tutorial seems to have been written using an earlier version of Swift, so I had to make several changes. Here is my receiptValidation() function:

func receiptValidation() {
    let receiptPath = Bundle.main.appStoreReceiptURL?.path
    if FileManager.default.fileExists(atPath: receiptPath!){
        var receiptData:NSData?
        do{
            receiptData = try NSData(contentsOf: Bundle.main.appStoreReceiptURL!, options: NSData.ReadingOptions.alwaysMapped)
        }
        catch{
            print("ERROR: " + error.localizedDescription)
        }
        let receiptString = receiptData?.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
        let postString = "receipt-data=" + receiptString! + "&password=" + SUBSCRIPTION_SECRET
        let storeURL = NSURL(string:"https://sandbox.itunes.apple.com/verifyReceipt")!
        let storeRequest = NSMutableURLRequest(url: storeURL as URL)
        storeRequest.httpMethod = "POST"
        storeRequest.httpBody = postString.data(using: .utf8)
        let session = URLSession(configuration:URLSessionConfiguration.default)
        let task = session.dataTask(with: storeRequest as URLRequest) { data, response, error in
            do{
                let jsonResponse:NSDictionary = try JSONSerialization.jsonObject(with: data!, options: JSONSerialization.ReadingOptions.mutableContainers) as! NSDictionary
                let expirationDate:NSDate = self.expirationDateFromResponse(jsonResponse: jsonResponse)!
                self.updateIAPExpirationDate(date: expirationDate)
            }
            catch{
                print("ERROR: " + error.localizedDescription)
            }
        }
        task.resume()
    }
}

The problem shows up when I try to call the expirationDateFromResponse() method. It turns out that the jsonResponse that gets passed to this method only contains: status = 21002;. I looked this up and it means "The data in the receipt-data property was malformed or missing." However, the device I'm testing on has an active sandbox subscription for the product, and the subscription seems to work correctly aside from this issue. Is there something else I still need to do to make sure the receiptData value will be read and encoded correctly, or some other issue that might be causing this problem?

EDIT:

I tried an alternate way of setting storeRequest.httpBody:

func receiptValidation() {
    let receiptPath = Bundle.main.appStoreReceiptURL?.path
    if FileManager.default.fileExists(atPath: receiptPath!){
        var receiptData:NSData?
        do{
            receiptData = try NSData(contentsOf: Bundle.main.appStoreReceiptURL!, options: NSData.ReadingOptions.alwaysMapped)
        }
        catch{
            print("ERROR: " + error.localizedDescription)
        }
        let receiptString = receiptData?.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0)) //.URLEncoded
        let dict = ["receipt-data":receiptString, "password":SUBSCRIPTION_SECRET] as [String : Any]
        var jsonData:Data?
        do{
            jsonData = try JSONSerialization.data(withJSONObject: dict, options: .prettyPrinted)
        }
        catch{
            print("ERROR: " + error.localizedDescription)
        }
        let storeURL = NSURL(string:"https://sandbox.itunes.apple.com/verifyReceipt")!
        let storeRequest = NSMutableURLRequest(url: storeURL as URL)
        storeRequest.httpMethod = "POST"
        storeRequest.httpBody = jsonData!
        let session = URLSession(configuration:URLSessionConfiguration.default)
        let task = session.dataTask(with: storeRequest as URLRequest) { data, response, error in
            do{
                let jsonResponse:NSDictionary = try JSONSerialization.jsonObject(with: data!, options: JSONSerialization.ReadingOptions.mutableContainers) as! NSDictionary
                let expirationDate:NSDate = self.expirationDateFromResponse(jsonResponse: jsonResponse)!
                self.updateIAPExpirationDate(date: expirationDate)
            }
            catch{
                print("ERROR: " + error.localizedDescription)
            }
        }
        task.resume()
    }
}

However, when I run the app with this code, it hangs upon reaching the line jsonData = try JSONSerialization.data(withJSONObject: dict, options: .prettyPrinted). It doesn't even make it to the catch block, it just stops doing anything. From what I've seen online, other people seem to have trouble using JSONSerialization.data to set the request httpBody in Swift 3.

Answer 1

Its working correctly with Swift 4

func receiptValidation() {
    let SUBSCRIPTION_SECRET = "yourpasswordift"
    let receiptPath = Bundle.main.appStoreReceiptURL?.path
    if FileManager.default.fileExists(atPath: receiptPath!){
        var receiptData:NSData?
        do{
            receiptData = try NSData(contentsOf: Bundle.main.appStoreReceiptURL!, options: NSData.ReadingOptions.alwaysMapped)
        }
        catch{
            print("ERROR: " + error.localizedDescription)
        }
        //let receiptString = receiptData?.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
        let base64encodedReceipt = receiptData?.base64EncodedString(options: NSData.Base64EncodingOptions.endLineWithCarriageReturn)

        print(base64encodedReceipt!)


        let requestDictionary = ["receipt-data":base64encodedReceipt!,"password":SUBSCRIPTION_SECRET]

        guard JSONSerialization.isValidJSONObject(requestDictionary) else {  print("requestDictionary is not valid JSON");  return }
        do {
            let requestData = try JSONSerialization.data(withJSONObject: requestDictionary)
            let validationURLString = "https://sandbox.itunes.apple.com/verifyReceipt"  // this works but as noted above it's best to use your own trusted server
            guard let validationURL = URL(string: validationURLString) else { print("the validation url could not be created, unlikely error"); return }
            let session = URLSession(configuration: URLSessionConfiguration.default)
            var request = URLRequest(url: validationURL)
            request.httpMethod = "POST"
            request.cachePolicy = URLRequest.CachePolicy.reloadIgnoringCacheData
            let task = session.uploadTask(with: request, from: requestData) { (data, response, error) in
                if let data = data , error == nil {
                    do {
                        let appReceiptJSON = try JSONSerialization.jsonObject(with: data)
                        print("success. here is the json representation of the app receipt: \(appReceiptJSON)")
                        // if you are using your server this will be a json representation of whatever your server provided
                    } catch let error as NSError {
                        print("json serialization failed with error: \(error)")
                    }
                } else {
                    print("the upload task returned an error: \(error)")
                }
            }
            task.resume()
        } catch let error as NSError {
            print("json serialization failed with error: \(error)")
        }



    }
}