IAP 实际验证收据 (Swift)

我一直在尝试在我的 spritekit 游戏中实现收据验证。我一直在关注各种教程，基本上最终得到了这段代码

enum RequestURL: String {
   case production = "https://buy.itunes.apple.com/verifyReceipt"
   case sandbox = "https://sandbox.itunes.apple.com/verifyReceipt"
   case myServer = "my server address"
}

enum ReceiptStatusCode: Int {

// Not decodable status
case unknown = -2

// No status returned
case none = -1

// valid status
case valid = 0

// The App Store could not read the JSON object you provided.
case JSONNotReadable = 21000

// The data in the receipt-data property was malformed or missing.
case malformedOrMissingData = 21002

// The receipt could not be authenticated.
case receiptCouldNotBeAuthenticated = 21003

// The shared secret you provided does not match the shared secret on file for your account.
// Only returned for iOS 6 style transaction receipts for auto-renewable subscriptions.
case sharedSecretNotMatching = 21004

// The receipt server is currently not available.
case receiptServerUnavailable = 21005

// This receipt is valid but the subscription has expired. When this status code is returned to your server, the receipt data is also decoded and returned as part of the response.
// Only returned for iOS 6 style transaction receipts for auto-renewable subscriptions.
case subscriptionExpired = 21006

//  This receipt is from the test environment, but it was sent to the production environment for verification. Send it to the test environment instead.
case testReceipt = 21007

// This receipt is from the production environment, but it was sent to the test environment for verification. Send it to the production environment instead.
case productionEnvironment = 21008
 }

  func validateReceipt(forTransaction transaction: SKPaymentTransaction) {

    guard let receiptURL = NSBundle.mainBundle().appStoreReceiptURL else { return }

    guard let receipt = NSData(contentsOfURL: receiptURL) else { return }

    let receiptData = receipt.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(rawValue: 0))
    let payload = ["receipt-data": receiptData]

    var receiptPayloadData: NSData?

    do {
        receiptPayloadData = try NSJSONSerialization.dataWithJSONObject(payload, options: NSJSONWritingOptions(rawValue: 0))
    }
    catch let error as NSError {
        print(error.localizedDescription)
        return
    }

    guard let payloadData = receiptPayloadData else { return }
    guard let requestURL = NSURL(string: RequestURL.sandbox.rawValue) else { return }

    let request = NSMutableURLRequest(URL: requestURL)
    request.HTTPMethod = "POST"
    request.HTTPBody = payloadData

    let task = NSURLSession.sharedSession().dataTaskWithRequest(request) { (data, response, error) in
         if let error = error {
            print(error.localizedDescription)
            return
        }  
         guard let data = data else { return }          

         do {
            let jsonData = try NSJSONSerialization.JSONObjectWithData(data, options: .MutableLeaves) as? NSDictionary

            guard let json = jsonData else { return }

            // Correct ?
            guard let status = json["status"] as? Int where status == ReceiptStatusCode.valid.rawValue else { return }

            // Unlock product here?
            // Other checks needed?
        }

        catch let error as NSError {
            print(error.localizedDescription)
            return
        }
     }

    task.resume()
}

这是非常漂亮的样板代码并且按预期工作。我现在的问题是我不知道如何实际验证最后一步（标记线）的收据。 我相信我现在必须携带 5 张左右的支票来验证收据。我只是不知道其中的大多数将如何快速完成。大多数教程要么是旧的，不包括此步骤，要么不是用 swift 编写的。

如果任何成功使用收据验证的人可以帮助我朝着正确的方向前进，我将不胜感激。非常感谢

Update:

在 JSA986I 和 cbartel 的出色回答之后，我将其变成了 github 上的助手。非常感谢您的帮助

https://github.com/crashoverride777/SwiftyReceiptValidator https://github.com/crashoverride777/SwiftyReceiptValidator

这是使用 Swift 2.1 版的解决方案，如下所示苹果指南 https://developer.apple.com/library/ios/releasenotes/General/ValidateAppStoreReceipt/Chapters/ValidateRemotely.html#//apple_ref/doc/uid/TP40010573-CH104-SW1.

苹果也推荐以下内容 https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/StoreKitGuide/Chapters/AppReview.html#//apple_ref/doc/uid/TP40008267-CH10-SW1:

在服务器上验证收据时，您的服务器需要能够处理从 Apple 测试环境获取收据的生产签名应用程序。建议的方法是让您的生产服务器始终首先根据生产 App Store 验证收据。如果验证失败并显示错误代码“生产中使用的沙盒收据”，请改为针对测试环境进行验证。

validateReceipt(NSBundle.mainBundle().appStoreReceiptURL) { (success: Bool) -> Void in
            print(success)
        }

private func receiptData(appStoreReceiptURL : NSURL?) -> NSData? {

    guard let receiptURL = appStoreReceiptURL,
        receipt = NSData(contentsOfURL: receiptURL) else {
            return nil
    }

    do {
        let receiptData = receipt.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(rawValue: 0))
        let requestContents = ["receipt-data" : receiptData]
        let requestData = try NSJSONSerialization.dataWithJSONObject(requestContents, options: [])
        return requestData
    }
    catch let error as NSError {
        print(error)
    }

    return nil
}

private func validateReceiptInternal(appStoreReceiptURL : NSURL?, isProd: Bool , onCompletion: (Int?) -> Void) {

    let serverURL = isProd ? "https://buy.itunes.apple.com/verifyReceipt" : "https://sandbox.itunes.apple.com/verifyReceipt"

    guard let receiptData = receiptData(appStoreReceiptURL),
        url = NSURL(string: serverURL)  else {
        onCompletion(nil)
        return
    }

    let request = NSMutableURLRequest(URL: url)
    request.HTTPMethod = "POST"
    request.HTTPBody = receiptData

    let task = NSURLSession.sharedSession().dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in

        guard let data = data where error == nil else {
            onCompletion(nil)
            return
        }

        do {
            let json = try NSJSONSerialization.JSONObjectWithData(data, options:[])
            print(json)
            guard let statusCode = json["status"] as? Int else {
                onCompletion(nil)
                return
            }
            onCompletion(statusCode)
        }
        catch let error as NSError {
            print(error)
            onCompletion(nil)
        }
    })
    task.resume()
}

public func validateReceipt(appStoreReceiptURL : NSURL?, onCompletion: (Bool) -> Void) {

    validateReceiptInternal(appStoreReceiptURL, isProd: true) { (statusCode: Int?) -> Void in
        guard let status = statusCode else {
            onCompletion(false)
            return
        }

        // This receipt is from the test environment, but it was sent to the production environment for verification.
        if status == 21007 {
            self.validateReceiptInternal(appStoreReceiptURL, isProd: false) { (statusCode: Int?) -> Void in
                guard let statusValue = statusCode else {
                    onCompletion(false)
                    return
                }

                // 0 if the receipt is valid
                if statusValue == 0 {
                    onCompletion(true)
                } else {
                    onCompletion(false)
                }

            }

        // 0 if the receipt is valid
        } else if status == 0 {
            onCompletion(true)
        } else {
            onCompletion(false)
        }
    }
}