如何从 Swift 中的加密 JSON 字符串中提取某些字段？答案

【问题标题】：How to extract certain fields from encrypted JSON string in Swift?如何从 Swift 中的加密 JSON 字符串中提取某些字段？
【发布时间】：2016-08-24 18:48:41
【问题描述】：

我正在将Apple Pay 集成到我的应用程序中。我有一个用 Java 编写的服务，它实际上获取从我的 iOS 应用程序发送的加密 blob 并对其进行解密并将其发回。

我在这里面临两个问题：

更大的问题 - 我的服务只使用 XML 有效负载，因此我需要在我的 iOS 应用程序中将 JSON 有效负载转换为 XML 有效负载，我不知道该怎么做。
小问题 - 我试图从这个加密的JSON 有效负载中提取字段并在控制台上打印出来。

例子：

let jsonBody = payment.token.paymentData
print("jsonBody = \(jsonBody)")    !!! WORKS (prints encrypted data) !!!

但是，我无法根据以下链接提取 paymentData 字典中存在的其他参数 https://developer.apple.com/library/ios/documentation/PassKit/Reference/PaymentTokenJSON/PaymentTokenJSON.html

例子：

let paymentDataDict:[String:String] = payment.token.paymentData
for (key, value) in paymentDataDict {
    print("Dictionary key \(key) -  Dictionary value \(value)")
}

Error: Cannot convert value of type 'NSData' to specified type '[String : String]'

来源：

 /*
     * This is the first method to be called by the passkit framework once the encrypted blob is received from the apple server.
     * Our implementation of the call back function below is calling payment service to decrypt the encrypted blob.
     * It then proceeds to call processPayment method to send this data down to payment service for authorization.
    */
    func paymentAuthorizationViewController(controller: PKPaymentAuthorizationViewController, didAuthorizePayment payment: PKPayment, completion: (PKPaymentAuthorizationStatus) -> Void) {
        let decryptUrl = NSURL(string: "http://lvsdevwsv04-01.us.gspt.net:1801/public-api-service/v1.0/stores/TMSUS/payments/decryptblob.xml")  // Decryption URL
        let decryptRequest = NSMutableURLRequest(URL: decryptUrl!)
        decryptRequest.HTTPMethod = "POST"
        decryptRequest.setValue("application/json", forHTTPHeaderField: "Content-Type")
        decryptRequest.setValue("application/json", forHTTPHeaderField: "Accept")
        let jsonBody = payment.token.paymentData
        print("jsonBody = \(jsonBody)")

        //ERROR IN THE BELOW LINE
        let paymentDataDict:[String:String] = payment.token.paymentData
        for (key, value) in paymentDataDict {
            print("Dictionary key \(key) -  Dictionary value \(value)")
        }

        decryptRequest.HTTPBody = jsonBody
        let task = NSURLSession.sharedSession().dataTaskWithRequest(decryptRequest) {data, response, error in
            guard error == nil && data != nil else {
                print("error=\(error)")
                return
            }
            if let httpStatus = response as? NSHTTPURLResponse where httpStatus.statusCode != 200 {
                print("statuscode should be 200, but is \(httpStatus.statusCode)")
                print("response = \(response)")
            } else {
                let responseString = NSString(data: data!, en

    //code removed for brevity

【问题讨论】：

标签： ios json swift applepay

【解决方案1】：

在将加密字符串转换为 NSString 对象后，我终于能够在控制台上打印加密字符串。这是经过一些小改动后对我有用的代码 sn-p。

    let encryptedPaymentData = payment.token.paymentData
    let paymentMethod = payment.token.paymentMethod
    let txId = payment.token.transactionIdentifier
    print("paymentMethod = \(paymentMethod)")
    print("txId = \(txId)")
    let decryptedPaymentData:NSString! = NSString(data: encryptedPaymentData, encoding: NSUTF8StringEncoding)
    print("decryptedPaymentData = \(decryptedPaymentData)")

【讨论】：