c# - 使用C#和PHP解压iOS应用收据

Question

我有带有应用内商品的Xamarin iOS应用。我得到base64编码的应用程序收据:

NSUrl receiptURL = NSBundle.MainBundle.AppStoreReceiptUrl;
String receiptData = receipt.GetBase64EncodedString(0);

根据Apple文档7.0+，应用程序收据使用ASN1包装在PKCS7容器中。当我将其发送到Apple服务器时，它将以JSON返回收据。但是我想在本地解析它，以了解iaps用户已经拥有了什么。我不需要验证，因为Apple远程进行验证，我只需要获取购买的inap的收据。

到目前为止，作为一项调查，我已经使用phpseclib在php中对其进行了解析，手动(不知道如何以编程方式执行此操作)定位了收据并也对其进行了解析。

$asn_parser = new File_ASN1();
//parse the receipt binary string
$pkcs7 = $asn_parser->decodeBER(base64_decode($f));
//print_r($pkcs7);
$payload_sequence = $pkcs7[0]['content'][1]['content'][0]['content'][2]['content'];

$pld = $asn_parser->decodeBER($payload_sequence[1]['content'][0]['content']);
//print_r($pld);
$prd = $asn_parser->decodeBER($pld[0]['content'][21]['content'][2]['content']);
print_r($prd);

但是即使这样，我仍然有一些混乱的属性，每个属性看起来像:

                                        Array
                                        (
                                            [start] => 271
                                            [headerlength] => 2
                                            [type] => 4
                                            [content] => 2016-08-22T13:22:00Z
                                            [length] => 24
                                        )

它不是人类可读的，我需要类似的东西(Apple返回的带有print_r的输出):

[receipt] => Array
(
    [receipt_type] => ProductionSandbox
    [adam_id] => 0
    [app_item_id] => 0
    [bundle_id] => com.my.test.app.iOS
...
    [in_app] => Array
        (
            [0] => Array
            (
                [quantity] => 1
                [product_id] => test_iap_1
                [transaction_id] => 1000000230806171
...
                [is_trial_period] => false
            )
        )
)

事情似乎太复杂了，我简直不敢相信开箱收据就这么复杂。有人知道如何管理吗？我找到了 this post，但是库是用Objective-C编写的，不适用于我当前的环境。我会说这个lib的来源使我感到害怕:这么多复杂的代码只是用来解包标准容器。我的意思是使用json，bson等非常容易，但不是asn1。

Answer 1

最后，我使用Liping Dai LCLib(lipingshare.com)打开了包装。 Asn1Parser返回带有根节点的类DOM树-非常方便的lib。

    public class AppleAppReceipt
    {
        public class AppleInAppPurchaseReceipt
        {
            public int Quantity;
            public string ProductIdentifier;
            public string TransactionIdentifier;
            public DateTime PurchaseDate;
            public string OriginalTransactionIdentifier;
            public DateTime OriginalPurchaseDate;
            public DateTime SubscriptionExpirationDate;
            public DateTime CancellationDate;
            public int WebOrderLineItemID;
        }

        const int AppReceiptASN1TypeBundleIdentifier = 2;
        const int AppReceiptASN1TypeAppVersion = 3;
        const int AppReceiptASN1TypeOpaqueValue = 4;
        const int AppReceiptASN1TypeHash = 5;
        const int AppReceiptASN1TypeReceiptCreationDate = 12;
        const int AppReceiptASN1TypeInAppPurchaseReceipt = 17;
        const int AppReceiptASN1TypeOriginalAppVersion = 19;
        const int AppReceiptASN1TypeReceiptExpirationDate = 21;

        const int AppReceiptASN1TypeQuantity = 1701;
        const int AppReceiptASN1TypeProductIdentifier = 1702;
        const int AppReceiptASN1TypeTransactionIdentifier = 1703;
        const int AppReceiptASN1TypePurchaseDate = 1704;
        const int AppReceiptASN1TypeOriginalTransactionIdentifier = 1705;
        const int AppReceiptASN1TypeOriginalPurchaseDate = 1706;
        const int AppReceiptASN1TypeSubscriptionExpirationDate = 1708;
        const int AppReceiptASN1TypeWebOrderLineItemID = 1711;
        const int AppReceiptASN1TypeCancellationDate = 1712;

        public string BundleIdentifier;
        public string AppVersion;
        public string OriginalAppVersion; //какую покупали
        public DateTime ReceiptCreationDate;

        public Dictionary<string, AppleInAppPurchaseReceipt> PurchaseReceipts;

        public bool parseAsn1Data(byte[] val)
        {
            if (val == null)
                return false;
            Asn1Parser p = new Asn1Parser();
            var stream = new MemoryStream(val);
            try
            {
                p.LoadData(stream);
            }
            catch (Exception e)
            {
                return false;
            }

            Asn1Node root = p.RootNode;
            if (root == null)
                return false;

            PurchaseReceipts = new Dictionary<string, AppleInAppPurchaseReceipt>();
            parseNodeRecursive(root);

            return !string.IsNullOrEmpty(BundleIdentifier);
        }


        private static string getStringFromSubNode(Asn1Node nn)
        {
            string dataStr = null;

            if ((nn.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.OCTET_STRING && nn.ChildNodeCount > 0)
            {
                Asn1Node n = nn.GetChildNode(0);

                switch (n.Tag & Asn1Tag.TAG_MASK)
                {
                    case Asn1Tag.PRINTABLE_STRING:
                    case Asn1Tag.IA5_STRING:
                    case Asn1Tag.UNIVERSAL_STRING:
                    case Asn1Tag.VISIBLE_STRING:
                    case Asn1Tag.NUMERIC_STRING:
                    case Asn1Tag.UTC_TIME:
                    case Asn1Tag.UTF8_STRING:
                    case Asn1Tag.BMPSTRING:
                    case Asn1Tag.GENERAL_STRING:
                    case Asn1Tag.GENERALIZED_TIME:
                        {
                            if ((n.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.UTF8_STRING)
                            {
                                UTF8Encoding unicode = new UTF8Encoding();
                                dataStr = unicode.GetString(n.Data);
                            }
                            else
                            {
                                dataStr = Asn1Util.BytesToString(n.Data);
                            }
                        }
                        break;
                }
            }
            return dataStr;
        }
        private static DateTime getDateTimeFromSubNode(Asn1Node nn)
        {
            string dataStr = getStringFromSubNode(nn);
            if (string.IsNullOrEmpty(dataStr))
                return DateTime.MinValue;
            DateTime retval = DateTime.MaxValue;
            try
            {
                retval = DateTime.Parse(dataStr);
            }
            catch (Exception e)
            {
            }
            return retval;
        }

        private static int getIntegerFromSubNode(Asn1Node nn)
        {
            int retval = -1;

            if ((nn.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.OCTET_STRING && nn.ChildNodeCount > 0)
            {
                Asn1Node n = nn.GetChildNode(0);
                if ((n.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.INTEGER)
                    retval = (int)Asn1Util.BytesToLong(n.Data);
            }
            return retval;
        }

        private void parseNodeRecursive(Asn1Node tNode)
        {
            bool processed_node = false;
            if ((tNode.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.SEQUENCE && tNode.ChildNodeCount == 3)
            {
                Asn1Node node1 = tNode.GetChildNode(0);
                Asn1Node node2 = tNode.GetChildNode(1);
                Asn1Node node3 = tNode.GetChildNode(2);

                if ((node1.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.INTEGER && (node2.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.INTEGER &&
                    (node3.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.OCTET_STRING)
                {
                    processed_node = true;
                    int type = (int)Asn1Util.BytesToLong(node1.Data);
                    switch (type)
                    {
                        case AppReceiptASN1TypeBundleIdentifier:
                            BundleIdentifier = getStringFromSubNode(node3);
                            break;
                        case AppReceiptASN1TypeAppVersion:
                            AppVersion = getStringFromSubNode(node3);
                            break;
                        case AppReceiptASN1TypeOpaqueValue:
                            break;
                        case AppReceiptASN1TypeHash:
                            break;
                        case AppReceiptASN1TypeOriginalAppVersion:
                            OriginalAppVersion = getStringFromSubNode(node3);
                            break;
                        case AppReceiptASN1TypeReceiptExpirationDate:
                            break;
                        case AppReceiptASN1TypeReceiptCreationDate:
                            ReceiptCreationDate = getDateTimeFromSubNode(node3);
                            break;
                        case AppReceiptASN1TypeInAppPurchaseReceipt:
                            {
                                if (node3.ChildNodeCount > 0)
                                {
                                    Asn1Node node31 = node3.GetChildNode(0);
                                    if ((node31.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.SET && node31.ChildNodeCount > 0)
                                    {
                                        AppleInAppPurchaseReceipt receipt = new AppleInAppPurchaseReceipt();

                                        for (int i = 0; i < node31.ChildNodeCount; i++)
                                        {
                                            Asn1Node node311 = node31.GetChildNode(i);
                                            if ((node311.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.SEQUENCE && node311.ChildNodeCount == 3)
                                            {
                                                Asn1Node node3111 = node311.GetChildNode(0);
                                                Asn1Node node3112 = node311.GetChildNode(1);
                                                Asn1Node node3113 = node311.GetChildNode(2);
                                                if ((node3111.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.INTEGER && (node3112.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.INTEGER &&
                                                    (node3113.Tag & Asn1Tag.TAG_MASK) == Asn1Tag.OCTET_STRING)
                                                {
                                                    int type1 = (int)Asn1Util.BytesToLong(node3111.Data);
                                                    switch (type1)
                                                    {
                                                        case AppReceiptASN1TypeQuantity:
                                                            receipt.Quantity = getIntegerFromSubNode(node3113);
                                                            break;
                                                        case AppReceiptASN1TypeProductIdentifier:
                                                            receipt.ProductIdentifier = getStringFromSubNode(node3113);
                                                            break;
                                                        case AppReceiptASN1TypeTransactionIdentifier:
                                                            receipt.TransactionIdentifier = getStringFromSubNode(node3113);
                                                            break;
                                                        case AppReceiptASN1TypePurchaseDate:
                                                            receipt.PurchaseDate = getDateTimeFromSubNode(node3113);
                                                            break;
                                                        case AppReceiptASN1TypeOriginalTransactionIdentifier:
                                                            receipt.OriginalTransactionIdentifier = getStringFromSubNode(node3113);
                                                            break;
                                                        case AppReceiptASN1TypeOriginalPurchaseDate:
                                                            receipt.OriginalPurchaseDate = getDateTimeFromSubNode(node3113);
                                                            break;
                                                        case AppReceiptASN1TypeSubscriptionExpirationDate:
                                                            receipt.SubscriptionExpirationDate = getDateTimeFromSubNode(node3113);
                                                            break;
                                                        case AppReceiptASN1TypeWebOrderLineItemID:
                                                            receipt.WebOrderLineItemID = getIntegerFromSubNode(node3113);
                                                            break;
                                                        case AppReceiptASN1TypeCancellationDate:
                                                            receipt.CancellationDate = getDateTimeFromSubNode(node3113);
                                                            break;
                                                    }
                                                }
                                            }
                                        }

                                        if (!string.IsNullOrEmpty(receipt.ProductIdentifier))
                                            PurchaseReceipts.Add(receipt.ProductIdentifier, receipt);
                                    }
                                }
                            }
                            break;
                        default:
                            processed_node = false;
                            break;
                    }
                }
            }


            if (!processed_node)
            {
                for (int i = 0; i < tNode.ChildNodeCount; i++)
                {
                    Asn1Node chld = tNode.GetChildNode(i);
                    if (chld != null)
                        parseNodeRecursive(chld);
                }
            }
        }
    }

和用法:

    public void printAppReceipt()
    {
        NSUrl receiptURL = NSBundle.MainBundle.AppStoreReceiptUrl;
        if (receiptURL != null)
        {
            Console.WriteLine("receiptUrl='" + receiptURL + "'");

            NSData receipt = NSData.FromUrl(receiptURL);
            if (receipt != null)
            {
                byte[] rbytes = receipt.ToArray();
                AppleAppReceipt apprec = new AppleAppReceipt();
                if (apprec.parseAsn1Data(rbytes))
                {
                    Console.WriteLine("Received receipt for " + apprec.BundleIdentifier + " with " + apprec.PurchaseReceipts.Count +
                                      " products");
                    Console.WriteLine(JsonConvert.SerializeObject(apprec,Formatting.Indented));
                }
            }
            else
                Console.WriteLine("receipt == null");
        }
    }