在 iOS 7 上本地验证应用内收据和捆绑收据的完整解决方案

以下是我如何在应用内购买库 RMStore 中解决此问题的演练。我将解释如何验证交易，包括验证整个收据。

一目了然

获取收据并验证交易。如果失败，请刷新收据，然后重试。这使得验证过程是异步的，因为刷新收据是异步的。

从 RMStoreAppReceiptVerifier：

RMAppReceipt *receipt = [RMAppReceipt bundleReceipt];
const BOOL verified = [self verifyTransaction:transaction inReceipt:receipt success:successBlock failure:nil]; // failureBlock is nil intentionally. See below.
if (verified) return;

// Apple recommends to refresh the receipt if validation fails on iOS
[[RMStore defaultStore] refreshReceiptOnSuccess:^{
    RMAppReceipt *receipt = [RMAppReceipt bundleReceipt];
    [self verifyTransaction:transaction inReceipt:receipt success:successBlock failure:failureBlock];
} failure:^(NSError *error) {
    [self failWithBlock:failureBlock error:error];
}];

获取收据数据

收据在 PCKS7 容器中，实际上是一个 PCKS7 容器。我不喜欢密码学，所以我使用OpenSSL来打开这个容器。其他人显然纯粹是用系统框架来做到这一点的。[[NSBundle mainBundle] appStoreReceiptURL]

将 OpenSSL 添加到您的项目并非易事。RMStore wiki 应该会有所帮助。

如果选择使用 OpenSSL 打开 PKCS7 容器，则代码可能如下所示。来自 RMAppReceipt：

+ (NSData*)dataFromPKCS7Path:(NSString*)path
{
    const char *cpath = [[path stringByStandardizingPath] fileSystemRepresentation];
    FILE *fp = fopen(cpath, "rb");
    if (!fp) return nil;

    PKCS7 *p7 = d2i_PKCS7_fp(fp, NULL);
    fclose(fp);

    if (!p7) return nil;

    NSData *data;
    NSURL *certificateURL = [[NSBundle mainBundle] URLForResource:@"AppleIncRootCertificate" withExtension:@"cer"];
    NSData *certificateData = [NSData dataWithContentsOfURL:certificateURL];
    if ([self verifyPKCS7:p7 withCertificateData:certificateData])
    {
        struct pkcs7_st *contents = p7->d.sign->contents;
        if (PKCS7_type_is_data(contents))
        {
            ASN1_OCTET_STRING *octets = contents->d.data;
            data = [NSData dataWithBytes:octets->data length:octets->length];
        }
    }
    PKCS7_free(p7);
    return data;
}

我们稍后将详细介绍验证。

获取收据字段

收据以 ASN1 格式表示。它包含一般信息、一些用于验证目的的字段（我们稍后会谈到）以及每个适用的应用内购买的具体信息。

同样，OpenSSL 在读取 ASN1 时派上了用场。在 RMAppReceipt 中，使用一些帮助程序方法：

NSMutableArray *purchases = [NSMutableArray array];
[RMAppReceipt enumerateASN1Attributes:asn1Data.bytes length:asn1Data.length usingBlock:^(NSData *data, int type) {
    const uint8_t *s = data.bytes;
    const NSUInteger length = data.length;
    switch (type)
    {
        case RMAppReceiptASN1TypeBundleIdentifier:
            _bundleIdentifierData = data;
            _bundleIdentifier = RMASN1ReadUTF8String(&s, length);
            break;
        case RMAppReceiptASN1TypeAppVersion:
            _appVersion = RMASN1ReadUTF8String(&s, length);
            break;
        case RMAppReceiptASN1TypeOpaqueValue:
            _opaqueValue = data;
            break;
        case RMAppReceiptASN1TypeHash:
            _hash = data;
            break;
        case RMAppReceiptASN1TypeInAppPurchaseReceipt:
        {
            RMAppReceiptIAP *purchase = [[RMAppReceiptIAP alloc] initWithASN1Data:data];
            [purchases addObject:purchase];
            break;
        }
        case RMAppReceiptASN1TypeOriginalAppVersion:
            _originalAppVersion = RMASN1ReadUTF8String(&s, length);
            break;
        case RMAppReceiptASN1TypeExpirationDate:
        {
            NSString *string = RMASN1ReadIA5SString(&s, length);
            _expirationDate = [RMAppReceipt formatRFC3339String:string];
            break;
        }
    }
}];
_inAppPurchases = purchases;

获取应用内购买项目

每个应用内购买也都在 ASN1 中。解析它与解析一般收据信息非常相似。

在 RMAppReceipt 中，使用相同的帮助程序方法：

[RMAppReceipt enumerateASN1Attributes:asn1Data.bytes length:asn1Data.length usingBlock:^(NSData *data, int type) {
    const uint8_t *p = data.bytes;
    const NSUInteger length = data.length;
    switch (type)
    {
        case RMAppReceiptASN1TypeQuantity:
            _quantity = RMASN1ReadInteger(&p, length);
            break;
        case RMAppReceiptASN1TypeProductIdentifier:
            _productIdentifier = RMASN1ReadUTF8String(&p, length);
            break;
        case RMAppReceiptASN1TypeTransactionIdentifier:
            _transactionIdentifier = RMASN1ReadUTF8String(&p, length);
            break;
        case RMAppReceiptASN1TypePurchaseDate:
        {
            NSString *string = RMASN1ReadIA5SString(&p, length);
            _purchaseDate = [RMAppReceipt formatRFC3339String:string];
            break;
        }
        case RMAppReceiptASN1TypeOriginalTransactionIdentifier:
            _originalTransactionIdentifier = RMASN1ReadUTF8String(&p, length);
            break;
        case RMAppReceiptASN1TypeOriginalPurchaseDate:
        {
            NSString *string = RMASN1ReadIA5SString(&p, length);
            _originalPurchaseDate = [RMAppReceipt formatRFC3339String:string];
            break;
        }
        case RMAppReceiptASN1TypeSubscriptionExpirationDate:
        {
            NSString *string = RMASN1ReadIA5SString(&p, length);
            _subscriptionExpirationDate = [RMAppReceipt formatRFC3339String:string];
            break;
        }
        case RMAppReceiptASN1TypeWebOrderLineItemID:
            _webOrderLineItemID = RMASN1ReadInteger(&p, length);
            break;
        case RMAppReceiptASN1TypeCancellationDate:
        {
            NSString *string = RMASN1ReadIA5SString(&p, length);
            _cancellationDate = [RMAppReceipt formatRFC3339String:string];
            break;
        }
    }
}]; 

需要注意的是，某些应用内购买项目（例如消耗品和不可续订订阅）只会在收据中出现一次。您应该在购买后立即验证这些内容（同样，RMStore 可以帮助您解决这个问题）。

验证一目了然

现在，我们从收据及其所有应用内购买中获得了所有字段。首先，我们验证收据本身，然后我们简单地检查收据是否包含交易产品。

下面是我们一开始调用的方法。从 RMStoreAppReceiptVerificator：

- (BOOL)verifyTransaction:(SKPaymentTransaction*)transaction
                inReceipt:(RMAppReceipt*)receipt
                           success:(void (^)())successBlock
                           failure:(void (^)(NSError *error))failureBlock
{
    const BOOL receiptVerified = [self verifyAppReceipt:receipt];
    if (!receiptVerified)
    {
        [self failWithBlock:failureBlock message:NSLocalizedString(@"The app receipt failed verification", @"")];
        return NO;
    }
    SKPayment *payment = transaction.payment;
    const BOOL transactionVerified = [receipt containsInAppPurchaseOfProductIdentifier:payment.productIdentifier];
    if (!transactionVerified)
    {
        [self failWithBlock:failureBlock message:NSLocalizedString(@"The app receipt doest not contain the given product", @"")];
        return NO;
    }
    if (successBlock)
    {
        successBlock();
    }
    return YES;
}

验证收据

验证收据本身归结为：

1. 检查收据是否有效 PKCS7 和 ASN1。我们已经隐含地这样做了。
2. 验证收据是否由 Apple 签名。这是在解析收据之前完成的，下面将详细介绍。
3. 检查收据中包含的捆绑标识符是否与您的捆绑标识符相对应。您应该对捆绑包标识符进行硬编码，因为修改您的 app bundle 并使用其他一些收据似乎并不困难。
4. 检查收据中包含的应用版本是否与您的应用版本标识符相对应。出于上述相同原因，您应该对应用版本进行硬编码。
5. 检查收据哈希，确保收据与当前设备相对应。

RMStoreAppReceiptVerificator 中的高级代码中的 5 个步骤：The 5 steps in code at a high-level， from RMStoreAppReceiptVerificator：

- (BOOL)verifyAppReceipt:(RMAppReceipt*)receipt
{
    // Steps 1 & 2 were done while parsing the receipt
    if (!receipt) return NO;   

    // Step 3
    if (![receipt.bundleIdentifier isEqualToString:self.bundleIdentifier]) return NO;

    // Step 4        
    if (![receipt.appVersion isEqualToString:self.bundleVersion]) return NO;

    // Step 5        
    if (![receipt verifyReceiptHash]) return NO;

    return YES;
}

让我们深入研究步骤 2 和 5。

验证收据签名

当我们提取数据时，我们浏览了收据签名验证。收据使用 Apple Inc. 根证书签名，该证书可从 Apple 根证书颁发机构下载。以下代码将 PKCS7 容器和根证书作为数据，并检查它们是否匹配：

+ (BOOL)verifyPKCS7:(PKCS7*)container withCertificateData:(NSData*)certificateData
{ // Based on: https://developer.apple.com/library/content/releasenotes/General/ValidateAppStoreReceipt/Chapters/ValidateLocally.html#//apple_ref/doc/uid/TP40010573-CH1-SW17
    static int verified = 1;
    int result = 0;
    OpenSSL_add_all_digests(); // Required for PKCS7_verify to work
    X509_STORE *store = X509_STORE_new();
    if (store)
    {
        const uint8_t *certificateBytes = (uint8_t *)(certificateData.bytes);
        X509 *certificate = d2i_X509(NULL, &certificateBytes, (long)certificateData.length);
        if (certificate)
        {
            X509_STORE_add_cert(store, certificate);

            BIO *payload = BIO_new(BIO_s_mem());
            result = PKCS7_verify(container, NULL, store, NULL, payload, 0);
            BIO_free(payload);

            X509_free(certificate);
        }
    }
    X509_STORE_free(store);
    EVP_cleanup(); // Balances OpenSSL_add_all_digests (), per http://www.openssl.org/docs/crypto/OpenSSL_add_all_algorithms.html

    return result == verified;
}

这是在一开始完成的，在分析收据之前。

验证收据哈希

收据中包含的哈希值是设备 ID 的 SHA1、收据中包含的一些不透明值和捆绑 ID。

这就是在 iOS 上验证收据哈希的方式。来自 RMAppReceipt：

- (BOOL)verifyReceiptHash
{
    // TODO: Getting the uuid in Mac is different. See: https://developer.apple.com/library/content/releasenotes/General/ValidateAppStoreReceipt/Chapters/ValidateLocally.html#//apple_ref/doc/uid/TP40010573-CH1-SW5
    NSUUID *uuid = [[UIDevice currentDevice] identifierForVendor];
    unsigned char uuidBytes[16];
    [uuid getUUIDBytes:uuidBytes];

    // Order taken from: https://developer.apple.com/library/content/releasenotes/General/ValidateAppStoreReceipt/Chapters/ValidateLocally.html#//apple_ref/doc/uid/TP40010573-CH1-SW5
    NSMutableData *data = [NSMutableData data];
    [data appendBytes:uuidBytes length:sizeof(uuidBytes)];
    [data appendData:self.opaqueValue];
    [data appendData:self.bundleIdentifierData];

    NSMutableData *expectedHash = [NSMutableData dataWithLength:SHA_DIGEST_LENGTH];
    SHA1(data.bytes, data.length, expectedHash.mutableBytes);

    return [expectedHash isEqualToData:self.hash];
}

这就是它的要点。我可能在这里或那里遗漏了一些东西，所以我可能会稍后再回到这篇文章。无论如何，我建议浏览完整的代码以获取更多详细信息。

我很惊讶没有人在这里提到 Receigen。它是一种自动生成混淆收据验证码的工具，每次都不同;它支持GUI和命令行操作。强烈推荐。

（不隶属于 Receigen，只是一个快乐的用户。

当我键入时，我使用这样的 Rakefile 自动重新运行 Receigen（因为它需要在每次版本更改时完成）：rake receigen

desc "Regenerate App Store Receipt validation code using Receigen app (which must be already installed)"
task :receigen do
  # TODO: modify these to match your app
  bundle_id = 'com.example.YourBundleIdentifierHere'
  output_file = File.join(__dir__, 'SomeDir/ReceiptValidation.h')

  version = PList.get(File.join(__dir__, 'YourProjectFolder/Info.plist'), 'CFBundleVersion')
  command = %Q</Applications/Receigen.app/Contents/MacOS/Receigen --identifier #{bundle_id} --version #{version} --os ios --prefix ReceiptValidation --success callblock --failure callblock>
  puts "#{command} > #{output_file}"
  data = `#{command}`
  File.open(output_file, 'w') { |f| f.write(data) }
end

module PList
  def self.get file_name, key
    if File.read(file_name) =~ %r!<key>#{Regexp.escape(key)}</key>\s*<string>(.*?)</string>!
      $1.strip
    else
      nil
    end
  end
end

注意：不建议在客户端进行此类验证

这是一个 Swift 4 版本，用于验证应用内购买收据......

让我们创建一个枚举来表示收据验证的可能错误

enum ReceiptValidationError: Error {
    case receiptNotFound
    case jsonResponseIsNotValid(description: String)
    case notBought
    case expired
}

然后，让我们创建一个验证收据的函数，如果无法验证收据，它将抛出错误。

func validateReceipt() throws {
    guard let appStoreReceiptURL = Bundle.main.appStoreReceiptURL, FileManager.default.fileExists(atPath: appStoreReceiptURL.path) else {
        throw ReceiptValidationError.receiptNotFound
    }
    
    let receiptData = try! Data(contentsOf: appStoreReceiptURL, options: .alwaysMapped)
    let receiptString = receiptData.base64EncodedString()
    let jsonObjectBody = ["receipt-data" : receiptString, "password" : <#String#>]
    
    #if DEBUG
    let url = URL(string: "https://sandbox.itunes.apple.com/verifyReceipt")!
    #else
    let url = URL(string: "https://buy.itunes.apple.com/verifyReceipt")!
    #endif
    
    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    request.httpBody = try! JSONSerialization.data(withJSONObject: jsonObjectBody, options: .prettyPrinted)
    
    let semaphore = DispatchSemaphore(value: 0)
    
    var validationError : ReceiptValidationError?
    
    let task = URLSession.shared.dataTask(with: request) { data, response, error in
        guard let data = data, let httpResponse = response as? HTTPURLResponse, error == nil, httpResponse.statusCode == 200 else {
            validationError = ReceiptValidationError.jsonResponseIsNotValid(description: error?.localizedDescription ?? "")
            semaphore.signal()
            return
        }
        guard let jsonResponse = (try? JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.mutableContainers)) as? [AnyHashable: Any] else {
            validationError = ReceiptValidationError.jsonResponseIsNotValid(description: "Unable to parse json")
            semaphore.signal()
            return
        }
        guard let expirationDate = self.expirationDate(jsonResponse: jsonResponse, forProductId: <#String#>) else {
            validationError = ReceiptValidationError.notBought
            semaphore.signal()
            return
        }
        
        let currentDate = Date()
        if currentDate > expirationDate {
            validationError = ReceiptValidationError.expired
        }
        
        semaphore.signal()
    }
    task.resume()
    
    semaphore.wait()
    
    if let validationError = validationError {
        throw validationError
    }
}

让我们使用这个帮助程序函数来获取特定产品的到期日期。该函数接收 JSON 响应和产品 ID。JSON 响应可以包含不同产品的多个收据信息，因此它获取指定参数的最后信息。

func expirationDate(jsonResponse: [AnyHashable: Any], forProductId productId :String) -> Date? {
    guard let receiptInfo = (jsonResponse["latest_receipt_info"] as? [[AnyHashable: Any]]) else {
        return nil
    }
    
    let filteredReceipts = receiptInfo.filter{ return ($0["product_id"] as? String) == productId }
    
    guard let lastReceipt = filteredReceipts.last else {
        return nil
    }
    
    let formatter = DateFormatter()
    formatter.dateFormat = "yyyy-MM-dd HH:mm:ss VV"
    
    if let expiresString = lastReceipt["expires_date"] as? String {
        return formatter.date(from: expiresString)
    }
    
    return nil
}

现在，您可以调用此函数并处理可能的错误情况

do {
    try validateReceipt()
    // The receipt is valid 😌
    print("Receipt is valid")
} catch ReceiptValidationError.receiptNotFound {
    // There is no receipt on the device 😱
} catch ReceiptValidationError.jsonResponseIsNotValid(let description) {
    // unable to parse the json 🤯
    print(description)
} catch ReceiptValidationError.notBought {
    // the subscription hasn't being purchased 😒
} catch ReceiptValidationError.expired {
    // the subscription is expired 😵
} catch {
    print("Unexpected error: \(error).")
}

您可以从 App Store Connect 获取密码。 打开此链接，点击https://developer.apple.com

• Account tab
• Do Sign in
• Open iTune Connect
• Open My App
• Open Feature Tab
• Open In App Purchase
• Click at the right side on 'View Shared Secret'
• At the bottom you will get a secrete key

复制该密钥并粘贴到密码字段中。