iPhone：应用程序重新启动后，NSHTTPCookie未保存

Question

在我的iPhone应用程序中，我希望在应用重新启动时能够重复使用相同的服务器端会话。服务器上的会话由一个cookie标识，在每次请求时发送。当我重新启动应用程序时，该cookie已丢失，我不能再使用相同的会话。

当我使用NSHTTPCookieStorage查找从服务器获取的cookie时，我注意到[cookie isSessionOnly]返回YES。我有这样的印象，这就是为什么cookie不会保存在我应用的重新启动过程中的原因。我需要做什么才能使我的cookie不是session only？从服务器发送哪些HTTP头？

- Tom van Zummeren

Answer 1

在重新连接之前，您可以通过保存其属性字典并将其作为新cookie进行恢复来保存cookie。

保存：

NSArray* allCookies = [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookiesForURL:[NSURL URLWithString:URL]];
for (NSHTTPCookie *cookie in allCookies) {
    if ([cookie.name isEqualToString:MY_COOKIE]) { 
        NSMutableDictionary* cookieDictionary = [NSMutableDictionary dictionaryWithDictionary:[[NSUserDefaults standardUserDefaults] dictionaryForKey:PREF_KEY]];
        [cookieDictionary setValue:cookie.properties forKey:URL];
        [[NSUserDefaults standardUserDefaults] setObject:cookieDictionary forKey:PREF_KEY];
    }
 }

加载：

NSDictionary* cookieDictionary = [[NSUserDefaults standardUserDefaults] dictionaryForKey:PREF_KEY];
NSDictionary* cookieProperties = [cookieDictionary valueForKey:URL];
if (cookieProperties != nil) {
    NSHTTPCookie* cookie = [NSHTTPCookie cookieWithProperties:cookieProperties];
    NSArray* cookieArray = [NSArray arrayWithObject:cookie];
    [[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookies:cookieArray forURL:[NSURL URLWithString:URL] mainDocumentURL:nil];
}

- Mike Katz

---

你需要同步 NSUserDefaults 吗？ - ninjaneer

只有在需要立即保存它们时才需要同步。否则，它们将在稍后的某个不确定时间保存。这是文档页面：http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSUserDefaults_Class/Reference/Reference.html#//apple_ref/occ/instm/NSUserDefaults/synchronize - Mike Katz

Answer 2

我已经赞了@TomIrving的回答，并在此做进一步的解释，因为许多用户可能会忽略他说的非常重要的评论：

“您需要设置过期日期，否则该cookie将被视为仅适用于会话。”

基本上，除非cookie有一个在未来的过期日期，否则在关闭应用程序时cookie将被删除。

如果您可以控制服务器并且可以要求服务器将“Expires”头设置为未来的某个值，则不需要在NSUserDefaults中存储和恢复cookie。如果您无法控制服务器或不希望覆盖服务器的行为，则可以通过从其中更改expiresDate 来“欺骗”您的应用程序：

• 从[[NSHTTPCookieStorage sharedHTTPCookieStorage] cookies]获取要修改的cookie
• 将其属性复制到新的NSMutableDictionary中，将"Expires"值更改为未来的某个日期。
• 使用[NSHTTPCookie.cookieWithProperties:]从新的NSMutableDictionary创建新cookie
• 使用[[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookie newCookie]保存新创建的cookie

当您重新打开应用程序时，您会注意到cookie没有被删除。

- Abdo

---

从服务器安全的角度来看，这应该是被接受的答案。 - MandisaW

Answer 3

仅会话cookie本质上会过期。如果您真的想要存储它们，可以在Keychain中手动存储。我更喜欢将其保存在Keychain中，而不是UserDefaults或档案中，因为cookie应该像用户密码一样安全。

不幸的是，保存仅会话cookie并没有太多帮助。下面的代码仅是存储cookie的示例，但无法以任何方式强制服务器接受此类cookie（除非您可以控制服务器）。

Swift 2.2

// Saving into Keychain
if let cookies = NSHTTPCookieStorage.sharedHTTPCookieStorage().cookies {
    let cookiesData: NSData = NSKeyedArchiver.archivedDataWithRootObject(cookies)
    let userAccount = "some unique string to identify the item in Keychain, in my case I use username"
    let domain = "some other string you can use in combination with userAccount to identify the item"           
    let keychainQuery: [NSString: NSObject] = [
                        kSecClass: kSecClassGenericPassword,
                        kSecAttrAccount: userAccount + "cookies", 
                        kSecAttrService: domain,
                        kSecValueData: cookiesData]
    SecItemDelete(keychainQuery as CFDictionaryRef) //Trying to delete the item from Keychaing just in case it already exists there
    let status: OSStatus = SecItemAdd(keychainQuery as CFDictionaryRef, nil)
    if (status == errSecSuccess) {
        print("Cookies succesfully saved into Keychain")
    }
}

// Getting from Keychain
let userAccount = "some unique string to identify the item in Keychain, in my case I use username"
let domain = "some other string you can use in combination with userAccount to identify the item"
let keychainQueryForCookies: [NSString: NSObject] = [
                             kSecClass: kSecClassGenericPassword,
                             kSecAttrService: domain, // we use JIRA URL as service string for Keychain
                             kSecAttrAccount: userAccount + "cookies",
                             kSecReturnData: kCFBooleanTrue,
                             kSecMatchLimit: kSecMatchLimitOne]
var rawResultForCookies: AnyObject?
let status: OSStatus = SecItemCopyMatching(keychainQueryForCookies, &rawResultForCookies)
if (status == errSecSuccess) {
    let retrievedData = rawResultForCookies as? NSData
    if let unwrappedData = retrievedData {
        if let cookies = NSKeyedUnarchiver.unarchiveObjectWithData(unwrappedData) as? [NSHTTPCookie] {
            for aCookie in cookies {
                NSHTTPCookieStorage.sharedHTTPCookieStorage().setCookie(aCookie)
            }
        }
    }
}

- Vitalii

Answer 4

我认为决定cookie是否仅限于会话的权力在服务器手中，你无法做任何事情。

- Tom Irving

---

明白，但服务器将告诉 iPhone 应用程序该 cookie 仅为会话期间使用。 - Tom Irving

是的，而且通过HTTP实现。因此我正在寻找从服务器发送正确的头文件，告诉iPhone应用程序可以将cookie保留更长时间。 - Tom van Zummeren

哦，我现在明白你在寻找什么了，我道歉。 你目前是如何设置cookie的？ - Tom Irving

如果不设置过期日期，那么Cookie将被视为仅限于当前会话。请您设定一个过期日期。 - Tom Irving

正如许多人所解释的那样，原因是没有设置过期日期。 - Ashwin G

Answer 5

Swift方式

存储：

static func storeCookies() {
    let cookiesStorage = NSHTTPCookieStorage.sharedHTTPCookieStorage()
    let userDefaults = NSUserDefaults.standardUserDefaults()

    let serverBaseUrl = "http://yourserverurl.com"
    var cookieDict = [String : AnyObject]()

    for cookie in cookiesStorage.cookiesForURL(NSURL(string: serverBaseUrl)!)! {
        cookieDict[cookie.name] = cookie.properties
    }

    userDefaults.setObject(cookieDict, forKey: cookiesKey)
}

恢复：

static func restoreCookies() {
    let cookiesStorage = NSHTTPCookieStorage.sharedHTTPCookieStorage()
    let userDefaults = NSUserDefaults.standardUserDefaults()

    if let cookieDictionary = userDefaults.dictionaryForKey(cookiesKey) {

        for (cookieName, cookieProperties) in cookieDictionary {
            if let cookie = NSHTTPCookie(properties: cookieProperties as! [String : AnyObject] ) {
                cookiesStorage.setCookie(cookie)
            }
        }
    }
}

- Wujo

---

这个答案（将您的烹饪存储为纯文本）是不安全的。请使用钥匙串而不是像这个答案中使用的NSUserDefaults。 - Andrew Plummer

Answer 6

Swift 5 版本

func storeCookies() {

    guard let serverBaseUrl = URL(string: Constants.baseURL) else {
        return
    }

    let cookiesStorage: HTTPCookieStorage = .shared

    var cookieDict: [String: Any] = [:]

    cookiesStorage.cookies(for: serverBaseUrl)?.forEach({ cookieDict[$0.name] = $0.properties })

    let userDefaults = UserDefaults.standard
    userDefaults.set(cookieDict, forKey: Constants.cookiesKey)
}

func restoreCookies() {

    let cookiesStorage: HTTPCookieStorage = .shared

    let userDefaults = UserDefaults.standard

    guard let cookieDictionary = userDefaults.dictionary(forKey: Constants.cookiesKey) else {
        return
    }

    let cookies = cookieDictionary
        .compactMap({ $0.value as? [HTTPCookiePropertyKey: Any] })
        .compactMap({ HTTPCookie(properties: $0) })

    cookiesStorage.setCookies(cookies, for: URL(string: Constants.baseURL), mainDocumentURL: nil)
}

- Alex Shoshiashvili

Answer 7

SWIFT 3

保存：

if let httpResponse = response as? HTTPURLResponse, let fields = httpResponse.allHeaderFields as? [String : String] {
            let cookies = HTTPCookie.cookies(withResponseHeaderFields: fields, for: response.url!)
            HTTPCookieStorage.shared.setCookies(cookies, for: response.url!, mainDocumentURL: nil)
            for cookie in cookies {
                if cookie.name == cookieName{
                    if cookieName == Constants.WS.COOKIES.COOKIE_SMS {
                        UserDefaults.standard.set(NSKeyedArchiver.archivedData(withRootObject: cookie), forKey: Constants.SHARED_DEFAULT.COOKIE_SMS)
                        UserDefaults.standard.synchronize()
                    }

                    return cookie.value
                }
            }
        }

获取：

let cookie: HTTPCookie = NSKeyedUnarchiver.unarchiveObject(with: UserDefaults.standard.object(forKey: Constants.SHARED_DEFAULT.COOKIE_SMS) as! Data) as! HTTPCookie
        HTTPCookieStorage.shared.setCookie(cookie)

- Mikel Sanchez