iPhone：NSHTTPCookie 不会在应用重新启动时保存

Question

在我的 iPhone 应用程序中，我希望能够在我的应用程序重新启动时重用相同的服务器端会话。服务器上的会话由 cookie 标识，该 cookie 在每个请求上发送。当我重新启动应用程序时，那个 cookie 就消失了，我不能再使用同一个会话了。

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。我的印象是，这就是为什么在我的应用程序重新启动时不保存 cookie 的原因。我该怎么做才能使我的 cookie 不是会话？我必须从服务器发送哪些 HTTP 标头？

Answer 1

您可以通过保存 cookie 的属性字典来保存 cookie，然后在重新连接之前恢复为新的 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];
}

Answer 2

我赞成 @TomIrving 的回答并在这里详细说明，因为许多用户不会看到他所说的非常重要的评论：

“您需要设置一个过期日期，否则cookie被假定为仅会话。”

基本上，当您关闭您的应用程序时，cookie 将被删除，除非 cookie 有一个未来的到期日期。

如果您可以控制服务器并且可以要求它在将来将“Expires”标头设置为某些内容，则您不需要在 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，则可以通过在其中更改 expiresDate 来“欺骗”您的应用：

• 从[[NSHTTPCookieStorage sharedHTTPCookieStorage] cookies]获取要修改的cookie
• 将其属性复制到新的 NSMutableDictionary ，将 "Expires" 值更改为未来的日期。
• 从新的NSMutableDictionary 创建一个新的cookie 使用：[NSHTTPCookie.cookieWithProperties:]
• 使用[[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookie newCookie]保存新创建的cookie

当您重新打开应用时，您会注意到 cookie 并未被删除。

Answer 3

仅限会话的 cookie 将按其性质过期。如果您真的需要，您可以手动将它们存储在钥匙串中。我更喜欢 Keychain 而不是保存在 UserDefaults 中或存档，因为 cookie 更安全，就像用户的密码一样。

很遗憾，保存 session-only cookie 不是很有帮助，下面的代码只是说明如何存储 cookie，但不能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）。

斯威夫特 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)
            }
        }
    }
}

Answer 4

我相信由服务器来决定 cookie 是否仅限会话，您对此无能为力。

Answer 5

快捷方式

商店：

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)
            }
        }
    }
}

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)
}

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)