无法在 URLSessionDelegate 中接收 NSURLAuthenticationMethodHTTPBasic

Question

我正在尝试使用 URLSessionDelegate 和 URLCredentials

实现 basic-authentication

func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Swift.Void)

苹果建议不要手动编写Authorizationheader。所以我正在尝试使用 URLCredentials.

我正在 Swift 游乐场中做一个非常简单的例子：

class Callback: NSObject {}

extension Callback: URLSessionDelegate {
    func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Swift.Void) {
        print("received challenge")
        print(challenge.protectionSpace.authenticationMethod)
        completionHandler(.performDefaultHandling, nil)
    }
}

let callback = Callback()
var configuration = URLSessionConfiguration.default
let session = URLSession(configuration: configuration, delegate: callback, delegateQueue: nil)

let string = "http://demo0230490.mockable.io/test"
var request = URLRequest(url: URL(string: string)!)
session.dataTask(with: request) { (data, response, error) in
    print("response")
    print(response)
}.resume()

import PlaygroundSupport
PlaygroundPage.current.needsIndefiniteExecution = true

问题是 – 我没有收到身份验证挑战。

如果您在浏览器中转到 http://demo0230490.mockable.io/test，您将看到浏览器显示基本身份验证警报。从我的模拟 http 我 return header 喜欢：

"Www-Authenticate" =     (
        "Basic realm=\"Access to MRM\""
    );

我还尝试切换到 https（我的意思是 https://demo0230490.mockable.io/test）来检查我是否会收到 NSURLAuthenticationMethodServerTrust 类型的身份验证质询。那行得通。这意味着我的 delegate 已正确设置并且在某些情况下可以正常工作。

所以问题是：任何人都可以指出问题或使用 URLCredentials（例如使用 https://www.mockable.io）提供基本身份验证的工作示例吗？

Answer 1

您应该使用 urlSession(_:task:didReceive:completionHandler:) 个 URLSessionTaskDelegate。您使用的方法是针对连接级别的挑战，而不是针对应用级别的挑战。

Answer 2

根据documentation urlSession(_:didReceive:completionHandler:)只在两种情况下被调用：

When a remote server asks for client certificates or Windows NT LAN Manager (NTLM) authentication, to allow your app to provide appropriate credentials

When a session first establishes a connection to a remote server that uses SSL or TLS, to allow your app to verify the server’s certificate chain

当您切换到 https 时，满足第二个条件，因此调用方法。

身份验证质询有两种类型：会话级和非会话级。对于非会话级别的挑战，URLSession 调用 urlSession(_:task:didReceive:completionHandler:)。对于会话级别的挑战，URLSession 调用 urlSession(_:didReceive:completionHandler:).

会话级别挑战和非会话级别挑战之间的区别在 urlSession(_:task:didReceive:completionHandler:) documentation 的讨论部分进行了描述：

For session-level challenges—NSURLAuthenticationMethodNTLM, NSURLAuthenticationMethodNegotiate, NSURLAuthenticationMethodClientCertificate, or NSURLAuthenticationMethodServerTrust—the NSURLSession object calls the session delegate’s urlSession(:didReceive:completionHandler:) method. If your app does not provide a session delegate method, the NSURLSession object calls the task delegate’s urlSession(:task:didReceive:completionHandler:) method to handle the challenge.

For non-session-level challenges (all others), the URLSession object calls the session delegate’s urlSession(:task:didReceive:completionHandler:) method to handle the challenge. If your app provides a session delegate and you need to handle authentication, then you must either handle the authentication at the task level or provide a task-level handler that calls the per-session handler explicitly. The session delegate’s urlSession(:didReceive:completionHandler:) method is not called for non-session-level challenges.

在您的情况下，您应该实施非会话级质询处理程序：

extension Callback: URLSessionTaskDelegate {
    func urlSession(_ session: URLSession, task: URLSessionTask, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
        print("received task challenge")
    }
}

Apple-forum 上也有工作示例。

无法在 URLSessionDelegate 中接收 NSURLAuthenticationMethodHTTPBasic

Can't receive NSURLAuthenticationMethodHTTPBasic in URLSessionDelegate

credentials

basic-authentication

ios

swift

urlsession