不良网络上的NEVPNManager身份验证弹出窗口

如何解决不良网络上的NEVPNManager身份验证弹出窗口

我正在使用一个VPN应用程序，其中所有服务器都使用IPSec协议。在iOS客户端上，我使用NEVPNManager建立我的VPN连接。它可以在适当的网络上正常运行。

但是有时用户在连接到VPN服务器时弹出，显示“输入您的用户身份验证” ，尽管我从钥匙串中设置了密码，但用户名字段已填写，但密码字段为空。

调查之后，我猜测用户的网络连接不良或不稳定时，会显示此弹出窗口。

为模拟这种情况，我从设置->开发人员中选择网络链接条件作为边缘或网络质量很差在我的设备上。这将使弹出窗口的发生率几乎达到95％。

是否可以检测何时触发弹出窗口？另外，当我从钥匙串设置密码时，显示此消息的原因是什么？

private var manager: NEVPNManager {
    return NEVPNManager.shared()
}

fileprivate func loadPreferances(_ completion: @escaping () -> Void) {
    manager.loadFromPreferences { error in
        assert(error == nil,"Failed to load preferences: \(error!.localizedDescription)")
        completion()
    }
}


fileprivate func _save(_ vpn: VPN,completion: VPNConfigureCompletion?) {
    #if targetEnvironment(simulator)
        assert(false,"I'm afraid you can not connect VPN in simulators.")
    #endif
    
    let ipsec = NEVPNProtocolIPSec()
    ipsec.useExtendedAuthentication = true
    ipsec.authenticationMethod = .sharedSecret
    ipsec.sharedSecretReference = KeychainHelper.getVPNPSK(for: vpn.serverIP)
    
    ipsec.username = vpn.username
    ipsec.passwordReference = KeychainHelper.getVPNPassword(for: vpn.serverIP)
    
    ipsec.serverAddress = vpn.serverIP
    ipsec.disconnectOnSleep = false

    manager.localizedDescription = "VPN"
    manager.protocolConfiguration = ipsec
    manager.isEnabled = true
    
    
    manager.ondemandRules = [NEondemandRule]()
    manager.isondemandEnabled = false
    
    manager.savetoPreferences { error in
        if let err = error {
            print("Failed to save profile: \(err.localizedDescription)")
        } else {
            completion?()
        }
    }
}

public func save(_ vpn: VPN,completion: VPNConfigureCompletion?) {
    loadPreferances { [weak self] in
        self?._save(vpn,completion: completion)
    }
}

public func connect() {
    do {
        try self.manager.connection.startVPNTunnel()
    } catch NEVPNError.configurationInvalid {
        
    } catch NEVPNError.configurationdisabled {
        
    } catch let error as NSError {
        print(error.localizedDescription)
    }
}

public func saveAndConnect(vpn: VPN,complition: @escaping ()->()) {
    KeychainHelper.setVPN(password: vpn.password,for: vpn.serverIP)
    KeychainHelper.setVPN(psk: vpn.serverPSK,for: vpn.serverIP)
    
    save(vpn) { [weak self] in
        self?.connect()
        dispatchQueue.main.async {
            complition()
        }
    }
}

KeychainHelper.swift

import KeychainAccess

struct KeychainHelper {
    
    private static var keychain: Keychain {
        return Keychain(service: Bundle.main.bundleIdentifier ?? "BundleIDDummy")
    }
        
    public static func setVPN(password: String,for address: String) {
        _ = try? keychain.remove("\(address)pass")
        keychain["\(address)pass"] = password
    }
    
    public static func getVPNPassword(for address: String) -> Data? {
        return keychain[attributes: "\(address)pass"]?.persistentRef
    }
    
    public static func setVPN(psk: String,for address: String) {
        _ = try? keychain.remove("\(address)psk")
        keychain["\(address)psk"] = psk
    }
    
    public static func getVPNPSK(for address: String) -> Data? {
        return keychain[attributes: "\(address)psk"]?.persistentRef
    }
    
}

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