8 Replies
      Latest reply on Sep 20, 2019 2:29 AM by kjacobs
      kjacobs Level 1 Level 1 (0 points)

        We have found that it's no longer possible to retrieve Wi-Fi SSIDs from within a Packet Tunnel Provider using CNCopyCurrentNetworkInfo.

         

        Observations:

        1. Both the app and the packet tunnel provider are properly configured to be able to use CNCopyCurrentNetworkInfo, by including the required entitlements.
        2. When the app calls this method, a dictionary containing a valid SSID is returned.
        3. When the packet tunnel provider calls this method, a dictionary containing "Wi-Fi" is returned, no matter to which network are we connected.
        4. When removing the entitlement from the packet tunnel provider, nil is returned.
        5. From the app we can also use the NEHotspotHelper to obtain this information, but it is not possible to use this method from the packet tunnel provider.
        Taking into consideration the newly updated documentation:
        The requesting app must meet one of the following requirements:
        • The app uses Core Location, and has the user’s authorization to use location information.
        • The app uses the NEHotspotConfiguration API to configure the current Wi-Fi network.
        • The app has active VPN configurations installed.
        An app that fails to meet any of the above requirements receives the following return value:
        •   An app linked against iOS 12 or earlier receives a dictionary with pseudo-values. In this case, the SSID is Wi-Fi (or WLAN in the China region), and the BSSID is 00:00:00:00:00:00.
        •   An app linked against iOS 13 or later receives NULL.

        Important

        To use this function, an app linked against iOS 12 or later must enable the Access WiFi Information capability in Xcode. For more information, see Access WiFi Information Entitlement. Calling this function without the entitlement always returns NULL when linked against iOS 12 or later.

        This function returns NULL for iPad apps running in macOS.

        It seems the rules no longer apply to packet tunnel providers, only to apps.

        The app has active VPN configurations installed.

        Explicitly states that this applies to apps that have a VPN configuration installed. Not about the associated packet tunnel provider, if available.

         

        Has there been a policy change in how network extensions (in our case, a packet tunnel provider) can access CNCopyCurrentNetworkInfo? If the app has permission to read the CNCopyCurrentNetworkInfo because it has a VPN configuration installed (namely its own packet tunnel provider), why should that packet tunnel not be allowed the same permission?