objective c - Connect to VPN programmatically in iOS 8

Question

Since the release of iOS 8 beta, I found a Network Extension framework in its bundle which is going to let developers configure and connect to VPN servers programmatically and without any profile installation.

The framework contains a major class called NEVPNManager. This class also has 3 main methods that let me save, load or remove VPN preferences. I’ve written a piece of code in viewDidLoad method as following:

NEVPNManager *manager = [NEVPNManager sharedManager];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(vpnConnectionStatusChanged) name:NEVPNStatusDidChangeNotification object:nil];
[manager loadFromPreferencesWithCompletionHandler:^(NSError *error) {
    if(error) {
        NSLog(@"Load error: %@", error);
    }}];
NEVPNProtocolIPSec *p = [[NEVPNProtocolIPSec alloc] init];
p.username = @“[My username]”;
p.passwordReference = [KeyChainAccess loadDataForServiceNamed:@"VIT"];
p.serverAddress = @“[My Server Address]“;
p.authenticationMethod = NEVPNIKEAuthenticationMethodCertificate;
p.localIdentifier = @“[My Local identifier]”;
p.remoteIdentifier = @“[My Remote identifier]”;
p.useExtendedAuthentication = NO;
p.identityData = [My VPN certification private key];
p.disconnectOnSleep = NO;
[manager setProtocol:p];
[manager setOnDemandEnabled:NO];
[manager setLocalizedDescription:@"VIT VPN"];
NSArray *array = [NSArray new];
[manager setOnDemandRules: array];
NSLog(@"Connection desciption: %@", manager.localizedDescription);
NSLog(@"VPN status:  %i", manager.connection.status);
[manager saveToPreferencesWithCompletionHandler:^(NSError *error) {
   if(error) {
      NSLog(@"Save error: %@", error);
   }
}];

I also placed a button in my view and set its TouchUpInside action to the method below:

- (IBAction)buttonPressed:(id)sender {
   NSError *startError;
   [[NEVPNManager sharedManager].connection startVPNTunnelAndReturnError:&startError];
   if(startError) {
      NSLog(@"Start error: %@", startError.localizedDescription);
   }
}

There are two problems here:

1) When I try to save the preferences, the following error will be thrown: ?Save error: Error Domain=NEVPNErrorDomain Code=4 "The operation couldn’t be completed. (NEVPNErrorDomain error 4.)”?What is this error? How can I solve this issue?

2) [[NEVPNManager sharedManager].connection startVPNTunnelAndReturnError:&startError]; method doesn’t return any error when I call it but the connection status changes from Disconnected to Connecting for just a moment and then it gets back to Disconnected state.

Any help will be appreciated :)

Answer 1

The problem is the error you are getting when saving: Save error: Error Domain=NEVPNErrorDomain Code=4

If you look in the NEVPNManager.h header file, you will see that error code 4 is "NEVPNErrorConfigurationStale". The configuration is stale and needs to be loaded. You should call loadFromPreferencesWithCompletionHandler: and in the completion handler modify the values you want to modify, and then call saveToPreferencesWithCompletionHandler:. The example in your question is modifying the configuration before the loading is completed, which is why you are getting this error.

More like this:

[manager loadFromPreferencesWithCompletionHandler:^(NSError *error) {
     // do config stuff
     [manager saveToPreferencesWithCompletionHandler:^(NSError *error) {
     }];
}];