NEVPNManager VPN Config SharedSecret Error

Question

I want to establish a VPN connection with my VPN server. I installed VPN server from digital oceans.

I want to make VPN application for IOS by using objective-C by using my VPN connection settings.

Here I faced problem: no VPN shared secret was provided.

Here I Used Codes

  - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.

    [[NEVPNManager sharedManager] setEnabled:YES];
    [[NEVPNManager sharedManager] loadFromPreferencesWithCompletionHandler: ^(NSError *error) {



        NEVPNProtocolIPSec *p = [[NEVPNProtocolIPSec alloc] init];
        p.serverAddress =@"178.62.78.101";
        p.authenticationMethod = NEVPNIKEAuthenticationMethodSharedSecret;
        p.useExtendedAuthentication = YES;

        NSString *secret = @"gfJL$$";
        NSData *secretData = [secret dataUsingEncoding:NSUTF8StringEncoding];


        p.sharedSecretReference=secretData;
        p.localIdentifier=@"londra1";
        p.username=@"root";
        p.passwordReference=[[SSKeychain passwordForService:@"2eee9fa59" account:@"2eee9fa5"] dataUsingEncoding:NSUTF8StringEncoding];
        p.disconnectOnSleep = NO;


        [NEVPNManager sharedManager].protocolConfiguration=p;

        NSMutableArray *rules = [[NSMutableArray alloc] init];
        NEOnDemandRuleConnect *connectRule = [NEOnDemandRuleConnect new];
        [rules addObject:connectRule];
        [[NEVPNManager sharedManager] setOnDemandRules:rules];
        [[NEVPNManager sharedManager] setLocalizedDescription:@"vpn"];

        [[NEVPNManager sharedManager] setEnabled:YES];



        [[NEVPNManager sharedManager] saveToPreferencesWithCompletionHandler: ^(NSError *error) {

            NSLog(@"Save VPN to preference complete");
            if (error) {
                NSLog(@"Save error: %@", error);
            }

        }];

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

    }];
    return YES;
}

Answer 1

You are setting sharedSecretReference as an NSData, but this conflicts with its definition.

NEVPNProtocolIPSec::sharedSecretReference is defined as:

A persistent keychain reference to a keychain item containing the IKE shared secret.

You need to create a keychain item of type kSecClassGenericPassword to use as the shared secret, and provide a persistent reference to the keychain item. A persistent reference is critical here, as it can be stored to disk or passed between processes, which is required for NEVPNManager to access the shared secret and connect your VPN. I suspect that although passwordReference seems to be set by a keychain item, it may not be returning a persistent reference either.

You will need to use SecItemCopyMatching with return type kSecReturnPersistentRef to achieve this.