gistfile1.m

    NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://staging.fuerteint.com/projects/polligraf/login.php"]];
    [request setHTTPMethod:@"POST"];
    [request setHTTPBody:[NSJSONSerialization dataWithJSONObject:@{ @"username" : @"some_username_here", @"pass" : @"some_password_here" } options:0 error:nil]];
    
    NSURLResponse* response;
    NSError* error;
    
    [NSURLConnection sendSynchronousRequest:request
                           returningResponse:&response
                                       error:&error];
    
    NSLog(@"%@", response);
    
    if (error) {
        NSLog(@"%@", error.localizedDescription);
    }