How to convert cURL form login code to Swift - forms

Question

I am trying to login (form) into a website and parse data with Swift and NSURLSession.
I have been using cURL to confirm that this is actually possible, and the following code returns the webpage-body as expected.
curl -c cookie.txt -d "username=karl" -d "password=ivar" https://talkmore.no/talkmore3/servlet/Login
curl -b cookie.txt https://talkmore.no/talkmore3/servlet/SubscriptionUsage
When I am trying to do this in Swift, I fetch the Cookie from the response header, then I try to retrieve the SubscriptionUsage-webpage by passing the cookie along. However I cannot get this to work.
How can I convert this simple curl syntax to Swift-code using NSURLSession?
Edit: What I've got so far.
func login() -> Void {
var session = NSURLSession.sharedSession()
var request = NSMutableURLRequest(URL: NSURL(string: "https://www.talkmore.no/talkmore3/servlet/Login")!)
request.HTTPMethod = "POST"
var params = "username=karl&password=ivar"
request.HTTPBody = params.dataUsingEncoding(NSUTF8StringEncoding)
request.addValue("text/html", forHTTPHeaderField: "Content-Type")
var task = session.dataTaskWithRequest(request, completionHandler: {(data, response, error) -> Void in
println("Response: \(response)")
println("Data: \(NSString(data: data, encoding: NSUTF8StringEncoding)))")
let httpResponse = response as NSHTTPURLResponse
var cookie = httpResponse.allHeaderFields["Set-Cookie"] as String
})
task.resume()
All seems good, I receive the response with a header including "Set-Cookie" = "JSESSIONID=D8307BA498EFE061C86636C51B8AC25D; Path=/talkmore3/; Secure; HttpOnly"; And I believe I have to send this cookie with the next request. But I have failed to replicate the cURL behavior.