LinkedIn login with Stormpath - swift

Question

I am able to get the access token of my LinkedIn account in swift using the LinkedIn SDK. How do I authenticate this login with Stormpath?
[Update]
let APIURL = "https://api.stormpath.com/v1/applications/LI_APPLICATION_ID/accounts"
func sendRequestWithJSON(accessToken:String)
{
let json = [ "providerData" : ["providerId": "linkedin", "accessToken": accessToken] ]
do {
let jsonData = try NSJSONSerialization.dataWithJSONObject(json, options: .PrettyPrinted)
let username = STORMPATH_API_KEY_ID
let password = STORMPATH_API_KEY_SECRET
let loginString = NSString(format: "%#:%#", username, password)
let loginData: NSData = loginString.dataUsingEncoding(NSUTF8StringEncoding)!
let base64LoginString = loginData.base64EncodedDataWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)
// create post request
let url = NSURL(string: APIURL)!
let request = NSMutableURLRequest(URL: url)
request.HTTPMethod = "POST"
// insert json data to the request
request.setValue("Basic \(base64LoginString)", forHTTPHeaderField: "Authorization")
request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
request.HTTPBody = jsonData
let task = NSURLSession.sharedSession().dataTaskWithRequest(request){ data, response, error in
if error != nil{
print("Error -> \(error)")
return
}
do {
let result = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [String:AnyObject]
print("Result -> \(result)")
} catch {
print("Error -> \(error)")
}
}
task.resume()
//return task
} catch {
print(error)
}
}
I am passing accessToken fetch from linkedin to above function, but it return below result:
["message": Authentication required., "status": 401, "code": 401, "developerMessage": Authentication with a valid API Key is required., "moreInfo": http://www.stormpath.com/docs/quickstart/connect]
What's wrong I am doing?

Answer 1

LinkedIn is an interesting beast, since their mobile SDKs have two flaws:
An end user NEEDS the LinkedIn app to be installed, otherwise the "login" button will redirect the user to the App Store.
The mobile access token cannot be used on the server. See this screenshot from LinkedIn's iOS documentation
So - to get auth working on mobile, I would recommend using a server to handle the flow, so you don't have to worry about those two downsides. This is roughly:
The app will redirect the user to your webserver.
The webserver begins the LinkedIn authentication flow, and redirects the user to LinkedIn.
The user logs into LinkedIn, and gets redirected back to your webserver.
The webserver reads the response, and exchanges the Authorization Code with LinkedIn for an access token.
The webserver redirects your user back to the app, using a custom url scheme to send it the LinkedIn access token.
The app uses the LinkedIn access token to login to Stormpath.
Sound complicated? It's actually more straightforward than it seems. I actually wrote some demo code for this flow using Express.js & Swift if you want to try it out. Let me know if it works for you!