Question

I’m building this iPhone application to connect to a secured TFS server (one that requires authentication before letting you access its web services). When I access this server in a browser, the first thing it will do is ask me for credentials (username/password) and then connect me to the TFS server if those credentials are correct.

I am using web services, as I don’t think there is any other way to use TFS functionality for an outside platform…without changing stuff on the TFS host machine. So my questions are:

• Are there any web services that can
  be accessed to log into the TFS
  server?
• This authentication mechanism seems
  to be something common among multiple
  websites (I have seen it in other
  websites). Is there a way to
  replicate that authentication
  mechanism by sending an HTTP request?
• Is there a way to replicate this
  authentication procedure in any way?

Answer 1

Use NSURLConnection to connect to the web server. Implement the following delegate method:

- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge;

After asking the user for credentials, or reading them from saved settings or whatever, call the challenge sender with the credentials:

- (void)useCredential:(NSURLCredential *)credential forAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge;

When you create an NSURLCredential you can set the persistence. If you create a persistent credential, then it should be checked automatically in future attempts to connect to the same server. That is the proposedCredential of an authentication challenge.