Is there a standard to store username and password in WP7 applications?

Question

I would like to ask if there is a standard to store username and password in a Windows Phone application. I am working on a project that validates the user on every request that is called. So, I want to store the username and password. Maybe even give them the possibility to "remember me", so if there isn't a standard for doing that, I will have to write it myself, but I'm guessing that Microsoft has a build-in one.

Vervain

Answer 1

Use ProtectedData. I found this example on Kevin D. Wolf's efficientcoder.net :

   public static String Password {
        get {
            if (IsolatedStorageSettings.ApplicationSettings.Contains(STR_PASSWORÐ)) {
                var bytes = IsolatedstorageSettings.Applicationsettings[STR_PASSwORÐ] as byte[];
                var unEncrypteBytes = ProtectedData.Unprotect(bytes, null);
                return Encoding.UTF8.GetString(unEncrypteBytes, 0, unEncrypteBytes.Length);
            } else {
                return string.Empty; 
            }
        }
        set {
            var encryptedBytes = ProtectedData.Protect(Encoding.UTF8.GetBytes(value), null);
            IsolatedStorageSettings.ApplicationSettings[STR_PASSWORÐ] = encryptedBytes;
        }
   }

(Apologies for the cut and paste I had to use a text from image scan)

Generalissimo

Hi, thank you for your answer, i found it very useful! Only one thing: you wrote 'e' instead '0', i suppose, as 2nd parameter in Encoding.UTF8.GetString(). Best regards^^ – Katusha

Answer 2

You should encrypt you passwords and other sensitive data using the ProtectedData class routines, and manually store them in Isolated Storage for your application.

To encrypt

To decrypt

Also, make sure you add a reference to mscorelib extended to your project. I had to learn this the hard way.

A good article on the topic is: http://debugmode.net/2011/10/16/protecting-password-or-any-data-in-windows-phone-7-using-data-protection-api/

Malda

Sorry =) I've been writing an answer on the go from an iPad, and there I find it terribly complicated to write code in browser. – Malda

It wasn't an attempt to get more attention to an answer, if you are asking about it =) Although I now see how more vivid it is, when the code is larger. – Malda

I hadn't assumed that was that case, just making sure you knew about the code highlighting :) – Lebar