Windows Store App Sign-in for OneDrive SDK

MsaForStoreApps.cs

using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
using Windows.Security.Authentication.OnlineId;

namespace OneDrive
{
    public class MsaForStoreApps
    {
        private const string OnlineIdTicketPolicyForLiveServices = "DELEGATION";
        private const int UserNotFoundLoginExceptionHResult = -2147023579;
        private const int ConsentNotGrantedExceptionHResult = -2138701812;
        private const int InvalidClientExceptionHResult = -2138701821;
        private const int InvalidAuthTargetExceptionHResult = -2138701823;


        private OnlineIdAuthenticator Authenticator { get; set; }

        public MsaForStoreApps()
        {
            Authenticator = new OnlineIdAuthenticator();
        }

        public async Task<AuthToken> SignInAsync(string[] requestedScopes, bool silent = false)
        {
            try
            {
                string accessToken = await GetAccessTokenAsync(requestedScopes, silent);
                AuthToken results = new AuthToken(AuthStatus.Successful, this, accessToken, requestedScopes);
                return results;
            }
            catch (TaskCanceledException)
            {
                return null;
            }
            catch (Exception comExp)
            {
                switch (comExp.HResult)
                {
                    case UserNotFoundLoginExceptionHResult:
                        return new AuthToken(AuthStatus.Unknown, this);
                    case ConsentNotGrantedExceptionHResult:
                        return new AuthToken(AuthStatus.Failure, this);
                    case InvalidClientExceptionHResult:
                    case InvalidAuthTargetExceptionHResult:
                        // This usually means you haven't assoicated your app with the store app yet.
                        return new AuthToken(AuthStatus.InvalidRequest, this);
                    default:
                        return new AuthToken(AuthStatus.ServerError, this);
                }
            }
        }


        private async Task<string> GetAccessTokenAsync(string[] requestedScopes, bool silent)
        {
            string accessToken = null;
            string scopes = BuildScopeString(requestedScopes);

            CredentialPromptType promptType = silent ? CredentialPromptType.DoNotPrompt : CredentialPromptType.PromptIfNeeded;
            var ticketRequests = new List<OnlineIdServiceTicketRequest>();
            ticketRequests.Add(new OnlineIdServiceTicketRequest(scopes, OnlineIdTicketPolicyForLiveServices));

            UserIdentity identity = await Authenticator.AuthenticateUserAsync(ticketRequests, promptType);
            if (identity.Tickets != null && identity.Tickets.Count > 0)
            {
                accessToken = identity.Tickets[0].Value;
            }
            return accessToken;
        }

        public bool CanSignOut
        {
            get { return Authenticator.CanSignOut; }
        }

        private static string BuildScopeString(string[] requestedScopes)
        {
            StringBuilder sb = new StringBuilder();
            foreach (string scope in requestedScopes)
            {
                if (sb.Length > 0)
                    sb.Append(' ');
                sb.Append(scope);
            }
            return sb.ToString();
        }

    }


    public class AuthToken : OneDrive.IAuthenticationInfo
    {

        public AuthToken(AuthStatus result, MsaForStoreApps client, string accessToken = null, string[] scopes = null)
        {
            AuthClient = client;
            AccessToken = accessToken;
            Scopes = scopes;
            Status = result;
        }

        public MsaForStoreApps AuthClient { get; private set; }

        public string AccessToken { get; private set; }

        public string[] Scopes { get; private set; }

        public AuthStatus Status { get; private set; }

        public string RefreshToken
        {
            get { throw new NotImplementedException(); }
        }

        public string TokenType
        {
            get { return "Bearer"; }
        }

        public DateTimeOffset TokenExpiration
        {
            get { return DateTimeOffset.MaxValue; }
        }

        public Task<bool> RefreshAccessTokenAsync()
        {
            throw new NotImplementedException();
        }

        public string AuthorizationHeaderValue
        {
            get { return "Bearer " + AccessToken; }
        }
    }

    public enum AuthStatus
    {
        Unknown,
        Successful,
        Failure,
        InvalidRequest,
        ServerError
    }


}

UsageExample.cs

private async void SignInButton_Click(object sender, RoutedEventArgs e)
{
    OneDrive.MsaForStoreApps authClient = new OneDrive.MsaForStoreApps();
    ODConnection oneDriveConnection = null;
    var token = await authClient.SignInAsync(new string[] { "wl.signin", "onedrive.readwrite" });

    if (token.Status == OneDrive.AuthStatus.Successful)
    {
        oneDriveConnection = new OneDrive.ODConnection("https://api.onedrive.com/v1.0", token);
        var rootItem = await oneDriveConnection.GetRootItemAsync(OneDrive.ItemRetrievalOptions.Default);
    }
    else
    {
        textBlockStatus.Text = string.Format("Error signing into OneDrive: " + token.Status.ToString());
    }
}