How to perform simple authentication from MVC to Office 365 AD

Question

I want to write a simple ASP.NET MVC based application that accepts the user's username and password via a form field, then authenticates to Office 365 and perform a simple Calendar lookup for that user. I do not need any fancy logic other than the above. I do not want to have the user redirected to any sites - I already have the user's Office 365 username/password.

My code so far - but it fails with an Object Reference not set on the first authContext.AquireTokenAsync call:

internal static async Task<OutlookServicesClient> EnsureOutlookServicesClientCreatedAsync(string capabilityName,
    string username, string password)
{

    var signInUserId = username;

    AuthenticationContext authContext = new AuthenticationContext(SettingsHelper.Authority,
        new NaiveSessionCache(signInUserId));

    try
    {
        DiscoveryClient discClient = new DiscoveryClient(SettingsHelper.DiscoveryServiceEndpointUri,
            async () =>
            {
                var authResult =
                    await
                        authContext.AcquireTokenAsync(SettingsHelper.DiscoveryServiceResourceId,
                            SettingsHelper.ClientId, new UserCredential(signInUserId, password));

                return authResult.AccessToken;
            });

        var dcr = await discClient.DiscoverCapabilityAsync(capabilityName);

        return new OutlookServicesClient(dcr.ServiceEndpointUri,
            async () =>
            {
                var authResult = await authContext.AcquireTokenAsync(dcr.ServiceResourceId,
                    SettingsHelper.ClientId, new UserCredential(signInUserId, password));

                return authResult.AccessToken;
            });
    }
    catch (AdalException exception)
    {
        //Handle token acquisition failure
        if (exception.ErrorCode == AdalError.FailedToAcquireTokenSilently)
        {
            authContext.TokenCache.Clear();
            throw exception;
        }
        return null;
    }
}

Can anyone advise how I should perform this authentication logic without having to redirect the user to some portal?

Jason Johnston Jason Johnston · Accepted Answer · 2014-12-17T16:27:46

You can't. The OutlookServicesClient requires the OAuth flow, which has the user sign in via redirects to the OAuth endpoint (login.windows.net). You should not have to ask the user for their username or password as that's all handled for you by the OAuth endpoint.

How to perform simple authentication from MVC to Office 365 AD

1 Answers