Uploading file to SharePoint Online site folder using Microsoft Graph API and MSAL Authentication

Question

I have a WPF/C# application and I am trying to upload files to a SharePoint site's subfolder.

I have followed this example to first register my application in Azure Active Directory. This step is needed since I want to use Microsoft's identity service in my application and avoid having the user enter username and password each time. Instead, Microsoft will return an access token that I can then use to query the Graph API and then SharePoint Online.

I registered the application with the following settings:

1. Supported Account Types: Accounts in any organization directory (Any Azure AD directory - Multitenant) and personal Microsoft accounts (e.g. Skype, Xbox)
2. Authentication: Mobile and Desktop Applications
3. Redirect URIs: https://login.microsoftonline.com/common/oauth2/nativeclient

In addition, I set the API Permissions like so: screenshot

In my code, I added the MSAL package and Microsoft Graph package. Below is the code for acquiring an access token (I followed from the same Microsoft Doc post I linked above).

Here is how I am getting my authorization token:

var authResult = await PublicClientApp.AcquireTokenInteractive(scopes)
                    .WithAccount(accounts.FirstOrDefault())
                    .WithPrompt(Microsoft.Identity.Client.Prompt.SelectAccount)
                    .ExecuteAsync();

Where scopes is:

string[] scopes = new string[] { "user.read" };

Then, after acquiring the authentication, I attempt to use get the SharePoint site's Id and drive Id's as demonstrated in this example.

        string site = "mytenant.sharepoint.com";
        string relativePath = "/sites/mytargetsite";

        if (authResult != null)
        {
            var authProvider = new DelegateAuthenticationProvider(async (request) =>
            {
                request.Headers.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", authResult.AccessToken);
            });

            GraphServiceClient graphClient = new GraphServiceClient(authProvider);

            var s = await graphClient
                .Sites[this.site]
                .SiteWithPath(this.relativePath)
                .Request()
                .GetAsync();

            var d = await graphClient
                .Sites[s.Id]
                .Drive
                .Request()
                .GetAsync();

        }

There is more to the code to upload a file, but at this point is where my code fails. The error I get is:

"Microsoft.Graph.ServiceException: 'Code: invalidRequest Message: Invalid hostname for this tenancy..."

This is where I am stuck. I am reaching out to see if there is anyone with clues as to what I am doing wrong. Thank you!

Answer 1

If you already have the token then you add it to the header. Then you make the call with the client like this, this works for send xml files:

        string path = $"{appSettings.UrlGraph}sites/{appSettings.SiteId}/drive/items/";
        string requestUrl = $"{path}root:/{file.xml}:/content";
        StreamContent requestContent = new StreamContent(new MemoryStream(Encoding.UTF8.GetBytes(content)));
        requestContent.Headers.ContentType = new MediaTypeHeaderValue("application/xml");
        HttpResponseMessage response = await _httpClient.PutAsync(requestUrl, requestContent);