Sharepoint Online C# CSOM MFA Issues

Question

I keep going round and round. Microsoft keeps changing how things work, so even examples from 2022 no longer work.

All I need help with is doing Multi-Factor Authentication to Sharepoint Online through C#. All the examples I find have you using older packages that no longer work with the latest Visual Studio environment. I use NuGet to get my packages, and if I try to use the older methods, they are not supported.

The previous way I see it was done is the following:

string siteUrl = "https://site-admin.sharepoint.com";
var authManager = new OfficeDevPnp.Core.AuthenticationManager();
ClientContext ctx = authManager.GetWebLoginClientContext(siteUrl);

I now need to use the following per Microsoft.

• Microsoft.SharePointOnline.CSOM
• PnP.Framework

With these new Packages, how am I supposed to create a ClientContext using a AuthenticationManager that supports Multi-Factor Authentication for a Username?

This works so easy with PowerShell using Microsoft.Online.Sharepoint.PowerShell.

Connect-SPOService -Url https://site-admin.sharepoint.com -Credential first.last@site.com

Answer 1

Hi Klein, John,

Per my test, the latest version of SharePointPnPCoreOnline doesn't contain authManager.GetWebLoginClientContext(siteUrl);. This function has been deleted.

I will recommend you to use app-only for authentication:

https://learn.microsoft.com/en-us/sharepoint/dev/solution-guidance/security-apponly-azureacs

Since you don't want to use app, the only way is to use old version pnpcore. You can follow the steps

1. Go to Manage NuGet Packet.
2. choose older version such as 3.25
3. Now the authManager.GetWebLoginClientContext(siteUrl) is available

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