Single Sign On between an ASP.NET application and SharePoint Online Site

Question

I'm using a ASP.NET site with links to an SharePoint online site. We are using AAD authentication (OAuth 2.0) for ASP.NET site and SharePoint online site (Not sure is it using OAuth2.0 or OAuth1.0). When we starts ASP.NET application, we are presented with a logon dialog. Once we login with work accounts (i.e. Microsoft accounts) and click on the link to the SharePoint online site, without asking the login screen, able to redirect to SharePoint online site.

But when we login with MSA accounts to asp.net and click the link to the SharePoint online site, it is asking the login screen.

Can you please help us, how to redirect to SharePoint online site without asking the login screen again.

Answer 1

Your ASP.Net app will need to auth to Azure AD, this should get you started in the right direction.

https://docs.microsoft.com/en-us/aspnet/aspnet/overview/developing-apps-with-windows-azure/building-real-world-cloud-apps-with-windows-azure/single-sign-on#create-an-aspnet-app-that-uses-azure-ad-for-single-sign-on