I am working on a project where we will be creating an MVC web app and a SharePoint 2010 environment. Users will be authenticating against Active Directory inside the MVC web app. There will be links inside this web app that redirect to SharePoint. MVC and SharePoint will be using the same AD. When a user is redirected to SharePoint - should I expect not to be prompted to log into SharePoint, since I logged into the MVC app? If not, how can I resolve this?
Since you are in an Active Directory environment, you can get a silent log in with Internet Explorer.
Both Claims-mode and Classic-mode authentication modes support NTLM authentication. For sites in the Trusted and Intranet zones, IE will automatically present the NT auth token to IIS so that the session will run under the end-users identity.
(This functionality is part of IE/IIS, so the same behavour would happen in the MVC application if it is configured to use "Windows Authentication.")