I have a Web API protected by using Bearer tokens form Azure AD (https://azure.microsoft.com/en-us/documentation/articles/active-directory-devquickstarts-webapi-dotnet/). Now, I would like to call this Web API from a provider hosted SharePoint AddIn with the signed on SharePoint Online user. Is there any option to use the SPO user token (posted as SPAppToken by appredirect.aspx) to access the Web API or to acquire a new token from AAD with the SP user token?
Thanks!