We have a few applications that currently use managed code CSOM against SP2010 - think of SharePoint as simply a large file store. The UI is not used at all and all the functionality for the remote app is in the remote app - SP is only a file store. All of this was developed with CSOM and authentication was handled via Kerberos delegation (browser->Remove App IIS->SP2010) under the end users credentials. In reality, the app reads files from about 50 sites - and that changes constantly as the data grows so we don't have too many items in a list or too large of a database.
We want to do the exact same thing but move the file store to SP2013 (on-prem) but SP2013 is only setup to use claims - not kerberos. Is there a way to get the CSOM code authenticated properly - everything we try throws 401's right now? Does this require a provider hosted app setup?
Anything to get me pointed in the right direction will be helpful!