Let me start by explaining my scenario. I have a list of items (about 40 000) that I added to a SharePoint Online list by means of a Provider-Hosted App. The data comes from an external atom feed that has it's own way of determining which user is allowed to see what. Now, before I go and try and decipher the ACL's built into the XML, I thought of digging though the SharePoint side first.
So, being fairly new, I'm having a little trouble realizing a solution or even a starting point. The list itself cannot be seen by anyone, so that's already set correctly, but the problem is when people search for things. They see results that they are not allowed to see.
So really the question is. Can I assign different permissions for different items in the same list? Or can I configure that in the results page? And can I then add this code to my Provider-Hosted App
It might just be the way I'm asking the question, but I cannot seem to really find useful info on the topic.
EDIT: I want to be able to do all this in the app in C# code using the CSOM. I would prefer not using the UI