How to restrict access to S3 assets (via CloudFront) based on asset meta data that is stored in a third party application?

One of my customers wants to restrict access to S3 bucket via Cloudfront. I assume Origin Access Identity (OAI) can be used here. But the access is conditional (i.e based on some asset meta data in third party application). What is the best way to achieve this ? Add some sort of custom header in CloudFront call after looking up that external asset and then use that header in Policy Statement ?