AWS Lamdba (node.js) and Apple Passbook suggestions

I’m trying to write a Serverless Apple Passbook service using node.js.

High-level

iOS --> AWS CloudFront --> API Gateway --> Lambda (node.js) --> passGenService

The passGenService would use something like https://github.com/destinationstransfers/passkit.

The problem I think I’m going to run into is the above signs the pass using certs that are buried in a directory that I won;t have access to.

Has anyone done anything like this? Any ideas for me before I get to work on this?

Thanks

J