Can't create Apple Pay Merchant Identity Certificate

[lachlanh]

I am trying to get apple pay working with 2024-04 api and tokenized payment, while we wait for pre-checkout features to arrive. Following this doc : https://shopify.dev/docs/storefronts/headless/mobile-apps/buy-sdk-ios#enable-apple-pay, When I try to upload the shopify csr in the apple developer portal I get an error CSR algorithm/size incorrect. Expected: RSA(2048) This is trying to create a merchant identity certificate as described in the doc linked above.

Is the csr faulty or is the documentation out of date ?

I have also tried using a csr from the Keychain tool locally, which apple accepted and provided me with a merchant Id certificate but was rejected with an error from shopify when trying to upload the certificate.

I have also created an Apple Pay Payment Processing certificate using the shopify csr, which was accepted by Apple and the resulting cert I was able to upload to the shopify ios buy sdk config. Unfortunately I keep getting generic payment processing errors : "There was an issue processing your payment. Try again or use a different payment method." (using the mobile buy sdk sample app and our own code).

I have seen some similar github issues and comments in the community forums but haven't been able to find a solution, any help with the certificate setup or how to debug the failed payments would be really appreciated.