There are third party libraries that provide support for decrypting Apple Pay token on the server side. Is there any such .NET library?
Third-paty Libraries
Ruby library for decrypting Apple Pay payment tokens
PHP library for decrypting Apple Pay payment tokens
What we're trying to accomplish
We're using Compass XML platform for payment processing, and the goad is to decrypt the payment token on our server and then use the Compass XML for final payment processing.
I just pushed my works into github, it uses Bouncy Castle C# library to decrypt token on the server side, and works both for Android Pay and Apple Pay, please check it out.
https://github.com/chengbo/ApplePayAndroidPayDecryption
NOTE: The token verification for Apple Pay not implement yet.
I don't know of any .net libraries specifically, but there's a number of implementations available on GitHub that you could take a look at - here's another PHP one, for example: https://github.com/etsy/applepay-php
Payment decryption is fairly straightforward if you're familiar with crypto, and is achievable using something like OpenSSL. There's some documentation on the exact process here:
https://developer.apple.com/library/ios/documentation/PassKit/Reference/PaymentTokenJSON/PaymentTokenJSON.html