How to decode signedTransactionInfo after GET request?

Hello!

Please let me know after I make a request for purchase information

GET https://api.storekit-sandbox.itunes.apple.com/inApps/v1/transactions/2000000411047647

I receive encrypted information in this format

  {
"signedTransactionInfo":"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***5UmhIRkQvM21lb3locG12T3dnUFVuUFdUeG5TNGF0K3FJeFVDTUcxbWloREsxQ"
}

Please tell me how I can decode the information signedTransactionInfo ? and what is needed for this? (I'm trying to decode on Node.js)

Replies

This is encoded in the JWS format, as described in https://developer.apple.com/documentation/appstoreserverapi/jwstransaction

We recommend using the App Store Server Library to verify and decode signed data like signed transactions. https://github.com/apple/app-store-server-library-node

Hi

How to decode signedTransactionInfo in laravel ?

As far as I understand you can just split the string into three parts and then base64 decode each part. The second part should give you all the necessary information about the transaction ( structure should be similar to JWSTransactionDecodedPayload: https://developer.apple.com/documentation/appstoreserverapi/jwstransactiondecodedpayload )

$array = explode(".", $json_decoded["signedTransactionInfo"]);
return json_decode(base64_decode( $array[1] ), true);

Update: While splitting the string into three parts and encoding the second part might be enough for processing calls like transactions or history, it is not recommended doing so, especially not when decoding App Store Server Notifications, since it is not safe. Try using a library like this instead:

https://github.com/readdle/app-store-server-api