Ruby library for decrypting Apple Pay payment tokens
Ruby
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README.md

Gala

Named after the Gala apple, Gala is a Ruby library for decrypting Apple Pay payment tokens.

Gala is available under the MIT License.

Install

Add to your Gemfile:

gem "gala", git: "https://github.com/spreedly/gala.git"

Usage

Gala works by:

  1. Initializing an instance of Gala::PaymentToken with the hash of values present in the Apple Pay token string (a JSON representation of this data).
  2. Decrypting the token using the PEM formatted merchant certificate and private key (the latter of which, at least, is managed by a third-party such as a gateway or independent processor like Spreedly).
require "gala"

# token_json = raw token string you get from your iOS app
token_attrs = JSON.parse(token_json)
token = Gala::PaymentToken.new(token_attrs)

certificate_pem = File.read("mycert.pem")
private_key_pem = File.read("private_key.pem")

decrypted_json = token.decrypt(certificate_pem, private_key_pem)
JSON.parse(decrypted_json)
# =>
{
  "applicationPrimaryAccountNumber"=>"4109370251004320",
  "applicationExpirationDate"=>"200731",
  "currencyCode"=>"840",
  "transactionAmount"=>100,
  "deviceManufacturerIdentifier"=>"040010030273",
  "paymentDataType"=>"3DSecure",
  "paymentData"=> {
    "onlinePaymentCryptogram"=>"Af9x/QwAA/DjmU65oyc1MAABAAA=",
    "eciIndicator"=>"5"
  }
}

Testing

$ ruby test/payment_token_test.rb
...
5 tests, 18 assertions, 0 failures, 0 errors, 0 skips

Contributors

  • jnormore for his help with figuring out how to decrypt this thing.
  • mrezentes implemented the signature verification.