kami-parse-server/src/Routers/IAPValidationRouter.js

import PromiseRouter from '../PromiseRouter';
const request = require('../request');
const rest = require('../rest');
import Parse from 'parse/node';

// TODO move validation logic in IAPValidationController
const IAP_SANDBOX_URL = 'https://sandbox.itunes.apple.com/verifyReceipt';
const IAP_PRODUCTION_URL = 'https://buy.itunes.apple.com/verifyReceipt';

const APP_STORE_ERRORS = {
  21000: 'The App Store could not read the JSON object you provided.',
  21002: 'The data in the receipt-data property was malformed or missing.',
  21003: 'The receipt could not be authenticated.',
  21004: 'The shared secret you provided does not match the shared secret on file for your account.',
  21005: 'The receipt server is not currently available.',
  21006: 'This receipt is valid but the subscription has expired.',
  21007: 'This receipt is from the test environment, but it was sent to the production environment for verification. Send it to the test environment instead.',
  21008: 'This receipt is from the production environment, but it was sent to the test environment for verification. Send it to the production environment instead.',
};

function appStoreError(status) {
  status = parseInt(status);
  var errorString = APP_STORE_ERRORS[status] || 'unknown error.';
  return { status: status, error: errorString };
}

function validateWithAppStore(url, receipt) {
  return request({
    url: url,
    method: 'POST',
    body: { 'receipt-data': receipt },
    headers: {
      'Content-Type': 'application/json',
    },
  }).then(httpResponse => {
    const body = httpResponse.data;
    if (body && body.status === 0) {
      // No need to pass anything, status is OK
      return;
    }
    // receipt is from test and should go to test
    throw body;
  });
}

function getFileForProductIdentifier(productIdentifier, req) {
  return rest
    .find(
      req.config,
      req.auth,
      '_Product',
      { productIdentifier: productIdentifier },
      undefined,
      req.info.clientSDK,
      req.info.context
    )
    .then(function (result) {
      const products = result.results;
      if (!products || products.length != 1) {
        // Error not found or too many
        throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, 'Object not found.');
      }

      var download = products[0].download;
      return Promise.resolve({ response: download });
    });
}

export class IAPValidationRouter extends PromiseRouter {
  handleRequest(req) {
    let receipt = req.body.receipt;
    const productIdentifier = req.body.productIdentifier;

    if (!receipt || !productIdentifier) {
      // TODO: Error, malformed request
      throw new Parse.Error(Parse.Error.INVALID_JSON, 'missing receipt or productIdentifier');
    }

    // Transform the object if there
    // otherwise assume it's in Base64 already
    if (typeof receipt == 'object') {
      if (receipt['__type'] == 'Bytes') {
        receipt = receipt.base64;
      }
    }

    if (process.env.TESTING == '1' && req.body.bypassAppStoreValidation) {
      return getFileForProductIdentifier(productIdentifier, req);
    }

    function successCallback() {
      return getFileForProductIdentifier(productIdentifier, req);
    }

    function errorCallback(error) {
      return Promise.resolve({ response: appStoreError(error.status) });
    }

    return validateWithAppStore(IAP_PRODUCTION_URL, receipt).then(
      () => {
        return successCallback();
      },
      error => {
        if (error.status == 21007) {
          return validateWithAppStore(IAP_SANDBOX_URL, receipt).then(
            () => {
              return successCallback();
            },
            error => {
              return errorCallback(error);
            }
          );
        }

        return errorCallback(error);
      }
    );
  }

  mountRoutes() {
    this.route('POST', '/validate_purchase', this.handleRequest);
  }
}