Verify License

index.js

const crypto = require('crypto');
const https = require('https');
const { parseString } = require('./xml2js/xml2js');

exports.handler = (event, context, callback) => {
    let { token } = event;
    let buf = Buffer.from(token, 'base64');
    let xml = buf.toString().replace(/\u0000/g, '');

    https.get('https://verificationservice.officeapps.live.com/ova/verificationagent.svc/rest/verify?token=' + encodeURIComponent(xml), (resp) => {
      let data = '';

      resp.on('data', (chunk) => {
        data += chunk;
      });

      resp.on('end', () => {
        parseString(xml, function (err, result) {
          if (err) {
            return callback(err, null);
          }
          let payload = result.r.t[0].$
          let purchaserId = payload.oid;
          parseString(data, function (err, result) {
            if (err) {
              return callback(err, null);
            }
            let res = result.VerifyEntitlementTokenResponse;
            let ret = { purchaserId };
            Object.keys(res).forEach((k) => {
              let value = res[k][0];
              if(!value) {
                return;
              } else if (value.$ && value.$['i:nil']) {
                value = null;
              } else if (/^(true|false)$/.test(value)) {
                value = value === 'true';
              } else if(/^(\d+)$/.test(value)) {
                value = parseInt(value, 10);
              }
              ret[k.replace(/^(.)/, (s) => s.toLowerCase())] = value;
            });
            ret.userHash = crypto.createHmac('sha256', process.env.INTERCOM_ID_HASH_SECRET)
                                 .update(ret.userId)
                                 .digest('hex');
            callback(null, ret);
          });
        });
      });

    }).on("error", (err) => {
      callback(err, null);
    });

}