'use strict';

let data = 'eyJQdWJsaWNLZXkiOiJGTFdQVUJLX1RFU1QtNTRjOTAxNDFiMDI4Nzg5ZDY3MTA2N2JkNzJmNzgxYTktWCIsIlNlY3JldEtleSI6IkZMV1NFQ0tfVEVTVC1jN2JiYzg2ZDdlNzEwMDI1NGM1ZTViYmYxNjJiZjJiMi1YIiwiRW5jcnlwdGlvbktleSI6IkZMV1NFQ0tfVEVTVGU5NDc0ZDRlMmNlNiJ9';
let buff = new Buffer(data, 'base64');
let text = buff.toString('ascii');
let json = JSON.parse(text);

console.log('"' + data + '" converted from Base64 to ASCII is "' + text + '"');
console.log(json);