'use strict';
var base64 = require('urlsafe-base64');
function log(n, x) {
  console.log(n, x.length, Buffer.isBuffer(x) ? base64.encode(x) : x);
}

/*var e = base64.decode('uNCkWiNYzKTnBN9ji3-qWAAAAAoCYTGH' +
                       'OqYFz-0in3dpb-VE2GfBngkaPy6bZus_' +
                       'qLF79s6zQyTSsA0iLOKyd3JqVIwprNzV' +
                       'atRCWZGUx_qsFbJBCQu62RqQuR2d'); */
var h1 = base64.decode('DGv6ra1nlYgDCS1FRnbzlwAAxowA');
log('h1', h1);
var dh = base64.decode('BP4z9KsN6nGRTbVYI_c7VJSPQTBtkgcy27mlmlMoZIIgDll6e3vCYLocInmYWAmS6TlzAC8wEqKK6PBru3jl7A8');
log('dh', dh);
h1.writeUIntBE(dh.length, 20, 1);
var c = base64.decode('Ig1VvoJvrVBFhclGlx4G2FuProCVzJY04Lg5vUP2LeswtWoBGHGoYXUzAwuxQGRGxoNbh8BROK3gmJ0');
log('c', c);
log('h2', Buffer.concat([h1, dh]));
log('m', Buffer.concat([h1, dh, c]));

var e = base64.decode('uNCkWiNYzKTnBN9ji3-qWAAAAAoAhzqmBc_tIp93aW_lRNhnwZ4JGj8um2brP6ixe_bOs0Mk0rANIizisndyalSMKazc1WrUQlmRlMf6rBWyQQkLutkakLkdnQ');

log('y', e);
log('x', Buffer.concat([base64.decode('uNCkWiNYzKTnBN9ji3-qW'), Buffer.from([0, 0, 0, 10, 2, 'a'.charCodeAt(0), '1'.charCodeAt(0)]), base64.decode('hzqmBc_tIp93aW_lRNhnwZ4JGj8um2brP6g'), base64.decode('sXv2zrNDJNKwDSIs4rJ3cmpUjCms3NVq1EI'), base64.decode('WZGUx_qsFbJBCQu62RqQuR2d') ]));

var salt = e.slice(0, 16);
log('salt', salt);
var rs = e.readUIntBE(16, 4);
log('rs', rs);
var idsz = e.readUIntBE(20, 1);
var id = e.slice(21, 21 + idsz);
log('id', id);
console.log('id', id.toString());
log('header', e.slice(0, 21 + idsz));
log('main', e.slice(21 + idsz, e.length - 16));
log('tag', e.slice(e.length - 16));