Simple Node server to encrypt Chrome 50 Payloads

encrypt-chrome-notification-payload.js

var http = require('http');
var encrypt = require('./encrypt');

function processPost(request, response, callback) {
    var queryData = "";
    if(typeof callback !== 'function') return null;

    if(request.method == 'POST') {
        request.on('data', function(data) {
            queryData += data;
            if(queryData.length > 1e6) {
                queryData = "";
                response.writeHead(413, {'Content-Type': 'text/plain'}).end();
                request.connection.destroy();
            }
        });

        request.on('end', function() {
            request.post = JSON.parse(queryData);
            callback();
        });

    } else {
        response.writeHead(405, {'Content-Type': 'text/plain'});
        response.end();
    }
}

function ub64(buffer) {
    return buffer.toString('base64').replace(/\+/g, '-').replace(/\//g, '_').replace(/\=/g, '');
}

var payload;

http.createServer(function(request, response) {
    if(request.method == 'POST') {
        processPost(request, response, function() {
            payload = encrypt(request.post.data, {
                endpoint: 'https://gcm-http.googleapis.com/gcm/' + request.post.regid,
                keys: {
                    p256dh: request.post.p256dh,
                    auth: request.post.auth
                }
            });
            response.writeHead(200, "OK", {'Content-Type': 'text/plain'});
            response.end(JSON.stringify({
                body: ub64(payload.ciphertext),
                salt: ub64(payload.salt),
                dh: ub64(payload.serverPublicKey)
            }));
        });
    } else {
        response.writeHead(200, "OK", {'Content-Type': 'text/plain'});
        response.end();
    }

}).listen(8888);