Node.js Summon portal

gistfile1.js

var crypto = require('crypto');
var http = require('http');
var querystring = require('querystring');
var url = require('url');
var util = require('util');

var accessID = 'xxxxx';
var key = 'xxxxxxxxxx';
var host = 'api.summon.serialssolutions.com';
var summon = http.createClient(80, host);
summon.on('error', function(e) {
  throw new Error('Client error: '+e);
});

http.createServer(function(request, response) {
  util.log(request.method+' http://'+request.headers.host+request.url);
  var urlParts = url.parse(request.url);
  var accept = 'application/xml';
  var date = (new Date()).toGMTString();
  var path = '/search';
  var query;
  var unQuery;
  if (urlParts.query) {
    var queryParts = urlParts.query.split('&');
    var params = [];
    for (var i=0; i<queryParts.length; i++) { 
      var param = queryParts[i];
      if (param && (param.indexOf('=') != -1)) {
        param = param.replace('+', '%20');
        params.push(param);
      }
    }
    params.sort();
    query = params.join('&');
    unQuery = querystring.unescape(query);
  } else {
    query = unQuery = '';
  }
  var idString = accept+'\n'+date+'\n'+host+'\n'+path+'\n'+unQuery+'\n';
  var hmac = crypto.createHmac('sha1', key);
  var hash = hmac.update(idString);
  var digest = hash.digest('base64');
  var summonRequest = summon.request('GET', path+'?'+query, {
    host: host,
    accept: accept,
    'x-summon-date': date,
    'x-summon-session-id': 'summon api test',
    authorization: 'Summon '+accessID+';'+digest
  });
  summonRequest.end();
  summonRequest.on('response', function(summonResponse) {
    if (summonResponse.statusCode != 200) {
      response.writeHead(summonResponse.statusCode, 
          {'Content-Type': 'text/html'});
    } else {
      response.writeHead(200, {'Content-Type': 'application/xml'});
    }
    summonResponse.setEncoding('utf8');
    summonResponse.on('data', function(chunk) {
      response.write(chunk);
    });
    summonResponse.on('end', function() {
      response.end();
    });
  });
}).listen(8124);

util.log('Listening at http://127.0.0.1:8124/');