Writing to a Windows Azure Storage Queue from Mobile Services

gistfile1.js

var request = require('request');
var crypto = require('crypto');
var url = require('url');

function insert(item, user, request) {
    put_message(account, 'queuename', item.text);
    request.execute(); 
}

var account = {
	name : "ACOUNT_NAME",
	key : "ACCOUNT_KEY",
	queue_storage_url : "https://ACOUNT_NAME.queue.core.windows.net"
}

var nl = '\n';

var canonicalized_headers = function(req) { 
	var h = to_array(req.headers).sort();
	var buffer = '';

	for (var k in h) {
		if (h[k][0].startsWith('x-ms-'))
			buffer += h[k][0] + ":" + h[k][1] + nl;
	}

	return buffer
}

String.prototype.startsWith = function(str) {
	return (this.indexOf(str) === 0);
}

var to_array = function(x) {
	var a = [];
	for (var k in x)
	      a.push([k, x[k]]);

	return a;
}

var canonicalized_resource_format_1 = function(name, req)  {
	var x = url.parse(req.url,true);
	var s = "/" + name + x.pathname;

	// http://msdn.microsoft.com/en-us/library/windowsazure/dd179428.aspx
	for (var k in x.query)  {
		// don't add dollar parameters (i.e. the table queries)
		if (k.charAt(0) != "$") {
			s += nl + k + ":" + x.query[k];
		}
	}
	return s;
}

var optional = function(x) {
	return (x ? x : "") + nl;
}

var string_to_sign_1 = function(name, req) {
	return "" +
	req.method + nl +
	optional(req.headers['Content-Encoding']) +
	optional(req.headers['Content-Language']) +
	optional(req.headers['Content-Length']) +
	optional(req.headers['Content-MD5']) +
	optional(req.headers['Content-Type']) +
	optional(req.headers['Date']) +
	optional(req.headers['If-Modified-Since']) +
	optional(req.headers['If-Match']) +
	optional(req.headers['If-None-Match']) +
	optional(req.headers['If-Unmodified-Since']) +
	optional(req.headers['Range']) +
	canonicalized_headers(req) +
	canonicalized_resource_format_1(name,req);
}

var pad = function(num, size) {
    var s = "000000000" + num;
    return s.substr(s.length-size);
}

function shared_key_for_blob_and_queue_services (account, req) {
	req.headers =  req.headers || {};
	req.headers['x-ms-date'] = (new Date()).toUTCString();
	req.headers['x-ms-version'] =  '2009-09-19';

	var s = string_to_sign_1(account.name, req);

	req.headers['Authorization'] = "SharedKey " + 
		account.name + ":" +
		hmac_string(account.key,s );
}

var hmac_string = function(key, str) {
	var secret = (new Buffer(key, 'base64')).toString('binary');
	var hmac = crypto.createHmac('sha256', secret);
	return hmac.update(str).digest('base64');
}

var put_message = function(account, queue_name, message) {
	var content = "<QueueMessage><MessageText><![CDATA[" + (new Buffer(message)).toString("base64") + "]]></MessageText></QueueMessage>";
	var req = {
		url: account.queue_storage_url + '/' + queue_name + '/messages',
		method: 'POST',
		body: content,
		headers:{
			"Content-Length": content.length
		}
	};
	shared_key_for_blob_and_queue_services(account,req);
	request.post(req, function (error, response, body) {
		if (error){
			console.error(error);
		}
	});
}