AzureIoTHubNodeHTTP

var crypto = require('crypto');
var https = require('https');

var generateSasToken = function (resourceUri, signingKey, policyName, expiresInMins) {
    resourceUri = encodeURIComponent(resourceUri.toLowerCase()).toLowerCase();

    // Convert mins to seconds and get expires code
    var expires = (Date.now() / 1000) + expiresInMins * 60;
    expires = Math.ceil(expires);

    // Set the string to sign
    var toSign = resourceUri + '\n' + expires;

    // Get hash
    var hmacHash = getHmacHash(signingKey, toSign);
    var base64UriEncoded = encodeURIComponent(hmacHash);

    // construct autorization string
    var token = "SharedAccessSignature sr=" + resourceUri + "&sig=" + base64UriEncoded + "&se=" + expires;
    if (policyName)
        token += "&skn=" + policyName;
    
    return token;
};

function getHmacHash(key, stringToSign) {
    var hmac = crypto.createHmac('sha256', new Buffer(key, 'base64'));
    hmac.update(stringToSign);
    return hmac.digest('base64');
}

var sendMessage = function (message) {
    var apiVersion = '2016-02-03';
    var hubName = 'jongiothub.azure-devices.net';
    var deviceId = 'device148';
    var devicePath = '/devices/' + deviceId;
    var hubDevicePath = hubName + devicePath;
    var deviceEventsPath = devicePath + '/messages/events?api-version=' + apiVersion;
    var deviceKey = '';

    var token = generateSasToken(hubDevicePath, deviceKey, null, 60);

    var options = {
        hostname: hubName,
        port: 443,
        path: deviceEventsPath,
        method: 'POST',
        headers: {
            'Authorization': token
        }
    };

    var req = https.request(options, function (res) {
        console.log('HTTP Status:' + res.statusCode);
    });

    req.write(message);
    req.end();
};

sendMessage('{"Value": 42}');