Send HTTPS post request via nodejs - node.js

Question

Edit: Code is typescript, but very similar to JS, so I hope thats not a problem ;)
I try to make an HTTPS request but only getting "read ECONNRESET" after some timeout in the error event.
To encode post data I use require('querystring'); and it works fine, data is exactly what the browser sends.
var postData = querystring.stringify(data);
var postOptions = {
host: 'my.host.com',
port: 443,
path: '/openid/loginsubmit',
method: 'POST',
headers: {
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'Accept-Encoding': 'gzip, deflate',
'Accept-Language': 'en-US,en;q=0.5',
'User-Agent': 'Mozilla/5.0 (Windows NT 6.3; WOW64; rv:26.0) Gecko/20100101 Firefox/26.0',
'Content-Type': 'application/x-www-form-urlencoded',
'Referer':' https://my.host.com/openid/login',
'Content-Length': postData.length // 157 in web
},
rejectUnauthorized: false
};
I took all the headers I tracked with Fiddler to be sure there is no reason to reject my request on serverside.
Then I start try to send the request using:
var resString = '';
var postReq:any = https.request(postOptions, (httpRes:any) => {
console.log("statusCode: ", httpRes.statusCode);
console.log("headers: ", httpRes.headers);
httpRes.on('data', function (chunk) {
resString += chunk;
console.log('Response: ' + chunk);
});
httpRes.on('end', function () {
res.send(resString);
});
});
postReq.on('error', (err) => {
console.error('ERROR failed to login into website');
res.send(err.message);
});
postReq.write(postData); // even tried to add 'utf8' as second parameter
postReq.end();
Now all I get is an error after some timeout with the message read ECONNRESET
If one could help me with an example (maybe on some arbitrary https host) where an https post request works it would help much.
Or are there some misstakes in it? Maybe I have to provide some server cert somewhere to encrypt my post data?