NodeJS SSH authentication host and command execution - node.js

Question

I want to have a NodeJS application to which I can connect over SSH with a public key and send some data to. To be more explicit it should go as follow:
NodeJS application has some functions written
From a server I ssh the nodejs application and tries to identify me by my public key
After I am authenticated, I can send some strings to it, the app is going to parse the string and execute different functions
The only problem is that I cannot manage to do this with any SSH npm package existing. I want the nodejs app to just accept SSH connection and do the authentication and wait for some strings. Is this possible?
EDIT: I want to go with this approach because I only want to call the node functions to execute something only from some allowed clients (servers) and I don't want to send those requests via HTTP so anyone could access it

Answer 1

You're probably better off using HTTPS with client certificates rather than using an SSH server within node (although you can do that with the ssh module, a binding to libssh2), if you want to use certificates.
Here's how you'd set up the HTTPS server:
var https = require('https'),
fs = require('fs');
var options = {
key: fs.readFileSync('server.key'), // server private key
cert: fs.readFileSync('server.crt'), // server certificate
ca: fs.readFileSync('server_ca.crt'), // server CA, this can be an array of CAs too
requestCert: true
};
https.createServer(options, function(req, res) {
if (req.client.authorized) {
res.writeHead(200);
res.end('Hello world!');
} else {
res.writeHead(401);
res.end();
}
}).listen(443);
Then it's just a matter of generating a client certificate using the server's CA that you use with your HTTPS client.
For connecting to the HTTPS server:
For cURL, the command line would look something like: curl -v -s --cacert server_ca.crt --key client.key --cert client.crt https://localhost or to skip server verification: curl -v -s -k --key client.key --cert client.crt https://localhost
For node.js, you might use client code like:
var https = require('https'),
fs = require('fs');
var options = {
// normal http.request()-specific options
method: 'GET',
path: '/',
// tls.connect()-specific options
key: fs.readFileSync('client.key'), // client private key
cert: fs.readFileSync('client.crt'), // client certificate
ca: fs.readFileSync('server_ca.crt'), // server CA, this can be an array of CAs too
// or comment out the `ca` setting and use the following to skip server verification,
// similar to cURL's `-k` option:
//rejectUnauthorized: false
};
https.request(options, function(res) {
if (res.statusCode === 200)
console.log('Accepted!');
else
console.log('Rejected!');
// drain and discard any response data
res.resume();
}).end();