Kerberos authentication in Node.js https.get or https.request

18
votes

I'm trying to write a simple script that requests some data from a tool on an internal network. Here is the code:

#!/usr/bin/node

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

var options = {
  host: '<link>',
  port: 443,
  path: '<path>',
  auth: 'username:password',
  ca: [fs.readFileSync('../.cert/newca.crt')]
};

https.get(options, function(res) {
  console.log("Got response: " + res.statusCode);
  res.on('data', function (d) {
    console.log('BODY: ' + d);
  });
}).on('error', function(e) {
  console.log("Got error: " + e.message);
});

Now the question is, how can I use a Kerberos ticket to authenticate rather than supplying my credentials in auth: in plain text?

5
javascriptnode.jshttpskerberos

5 Answers

4
votes

In Paul Scheltema's answer, you need to get ticketdata from depth of operating system. You (or a module on behalf of you) must use GSS-API to have ticketdata generated by Active Directory for you.

Such mechanism is present in Chrome, but it seems that it's not included in Node.js (only the javascript engine from Chrome), so you may need to add a module, for example:

To install/compile such module you may need to have Visual Studio.

To set up environment, - On all computers you must have tcp and udp enabled on ports 88 (Kerberos) and 53 (dns). - On Windows Server Active Directory must be running (ldap, dns, kdc) - On the page https://www.npmjs.org/package/passport-kerberos they use term REALM. It's a name of domain, written uppercase.

8
votes

from http://docs.oracle.com/cd/E24191_01/common/tutorials/authn_kerberos_service.html

Client Token Location for Message-Level Standards: The Kerberos Service ticket can either be sent in the Authorization HTTP header or inside the message itself, for example, inside a element. Alternatively, it may be contained within a message attribute. Select one of the following options:

so instead of your username:password you provide the ticket

alternatively you can as stated below that information put it in the message body or as a message attribute

var request = https.request(options, function(resource) {
  var chunks = [];
   resource.on('data', function (chunk) {
     chunks.push(chunk);
   });
   resource.on('end', function () {
     var data = chunks.join('');
     console.log(data);
   });
}

request.on('error',...)
request.send('<body-with-ticket>');
request.end();

EDIT:

the "" part was my example of where to use the ticket, put it in a multiytype body and send that, alternatively use the WWW-Authenticate header to send it

eg. add it to the options on https.request

options = {
    host: 'hostname',
    port: 443, 
    'WWW-Authenticate': 'Negotiate ' + ticketdata
};

google has some nice diagrams on how it works: https://developers.google.com/search-appliance/kb/secure/kerberos-diagram

6
votes

I have gotten this to work using "kerberos" module, version 0.0.12. I have created a Gist with the working example:

https://gist.github.com/dmansfield/c75817dcacc2393da0a7

Basically, you use three methods to obtain the "Authorization" header data:

  • authGSSClientInit, which requires the service name, e.g. HTTP@somehost.com
  • authGSSClientStep, which requires the existence of a credentials cache (on Linux you get this by doing "kinit" and can verify it with "klist"), and actually gives you back the base64 stuff you need (without the leading "Negotiate " string)
  • authGSSClientClean, which frees all allocated memory structures

Then you create an "Authorization" header (NOT WWW-Authenticate as shown above, which is what the server sends back) and it should work.

Note also: typically, web browsers request a resource, get a 401 back with a WWW-Authenticate: Negotiate header in the response, then re-request the resource with the ticket data supplied in the "Authorization" header. This two-step dance happens for every resource. I'm not sure if it means anything or not.

1
votes

2020 UPD:

The newer version of kerberos npm package has much less methods. But I make it work:

const kerberos = require('kerberos').Kerberos;
const fetch = require('node-fetch');

(async () => {
    const client = await kerberos.initializeClient("HTTP@site.internal.net", {
        mechOID: kerberos.GSS_MECH_OID_SPNEGO,
    })

    const ticket = await client.step("")

    const resp = await fetch("https://site.internal.net/api/v1/hello", {
        headers: {
            'Authorization': 'Negotiate ' + ticket
        }
    })

    console.log(await resp.json())
})();

Works perfectly at Windows and Linux, should work at macOS too.

0
votes

If you are on Windows, you can use the SSPI interface. It is exposed on Node with the project node-expose-sspi.

The SSPI interface allows you to write any client or server using SSO (NTLM and Kerberos).

https://github.com/jlguenego/node-expose-sspi

Note: I am the author of node-expose-sspi.