We are hosting an application in the preprod azure PCF environment which exposes websocket endpoints for client devices to connect to. Is there a prescribed methodology to secure the said websocket endpoint using TLS/SSL when hosted on PCF and running behind the PCF HAProxy?
I am having trouble interpreting this information, as in, are we supposed to expose port 4443 on the server and PCF shall by default pick it up to be a secure port that ensures unsecured connections cannot be established? Or does it require some configuration to be done on HAProxy?
Is there a prescribed methodology to secure the said websocket endpoint using TLS/SSL when hosted on PCF and running behind the PCF HAProxy?
A few things:
You don't need to configure certs or anything like that when deploying your app to PCF. The platform takes care of all that. In your case, it'll likely be handled by HAProxy, but it could be some other load balancer or even Gorouter depending on your platform operations team installed PCF. The net result is that TLS is first terminated before it hits your app, so you don't need to worry about it.
Your app should always force users to HTTPS. How you do this depends on the language/framework you're using, but most have some functionality for this.
This process generally works by checking to see if the incoming request was over HTTP or HTTPS. If it's HTTP, then you issue a redirect to the same URL, but over HTTPS. This is important for all apps, not just ones using WebSockets. Encrypt all the things.
Do keep in mind that you are behind one or more reverse proxies, so if you are doing this manually, you'll need to consider what's in x-forwarded-proto or x-forwarded-port, not just the upstream connection which would be Gorouter, not your client's browser.
https://docs.pivotal.io/platform/application-service/2-7/concepts/http-routing.html#http-headers
You'll get a message like The operation is insecure in Firefox or Cannot connect: SecurityError: Failed to construct 'WebSocket': An insecure WebSocket connection may not be initiated from a page loaded over HTTPS. in Chrome.
I am having trouble interpreting this information, as in, are we supposed to expose port 4443 on the server and PCF shall by default pick it up to be a secure port that ensures unsecured connections cannot be established? Or does it require some configuration to be done on HAProxy?
From the application perspective, you don't do anything different. Your app is supposed to start and listen on the assigned port, i.e. what's in $PORT. This is the same for HTTP, HTTP, WS & WSS traffic. In short, as an app developer you don't need to think about this when deploying to PCF.
The only exception would be if your platform operations team uses a load balancer that does not natively support WebSockets. In this case, to work around the issue they need to separate traffic. HTTP and HTTPS go on the traditional ports 80 and 443, and they will route WebSockets on a different port. The PCF docs recommend 4443, which is where you're probably seeing that port. I can't tell you if your platform is set up this way, but if you know that you're using HAproxy, it is probably not.
https://docs.pivotal.io/platform/application-service/2-8/adminguide/supporting-websockets.html
At any rate, if you don't know just push an app and try to initiate a secure WebSocket connection over port 443 and see if it works. If it fails, try 4443 and see if that works. That or ask your platform operations team.
For what it's worth, even if your need to use port 4443 there is no difference to your application that runs on PCF. The only difference would be in your JavaScript code that initiates the WebSocket connection. It would need to know to use port 4443 instead of the default 443.