NetCreate Server Crashes when Client behind SOCKS Proxy attempts to connect

[daveseah]

ORIGINAL FEB 4, 2020

Joshua wrote:

For some reason, one of our Net.Create versions is crashing… Here is the error, that I can’t seem to find the cause for. Do we have any time left on the budget, or do you see anything at a glance? I see nothing in the log or javascript console

The REALLY weird thing is that I’ve been testing this install for a week straight and it runs fine (http://67.205.166.16:3000) but then Cindy’s students hit it and it went right down. I had one of the students (using mac, chrome, but with a load of plugins and a security settings) then hit another network that was fine, and it went right down. So I’m trying to see if there is any way they are using a funky url that is causing the crash, but … yeah. it is ODD

UPDATE FEB 9, 2020

Joshua wrote:

Just an update that I was able to work with the student to try and figure out what their machine was doing. It turns out they were using a proxy server (Socks?) that was causing the crash. Interestingly, when in Safari it just didn’t open, but Chrome caused the crash. Either way, turning the proxy server off solved the problem. We also ran Net.Create in an undergraduate classroom again with 25+ students hitting it and zero problems so we are assuming that the proxy is the problem. I’ll see if I can figure out what the proxy is doing, but we are assuming for now that this is exceedingly rare and won’t worry about it. Cindy’s student will simply not use it in class and will tell the other students how to check in case they were the problem (I don’t think anyone else had it). I can also show Megan how to re-start the server just in case, but I don’t anticipate any more problems.

[daveseah]

I might be able to harden the socket connection handshake. My guess from the stack trace is that it's happening deep in the socket library's "listen" code which is independent of our server code that relies on it. Possibly this is a bug in the socket library or the version of node we're using too.

In the meantime I'll leave it alone until it becomes more pressing!

[benloh]

Joshua's update:

When you go in later in the month, I was wondering if you could try one or two things to address that persistent crash we have when the Socks Proxy server is being used to hit net.create? Near as I can tell, it is only the malware version, which makes it REALLY hard to test, but a handful of Kalani’s students had that malware this semester. The console report is attached. I realize this is virtually impossible to track down. But I think there are 1-2 things we might try if you can do them quickly.

First, we are still running node version 10.9. If it is easy to update that includes an update to zlib and so might solve the issue and seems like a good idea either way? If it is fast / easy. I accidentally ran with the same node version you have for GsGo and it had compile errors so I rolled back and decided to leave that to you :)

Second, I found this: https://github.com/node-fetch/node-fetch/issues/378

I don’t know if this is the issue, but if it is, it seems it’d be easy to add that one line of code in the key places? Again, if it is easy. I looked and got lost trying to find the networking code but figured you’d know where to look.

If we can try either or both, Kalani things her student might still have the malware and be willing to hit the server to test it for us.

If not, I agree it is not worth you tracking down because it is weird and we know it when we see it, but … it’d be nice if we could stop it since it seems prevalent on campus.