Is my private SSH key compromised if someone hacks my Wi-Fi?

Question

I'm new to this and trying to understand, so bear with me.

I set up a droplet on Digital Ocean and configured SSH keys per Digital Ocean's tutorial. This required running ssh-keygen -t rsa on my laptop and then providing my Digital Ocean droplet with the public key.

My understanding is that these private and public keys were generated on my laptop; in other words, if my laptop were damaged/stolen, my private key would be gone forever (don't worry, I have a backup that I printed out and stored away safely). However, my question is this: is this private key accessible to someone who is able to access my Wi-Fi network?

Answer 1

Getting your private key would require that someone has the ability to read data off of your computer. If they're on your wifi it makes it significantly more likely that they can get this information but it still requires that there is some sort of vulnerability that allows them to get at the data on your harddisk (assuming you don't just start sending your private key over the network for any reason).

Common problems might be having a share on your computer you might've forgotten about or unpatched software + bad firewall configuration that would allow them to perform some sort of read operation via a previously known vulnerability (think: old IIS and directory traversal).

Another attack vector to look at is if they are on your network, they have the ability to influence the traffic going to your machine. DNS Spoofing a website on your local network and then tricking you into downloading some sort of malicious application would be another route they could take.

Tl;dr: Just because they're on your network does not explicitly mean they can read the private key but it opens up a lot of different attack vectors that may not have been possible before making it more likely that they could get to your private key.