SSH Into WSL2

ssh_into_wsl2.md

Guide: How to SSH Into WSL2

Install WSL2 SSH server

1. Open your wsl ubuntu terminal

2. install open-ssh server

   sudo apt update 
   sudo apt install openssh-server

3. Configure the ssh server: sudo vim /etc/ssh/sshd_config

   1. PermitRootLogin no - disallows root login for security
   2. PasswordAuthentication yes - if you want to allow password login
   3. PubkeyAuthentication yes - if you want to use key-based authentication (recommended)
   4. Port 2222 - Windows ssh server already uses port 22, so we need to pick a different one.
   5. ListenAddress 0.0.0.0

4. Activate and start the ssh server:

   sudo systemctl start ssh
   sudo systemctl enable ssh

5. Set mirrored networking mode in .wslconfig

   [wsl2]
   networkingMode=mirrored
   

6. Restart wsl by shutting it down (wsl --shutdown) and then starting it again (wsl)

Using SSH Keys to login

1. Generate new ssh keys on your remote machine by following this guide from GitHub

2. Add your keys to your wsl's user ~/.ssh/authorized_keys

   1. Copy the contents of the public key you created in step 1.
   2. Run: public_key_placeholder >> ~/.ssh/authorized_keys - make sure to replace public_key_placeholder with the actual contents of the public key

3. [Optional] Add ssh config

   1. Edit your ssh config file: vim ~/.ssh/config
   2. Add the following config (make sure to replace placeholder values):

   Host wsl_hostname_placeholder
     Hostname wsl_hostname_placeholder
     Port 2222
     User wsl_user_placheolder
     UseKeychain yes
     AddKeysToAgent yes
     IdentityFile ~/.ssh/id_rsa
   

4. Now you can ssh to your wsl2 instance: ssh wsl_hostname_placeholder

   1. If you didn't add a ssh config, then you need specify those options: ssh wsl_user_placheolder@wsl_hostname_placeholder -p 2222