Background story

I want to access my laptop remotely through SSH. However, my laptop are firewalled on strict network environment, I can't even access github.com. and to download the MSYS2 installer that are hosted on github, I need to download from different network, upload it to gdrive and finally I can download the installer through gdrive, you can imagine how troublesome it is. Therefore I need tailscale to overcome this situation.

Choose the OpenSSH server

The OpenSSH server I installed are provided by MSYS2, while there's Windows version available out there, I choose this one because I have two reason:

somehow I can't install the Windows version, it's always failed when I install it
the MSYS2 version provide unix environment that could be useful for me personally

Setup OpenSSH server

My C:\msys64\etc\ssh\sshd_config file (I've omitted default config for the sake of brevity):

bash

# Logging
#SyslogFacility AUTH
#LogLevel INFO
LogLevel DEBUG3
SyslogFacility LOCAL0

StrictModes no

PubkeyAuthentication yes

# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication no
#PermitEmptyPasswords no

Match Group administrators
       AuthorizedKeysFile ".ssh/authorized_keys"

Logging is super useful if you encounter any problem while attempting to connect to your machine.

in case you don't know how to generate a pair of key for authentication, visit this post.

validate the authorized_keys by exec ssh-keygen -l -f <path-to-authorized_keys>
validate sshd service are running properly by check the log: /var/log/msys2_sshd.log and check the status: sc.exe query msys2_sshd
for debugging purposes: tail -n 1 /var/log/msys2_sshd.log
The authentication method I used is public key-based authentication, remember to setup the authorized_keys on MSYS2 environment (in my case C:\msys64\home\ACER).
You need to run the bash script script as administrator/root, it will setup sshd service and automatically start on boot.
By default, tailscale will auto start on boot, you can verify this by execute ipconfig on cmd and see whether tailscale interface is exist or not.
See the respective manual page for further explanation.