Skip to content

ssh

  • Generate the ssh key
$ mkdir -p ~/.ssh && chmod 700 ~/.ssh   # Create the .ssh directory
$ ssh-keygen  # Creates id_rsa* in ~/.ssh

# With comment & path
$ ssh-keygen -t rsa -b 4096 -C "[email protected]" -f $HOME/.ssh/id_rsa
  • Copy the ssh public key to server
$ ssh-copy-id USER@HOST
OR
$ ssh USER@HOST 'mkdir -p ~/.ssh;chmod 700 ~/.ssh;cat >> ~/.ssh/authorized_keys' < ~/.ssh/id_rsa.pub
  • ssh-copy-id on windows
type %userprofile%\.ssh\id_rsa.pub | ssh <host> "cat >> .ssh/authorized_keys"

sshd

  • Disable password authentication
  • in /etc/ssh/sshd_config
PasswordAuthentication no
PubkeyAuthentication yes

And restart the sshd service

$ sudo service sshd restart
$ sudo systemctl restart sshd  # OR
$ sudo /etc/init.d/ssh restart # OR

Tunnel

  • reverse tunnel
# On target
ssh -NfR 12345:localhost:22 username@myhost
# On myhost
ssh localhost -p 12345
  • SOCK5 proxy
  • -C Compress
ssh -gfND 8080 username@<your host>

TODO: autossh

Windows sftp

  • Setting > Apps > Optional features > Add an optional feature > OpenSSH Server

  • Powershell Run as administrator

Start-Service sshd
Set-Service -Name sshd -StartupType 'Automatic'
New-NetFirewallRule -Name sshd -DisplayName 'OpenSSH Server (sshd)' -Enabled True -Direction Inbound -Protocol TCP -Action Allow -LocalPort 22

References

https://kb.iu.edu/d/aews https://blog.gtwang.org/linux/linux-ssh-public-key-authentication/ https://askubuntu.com/questions/346857/how-do-i-force-ssh-to-only-allow-users-with-a-key-to-log-in

Reverse SSH Tunnel 反向打洞實錄
https://fred-zone.blogspot.com/2010/08/reverse-ssh-tunnel.html

SSH Tunnel 通道打造加密 Proxy，透過外部 Linux 伺服器上網
https://blog.gtwang.org/linux/ssh-tunnel-socks-proxy-forwarding-tutorial/

https://berglas.github.io/dest/articles/2020/7/note_SFTP_setting_1.html

https://winscp.net/eng/docs/guide_windows_openssh_server