Passwordless SSH

Overview

Passwordless SSH lets you log in without typing your SeaWulf password each time. You need an active SeaWulf account before proceeding.

macOS and Linux

1. Generate a key pair.

   ssh-keygen -t rsa -b 4096 -C "<your_netid>@login.seawulf.stonybrook.edu"

2. Name the file (or accept the default ~/.ssh/id_rsa) and set an optional — but recommended — passphrase.
3. Add the key to your ssh-agent.

   ssh-add <private key>

4. Upload your public key.

   ssh-copy-id -i <mykey> <your_netid>@login.seawulf.stonybrook.edu

   If ssh-copy-id is unavailable:

   cat ~/.ssh/id_rsa.pub | ssh <your_netid>@login.seawulf.stonybrook.edu 'cat >> .ssh/authorized_keys && echo "Key copied"'

Windows · MobaXterm

1. Install MobaXterm Home Edition and open "Start local terminal".
2. Generate a key pair:

   ssh-keygen -t rsa

3. Upload the public key:

   cat ~/.ssh/id_rsa.pub | ssh <your_netid>@login.seawulf.stonybrook.edu "cat - >> ~/.ssh/authorized_keys"

4. Create a new SSH session to login.seawulf.stonybrook.edu, enable "Specify username" with your NetID, open Advanced SSH Settings, activate "Use private key", select your key, and click OK.

Windows · PuTTY

Generate an SSH-2 RSA 4096-bit key in PuTTYgen (move the cursor to seed randomness), save both keys, and paste the public key onto a new line of ~/.ssh/authorized_keys on SeaWulf. Then in PuTTY, under Connection → SSH → Auth, browse to your private key file, save the session, and connect.