SSH Key Setup Guide - webdev.cs.umt.edu

Why Set Up SSH Keys?

SSH keys allow you to connect to the server without entering your password and Duo authentication every time. This is especially useful when using FileZilla or other SFTP clients that open multiple connections.

1 Open PowerShell

On your Windows 11 computer:

Press Windows + X
Click "Terminal" or "Windows PowerShell"

2 Check for Existing Key or Generate a New One

First, check if you already have an SSH key:

ls ~/.ssh/id_ed25519.pub

If you see your key file listed: Great! Skip to Step 3 — you already have a key.

If you see "Cannot find path" or an error: Generate a new key by running:

ssh-keygen -t ed25519

You'll see the following prompts:

"Enter file in which to save the key" — Press Enter to accept the default location
"Enter passphrase" — Press Enter for no passphrase (or enter one for extra security)
"Enter same passphrase again" — Press Enter again

Success! Your key pair has been created:

Private key: C:\Users\YourName\.ssh\id_ed25519
Public key: C:\Users\YourName\.ssh\id_ed25519.pub

3 Copy Your Public Key to the Server

Run this command in PowerShell (replace your-netid with your actual NetID):

type $env:USERPROFILE\.ssh\id_ed25519.pub | ssh your-netid@webdev.cs.umt.edu "mkdir -p ~/.ssh && chmod 700 ~/.ssh && cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys"

You'll need to enter your password and complete Duo authentication one last time.

Note: This is a single long command. Make sure to copy it completely.

4 Test Your Connection

Try connecting to the server:

ssh your-netid@webdev.cs.umt.edu

Success! If everything is set up correctly, you should connect immediately without a password or Duo prompt.

5 Configure FileZilla

To use your SSH key with FileZilla:

Open FileZilla
Go to Edit → Settings
Select Connection → SFTP
Click "Add key file..."
Navigate to C:\Users\YourName\.ssh\
Change the file filter to "All files" (the key file has no extension)
Select id_ed25519 (the private key, not the .pub file)
Click OK

Note: FileZilla may ask to convert the key to its own format. Click Yes to allow this.

Now set up your site connection:

Go to File → Site Manager
Click "New site"
Enter the following settings:
- Protocol: SFTP - SSH File Transfer Protocol
- Host: webdev.cs.umt.edu
- Port: 22
- Logon type: Key file
- User: your-netid
- Key file: Browse to your converted key file
Click Connect

Troubleshooting

Still being asked for a password?

Make sure you copied the public key (step 3) correctly
Verify the permissions on the server by running:
```
ssh your-netid@webdev.cs.umt.edu "ls -la ~/.ssh"
```
The .ssh directory should be 700 and authorized_keys should be 600

FileZilla still prompting for credentials?

Make sure you selected "Key file" as the logon type in Site Manager
Verify you selected the private key file (without .pub extension)