SSH¶

(
  [ -d ~/.ssh ] || mkdir ~/.ssh &&
  curl https://github.com/nicholaswilde.keys -o ~/.ssh/authorized_keys &&
  cp id_ed25519.txt  ~/.ssh/id_ed25519 &&
  chmod 600 ~/.ssh/id_ed25519 &&
  ssh-keygen -y -f ~/.ssh/id_ed25519 > ~/.ssh/id_ed25519.pub &&
  chmod 644 ~/.ssh/id_ed25519.pub &&
  chmod 0700 ~/.ssh
)

(
  [ -d ~/.ssh ] || mkdir ~/.ssh &&
  curl https://github.com/nicholaswilde.keys -o ~/.ssh/authorized_keys &&
  lpass show ssh --attach=att-4322045537695550419-20689 -q > ~/.ssh/id_ed25519 &&
  chmod 600 ~/.ssh/id_ed25519 &&
  ssh-keygen -y -f ~/.ssh/id_ed25519 > ~/.ssh/id_ed25519.pub &&
  chmod 644 ~/.ssh/id_ed25519.pub &&
  chmod 0700 ~/.ssh
)

Authentication¶

(
  sudo sed -i 's/#PubkeyAuthentication yes/PubkeyAuthentication yes/g' /etc/ssh/sshd_config && \
  echo "RSAAuthentication yes" | sudo tee -a /etc/ssh/sshd_config
)

# /etc/ssh/sshd_config
...
RSAAuthentication yes
PubkeyAuthentication yes
...

# Restart ssh
sudo systemctl restart sshd

Verify that Keys Match¶

To verify if a public and private RSA SSH key pair match, you can compare their fingerprints using the ssh-keygen command. If the fingerprints generated from both the private and public keys are identical, then the keys are a matching pair.

1. Get the fingerprint of the private key:

   ssh-keygen -lf /path/to/your/private_key
   

   Replace /path/to/your/private_key with the actual path to your private key file (e.g., ~/.ssh/id_rsa).

2. Get the fingerprint of the public key:

   ssh-keygen -lf /path/to/your/public_key.pub
   

   Replace /path/to/your/public_key.pub with the actual path to your public key file (e.g., ~/.ssh/id_rsa.pub).

3. Compare the outputs: The output for both commands will be a string containing the key size, the fingerprint (a series of hexadecimal numbers separated by colons), and a comment. If the SHA256 fingerprint values are exactly the same for both the private and public keys, then they are a matching pair.