SSH General Reference

By Dan Aukes

Create a new SSH key

  1. Use a key like “ed25519”

    ssh-keygen -t ed25519 -f <path/to/key>

  2. print the public key:

    cat <path/to/key>.pub

  3. add your key(s) to authorized keys:

    edit:

    sudo nano ~/.ssh/authorized_keys

    or copy directly:

    cat ~/.ssh/id_ed25519.pub >> ~/.ssh/authorized_keys

    or distribute your keys with ssh-copy-id

    ssh-copy-id -f -i <path/to/your/key>.pub user@server

  4. update your .ssh/config file

    Host *
    IdentitiesOnly yes
    IdentityFile [path/to/new_file]
    ForwardAgent yes
    AddKeysToAgent yes
    User <user>

Default Permissions

chmod 700 ~/.ssh # the .ssh directory itself
chmod 600 ~/.ssh/* # by default all the files in .ssh
chmod 644 ~/.ssh/*.pub # change public key permissions

Other Helpful Stuff

list all keys

ssh-add -l

remove all keys

ssh-add -D

add passphrase

ssh-keygen -p -f <path-to-key>

create cert/key

from here:

openssl req -newkey rsa:2048 -new -nodes -x509 -days 3650 -keyout key.pem -out cert.pem

References