18.7.3.1. Generating an RSA Key Pair for Version 2

18.7.3.1. Generating an RSA Key Pair for Version 2

Use the following steps to generate an RSA key pair for version 2 of the SSH protocol. This is the default starting with OpenSSH 2.9.

  1. To generate an RSA key pair to work with version 2 of the protocol, type the following command at a shell prompt:

    ssh-keygen -t rsa
    

    Accept the default file location of ~/.ssh/id_rsa. Enter a passphrase different from your account password and confirm it by entering it again.

    The public key is written to ~/.ssh/id_rsa.pub. The private key is written to ~/.ssh/id_rsa. Never distribute your private key to anyone.

  2. Change the permissions of the .ssh directory using the following command:

    chmod 755 ~/.ssh
    
  3. Copy the contents of ~/.ssh/id_rsa.pub into the file ~/.ssh/authorized_keys on the machine to which you want to connect. If the file ~/.ssh/authorized_keys exist, append the contents of the file ~/.ssh/id_rsa.pub to the file ~/.ssh/authorized_keys on the other machine.

  4. Change the permissions of the authorized_keys file using the following command:

    chmod 644 ~/.ssh/authorized_keys
    
  5. If you are running GNOME or are running in a graphical desktop with GTK2+ libraries installed, skip to Section 18.7.3.4, “Configuring ssh-agent with a GUI”. If you are not running the X Window System, skip to Section 18.7.3.5, “Configuring ssh-agent.