Public key authentication (SSH Key) is a more secure alternative to password
authentication that allows users to avoid entering or storing a password, or sending it over
the network. Public key authentication uses the client computer to generate the key-pair (a
public key and a private key). The public key is then provided to the remote computer's
administrator to be installed on that machine.
-
Create a .ssh directory in your home directory if it does
not already exist:
$ mkdir /home/username/.ssh
Go to the .ssh folder:
$ cd /home/username/.ssh
-
Run ssh-keygen to generate an SSH key-pair.
Run the following command in the .ssh folder. The
program prompts you for the key-pair's filename. Press ENTER to use the
default name id_rsa. For a passphrase, you can either
enter a password, or press return twice to leave it blank:
# ssh-keygen -t rsa
-
Retrieve the public key file.
The key-pair is generated to your home directory's
.ssh folder. For
example, assuming you generated the key with the default name
id_rsa:
/home/username/.ssh/id_rsa.pub
Provide
the public key file (for example, id_rsa.pub) to your
server administrator so that it can be set up for your server connection.
The instructions for installing the public key on the server can be
found in the Setting Up a User's Public Key on the Server; however, the server may be
installed on an operating system that is different from the one where
your client has been installed.
-
Use the key in an async session.
Use the option -i
private_key_file, instead of -w
password, as in the following example:
$ async -N TestBackup -d /tmp/dir -r user@server:/tmp/dir -i PATH_TO_THE_PRIVATE_KEY_FILE
Note: Your private key and public key must be located in the same directory.