Configuring SSH Key-based Authentication

Configuring Public and Private Keys on Linux

1. Use an SSH tool to remotely log in to the Linux CLI as the OS user.
2. Create a public-private key pair.

   1	ssh-keygen -t rsa -b 4096

   During the process, perform the following operations:

   • (Optional) Enter the key file names. By default, the id_rsa file (private key file) and id_rsa.pub file (public key file) are saved in the /userhome/.ssh directory.
   • (Optional) Set the password of the key.

   The following information is displayed:

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   Generating public/private rsa key pair. Enter file in which to save the key (/userhome/.ssh/id_rsa): /root/.ssh/id_rsa already exists. Overwrite (y/n)? y Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /userhome/.ssh/id_rsa. Your public key has been saved in /userhome/.ssh/id_rsa.pub. The key fingerprint is: SHA256:g8T/XaRUqANpuIjxnI34In89+R68QckZPw7eyEaCU+o root@host11 The key's randomart image is: +---[RSA 4096]----+ | . . .. | | . .. + .. | | * =+o.. .. . | | o *=o+ =o. o | | .+ o S o.. . | |. .... B B o . | | o .E. .O + . | | . . +. + | | . ++ | +----[SHA256]-----+

3. Upload the public key file to the node server.

   1	ssh-copy-id -i /userhome/.ssh/id_rsa.pub root@Server IP

   

   • /userhome/.ssh/id_rsa.pub is the generated public key file. Replace /userhome/ (/root/ for the root user and /home/Common_user_name/ for a common user) with the actual file name.
   • Server IP indicates the node server IP address. Replace it with the actual IP address.

   During the process, enter the password of the node server user.