OL 9 SSHD must accept public key authentication.

Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. A privileged account is defined as an information system account with authorizations of a privileged user. A DoW CAC with DoW-approved PKI is an example of multifactor authentication.

Satisfies: SRG-OS-000105-GPOS-00052, SRG-OS-000106-GPOS-00053, SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055

Verify that OL 9 SSH daemon accepts public key encryption with the following command:

$ sudo grep -i PubkeyAuthentication /etc/ssh/sshd_config PubkeyAuthentication yes

If "PubkeyAuthentication" is set to no, the line is commented out, or the line is missing, this is a finding.

Configure OL 9 to accept public key authentication by adding or modifying the following line in "/etc/ssh/sshd_config".

PubkeyAuthentication yes

Restart the SSH daemon for the settings to take effect:

$ sudo systemctl restart sshd.service