NixOS must use multifactor authentication for network access to privileged accounts.

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.

Factors include: 1) something a user knows (e.g., password/PIN); 2) something a user has (e.g., cryptographic identification device, token); and 3) something a user is (e.g., biometric).

A privileged account is defined as an information system account with authorizations of a privileged user.

Network access is defined as access to an information system by a user (or a process acting on behalf of a user) communicating through a network (e.g., local area network, wide area network, or the internet).

The DOD CAC with DOD-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 NixOS has the packages required for multifactor authentication installed with the following command:

$ which p11sak

/run/current-system/sw/bin/p11sak

If the "p11sak" program is not found in PATH, this is a finding.

Configure NixOS to have a package that enforces multifactor authentication installed.

Add the following Nix code to the NixOS Configuration, usually located in /etc/nixos/configuration.nix or /etc/nixos/flake.nix:

environment.systemPackages = [ pkgs.opencryptoki ];

Rebuild and switch to the new NixOS configuration: $ sudo nixos-rebuild switch