NixOS must protect the confidentiality and integrity of transmitted information.

Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered.

This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification.

Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa.

Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000112-GPOS-00057, SRG-OS-000113-GPOS-00058, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190

Verify NixOS enables sshd for remote access with the following command:

$ systemctl status sshd

sshd.service - SSH daemon Loaded: loaded (/etc/systemd/system/sshd.service; enabled; present: enabled) Active: active (running) since Sat 2022-06-04 02:51:43 UTC; 13min ago

If the sshd.service is not "active" and "running", this is a finding.

Configure NixOS to enable sshd for remote access.

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

services.sshd.enable = true;

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