NixOS must prevent the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
high	V-268154	SRG-OS-000366-GPOS-00153	ANIX-00-001480	SV-268154r1039350_rule	2024-10-25	1

Description
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved certificate authority (CA).

Description

Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved certificate authority (CA).

ℹ️ Check
Verify NixOS prevents installations that have not been digitally signed with the following command: $ grep -R require-sigs /etc/nixos/ /etc/nixos/configuration.nix:nix.settings.require-sigs = true; If "nix.settings.require-sigs" is not set to "true", is commented out, or is missing, this is a finding.

✔️ Fix
Configure NixOS to require signatures by adding the following configuration settings: Add or edit the following in the NixOS configuration "/etc/nixos/configuration.nix" file: nix.settings.require-sigs = true; Rebuild the system with the following command: $ sudo nixos-rebuild switch