NixOS must implement DOD-approved encryption to protect the confidentiality of remote access sessions.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-268089 | ANIX-00-000150 | SV-268089r1039597_rule | High |
| Description |
| Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000250-GPOS-00093, SRG-OS-000394-GPOS-00174 |
| STIG | Date |
| Anduril NixOS Security Technical Implementation Guide | 2024-10-25 |
Details
| Check Text (C-72013r1039153_chk) |
| Verify NixOS is configured to only use ciphers employing FIPS 140-3 approved algorithms with the following command: $ grep -R -A 4 openssh.setting.Ciphers /etc/nixos/configuration.nix:services.openssh.setting.Ciphers = [ /etc/nixos/configuration.nix- "aes256-ctr" /etc/nixos/configuration.nix- "aes192-ctr" /etc/nixos/configuration.nix- "aes128-ctr" /etc/nixos/configuration.nix- ]; If the cipher entries in the "configuration.nix" file have any ciphers other than "aes256-ctr,aes192-ctr,aes128-ctr", the order differs from the example above, they are missing, or commented out, this is a finding. |
| Fix Text (F-71916r1039154_fix) |
| Configure NixOS to use only ciphers employing FIPS 140-3 approved algorithms. To configure OpenSSH, add the following Nix code to the NixOS Configuration usually located in /etc/nixos/configuration.nix: services.openssh.setting.Ciphers = [ "aes256-ctr" "aes192-ctr" "aes128-ctr" ]; Rebuild the NixOS configuration with the following command: $ sudo nixos-rebuild switch A reboot is required for the changes to take effect. |