{ config, pkgs, lib, ... }: with lib; let cfg = config.aviallon.hardening; desktopCfg = config.aviallon.desktop; in { options.aviallon.hardening = { enable = mkOption { default = true; example = false; description = "Enable aviallon's hardening"; type = types.bool; }; hardcore = mkOption { default = !desktopCfg.enable; example = desktopCfg.enable; description = "Enable hardcore hardening, which might break things."; type = types.bool; }; }; config = mkIf cfg.enable { # imports = [ # (modulesPath + "/profiles/hardened.nix") # ]; boot.kernelPackages = mkIf cfg.hardcore pkgs.linuxPackages_hardened; security.lockKernelModules = mkIf cfg.hardcore (mkOverride 500 true); security.protectKernelImage = mkIf cfg.hardcore (mkOverride 500 false); # needed for kexec security.apparmor.enable = true; services.dbus.apparmor = "enabled"; boot.kernelParams = [ # Slab/slub sanity checks, redzoning, and poisoning "slub_debug=FZP" # Overwrite free'd memory "page_poison=1" # Enable page allocator randomization "page_alloc.shuffle=1" # Apparmor https://wiki.archlinux.org/title/AppArmor#Installation "lsm=landlock,lockdown,yama,apparmor,bpf" ]; boot.kernel.sysctl = { "kernel.yama.ptrace_scope" = lib.mkOverride 500 1; "kernel.kptr_restrict" = lib.mkOverride 500 2; "net.core.bpf_jit_enable" = lib.mkOverride 500 false; "kernel.ftrace_enabled" = lib.mkOverride 500 false; }; security.allowUserNamespaces = mkDefault true; boot.blacklistedKernelModules = mkForce [ ]; nix.allowedUsers = mkIf cfg.hardcore [ "@wheel" ]; security.audit.enable = true; security.auditd.enable = true; security.audit.rules = [ "-a exit,always -F arch=b64 -S execve" ]; systemd.services.dbus.serviceConfig = { # Hardening CapabilityBoundingSet = [ "CAP_SETGID" "CAP_SETUID" "CAP_SETPCAP" "CAP_SYS_RESOURCE" "CAP_AUDIT_WRITE" ]; DeviceAllow = [ "/dev/null rw" "/dev/urandom r" ]; DevicePolicy = "strict"; IPAddressDeny = "any"; LimitMEMLOCK = 0; LockPersonality = true; MemoryDenyWriteExecute = true; NoNewPrivileges = true; PrivateDevices = true; PrivateTmp = true; ProtectControlGroups = true; ProtectHome = true; ProtectKernelModules = true; ProtectKernelTunables = true; ProtectSystem = "strict"; ReadOnlyPaths = [ "-/" ]; RestrictAddressFamilies = [ "AF_UNIX" ]; RestrictNamespaces = true; RestrictRealtime = true; SystemCallArchitectures = "native"; SystemCallFilter = [ "@system-service" "~@chown" "~@clock" "~@cpu-emulation" "~@debug" "~@module" "~@mount" "~@obsolete" "~@raw-io" "~@reboot" "~@resources" "~@swap" "~memfd_create" "~mincore" "~mlock" "~mlockall" "~personality" ]; UMask = "0077"; }; }; }