import ./make-test-python.nix ({ pkgs, ... } : { name = "hardened"; meta = with pkgs.lib.maintainers; { maintainers = [ joachifm ]; }; nodes.machine = { lib, pkgs, config, ... }: with lib; { users.users.alice = { isNormalUser = true; extraGroups = [ "proc" ]; }; users.users.sybil = { isNormalUser = true; group = "wheel"; }; imports = [ ../modules/profiles/hardened.nix ]; environment.memoryAllocator.provider = "graphene-hardened"; nix.settings.sandbox = false; nixpkgs.overlays = [ (final: super: { dhcpcd = super.dhcpcd.override { enablePrivSep = false; }; }) ]; virtualisation.emptyDiskImages = [ 4096 ]; boot.initrd.postDeviceCommands = '' ${pkgs.dosfstools}/bin/mkfs.vfat -n EFISYS /dev/vdb ''; virtualisation.fileSystems = { "/efi" = { device = "/dev/disk/by-label/EFISYS"; fsType = "vfat"; options = [ "noauto" ]; }; }; boot.extraModulePackages = optional (versionOlder config.boot.kernelPackages.kernel.version "5.6") config.boot.kernelPackages.wireguard; boot.kernelModules = [ "wireguard" ]; }; testScript = let hardened-malloc-tests = pkgs.graphene-hardened-malloc.ld-preload-tests; in '' machine.wait_for_unit("multi-user.target") with subtest("AppArmor profiles are loaded"): machine.succeed("systemctl status apparmor.service") # AppArmor securityfs with subtest("AppArmor securityfs is mounted"): machine.succeed("mountpoint -q /sys/kernel/security") machine.succeed("cat /sys/kernel/security/apparmor/profiles") # Test loading out-of-tree modules with subtest("Out-of-tree modules can be loaded"): machine.succeed("grep -Fq wireguard /proc/modules") # Test kernel module hardening with subtest("No more kernel modules can be loaded"): # note: this better a be module we normally wouldn't load ... machine.wait_for_unit("disable-kernel-module-loading.service") machine.fail("modprobe dccp") # Test userns with subtest("User namespaces are restricted"): machine.succeed("unshare --user true") machine.fail("su -l alice -c 'unshare --user true'") # Test dmesg restriction with subtest("Regular users cannot access dmesg"): machine.fail("su -l alice -c dmesg") # Test access to kcore with subtest("Kcore is inaccessible as root"): machine.fail("cat /proc/kcore") # Test deferred mount with subtest("Deferred mounts work"): machine.fail("mountpoint -q /efi") # was deferred machine.execute("mkdir -p /efi") machine.succeed("mount /dev/disk/by-label/EFISYS /efi") machine.succeed("mountpoint -q /efi") # now mounted # Test Nix dæmon usage with subtest("nix-daemon cannot be used by all users"): machine.fail("su -l nobody -s /bin/sh -c 'nix --extra-experimental-features nix-command ping-store'") machine.succeed("su -l alice -c 'nix --extra-experimental-features nix-command ping-store'") # Test kernel image protection with subtest("The kernel image is protected"): machine.fail("systemctl hibernate") machine.fail("systemctl kexec") with subtest("The hardened memory allocator works"): machine.succeed("${hardened-malloc-tests}/bin/run-tests") ''; })