138 lines
4.6 KiB
Nix
138 lines
4.6 KiB
Nix
import ./make-test-python.nix ({ pkgs, latestKernel ? false, ... } : {
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name = "hardened";
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meta = with pkgs.lib.maintainers; {
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maintainers = [ joachifm ];
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};
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machine =
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{ lib, pkgs, config, ... }:
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with lib;
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{ users.users.alice = { isNormalUser = true; extraGroups = [ "proc" ]; };
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users.users.sybil = { isNormalUser = true; group = "wheel"; };
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imports = [ ../modules/profiles/hardened.nix ];
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boot.kernelPackages =
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lib.mkIf latestKernel pkgs.linuxPackages_latest_hardened;
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environment.memoryAllocator.provider = "graphene-hardened";
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nix.useSandbox = false;
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virtualisation.emptyDiskImages = [ 4096 ];
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boot.initrd.postDeviceCommands = ''
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${pkgs.dosfstools}/bin/mkfs.vfat -n EFISYS /dev/vdb
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'';
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virtualisation.fileSystems = {
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"/efi" = {
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device = "/dev/disk/by-label/EFISYS";
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fsType = "vfat";
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options = [ "noauto" ];
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};
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};
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boot.extraModulePackages =
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optional (versionOlder config.boot.kernelPackages.kernel.version "5.6")
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config.boot.kernelPackages.wireguard;
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boot.kernelModules = [ "wireguard" ];
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};
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testScript =
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let
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hardened-malloc-tests = pkgs.stdenv.mkDerivation {
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name = "hardened-malloc-tests-${pkgs.graphene-hardened-malloc.version}";
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src = pkgs.graphene-hardened-malloc.src;
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buildPhase = ''
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cd test/simple-memory-corruption
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make -j4
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'';
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installPhase = ''
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find . -type f -executable -exec install -Dt $out/bin '{}' +
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'';
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};
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in
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''
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machine.wait_for_unit("multi-user.target")
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with subtest("AppArmor profiles are loaded"):
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machine.succeed("systemctl status apparmor.service")
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# AppArmor securityfs
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with subtest("AppArmor securityfs is mounted"):
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machine.succeed("mountpoint -q /sys/kernel/security")
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machine.succeed("cat /sys/kernel/security/apparmor/profiles")
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# Test loading out-of-tree modules
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with subtest("Out-of-tree modules can be loaded"):
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machine.succeed("grep -Fq wireguard /proc/modules")
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# Test hidepid
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with subtest("hidepid=2 option is applied and works"):
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# Linux >= 5.8 shows "invisible"
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machine.succeed(
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"grep -Fq hidepid=2 /proc/mounts || grep -Fq hidepid=invisible /proc/mounts"
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)
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# cannot use pgrep -u here, it segfaults when access to process info is denied
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machine.succeed("[ `su - sybil -c 'ps --no-headers --user root | wc -l'` = 0 ]")
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machine.succeed("[ `su - alice -c 'ps --no-headers --user root | wc -l'` != 0 ]")
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# Test kernel module hardening
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with subtest("No more kernel modules can be loaded"):
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# note: this better a be module we normally wouldn't load ...
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machine.fail("modprobe dccp")
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# Test userns
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with subtest("User namespaces are restricted"):
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machine.succeed("unshare --user true")
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machine.fail("su -l alice -c 'unshare --user true'")
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# Test dmesg restriction
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with subtest("Regular users cannot access dmesg"):
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machine.fail("su -l alice -c dmesg")
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# Test access to kcore
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with subtest("Kcore is inaccessible as root"):
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machine.fail("cat /proc/kcore")
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# Test deferred mount
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with subtest("Deferred mounts work"):
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machine.fail("mountpoint -q /efi") # was deferred
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machine.execute("mkdir -p /efi")
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machine.succeed("mount /dev/disk/by-label/EFISYS /efi")
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machine.succeed("mountpoint -q /efi") # now mounted
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# Test Nix dæmon usage
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with subtest("nix-daemon cannot be used by all users"):
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machine.fail("su -l nobody -s /bin/sh -c 'nix ping-store'")
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machine.succeed("su -l alice -c 'nix ping-store'")
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# Test kernel image protection
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with subtest("The kernel image is protected"):
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machine.fail("systemctl hibernate")
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machine.fail("systemctl kexec")
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# Test hardened memory allocator
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def runMallocTestProg(prog_name, error_text):
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text = "fatal allocator error: " + error_text
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if not text in machine.fail(
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"${hardened-malloc-tests}/bin/"
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+ prog_name
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+ " 2>&1"
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):
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raise Exception("Hardened malloc does not work for {}".format(error_text))
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with subtest("The hardened memory allocator works"):
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runMallocTestProg("double_free_large", "invalid free")
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runMallocTestProg("unaligned_free_small", "invalid unaligned free")
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runMallocTestProg("write_after_free_small", "detected write after free")
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'';
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})
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